JAPACVS Vol. 5 No. 3

VOLUME 5 •

NUMBER 3 •

FALL 2023 •

www.japacvs.org

APACVS J

Journal of The Association of PAs in Cardiothoracic and Vascular Surgery

Cystic Tumor of the Atrioventricular Node: A Rare and Potentially Fatal Condition

Official Journal of The Association of Physician Assistants in Cardiothoracic and Vascular Surgery

Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

JAPACVS

Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

Editor-in-Chief Aaron R. Morton, DMSc, MMSc, PA-C, ATC, FAPACVS Emory University, Atlanta, GA Associate Editor—International Vicky Vink PA Switzerland Associate Editor—Writer Development Edward A. Ranzenbach, PA-C, MPAS, CAQ-CVTS, FAPACVS, DFAAPA Misenheimer, NC

Editorial Board Cardiac Section Editor Michael Lalonde, MHA, PA-C

Branford, CT Thoracic Section Editor Matthew Vercauteren MPAS, PA-C, FAPACVS Pittsburgh, PA Vascular Section Editor Daniel Geersen MPAP, PA-C Morrisville, NC Editorial Member at Large

EDITORIAL MISSION: The JAPACVS is the official clinical journal of the Association of PAs in Cardiothoracic and Vascular Surgery. The mission of the JAPACVS is to improve Cardiac, Vascular and Thoracic Surgical and CVT Critical Care patient care by publishing the most innovative, timely, practice-proven educational information available for the physician assistant profession.

PUBLISHED CONTENT IN THE JAPACVS: Statements and opinions expressed in the articles and communications herein are those of the authors and not necessarily those of the Publisher or the Association of PAS in Cardiothoracic and Vascular Surgery (APACVS). The Publisher and the APACVS disclaim any responsibility or liability for such material, including but not limited to any losses or other damage incurred by readers in reliance on such content. Neither Publisher nor APACVS verify any claims or other information appearing in any of the advertisements contained in the publication and cannot take responsibility for any losses or other damage incurred by readers in reliance on thereon. Neither Publisher nor APACVS guarantees, warrants, or endorses any product or service advertised in this publication, nor do they guaranty any claim made by the manufacturer of such product or service.

SALES OFFICE APACVS 1208 Victoria Crossing Festus, MO 63028 Phone (502) 321-6155 admin@apacvs.org

Hantz B. Fontaine PA-C New York, NY

Publisher David E. Lizotte, Jr. MPAS, PA-C, FAPACVS Executive Director APACVS Festus, MO

JAPACVS/Journal of the Association of PAs in Cardiothoracic and Vascular Surgery is published quarterly (4 issues per volume, one volume per year) by APACVS 1208 Victoria Crossing, Festus, MO 63028. Volume 5, Number 1, Winter 2023. One year subscription rates: $40 in the United States and Possessions. Single copies (prepaid only): $20 in the United States

© 2023 APACVS, INC. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including by photocopy, recording, or information storage and retrieval system, without permission in writing from the publisher.

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Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

Editorial 4 From the Editor’s Desk Aaron R. Morton, DMSc, MMSc, PA-C, ATC, FAPACVS— Editor -In-Chief Peer Reviewed Content 7 Cystic Tumor of the Atrioventricular Node: A Rare and Potentially Fatal Condition

Lona Ernst Rizkallah MS, PA-C Peer Reviewed Content 14 Outcomes of Surgical Ablation for Atrial Fibrillation During Concomitant Cardiac Surgery Andrew Caruso, MPAS, PA-C, DFAAPA Peer Reviewed Content 29 Eliminating Sternal Wound Infections: Why Every Cardiac Surgery Program Needs an I Hate Infections Team Maren Downing, MEng,a,b Michael Modrow, PA-C,a,c Kelly A. Thompson-Brazill, DNP,a,c J. Erin Ledford, PharmD,a,c Charles D. Harr, MD, MBA,a,c and Judson B. Williams, MD, MHSa,c

APACVS is the only association representing Cardiac, Thoracic and Vascular Surgery and CTV Critical Care PAs. By PAs, For PAs!

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_________________________________________________________________________________________________________

From the Editor's Desk

Aaron R. Morton, DMSc, MMSc, PA-C, ATC, FAPACVS Editor-in-Chief

In this issue, I wanted to take time to open a new “From the Editors Desk,” series, which I hope professionally enlightens our journal’s readers. The series will focus on the benefits of membership to professional organizations like the APACVS and the need for us to continue to support our organization.

It would be a tall challenge to find an organization as strongly devoted to education as the

APACVS. Education has long been the bedrock of the organization as the only association dedicated to sub-specialty-based education for PAs and other non-specialty providers The educational opportunity was unlike anything else I could find when I started practice, and literally made my transition from PA school to practice possible. Since then, it has allowed me to remain current with practices, clinical guidelines and develop as a leader with attendance at the national meeting. While the didactic content is broad and easy to access in person or online, the hands-on education really gave me the confidence and provided a safe practice 4

Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

space under the guidance of peers to learn. This peer level education provided by experienced

providers who do what I do daily, who understood my struggles, helped provide an easier pathway and understanding for me as a learner and provider. Simply put, I have greatly benefited from the educational opportunities both in starting my career and in my ongoing quest to refine my practice and continue lifelong learning.

While the APACVS is the place for Cardiothoracic, Vascular and CVT Critical Care education it has also provides a professional community for its members. This community is comprised of dedicated and insightful colleagues who, as I previously shared, understood my daily life, and were able to be a sounding board for ideas. The ability to message a member whom I have met previously and who is in a position to provide guidance and perspective is an amazing resource that has been very beneficial to my professional and clinical growth. This community helped me transverse job searches, cross country moves, practice transitions and eventually my role in leadership, both locally in my employment as well as in our organization. A great example of supporting our own community is the Women in Cardiothoracic and Vascular Surgery group,

which was created several years ago in efforts to support the challenges our female colleagues face in our specialty. In no other venue will you find a group of PA’s supporting each other in this demanding sub-specialty space as you do with the APACVS. The educational opportunities and community created with professional organizations are certainly some of the highlights of the APACVS, but there are also multiple additional benefits of membership. As this series continues, I hope to share some of these with you and convey the importance of active membership.

-AM Aaron Morton DMSc, MMSc, PA-C, ATC, FAPACVS Editor-in-Chief

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Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

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Peer Reviewed Content

CYSTIC TUMOR OF THE ATRIOVENTRICULAR NODE: A RARE AND POTENTIALLY FATAL CONDITION Author: Lona Ernst Rizkallah MS, PA-C

INTRODUCTION Cystic tumors of the atrioventricular (AV) node are particularly rare benign primary cardiac tumors, comprising less than 3% of all cardiac tumors. Located in the triangle of Koch in the AV nodal region of the interatrial septum, these tumors can eventually cause complete heart block or other fatal ventricular arrhythmias, especially if left untreated. Furthermore, atrioventricular cystic tumors are the smallest among all cardiac tumors to cause sudden death.1-3 These lesions are considered congenital in origin and arise during cardiac embryogenesis, while embryonic fusion occurs in the AV nodal region, thereby leading to tissue entrapment and tumor formation.1,4 These tumors are found predominantly in women, and a vast majority of the patients are asymptomatic.

Previous studies have reported a mean age of 40 years, of those suffering from these tumors, with no particular racial or ethnic prevalence at diagnosis.2,4 Diagnostic imaging modalities have varied between echocardiography, computer tomography (CT), and magnetic resonance imaging (MRI).

Many patients, however, present primarily with some degree of cardiac conduction delay noted on an electrocardiogram. The mode of how these tumors are diagnosed varies; however, many are unfortunately diagnosed post-mortem. A literature review contains a limited number of case

reports of antemortem diagnosis with successful resection.1 In this paper, we report a case of a cystic tumor of the atrioventricular node that was incidentally diagnosed on imaging when the patient was hospitalized for symptoms of dyspnea. The patient underwent successful tumor excision and required a concomitant permanent pacemaker and mitral valve replacement due to extensive tumor infiltration.

CASE PRESENTATION A 46-year-old woman with a past medical history of asthma presented to our emergency 7

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with symptoms of progressive dyspnea. Incidentally, the patient had recently undergone abdominal surgery a few weeks prior. Cardiac and pulmonary exams were unremarkable. A chest computed tomography angiography (CTA) ruled out a pulmonary embolus. Subsequently, an ECG in the ED demonstrated sinus rhythm with a first-degree heart block. Transthoracic echocardiography revealed normal bi-ventricular function and no significant valvular pathology.

However, a 2cm fixed mass was seen attached to the interatrial septum and the septal leaflet of the tricuspid valve. A cardiac MRI validated the presence of a well-circumscribed cyst-like mass in the triangle of Koch measuring 2.0cm x 2.0cm (Fig 1). There was no MR evidence for myocardial infarction, scarring, or infiltrative disease. The uniqueness of her case prompted open discussions between our cardiovascular surgeons and cardiology consultants, and the diagnosis of an AV nodal tumor, though rare, was contemplated. After sharing our literature review and thoughts with the patient and her family, the decision was made to perform surgical resection.

Figure 1. Magnetic resonance imaging (MRI) showing the atrioventricular tumor

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The patient underwent a median sternotomy and was systemically heparinized (300-400 units/kg) to achieve an activated clotting time of over 400 seconds. She was then placed on aorto bi-caval cardiopulmonary bypass with mild hypothermic cooling to 32 degrees Celsius. The aorta was cross-clamped, and the heart was arrested with antegrade cardioplegia and topical slush ice cooling for myocardial protection. Once the heart was arrested, the superior and inferior vena cava were isolated, and a right atriotomy was performed to visualize the right-sided structures. Upon inspection, a 2cm x 2cm cystic mass was seen in the triangle of Koch near the septal leaflet of the tricuspid valve and attached to the interatrial septum (Fig 2A). Careful dissection was performed around the cystic tumor for en block excision (Fig 2B). Complete resection of the cystic mass resulted in a 3 x 3 cm atrial septal defect, necessitating repair with a 0.6mm thick polytetrafluoroethylene (PTFE) patch (Gore-Tex; Gore Medical, Phoenix, AZ) for closure (Fig 2C and 2D). The cystic mass was incised after removal, and a yellow/brown caseous material was seen within it, along with some smaller cysts distributed in a honeycomb appearance.

Figure 2. Serial images of tumor resection and surgical repair

(A) the cystic mass lies within the interatrial septum and near the septal leaflet of the tricuspid valve bordering the triangle of Koch. The coronary sinus borders the lateral wall of the mass (B) AV nodal cyst after resection, measuring 2cm x 2cm in greatest diameter. Noted is the fibrous connective tissue of the cystic wall. (C) Following resection of the mass, a significant residual defect was noted in the atrioventricular septal wall. (D) Complete repair of the 3cm x 3 cm defect was achieved with a PTFE Gore-Tex patch.

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The atriotomy was closed, normothermia regained, and the aortic cross-clamp was removed. De-airing was completed via the aortic root and a left ventricular vent. An intraoperative transesophageal echocardiogram performed after coming off bypass showed severe mitral regurgitation. Given the concern for anterior mitral annulus and leaflet compromise caused by the mitral valve annular extension of the tumor, a decision was made to perform mitral valve replacement with a 29 mm Sorin mechanical valve prosthesis through a separate left atriotomy. The atrial incisions were closed, and the patient was re-warmed to normothermia.

After satisfactorily de-airing the cardiac chambers, she was separated from cardiopulmonary bypass. Protamine was utilized to reverse heparinization. At that time, the patient was noted to be in complete heart block. Given concern for an unlikely recovery of her cardiac rhythm, a dual chamber St. Jude Medical (Minneapolis, MN) pacemaker via epicardial lead system was placed by tunneling the epicardially placed leads through the left pleural cavity and connecting them to the pacemaker generator in a subcutaneous infra-clavicular pocket. Once hemostasis was achieved, the sternotomy was closed with interrupted stainless steel wires. Tissue closure was performed in

the usual fashion, and the patient was transported to the intensive care unit in stable condition.

Her postoperative course was complicated by heparin-induced thrombocytopenia (HIT), confirmed by serum antibody and serotonin assay testing. Digital ischemic changes observed on her left fingers responded well to anticoagulation with Argatroban, which was discontinued once her blood international normalized ratio (INR) became therapeutic on warfarin (coumadin).

Acute renal insufficiency was also noted postoperatively but improved without intervention. She was discharged home with her family in stable condition. To date, we have been following the

patient closely for nearly 24 months. She has had complete recovery of her kidney function and left-hand ischemia. She has maintained the paced cardiac rhythm along with underlying atrial fibrillation.

Histopathological examination of the excised lesion confirmed a cystic tumor of the AV node with endodermal remnants. In addition, immunohistochemical staining demonstrated positive staining for epithelial membrane antigen (EMA), cytokeratins 5/6, and carcinoembryonic

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antigen (CEA), confirming that the tumor cells were of endodermal origin.

DISCUSSION: Cystic tumors of the atrioventricular node (AV node) are rare, congenital, primary cardiac tumors that can ultimately lead to physiologic cardiac conduction delays, malignant arrhythmias, or even sudden cardiac death. This tumor entity was first described in 1911 in a five-yearold boy and has since been studied in more detail.5 Previously published reports have confirmed that these benign tumors are most prevalent in women, with a female-to-male ratio of 3:1.2,4 Unfortunately, most of these tumors are diagnosed post-mortem, as early detection signs and symptoms are disregarded. As demonstrated in this present case, early detection is imperative in developing a treatment plan and preventing cardiac demise. Symptoms may or may not be present; however, any patient with new cardiac conduction delays noted on ECG may warrant further workup with diagnostic imaging. Imaging modalities such as echocardiography, CT, or cardiac MRI are critical in obtaining a timely diagnosis.5,7 Given the rarity of reported cases, clinical management remains challenging. In our

literature review, only fourteen cases have been diagnosed antemortem and treated successfully with surgery, to which we add the case presented. Treatment decisions are based on limited case reports as no clinical or surgical guidelines exist.5 Partial or complete surgical resection of the tumor is the most prevalent option to prevent fatal complications, yet this therapy remains controversial. Partial resection may lessen the likelihood of the need for pacemaker placement but risks the possibility of persistent signs and symptoms related to cardiac rhythm disturbances.4 This latter option in treatment also calls for regularly scheduled follow-up

imaging to monitor tumor progression. Isolated implantation of a permanent pacemaker to address the heart block that occurs in these cases without addressing the tumor is a wellreported alternative treatment option should the decision be made to forgo surgery. However, there is concern that the isolated placement of a pacemaker to address heart block may not address the potential of ventricular arrhythmias leading to malignant arrhythmias and sudden death.6 Lastly, placement of a cardiac defibrillator alone as a preventative therapy for potentially fatal ventricular arrhythmias is not well studied as a viable treatment modality.

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After extensive discussions of the above treatment options among the managing physician teams and an extensive review of the existing literature, our patient opted for complete surgical resection. She ultimately required a permanent pacemaker and mitral valve replacement due to the size and critical location of the tumor and its proximity to the anterior annulus of the mitral valve. The patient continues to follow up with us for surveillance imaging to monitor for recurrence and routine device checks. Nearly two years postoperatively, there has been no evidence for recurrence. In such cases, more research is needed to determine any potential genetic associations and further strides toward developing definitive treatment guidelines.

Acknowledgment: I want to thank Dr. Malek Massad for sharing his expertise in the critical review of the original manuscript.

References 1. Saito S, Kobayashi J, Tagusari O, et al. Successful excision of a cystic tumor of the atrioventricular nodal region. Circ J. 2005;69(10):1293-1294. doi:10.1253/circj.69.1293

2. Giuliano K, Scully B, Etchill E, Lawton J. Cystic tumor of the atrioventricular node. Glob Cardiol Sci Pract. 2020;2020(2):e202028. doi:10.21542/gcsp.2020.28 3. Guo J, Zuo S, Lin C, Ji Y. Surgical treatment of a giant cystic tumor of the atrioventricular nodal region. Interact Cardiovasc Thorac Surg. 2009;8(5):592-593. doi:10.1510/icvts.2008.191866 4. Luc JGY, Phan K, Tchantchaleishvili V. Cystic tumor of the atrioventricular node: a review of the literature. J Thorac Dis. 2017;9(9):3313-3318. doi:10.21037/jtd.2017.08.101 5. Abuzeid W, Myers RBH. Cystic tumour of the atrioventricular node: treatment dilemma. BMJ

Case Rep. 2017;2017. doi:10.1136/bcr-2017-219314 6. Li Z, Li G, Jiang X, Fu X. Intraoperative frozen pathological diagnosis of cystic tumor of the atrioventricular node: a case report and review of the literature. Int J Clin Exp Pathol. 2018;11 (4):2165-2169 7. Joshi M, Kumar S, Noshirwani A, Harky A. The current management of cardiac tumours: A comprehensive literature review. Braz J Cardiovasc Surg. 2020;35(5):770-780. doi:10.21470/1678 -9741-2019-0199 12

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8. Fiset S, Butany J, Ing DJ, Cusimano RJ, Nguyen ET. Multimodality imaging of a rare atrioventricular nodal tumor: Applications of T1 and T2 mapping. Circ Cardiovasc Imaging. 2018;11

(10):e008159. doi:10.1161/CIRCIMAGING.118.008159 9. Cohle SD. Cystic tumour of the atrioventricular node: case report and literature review. Forensic Sci Res. 2019;4(3):287-289. doi:10.1080/20961790.2019.1595349 10.Ojha V, Pandey NN, Sharma G, Jagia P. Cystic tumor of the atrioventricular node in a patient with intermittent complete heart block. BMJ Case Rep. 2021;14(6):e244442. doi:10.1136/ bcr-2021-244442

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Peer Reviewed Content

OUTCOMES OF SURGICAL ABLATION FOR ATRIAL FIBRILLATION DURING CONCOMITANT CARDIAC SURGERY Author: Andrew Caruso, MPAS, PA-C, DFAAPA Piedmont Healthcare in Atlanta, GA

ABSTRACT Atrial fibrillation (AF) significantly elevates the risk of heart failure, stroke, and mortality while also imposing a substantial burden on patients in terms of reduced productivity, quality of life, and increased healthcare expenditure. It is evident from published research that patients undergoing heart surgery suffer unfavorable outcomes if pre-existing AF is not treated. Surgical ablation (SA) is a well-established therapy for patients with AF and should be performed concomitantly during cardiac surgery. Despite SA for AF having a class I recommendation to be performed concomitantly during cardiac surgery, treatment rates remain low. Freedom from AF following bi-atrial Cox-Maze SA has been well documented but the long-term mortality outcomes of SA for AF during cardiac surgery remained unclear. A review of the literature that contrasted patients getting SA for AF while undergoing any type of cardiac surgery with patients not receiving SA for AF was included. AF ablation performed concomitantly during cardiac surgery is safe, does not raise the incidence of perioperative risks, and contributes to adult

patients' long-term survival following cardiac surgery. Compared to the matched general AF group, AF ablation increased the long-term survival of cardiac surgery patients.

Keywords: atrial fibrillation, Cox-Maze, ablation, cardiac surgery INTRODUCTION Atrial fibrillation (AF) is a widespread condition, with an estimated 37 to 46 million individuals affected globally.1 AF is the most common arrhythmia encountered by healthcare 14

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professionals and the incidence and prevalence are increasing globally.2 Preoperatively,

AF is observed in approximately 10% to 28% of patients undergoing heart surgery.3 McCarthy et al4 showed that AF was present in 28.4% of 79, 134 cardiac surgeries over 3 years before the surgeries. Interestingly, only 22.1% of patients with a prior history of AF received concomitant surgical ablation (SA).4 AF causes increasing cardiac dysfunction because it is characterized by a lack of atrial contraction and rapid, irregular ventricular contraction.2 AF is a condition that can be caused by several risk factors, including an aging population, diabetes, obesity, chronic obstructive pulmonary disease, heart failure, coronary artery disease, obstructive sleep apnea, alcohol use, physical inactivity, and smoking.1 When present at the time of surgery, AF has a detrimental impact on the 30-day outcome and survival rate compared to sinus rhythm (SR).1 Many population-based analyses using data from the Framingham Heart Study and other sources have revealed that AF is an independent predictor of mortality.5 Having preoperative AF increases allcause mortality, stroke, and heart failure after cardiac surgery.5 A stroke is three to five times

more likely to occur in people with AF, and these strokes are more severe than strokes that aren’t associated with AF.1 The 2017 Society of Thoracic Surgeons (STS) Clinical Practice Guidelines for the surgical treatment of AF issued a class IA recommendation for SA during concurrent mitral valve (MV) operations to restore SR.6 A class IB recommendation was issued for SA during single and combined coronary artery bypass grafting (CABG).6 SA of AF during concomitant cardiac surgery is also advised by the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS).2 Prior literature has shown that SA of AF effectively restores SR and improves cardiac surgery outcomes.3 However, there is not an abundance of data that shows that SA of AF shows a definitive long-term survival benefit.3 Past studies have not reported data past 12-month outcomes. This manuscript aims to review the literature on long-term survival outcomes of SA of AF during concomitant cardiac surgery.

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LITERATURE SEARCH A search utilizing PubMed from the National Library of Medicine and Google Scholar was performed. The aim was to source pertinent articles published within the last 5 years. The initial search parameters included “surgical ablation and atrial fibrillation,” “long-term outcomes of surgical ablation,” “mortality of surgical ablation,” “Cox-Maze procedure,” “concomitant cardiac surgery,” “atrial fibrillation guidelines,” and “stroke reduction with surgical ablation of atrial fibrillation.”

In addition to this, cited references of the initially identified relevant articles were performed to ensure a comprehensive literature review. The initial search yielded a total of 96 results, but with fine-tuned keyword parameters, this figure was reduced to 43 results. Further curation was conducted by applying filters for free full text and full text, which left a refined set of 19 results. The primary focus was on articles that presented data on mortality rates or the long -term outcomes of patients who had undergone surgical ablation of atrial fibrillation during concomitant cardiac surgery. Ultimately, 16 articles were selected for inclusion in the literature

review. Additionally, seminal articles that, while falling outside the 5-year search period, were found in the references of relevant articles. Excluded were articles that delved into topics such as catheter ablation, atrial fibrillation management, ablation techniques, different ablation methods, management of anticoagulation, and congenital heart surgery.

DISCUSSION AF is a burden to patients and healthcare systems around the world. AF requires a team

approach to include healthcare providers from across a network of specialties. The introduction of wearable health monitoring devices that can detect AF along with advertising by pharma companies has raised public awareness of AF and the associated health risks that come along with it. The definition of AF is having a documented 12-lead or single-electrode lead electrocardiogram episode of 30 seconds or greater with irregular RR intervals and no discernable waves.7 PAF stands as the most common enduring cardiac arrhythmia found in adults worldwide, and it’s notably associated with elevated rates of both mortality and morbidity, as well as a 16

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reduction in the quality of life for patients.7 The occurrence of AF in the adult population is

currently estimated to fall within the range of 2% to 4%.7 There is an expected 2.3-fold increase in cases, largely due to the aging of the general population and more intensive efforts to identify undiagnosed AF.7 It’s worth noting that AF is more frequently observed in white males, and the previously projected lifetime risk of 1 in 4 individuals has recently been adjusted to 1 in 3 individuals.7

Classifications of AF

The Heart Rhythm Society (HRS), American College of Cardiology (ACC), STS, and ESC have all agreed on four classifications of AF. These are paroxysmal (AF that terminates spontaneously or with intervention within 7 days), persistent (AF continuously sustained beyond 7 days, including episodes terminated by cardioversion beyond 7 days), long-standing persistent (continuous AF greater than 12 months duration), and permanent (AF that is accepted by the physician and patient to no longer attempt to achieve SR).7 Progression of AF While a patient's burden of AF can be categorized by a classification, AF is a complex disease with complex triggers and substrate modifications. By raising left atrial pressure and causing left atrial enlargement, structural heart disease plays a role in AF development.1 Chronic atrial stretch subsequently causes fibrosis and remodeling of the heart, which start and maintain AF.1 Screening for AF in aging populations is justified as the risk of AF and stroke increases as you get older.7 AF often contributes to left ventricular dysfunction which often leads to heart

failure. The goal should be to restore SR. Left ventricular myocyte function is affected by AF and is independent of heart rate.1 Thus a rate control strategy of AF will not prevent left ventricular damage.1 Surgical Management of AF Several studies of matched cohorts have found that when undergoing concomitant CABG or valve surgery, patients with preoperative AF have higher morbidity and death than those compared to SR before surgery.1 In his quest to try and

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find a surgical cure for AF, Dr. James Cox created a surgical maze of lesions in both atria to

prevent reentry but also allow preservation of the heart’s natural conduction system postoperatively.8 In 1987, the first cut-and-sew procedure was performed on a human and the term Cox-Maze was born.8 Following this, Dr. Cox made adjustments over time to the location of the lesions, and before 2002, the Cox-Maze III was the standard of care for those performing the procedure.1 In 2002, Dr. Sydney Gaynor realized how challenging the cut-and-sew procedure was to be adapted on a large-scale basis.9 Gaynor et al9 showed that the Cox-Maze III was able to be reproduced with radiofrequency bipolar clamps and further modifying the Cox-Maze III with both radiofrequency and cryoablation with medical devices to bring about the Cox-Maze IV (CM4) to improve adaptability. The use of cryoablation for SA of AF was first proposed by Dr. Cox in 1996; however, there was no detailed lesion set described at that time on how best to perform cryoablation.1 The CM4 is the current gold standard of care when performing a surgical ablation; omitting any of the lesions is only a type of SA and is not a CM4, so similar outcomes

should not be anticipated.1 The current guidelines from STS that were published in 2017 state that SA of AF at the time of concomitant structural heart surgery is a class I recommendation.6 The ESC and EACTS also recommend SA of AF during concomitant heart surgery.2 While the benefits of SA on rhythm outcome—that is, the return to SR or freedom from AF—have been amply documented, adoption remains low and the impact on endpoints like quality of life, hospitalization, stroke, and mortality have not yet been thoroughly investigated.7 Long-Term Outcomes of SA for AF From July 2011 to June 2014, Badhwar et al11 examined the STS database and found that 86,941 individuals with AF received non-emergent cardiac surgeries. Six surgical categories—CABG, aortic valve replacement (AVR) with or without CABG, mitral valve repair or replacement (MVRR) with or without CABG, aortic valve replacement (AVR) with MVRR, stand-alone SA, and other concomitant surgeries—were looked at for performance patterns of SA. Propensity matching of 28,739 patient-pairs was analyzed for risk of 18

Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

concomitant SA with or without SA by AF type, 1:1 matching algorithms, primary operation, and

STS comorbid risk variables.

The percentage of patients with AF who underwent SA was 48.3% (42,966 of 86,941).

Mitral surgeries had the highest percentage of SA, while CABG and AVR rates were lower. After propensity matching, SA was associated with a reduction in relative risk (RR) of 30-day mortality of 8% [RR 0.92, 95% confidence interval (CI) (0.85-0.99)] and stroke of 16% [RR 0.84, 95% CI (0.74-0.94)], but an increase in renal failure [RR 1.12, 95% CI 1.03-1.22)] and pacemaker implantation [RR 1.33, 95% CI 1.24-1.43)]. Limitations of this study include nonrepresentative populations and the amount of AF type documented. There was also limited information on the lesion method performed and on which atria, whether endocardial or epicardial lesions were performed, and the efficacy of left atrial appendage (LAA) obliteration during the procedure which was 86.4%.11 Rankin et al12 divided the 3745 risk-adjusted Medicare patients who had CABG in 2013 and had previously been diagnosed with AF into two groups: those who had concurrent SA and those

who did not. The two groups had similar risk-adjusted operative mortality and stroke rates. A total of 626 patients (17%) underwent concomitant SA. At one-year post-CABG, the SA group had lower unadjusted mortality than patients without SA (9.7% vs 13.9%; p < 0.007). Once risk adjustment was completed, survival in the early postoperative period (0-90 days) was similar with and without SA [hazard ratio (HR) = 1.03, 95% CI (0.74-1.43); p = 0.86]. In the late postoperative period (91-364 days), the SA group had a 42% reduction in all-cause mortality than patients without SA [HR = 0.58, 95% CI (0.35-0.95); p = 0.03]. The risk-adjusted incidence of cardiovascular implantable electronic device (CIED) implantation at 1 year was greater in SA (HR = 1.20; p = 0.01).

CABG admission risk-adjusted costs (HR = 1.11; p < 0.01) and inpatient care at 1 year were also greater with SA (HR = 1.06; p = 0.02).

Rankin et al13 then examined 2-year risk-adjusted mortality and total hospital costs using the same 3745 risk-adjusted Medicare patients as in his prior 1-year study of those with persistent AF who either underwent CABG and SA or CABG and no SA. Risk-adjusted mortality was

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Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

AF who either underwent CABG and SA or CABG and no SA. Risk-adjusted mortality was

calculated using a piecewise Cox proportional hazard model (0-90 days and 91-729 days). After two years, risk-adjusted hospital days and inpatient expenses were comparable (RR 0.97, p = 0.31; RR 1.04, p = 0.17). This was because of the greater readmission costs in the non-SA group.

Risk-adjusted hazard for late death (91–729 days) in the SA group was shown to be 29% lower at 2 years [HR 0.71, 95% CI (0.52-0.97); p = 0.03].

Musharbash et al14 looked at the late survival of patients undergoing a concomitant CM4.

This was a retrospective review of patients from 2001 to 2016 (n = 10,859). The three groups were categorized as patients with AF receiving concomitant CM4 (n = 438), patients with AF unaddressed during surgery (n = 1510), and patients without AF history (n = 8911). Propensity score matching was done between the groups and data was collected from the STS database and the center’s own AF database. Similar 30-day death rates were seen in the matched groups.

Kaplan-Meier analysis showed greater survival for CM4 compared to untreated AF (p = 0.04).

Ten-year survival was 62% for CM4 and 42% for untreated AF [adjusted HR 0.47, 95% CI (0.26-

0.86); p = 0.014]. There was no difference in survival between the CM4 and no AF groups by Kaplan-Meier analysis (p = 0.847). Ten-year survival was 63% for CM4 and 55% for no AF [adjusted HR 1.03, 95% CI (0.51-2.11); p = .929]. The CM4 group did have a higher rate of CIED implantations compared to the untreated AF group (12% vs 5%; p = 0.002).

Iribarne et al5 did a retrospective analysis from 2008 to 2015 of 20,407 CABG and valve procedures from the Northern New England Cardiovascular Disease Study Group (NNECDSG) Cardiac Surgery Registry looking at all-cause mortality. They compared patients receiving SA to patients receiving no SA. After exclusions, of the 2740 AF patients, 634 (23.1%) patients received SA and 2106 patients did not. The group with the highest SA rates was valve procedures, followed by valve and CABG, and then CABG alone.

Unadjusted survival of patients who underwent SA showed significant improvement [HR 0.54, 95% CI (0.42-0.70)]. The team also found no difference in postoperative complications.

The SA group had a shorter length of stay (p < 0.001) but a longer bypass time (141.3 versus 20

Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

122.3 minutes, p < 0.001). After risk adjustment, SA had an improved 5-year survival regardless

of which primary cardiac procedure was performed [HR 0.69, 95% CI (0.51-0.92)].

In patients undergoing MV surgery with concomitant SA for AF, Suwalski et al15 assessed late survival. Retrospective data collection was done on procedure-related information from the Polish National Registry of Cardiac Surgery Procedures (KROK). The analysis involved 11,381 patients with baseline AF (mean age 65.6 +/- 9.0 years; 46.6% men) who had MV surgery between 2006 and 2017 at 37 reference facilities across Poland and were in the registry. The median follow-up was 5 years (interquartile range, 1.9–7.9 years; mean, 4.6 years). For the calculations, Cox proportional hazards models were employed. The evaluation of MV ablation with MV alone was done using propensity score matching. There were 2449 (21.5%) included patients who underwent surgical ablation for AF. When MV plus ablation was performed instead of MV alone there was a significant improvement in survival over the course of the 12-year trial [HR 0.71, 95% CI (0.63-0.79); p < 0.001]. SA was linked to an almost 20% improvement in survival following meticulous

propensity matching [logit model, 1784 pairs; HR 0.82; 95% CI (0.70-0.96); p < 0.011]. In patients having isolated CABG and concurrent SA for AF, Suwalski et al6 also assessed early outcomes and long-term survival using procedural data from the KROK. At 37 reference centers across Poland between 2006 and 2018, 7879 patients with underlying AF received standalone CABG. The median (interquartile range) follow-up was 4.3 years (1.7-7.4); the mean follow-up was 4.7 +/- 3.5 years. To compare isolated CABG plus ablation with isolated CABG, propensity score matching and Cox proportional hazards models were utilized. SA was performed on 346 (4.39%) of the patients included.

SA was linked to a lower 30-day risk of death [RR 0.37, 95% CI (0.15-0.91); p = 0.032] and multiorgan failure [RR 0.29, 95% CI (0.10-0.94); p = 0.029] following a rigorous 1:3 propensity matching (logit model: 306 cases of isolated CABG plus ablation vs 918 of isolated CABG alone). SA was linked to a 33% longer overall survival rate over the long term [HR 0.67, 95% CI (0.49-0.90); p = 0.008]. Kowalewski et al16 set out to evaluate the long-term mortality of 21

Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

SA with concomitant cardiac surgery. The heart surgery in AF and supraventricular tachycardia

(HEIST) registry provided the data. In 8 tertiary facilities in Poland, the Netherlands, and Italy, they discovered between 2010 and 2021, 20,765 adult patients (62% men) with preoperative AF underwent traditional sternotomy heart surgery. To reduce variations in baseline attributes, they used propensity score matching and Cox proportional hazards models for computations. Of the patients who were included, 2755 (13.4%) underwent SA for AF.16 While mitral and tricuspid procedures had the highest rates of SA, CABG procedures had the lowest treatment rates. SA was linked to a decrease in mortality during the 11-year trial period [HR 0.57; 95% CI (0.52-0.62); p < 0.001]. There were 2750 matches with comparable baseline characteristics found after propensity matching. SA was linked to a 16% decrease in mortality [HR 0.84; 95% CI (0.75–0.94); p = 0.003].

To fully assess the value of AF ablation in patients with AF, Cheng et al3 used Taiwan's National Health Insurance Research Database (NHIRD) to look at the late outcomes of AF ablation across all types of adult cardiac surgeries and then compared them with those of general

patients with AF who did not undergo cardiac surgery. The NHIRD data gathered from the Health and Welfare Data Center were used in this population-based retrospective cohort study conducted across the country. Between January 1, 2001, and December 31, 2016, 11,459 individuals who had been diagnosed with AF during cardiac surgery were deemed suitable for analysis. Following propensity score matching, the SA group's 1278 and 1550 patients had 2 and 1 matched counterparts, respectively, yielding 4106 patients in the control group. Radiofrequency accounted for 71.22 % of the principal energy source used for SA, whereas cryo-

ablation accounted for 28.78 %. In the SA group, the average follow-up time was 5.1 +/- 3.8 years, compared to 5.0 +/- 4.0 years in the control group for these patients. All-cause mortality (5.74 and 7.69 events per 100 patient-years, respectively) and ischemic stroke after discharge (1.88 and 2.52 events per 100 patient-years, respectively) were significantly lower in the SA group [HR 0.75; 95% CI (0.69-0.81)].3 Long-term survival was considerably improved by concomitant AF ablation with CABG, tissue AVR, tissue mitral valve replacement, or mitral valve

22

Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

repair (p = 0.0176, p = 0.0001, p < 0.0001, and p < 0.0001, respectively). Additionally, the SA

group outlived the matched general AF population throughout the long term (log-rank test, p < 0.001).

CONCLUSION Concomitant SA of AF during cardiac surgery improved long-term survival in an adult population and has shown evidence-based data for safety and does not increase perioperative complications.3 It is evident from published propensity-matched research that patients under-

going heart surgery suffer unfavorable outcomes if pre-existing AF is not treated. The adoption of SA of AF remains low unless a patient is undergoing MVRR surgery. When one underwent a CM4 (bi-atrial lesion set) concomitantly during cardiac surgery for AF, this was the most successful in restoring SR and having an improvement in quality of life.1 The medical device industry has taken on the role of educating surgeons on how to properly per-form the CM4 which has led to surgeons performing the procedure worldwide.

Despite this, the percentage of SA of AF being performed with CABG, AVR, or CABG/AVR patients remains low in comparison to MVRR procedures. Despite the safety of performing a CM4, there is consensus among the surgeon community that a surgeon may not want to open the left atrium if not per-forming an MVRR; which then leads to a SA that is not a CM4. SA should be broadly incorpo-rated into the treatment of AF other than those undergoing MVRR.5 A surgeon’s skill set, under-standing of AF and atrial substrate modification, and consultation with an electrophysiologist should all play a part in which surgical lesions are performed.1 Gerdisch1 describes that if one is not performing a CM4 then priority should be given to complete LAA closure and posterior wall—pulmonary vein box isolation in the left atrium lesion set. The LAA is part of the CM4 and is known to be arrhythmogenic as well as a site of thrombus formation in those with AF. Early studies felt that the low rate of strokes after a CM4 was due to being in SR, however, it’s hypothe-sized that elimination of the LAA played a significant role as not all patients maintained SR.1 Therefore, management of the LAA is extremely important when treating AF, and larger-scale trials surrounding LAA management are needed.

23

Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

Patient selection should be taken into consideration when deciding to perform a CM4. It

has been suggested that a left atrium greater than 8 cm would lead to a 50% recurrence of AF and that a larger atrium is a predictor for tachyarrhythmia recurrence.1 Procedural complexity and patient characteristics should all be considered when deciding to perform a SA.1 There were limitations while performing the literature review. Not all the literature provided modality used to perform a SA (radiofrequency or cryotherapy), type of AF before surgery, exact lesion sets performed, whether the LAA was managed, data being collected from a retrospective registry, and a Medicare claims database was used which does not capture comprehensive clinical details. Given the conclusive data showing long-term mortality benefits from SA of AF during concomitant cardiac surgery, increasing education and surgeon training will hopefully increase the frequency of when SA will be performed.

REFERENCES 1. Gerdisch MW. The most beneficial options for patients with arrhythmia and concomitant structural heart disease: a review. AME Surg J. 2022;0(0). doi:10.21037/asj-22-18 2. Dominici C, Chello M. Concomitant surgical ablation for treatment of atrial fibrillation in patients undergoing cardiac surgery. Rev Cardiovasc Med. 2022;23(3):101. doi:10.31083/ j.rcm2303101 3. Cheng YT, Huang YT, Tu HT, et al. Long-term outcomes of concomitant surgical ablation for atrial fibrillation. Ann Thorac Surg. October 7, 2022. doi:10.1016/j.athoracsur.2022.09.036

4. McCarthy PM, Davidson CJ, Kruse J, et al. Prevalence of atrial fibrillation before cardiac surgery and factors associated with concomitant ablation. J Thorac Cardiovasc Surg. 2020;159 (6):2245-2253.e15. doi:10.1016/j.jtcvs.2019.06.062 5. Iribarne A, DiScipio AW, McCullough JN, et al. Surgical atrial fibrillation ablation improves long-term survival: a multicenter analysis. Ann Thorac Surg. 2019;107(1):135-142. doi:10.1016/j.athoracsur.2018.08.022 24

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6. Suwalski P, Kowalewski M, Jasiński M, et al. Surgical ablation for atrial fibrillation during

isolated coronary artery bypass surgery. Eur J Cardiothorac Surg. 2020;57(4):691-700. doi:10.1093/ejcts/ezz298 7. Hindricks G, Potpara T, Dagres N, et al. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2021;42(5):373-498. doi:10.1093/eurheartj/ ehaa612 8. Cox JL, Schuessler RB, D’Agostino HJ, et al. The surgical treatment of atrial fibrillation. J Thorac Cardiovasc Surg. 1991;101(4):569-583. doi:10.1016/S0022-5223(19)36684-X 9. Gaynor SL, Diodato MD, Prasad SM, et al. A prospective, single-center clinical trial of a modified Cox maze procedure with bipolar radiofrequency ablation. J Thorac Cardiovasc Surg.

2004;128(4):535-542. doi:10.1016/j.jtcvs.2004.02.044 10. Ad N, Henry LL, Holmes SD, Hunt SL. The impact of surgical ablation for atrial fibrillation in high-risk patients. Ann Thorac Surg. 2012;93(6):1897-1904. doi:10.1016/ j.athoracsur.2012.02.094 11. Badhwar V, Rankin JS, Ad N, et al. Surgical ablation of atrial fibrillation in the United States: trends and propensity matched outcomes. Ann Thorac Surg. 2017;104(2):493-500. doi:10.1016/j.athoracsur.2017.05.016 12. Rankin JS, Lerner DJ, Braid-Forbes MJ, Ferguson MA, Badhwar V. One-year mortality and costs associated with surgical ablation for atrial fibrillation concomitant to coronary artery bypass grafting. Eur J Cardiothorac Surg. 2017;52(3):471-477. doi:10.1093/ejcts/ezx126 13. Rankin JS, Lerner DJ, Braid-Forbes MJ, McCrea MM, Badhwar V. Surgical ablation of atrial fibrillation concomitant to coronary-artery bypass grafting provides cost-effective mortality reduction. J Thorac Cardiovasc Surg. 2020;160(3):675-686.e13. doi:10.1016/ j.jtcvs.2019.07.131 25

Journal of the Association of PAs in Cardiothoracic and Vascular Surgery

14. Musharbash FN, Schill MR, Sinn LA, et al. Performance of the Cox-Maze IV procedure is as-

sociated with improved long-term survival in patients with atrial fibrillation undergoing cardiac surgery. J Thorac Cardiovasc Surg. 2018;155(1):159-170. doi:10.1016/ j.jtcvs.2017.09.095 15. Suwalski P, Kowalewski M, Jasiński M, et al. Survival after surgical ablation for atrial fibrillation in mitral valve surgery: analysis from the Polish National Registry of Cardiac Surgery Procedures (KROK). J Thorac Cardiovasc Surg. 2019;157(3):1007-1018.e4. doi:10.1016/

j.jtcvs.2018.07.099 16. Kowalewski M, Pasierski M, Kołodziejczak M, et al. Atrial fibrillation ablation improves late survival after concomitant cardiac surgery. J Thorac Cardiovasc Surg. 2022;0(0). doi:10.1016/j.jtcvs.2022.04.035

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Eliminating sternal wound infections: Why every cardiac surgery program needs an I hate infections team Maren Downing, MEng,a,b Michael Modrow, PA-C,a,c Kelly A. Thompson-Brazill, DNP,a,c J. Erin Ledford, PharmD,a,c Charles D. Harr, MD, MBA,a,c and Judson B. Williams, MD, MHSa,c Reprinted under common creative license, under author request. doi: https://doi.org/10.1016/j.xjtc.2023.03.019

ABSTRACT

ChasingZER

Objectives: The majority of studies examining deep sternal wound infection (DSWI) prevention focus on ameliorating 1 variable at a time. There is a paucity of data regarding the synergistic effects of combining clinical and environmental interventions. This article describes an interdisciplinary, multimodal approach to eliminate DSWIs at a large community hospital.

Methods: We developed a robust, multidisciplinary infection prevention team to evaluate and act in all phases of perioperative care to achieve a cardiac surgery DSWI rate of 0, named: the I hate infections team. The team identified opportunities for improved care and best practices and implemented changes on an ongoing basis.

Results: Patient-related interventions consisted of preoperative methicillinresistant Staphylococcus aureus identification, individualized perioperative antibiotics, antimicrobial dosing strategies, and maintenance of normothermia.

Operative-related interventions involved glycemic control, sternal adhesives, medications and hemostasis, rigid sternal fixation for high-risk patients, chlorhexidine gluconate dressings over invasive lines, and use of disposable health care equipment. Environment-related interventions included optimizing operating room ventilation and terminal cleaning, reducing airborne particle counts, and decreasing foot traffic. Together, these interventions reduced the DSWI incidence from 1.6% preintervention to 0% for 12 consecutive months after full bundle implementation.

Conclusions: A multidisciplinary team focused on eliminating DSWI identified known risk factors and implemented evidence-based interventions in each phase of care to ameliorate risk. Although the influence of each individual intervention on DSWI remains unknown, use of the bundled infection prevention approach reduced the incidence to 0 for the first 12 months after implementation. (JTCVS Techniques 2023;19:93-103)

Deep sternal wound infection (DWSI) is a serious complication after median sternotomy, affecting 0.25% to 5% of patients.1 DSWI is associated with significant morbidity and has a mortality rate ranging from 10% to 50%.1

From the aWakeMed Health and Hospitals, Raleigh, NC; bCampbell University School of Osteopathic Medicine, Lillington, NC; and cDepartment of Cardiovascular and Thoracic Surgery, WakeMed Heart and Vascular, Raleigh, NC. Received for publication Oct 3, 2022; revisions received Feb 23, 2023; accepted for publication March 27, 2023; available ahead of print April 14, 2023.

Address for reprints: Maren Downing, MEng, Campbell University School of Osteopathic Medicine, Leon Levine Hall of Medical Sciences, 4360 US-421, Lillington, NC 27546 (E-mail: m_downing0106@email.campbell.edu).

2666-2507 Copyright Ó 2023 The Author(s). Published by Elsevier Inc. on behalf of The American Association for Thoracic Surgery. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). https://doi.org/10.1016/j.xjtc.2023.03.019

IHIT

I HATE INFECTIONS TEAM

Pre-op Anesthesia Sternotomy/EVH Radial Techniques

Infection Prevention

Intra-op Environment IHIT Co-Coordinators Advanced Practice Providers & CV Surgeon

Education Specialist

Cardiothoracic ICU

3B Cardiothoracic Surgery Intermediate Care

The I hate infections team organizational structure.

CENTRAL MESSAGE

An interdisciplinary, multimodal approach by an infection prevention team that evaluates and acts in all phases of perioperative care can achieve a deep sternal wound infection rate of 0.

PERSPECTIVE DSWI is a serious complication after median sternotomy and is associated with significant morbidity and mortality often causing rehospitalization and higher health care costs. A multidisciplinary team focused on infection prevention can identify and implement evidence-based strategies across all levels of care to ameliorate risk and reduce the DSWI incidence to zero.

Roughly 4.3% of cardiac surgery patients are readmitted for treatment of postoperative infections, including DSWI.2 The Swedish National Study revealed that 80% of patients with DSWI had coronary revascularization either alone or in combination with other cardiac procedures.3 In a recent study, patients readmitted within 30 days after cardiac surgery had significantly higher early (6 months) and late (60 months) mortality rates compared with those who did not require rehospitalization.2 A DSWI is associated with increased health care costs of $111,175 compared with $7981 for a superficial sternal wound infection in the United States.4 Infection prevention research highlights ways hospital personnel and institutional policies may mitigate surgical site infection (SSI). The majority of studies examining

Abbreviations and Acronyms ACS ¼ American College of Surgeons CHG ¼ chlorhexidine gluconate CTICU ¼ cardiothoracic intensive care unit DoOR Traffic ¼ decrease our operating room traffic DSWI ¼ deep sternal wound infection ERAS ¼ enhanced recovery after cardiac surgery IHIT ¼ I hate infections team IHI ¼ Institute for Healthcare Improvements MRSA ¼ methicillin-resistant Staphylococcus aureus SSI ¼ surgical site infections

DSWI prevention focus on ameliorating 1 variable at a time (Table 1). However, Konishi and colleagues26 employed a multifaceted approach to decreasing the incidence of DSWI that targeted patient-related and intraoperativerelated risk factors, such as preoperative methicillinresistant Staphylococcus aureus (MRSA) screening and decolonization, decreasing the frequency of on-pump coronary artery bypass grafting procedures, allowing for higher intraoperative body temperatures, and using antimicrobial skin sealants. These combined measures significantly reduced the incidence of DSWI (0.2% vs 3.6%; P < .0001).26 Unfortunately, there is a paucity of studies evaluating the effects of infection-related bundling addressing patient risk factors, intraoperative strategies, and

environmental risk reduction. This article describes an interdisciplinary and multimodal approach to eliminating DSWI in patients undergoing adult cardiac surgery at a large community-based health system and its outcomes over a 12-month period.

FORMING A TEAM Composition In 2020, the cardiac surgery I hate infections team (IHIT) was formed in alignment with the hospital’s Chasing Zero Initiative. IHIT worked in the framework of an existing enhanced recovery after cardiac surgery (ERAS) program.27 The team consisted of the executive medical director, cardiac surgeons, key advanced practice providers, clinical pharmacists, perfusionists, infectious diseases physicians, infection prevention nurses, operating room personnel, anesthesia and nursing staff, and importantly our environmental services personnel (Figure 1).

Setting Goals Once assembled, the team adopted the Institute for Healthcare Improvement’s (IHI) Model.28 The IHI Model incorporates W. Edwards Demings’ Plan-Do-Study-Act model.28 It poses 3 questions: “What are we trying to accomplish? How will we know that a change is an improvement? What changes can we make that will result in improvement?”28 The team performed a literature review to identify applicable guidelines and current evidencebased SSI prevention methods (Table 2). A number of interventions from across the perioperative continuum were selected for the IHIT bundle. The interventions selected for implementation by IHIT are grouped by the risk factors

TABLE 1. Individual deep sternal wound infection prevention variables Variable

Specifics

Reducing skin flora5

Chlorhexidine baths for infection control of multidrug-resistant organisms

Preoperative nasal MRSA screening5,6

Antibiotic selection, preoperative decolonization

Perioperative antibiotics5,7-10

Selection, coverage, concentration

Perioperative normothermia

Warming devices, room temperatures

Clean operating room environment11-13

Air quality, air turnover rates, temperature, cleanliness, foot traffic

Operating room door openings11,14

Airborne particle counts, staff movement, ventilation

Blood product transfusion7

Hemodilution, blood exposure

Sternal topical adhesives and medications15,16

Topical vancomycin, sterilization techniques, preventing dehiscence

Hypothermia prevention17-19

Airborne particles

20-23

Sternal closure method

Figure-of-8, wire cerclage, rigid fixation

Using disposable equipment24,25

ECG leads, electrocautery pad chords

Intravenous line dressings

CHG-impregnated dressing, CHG-impregnated patch

MRSA, Methicillin-resistant Staphylococcus aureus; ECG, electrocardiogram; CHG, chlorhexidine gluconate.

ChasingZER

IHIT

I HATE INFECTIONS TEAM

Pre-op Anesthesia Sternotomy/EVH Radial Techniques

Infection Prevention

Intra-op Environment IHIT Co-Coordinators Advanced Practice Providers & CV Surgeon

Education Specialist

Cardiothoracic ICU

3B Cardiothoracic Surgery Intermediate Care

Nursing Perfusion Cardiothoracic Infectious Anesthesia Pharmacy Surgical Environmental Services Services Leadership Surgery Disease

*The purpose of this team is NOT to usurp any infection committees currently formed, but to work closely with them to reduce infections in heart surgery.

FIGURE 1. The I Hate Infections Team (IHIT) organizational structure. ICU, Intensive care unit; CV, cardiovascular.

they address: patient-related, environment-related, and operative-related (Figure 2). Changes were implemented on an ongoing basis. IHIT periodically assessed compliance, re-educated team members, and identified additional opportunities for improvement.

Execution The IHIT team conducted literature reviews on an ongoing basis while also participating in continuing educational opportunities such as infection prevention conferences. Literature topics for review were not compartmentalized by team member position; however, most members identified opportunities in their area of expertise. Opportunities for improvement were then brought forward at the bimonthly interdisciplinary Conference of Excellence meetings held by the heart and

vascular service line. Ad hoc meetings were also conducted on an as-needed basis. At the forefront of IHIT was the initiative’s champion, a long-tenured cardiac surgery physician assistant with passion and expertise in infection prevention. Interventions were made after the IHIT team identified corrective action or after a new process was trialed and supported by health system administration. Electronic medical record and standard work processes were then put in place to maintain these IHIT interventions appropriately. The Institutional Review Board of WakeMed Health and Hospitals did not approve this study given that the research design was focused on literature review and environmental quality initiatives. Patient written consent for the publication of the study was not received due to the absence of use or inclusion of any patient information.

Patient-related interventions

• Preoperative MRSA identification • Individualized perioperative antibiotics • Antimicrobial dosing strategies • Normothermia maintenance

Environment-related interventions

• Proper OR ventilation • OR professional cleaning • Reducing airborne particle counts • Decreasing OR foot traffic

Operative-related interventions

• Glycemic control • Sternal adhesives and medications • Rigid sternal plating for high risk patients • Use of disposable healthcare equipment • Use of CHG dressings over invasive lines

FIGURE 2. The interventions made by the I Hate Infections Team (IHIT) grouped by the risk factors they address. MRSA, Methicillin-resistant Staphylococcus aureus; OR, operating room: CHG, chlorhexidine gluconate.

DSWI incidence has been historically recorded. Neither the method of surveillance nor the definition of DSWI has changed over the course of this study. We define DSWI as an infection involving the muscle, bone, or mediastinum within 90 days of surgery, consistent with the Society of Thoracic Surgeons database classification.

IDENTIFYING ADDRESSABLE FACTORS Patient-Related Risk Factors There are numerous established risk factors for developing DSWI.1,2 Patients with prolonged hospital stays before surgery, those who undergo urgent or emergency procedures, as well as those undergoing redo surgeries are at risk for developing DSWI.1 Additional patient-related risk factors include hyperglycemia, hypothermia, renal TABLE 2. Guidelines referenced by the I hate infections team Guideline

Organization

Surgical Site Infection Guidelines, 20165

American College of Surgeons and Surgical Infection Society

2019 merican Society of Heating, Refrigerating and Air-Conditioning Engineers Handbook— HVAC Applications: Health Care Facilities29

American Society of Heating, Refrigerating, and Air Condition Engineers

Practice Guideline Series: Antibiotic Prophylaxis in Cardiac Surgery, Parts I and II8,10

The Society of Thoracic Surgeons

Anesthetic Gases: Guidelines for Workplace Exposures

Occupational Health & Safety Administration

ISO 14644-1:2015

International Standards Organization

ISO, International Standards Organization

dysfunction with or without hemodialysis, nasal and skin colonization with specific pathogens, chronic obstructive pulmonary disease, female sex, obesity, older age, peripheral arterial disease, heart failure, and left ventricular dysfunction.1,2,30 Skin flora is another risk factor that can be proactively modified. S aureus is a commensal organism found on human skin and nasal passages. It predisposes patients to surgical site infections including DSWI.24 The American College of Surgeons (ACS) recommends testing all patients for intranasal MRSA colonization. Although routine perioperative antibiotics such as first and second-generation cephalosporins cover methicillin-sensitive isolates, they are not effective against MRSA. Despite use of evidencebased regimens to reduce skin bioburden like preoperative nasal MRSA screening and chlorhexidine (CHG) baths or showers the evening before surgery, our institution still experienced DSWI at a rate consistent with national averages.5,20 Avoiding unnecessary hypothermia, defined perioperatively as a core temperature below 36 C, is important in preventing surgical site infections, including DSWI. Hypothermia leads to vasoconstriction, which decreases blood flow and oxygen delivery to the tissues, impairs coagulation, and reduces antibiotic concentrations at surgical sites.

Mitigating Intraoperative-Related Risk Factors Operative risk factors associated with DSWI include use of bilateral internal thoracic arteries as coronary artery bypass conduits, excessive electrocautery, hyperglycemia, contaminated equipment, blood product transfusion, sternal closure technique, and prolonged operative, aortic crossclamp, and/or cardiopulmonary bypass pump times.1 Some of these risk factors are modifiable. Hyperglycemia is associated with excess morbidity and mortality in adult

critically ill patients, in particular infection, and can be ameliorated with endocrine management teams and insulin protocols. Approximately 60% to 90% of cardiac surgery patients develop perioperative stress hyperglycemia.31 Patients without diabetes developing stress hyperglycemia have a 4-fold increase in complications and a 2-fold increase in death.31 Intraoperative hyperglycemia has also been associated with excess morbidity and mortality for patients undergoing cardiopulmonary bypass. A metaanalysis demonstrated that intensive insulin therapy titrated to achieve blood glucose values from 70 to 200 mg/dL significantly reduced infection rates compared with higher target ranges. There were no differences in the incidence of hypoglycemia between treatment groups.

Topical adhesives and medications applied to the sternum before cardiac surgery can influence the incidence of infection by interfering with sterilization techniques. Bone wax was in the past believed to reduce bleeding and sternal wound infections, but more recent data suggest the opposite may be true.20,30 Bone wax also inhibits bone union, increasing the risk of sternal dehiscence.20,30 Alternative sternal applications may be more efficacious and safer. Vancomycin slurry paste, when applied to the cut edges of a sternum, may reduce superficial and DSWI.15,16 A large single-center study failed to confirm this finding but the overall incidence of DSWI was <1%; thus, it may have been underpowered. In summary, use of vancomycin paste has not been associated with harm and may improve outcomes.15 Additionally, several observational studies have demonstrated an association between blood product transfusion and DSWI although data from a randomized controlled trial is conflicting.7 The method of sternal closure may reduce risk. Traditional wire cerclage using parasternal or transsternal wires can potentially cut through the very bone to which they are applied.20,30 When compared with transsternal closure, 1 report suggested a figure-of-8 approach may reduce DSWI and superficial sternal wound infections.20 Rigid sternal fixation with plates may provide even more benefit by eliminating micromovements of the osteotomy edges. Allen and colleagues’21 prospective, single-blinded, multicenter randomized controlled trial of 226 patients showed better sternal healing and nonunion rates at 3 and 6 months in those who underwent rigid fixation compared with wire cerclage.

Moreover, there were decreased sternal complication rates at 6 months and a trend toward decreased infection.21 A randomized controlled trial demonstrated improved bone healing with rigid plate fixation as assessed by radiography.22 A meta-analysis that included unmatched observational studies concluded sternal plate fixation may improve survival, decrease hospital length of stay, and other complications compared with wire cerclage in patients at high risk.23 Central intravenous access is an important tool for invasive hemodynamic monitoring and preferred route for

vasopressor infusions. Antibiotic-impregnated dressings are often placed over the insertion sites to prevent central line-associated bloodstream infections. A recent study evaluated a CHG-impregnated dressing vs a CHG-impregnated patch applied at central line insertion sites. There was no significant difference in central line-associated bloodstream infections rates between the 2 groups.32 However, they noted the CHG-impregnated dressings were easier to apply and had statistically significantly less dressing interruptions compared with the CHG-impregnated patch.32 Reusable equipment has the potential to introduce bacteria into surgical sites if it is not properly cleaned or if design prohibits thorough and complete disinfection. This is particularly true of telemetry wires that may be colonized with bacteria known to cause DSWI. Studies have demonstrated the presence of enterococci, including vancomycinresistant Enterococcus, as well as Escherichia coli and other gram-negative rods on telemetry wires despite cleaning.

The Descriptive Evaluation of EKG Telemetry Pathogens study showed 69% of remote telemetry monitoring systems in medical units were colonized despite standard cleansing methods.24 Twenty-four percent were still colonized (P <.001) after instituting a sanitization protocol utilizing 0.52% sodium hypochlorite wipes (Dispatch, Clorox).24 Lankiewicz and colleagues25 showed similar data with 77% of clean reusable electrocardiogram leads being contaminated with bacteria. Switching to disposable electrocardiogram leads was associated with a 25% reduction in sternal wound infections over a 90-day period in Medicare patients. Another potential benefit of this change is the reduction in nursing time spent cleaning the reusable leads.33 Environment-Related Risk Factors The majority of nonpatient risk factor-related SSIs arise from contamination during surgery.30 Direct contamination can occur from gloves, hands, or hard-to-clean equipment.11 Indirect contamination can occur from particulate matter such as respiratory droplets and dust.11 Environmental elements, including operating room air quality, air turnover rates, poor ventilation, higher amounts of airborne contaminants, temperature, cleanliness, and foot traffic may contribute to the development of DSWI and other SSIs.5,11 Ventilation systems help prevent contamination of surgical fields.12,13 Studies have revealed the presence of both methicillin-sensitive and MRSA, Staphylococcus epidermidis, coagulase-negative Staphylococcus, Enterobacter, Acinetobacter, and Pseudomonas.11 The American Society of Heating, Refrigerating, and Air Conditioner Engineers’ ventilation requirements for operating rooms specifies there must be a minimum of 4 outdoor air exchanges per hour, a minimum of 20 air changes per hour, 20% to 60% relative humidity, and design temperature of 20 to 24 C.29 The amount of particulate matter in the air can be measured

via air particulate counts done with specialized equipment, or by using a microbiological approach using agar plates and counting colony forming units.11,34 Prior studies have demonstrated that UV light cleaning of operating rooms may decrease hospital-acquired infection transmission.

Airborne particle counts within operating suites have been attributed to the number of intraoperative staff present, staff movement, ventilation, and number of door openings.11 Door openings are primarily attributed to nursing and non-nursing operating room staff, anesthesia providers, and visitors who are not involved in the procedure.14 Elliot and colleagues35 reported an average of 54 door openings per hour in cardiac surgery cases compared with 33 per hour during general surgery cases. The most common reason for door openings was supply retrieval.35 Birgand and colleagues’14 multicenter observational study during 34 orthopedic and 25 cardiac surgeries demonstrated a statistically significant increase in log10 0.3 mm particle and microbial air counts in cases with more door openings.

From beginning to end of cardiac procedures, the median number of door openings per hour of the case was 23.4, with a range of 19.7 to 30.14 The average time the doors were open during each cardiac case was 13.1 minutes, equivalent to 7.3% of the surgery duration.14 Each door opening increases the likelihood of intraoperative surgical site contamination and SSI.14 Convection patient warmers are commonly used on patients in operating rooms to prevent or mitigate hypothermia; however, there are concerns that these devices may not only harbor bacteria and dust but mobilize infectious particles that could potentially seed wounds.17,18 Their internal fans can disturb air flow currents in an operating room, causing dust, debris, and/or bacteria to settle on the sterile field.19

INTERVENTIONS AND IMPLEMENTATION Mitigating Modifiable Patient-Related Risk Factors The ACS’s preoperative MRSA bundle, which includes CHG baths and nasal decolonization with mupirocin, is designed to limit surgical wound infections; however, it is less effective if all components are not completed.5 Regardless of the swab results, all preoperative patients are given intranasal mupirocin twice daily for 5 days based on current ACS recommendations.5 Although use of a universal decolonization strategy has not been shown to reduce infections in noncarriers of S aureus, targeted decolonization is difficult to operationalize because it is most effective when doses are completed before surgery.6 Because the interval between preadmission testing for outpatients or cardiac catheterization for inpatients and cardiac surgery is short, many patients do not complete 10 doses of mupirocin before surgery, putting colonized patients at risk for developing MRSA DSWI.

Our institution screens all nonemergency cardiac surgery patients for intranasal MRSA colonization with either a culture-based or polymerase chain reaction test, depending on the urgency of the procedure. The MRSA screen is used to guide periprocedural antibiotic selection, regardless of whether or not the mupirocin course is completed preoperatively. MRSA-negative patients receive cefazolin, a firstgeneration cephalosporin, with activity against common gram-positive and gram-negative pathogens associated with SSIs.8 To optimize pharmacokinetics and pharmacodynamics, a weight-based dose undiluted cefazolin is given as an intravenous push just before incision. Intraoperative doses of cefazolin are repeated every 4 hours during surgery per guideline recommendations.5 IHIT altered the standard cefazolin-dosing based on newer literature suggesting higher plasma concentrations at skin closure are associated with lower rates of SSI.9 Beginning in January 2021, patients prescribed perioperative cefazolin received an additional 1 g at the time of closure to ensure higher antibiotic levels in the skin before closure. Antibiotics are given for 24 hours after surgery. In addition to cefazolin for both gram-positive and gram-negative coverage, MRSApositive patients receive perioperative vancomycin, which is active in vitro against MRSA.7,10 Emergency cases or patients for whom MRSA results are not available are treated as if they are MRSA-colonized.

All perioperative care team members were educated and engaged in keeping patients warm from operating room to the cardiothoracic intensive care unit (CTICU). CTICU management audited all patients for adherence to the normothermia protocol. Preoperative temperatures are generally measured axillary or oral, intraoperatively with invasive catheters, and postoperatively with axillary or oral route or in some cases by remaining vascular or bladder catheters. If a patient was found to be hypothermic postoperatively, IHIT assessed whether or not the relevant patient warmers in the operating room were functioning appropriately, whether or not room temperatures were appropriate, and whether or not accurate patient temperatures were being achieved.

Mitigating Intraoperative-Related Risk Factors To combat intraoperative hyperglycemia, we targeted an intraoperative blood glucose level from 110 to 180 mg/dL utilizing insulin infusions for all patients by standardized nomogram. With regard to cardiopulmonary bypass, to reduce the risk of hemodilution, our perfusionists had previously worked to optimize the perfusion circuits to achieve the smallest possible extracorporeal volumes and minimize blood exposure to the circuit by reducing the length. They continue to work on hematocrit optimization in the setting of goal-directed perfusion practice.

Before the implementation of IHIT, we occasionally employed the use of sterile bone wax to augment

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Mitigating Environment-Related Risk Factors Although there are no standard limits for particle or colony forming units counts, IHIT sought to reduce particulate matter as much as possible.13,34 Ventilation ductwork in operating rooms was identified as another opportunity for improvement. Scrub sink faucet aerator tips were replaced and put on a regular cleaning and replacement plan because these were identified as possible contamination points if not regularly changed out and maintained.

Use of disinfecting UV light to enhance terminal cleaning of the operating room at the end of each day was noted to be suboptimal. Barriers to UV light use were identified via discussion with EVS personnel. These barriers included beliefs that UV use was prohibited around certain perfusionrelated machines, intravenous fluids left in the operating room, and insufficient UV lights to accomplish terminal cleaning of all operating rooms on a nightly basis due to time constraints. This resulted in staff education and the purchase of additional UV light machines. There was a steady increase in usage of UV light after remediation and education with 100% compliance in all operating rooms achieved.

Outside of operating rooms, terminally cleaned ICU rooms were targeted to prevent potential contamination of

fresh surgical sites and invasive devices. Cloth ICU room privacy curtains were replaced with a disposable version to reduce risk of bioburden cross-contamination and facilitate cleaning both in the ICU and in the preoperative patient bays in the preoperative holding area.

The IHIT team started the Decrease Our Operating Room Traffic (DoOR Traffic) initiative to limit movement into and out of operating rooms. The baseline number of door openings was established by observing 2 CABG surgeries and 8 other surgical procedures. Staff began door counts during set up of the sterile field and ended the counts after wound closure. To capture potential pathogens associated with operating room traffic and personnel, agar plates were placed in each operating room. Control agar plates were placed inside the operating room after the room was terminally cleaned and were recovered before the next surgical procedure. After baseline data was collected, operating room staff were asked to limit unnecessary entry into active cases and strategically implement mitigation measure to reduce traffic. Par levels of supplies were optimized. Surgeons and schedulers verified that cases were posted accurately to ensure that appropriate equipment carts were placed in rooms and extra inventory was minimized. Sizeable STOP sign stickers were placed on the doors of each operating room (Figure 3). After implementation, door opening counts and agar plate studies were repeated. The DoOR Traffic initiative resulted in an approximated 63% reduction in operating room traffic from an average of 310 to 114 door openings and a marked visual reduction in aerosolized bacterial particles were noted on the blood agar plates (Figure 4). This image proved a powerful tool to galvanize support for IHIT across each phase of cardiac

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hemostasis at the osteotomy site. Now by IHIT consensus, the use of bone wax was eliminated. IHIT employs rigid sternal fixation for those patients most likely to experience nonunion as determined by the surgeon and multidisciplinary team seeking to optimize value and risk for each patient in this manner. The decision for rigid sternal fixation was patient and surgeon-specific and not protocolized. Key factors weighing toward consideration of rigid sternal fixation included the following: bilateral internal thoracic artery harvest, poorly controlled diabetes mellitus, chronic obstructive pulmonary disease, body habitus, and amputee status. Wire cerclage was also surgeon-dependent and involved a combination of stainless-steel single and double-strand wires in simple and figure-of-8 configurations to fit patient anatomy.

Braided cables or other multifilament cerclage options were not used.

IHIT found that practitioners were inconsistent with antimicrobial patch application techniques. IHIT found that the CHG-impregnated (3M) dressing was not only easier to apply but that it was also more economical. Following this change, audits showed 100% of dressings were applied correctly.

The placement of leads and other devices were targeted preoperatively to avoid the anticipated surgical sites. Our institution trialed and ultimately switched to disposable leads. Additionally, reusable electrocautery pad chords were replaced with a disposable version to decrease the risk of bioburden spread.

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FIGURE 3. The Decrease Our Operating Room Traffic initiative STOP sign that was placed on the door of each operating room to limit movement into and out of the operating room.

FIGURE 4. Agar plates placed inside the operating room before and after implementation of the Decrease Our Operating Room Traffic initiative (DoOR Traffic) initiative. A, Microorganism growth on a control agar plate before DoOR Traffic Initiative implementation. B, Microorganism growth on an experimental agar plate after DoOR Traffic Initiative implementation.

surgical care. As a result of convection patient warmers potentially disturbing airflow currents, alternative devices capable of controlling body temperature with less airborne risk were identified by IHIT; thus, intraoperative convection warmers were replaced with water temperature-controlled heater-coolers.

Outcomes In the 12 months since implementation, our incidence of DSWI fell from 1.6% to 0% (Figure 5). Although our mission was to eliminate DSWI, superficial sternal wound infections were also tracked and as a byproduct, the incidence also fell to 0%. These efforts may have resulted in

secondary benefits of infection prevention such as decreased morbidity and mortality; however, that was not quantified and was deemed beyond the scope of this piece.

The IHIT approach has led individuals in each phase of care to take a deep dive into best practice in their area and through that effort has uncovered shortcomings and opportunities to achieve many small gains resulting in a big win for our patients.

DISCUSSION In an effort to proactively strive for a cardiac surgery DSWI rate of 0, our system developed a robust, multidisciplinary infection prevention team called the IHIT to identify

Infection Rate By Quarter 5.00% 4.50% 4.00% 3.50% 3.00% 2.50% 2.00% 1.50% 1.00% 0.50% Oct-Dec 09 Jan-Mar 10 Apr-Jun 10 Jul-Sep 10 Oct-Dec 10 Jan-Mar 11 Apr-Jun 11 Jul-Sep 11 Oct-Dec 11 Jan-Mar 12 Apr-Jun 12 Jul-Sep 12 Oct-Dec 12 Jan-Mar 13 Apr-Jun 13 Jul-Sep 13 Oct-Dec 13 Jan-Mar 14 Apr-Jun 14 Jul-Sep 14 Oct-Dec 14 Jan-Mar 15 Apr-Jun 15 Jul-Sep 15 Oct-Dec 15 Jan-Mar 16 Apr-Jun 16 Jul-Sep 16 Oct-Dec 16 Jan-Mar 17 Apr-Jun 17 Jul-Sep 17 Oct-Dec 17 Jan-Mar 18 Apr-Jun 18 Jul-Sep 18 Oct-Dec 18 Jan-Mar 19 Apr-Jun 19 Jul-Sep 19 Oct-Dec 19 Jan-Mar 20 Apr-Jun 20 Jul-Sep 20 Oct-Dec 20 Jan-Mar 21 Apr-Jun 21 Jul-Sep 21 Oct-Dec 21 Jan-Mar 22 Apr-Jun 22

0.00%

Superficial Infection Rate

Deep Infection Rate

FIGURE 5. Quarterly results of deep sternal wound infection incidence leading up to the I hate infections team intervention and 12 months after implementation. The x-axis represents time reported in quarterly intervals. The y-axis shows infection rate.

Adult: Perioperative Management

Eliminating Sternal Wound Infections: Why Every Cardiac Surgery Program Needs an “I Hate Infections Team” [IHIT]

Implementation We developed a robust, multidisciplinary infection team to evaluate and act in all phases of perioperative care.

We identified opportunities for improved care and best practices and implemented changes on an ongoing basis.

Together these interventions reduced the DSWI incidence to 0% for 12 consecutive months after full bundle implementation.

CHASING ZERO Disposable EKG leads Decreasing OR traffic Antibiotic stewardship Sternal adhesives Glycemic control OR ventilation Normothermia MRSA checks Vanco paste UV light ...

Outcomes Patient-related • Preoperative MRSA identification • Individualized perioperative antibiotics • Antimicrobial dosing strategies • Normothermia maintenance Environment-related • OR ventilation & cleaning • Reducing airborne particle counts • Decreasing foot traffic Operative-related • Glycemic control • Sternal adhesives & medications • Rigid sternal plating* • Use of disposable healthcare equipment • CHG dressings

Implications An interdisciplinary, multimodal approach by an infection prevention team that evaluates and acts in all phases of perioperative care can achieve a cardiac surgery post-infection rate of zero.

FIGURE 6. Pertinent interventions and outcomes. The iceberg image in the center depicts many, but not all, of the interventions made and represents that no action in particular tipped the iceberg, and the individual influence of each variable is unknowable. IHIT, I hate infections team; MRSA, methicillin-resistant Staphylococcus aureus; EKG, electrocardiogram; OR, operating room; DSWI, deep sternal wound infection; UV, ultraviolet light; CHG, chlorhexidine gluconate.

best practices in all phases of perioperative care. There are a substantial number of variables and pathway etiologies that can lead to DSWI. Our categorical initiatives toward operating room cleanliness and traffic, a shift to sterile disposable equipment, and a focus on reducing patient bioburden and antibiotic stewardship were altogether successful in this effort. Few studies explored outcomes associated with multiple interventions. To our knowledge, IHIT was the first multidisciplinary group to bundle patientand operative-related interventions with environmental changes.

Implementing an evidence-based, bundled effort toward infection prevention aligns with the ERAS Cardiac Surgery objective of improving perioperative outcomes. Our IHIT has been working with other operating room clusters and service lines on infection prevention strategies and implementation, specifically the DoOR Traffic initiative. Opportunities for improvement in pediatric surgery have been identified, including sterile technique and the anesthesia work environment, as well as adopting the ERAS bundle.

Moving forward, audits will be conducted, regardless of patient infection status, to ensure IHIT compliance. We will

continue scheduled quarterly meetings to empower leaders in the setting of post-pandemic staff turnover.

Unfortunately, a shortcoming of implementing a set of bundled set interventions is that the influence of each variable on the incidence of DSWI is unknowable (Figure 6).

Our IHIT leadership believes the most low-hanging fruit to be the elimination of bone wax and the implementation instead of vancomycin paste to augment hemostasis of the sternal edges and reducing door openings during surgical procedures (DoOR Traffic initiative). Our IHIT bundle was employed at a single center. Other institutions that implement an infection prevention bundle in a larger patient population may fail to achieve a similar magnitude of benefit. Data have been presented as the number of infections per the number of procedures, combatting potential cofounders of decreased or increased procedure numbers.

However, it is still possible there are other cofounders contributing to infection decrease that we are unaware of.

Despite these potential limitations, we remain optimistic that adoption of the IHIT approach and process will positively influence patient outcomes. It certainly has led to a more cohesive team effort and system-thinking regarding

infection prevention. Expenses associated with IHIT implementation were variable and included an increased cost for disposable equipment and the need in some instances for additional equipment.

Before embarking on an initiative to reduce DSWI at other health systems, we recommend a multidisciplinary audit of current institutional processes. Creating a gap analysis of current and best practices can help identify areas needing improvement. We recommend focusing on the often-neglected environmental risk factors for SSIs. This effort allowed IHIT to uncover many opportunities for improvement. Lastly, we recommend continuous assessments of the influence of interventions, scheduled audits to ensure best-practice adherence, and identification of new opportunities for improvement.

CONCLUSIONS As part of WakeMed’s Chasing Zero Infections campaign, a multidisciplinary IHIT was created. The goal was to eliminate DSWI in our adult cardiac surgery population. The team assessed current perioperative infection prevention measures and reviewed various SSI prevention literature. The team adopted the IHI Improvement Model, which incorporates W. Edwards Demings’ Plan-DoStudy-Act cycle to evaluate rapid change.5 Initiatives focused on reducing patient bioburden, optimizing perioperative antibiotics, using disposable equipment, and operating room cleanliness. This bundle was successful in achieving a postsurgical DSWI rate of 0 during the first 12 months after implementation. This cumulation of incremental gains demonstrates why every cardiac surgery program needs an IHIT. Conflict of Interest Statement The authors reported no conflicts of interest The Journal policy requires editors and reviewers to disclose conflicts of interest to decline handling or reviewing manuscripts for which they have a conflict of interest.

The editors and reviewers of this article have no conflicts of interest.Acknowledgments The authors thank all the members of the WakeMed team who have worked tirelessly to improve the care of our cardiothoracic surgery patients in the reported initiative: Bryon Boulton, MD, Abdul Chaudhry, MD, Trevor Upham, MD, Alden Maier, MD, Christopher Ingram, MD, Kathy Kane, RN, Jessica Adams, NP, Laura Barton, PA-C, Allison Broderick, PA-C, Christina Bull, NP, Teena Chavis, NP, Denise Chernoff, PA-C, Ron Fazio, PA-C, Suzanne Graves, RN, Robin Johnson, PA-C, S. Taylor Kerr, PA-C, Jeffrey Lamphere, PA-C, Matthew McEntire, PA-C, Lauren Parker, NP, Lindsay Rice, PA-C, Lauren Scarfo, PA-C, Samantha Tambunan, PA-C, Jon Van Hoose, NP, Leslie Terbet, RN, Jessica Dixon, MHA, RN, CIC, FAPIC, Julie Brewer, CRNA, Dennis Williams, CRNA, Hazel Covington, RN, Daniella Johnson, RN, Jodi Donahue, MSN, RN, Jonathan Laulis, MSW, SWCM; preoperative

testing; operating room; cardiothoracic intensive care unit and 3B nursing staff; anesthesia providers; infection prevention staff; respiratory therapists; clinical pharmacists; physical, occupational, and speech therapists; medical laboratory technicians; imaging staff; office staff; perfusion services; and environmental services staff across all care areas.

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Key Words: sternal wound infections, mediastinitis, prevention, enhanced recovery after surgery, cardiac surgery, operating room airborne contaminants, operating room traffic

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