Advances in Aortic Root Surgery Basel Ramlawi,MD, MMSc, FACS, FACC, FRCSC Co-Director, Methodist Aortic Network Cardiothoracic Surgery & Transplantation Methodist DeBakey Heart Center The Methodist Hospital Houston, TX
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Outline Advances in: Aortic Center Paradigm: Benefit of the multidisciplinary aortic and valve program Review Anatomy and Clinical Presentations of aortic root pathology Brief review of recent guidelines and indications for intervention Describe surgical techniques and algorithm for aortic root repair Personal experience following Valve-Sparing Root Replacement (VSRR) Procedures – factors that impact long-term outcomes
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Traditional Model of Aortic Care Incidental finding prompting surgical referral to: CT surgery for thoracic aortic pathology Vascular Surgery for abdominal aortic pathology Variable cardiology / medical involvement Minimal emphasis on medical management or prevention. Isolated pockets of expertise – lone practitioners.
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Aortic Center Paradigm Objectives:
Methodist Aortic Network
1.Expand model to address aortic pathology at the acute, sub-acute and elective stage – including medical management and screening. 2.Deliver state of the art aortic care to patients throughout Houston and beyond by involving satellite/community hospitals 3.Comprehensive aortic management from aortic valve to aortic bifurcation 4.Apply and develop less invasive approaches to aortic treatment 5.Promote aortic education and research through viable database
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Methodist Aortic Network Aortic Clinic – TMH and satellite hospitals Database – prospective data collection Research protocols Multi-disciplinary care focused aortic management Cardiac Surgery Vascular surgery Cardiology CV Imaging Anesthesia and critical care Nursing Perfusion
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Methodist Aortic Network Clinical Goals: • Minimize door-OR time for aortic emergencies • Minimally invasive & Hybrid approaches • Multi-modality neuro-monitoring • Medical management of aneurysms • Screening for high-risk populations (imaging/genetic) • Outcomes monitoring
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Aortic Imaging at MDHVC • 3D CT Scan • Computational fluid dynamic analysis (CFD) • Magnetic resonance angiography
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Computational Fluid Dynamics Re-Entry Tears FlowLines
0.24 m/s
0.01 m/s
0 m/s
Christof Karmonik, PhD Research Scientist
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Aortic Dissection • Incidence: 14-20 per million/year • Type A: 59-66% • Type B: 34-44%
80 – 120 dissections in Houston per year
• Untreated Type A MR: 21% @ 1 day; 83% @ 1 month • Acute Type A mortality: • Med - 32-64% • Surg - 20-35% • Branch vessel involvement: 30-42% • Aneurysm formation (Type B): 30-50% @ 4 yrs
Anatomy of the Aortic Root ♥ ♥ ♥ ♥ ♥
Aortic annulus Sinuses of Valsalva Aortic cusps Sinotubular junction Sub-commissural triangles Basel Ramlawi, MD Bramlawi@TMHS.ORG
Aortic Size •
– 1147 women – 1805 men – Normalized subjects are without factors that affect size
Prediction Model Developed Ascending Aorta Diameter = 14.10 + (0.13 X AGE) – 1.09 (if male) + (0.04 X AGE [if male])+ (5.80 X BSA)
Ascending aorta mean diameter was 3.3 ± 0.4 cm for final analysis group of 2952 "normalized" subjects combined genders
•
Upper limits of normal size for the ascending aorta was 4.1 cm Mean Ascending Aorta
Upper Limit of Ascending Aorta
Female
3.14± 0.32cm
3.74 cm
Male
3.35± 0.36 cm
4.07 cm
Wolak 2008 J Am Coll Cardiol Img Basel Ramlawi, MD Bramlawi@TMHS.ORG
Complications of Aortic Valve and Root Stenosis
Insufficiency
Both
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Marfan Syndrome • Most common inherited connective tissue disorder •Aortic rupture or dissection of aortic root is most common cause of premature death • Lifespan shortened by 1/3 Basel Ramlawi, MD Bramlawi@TMHS.ORG
Fibrillin-1 Mouse model of Marfan syndrome – FBN1 mutation – Aortic root aneurysms – Elastin fragmentation – Increased TGF-β activity
Habashi • Science 2006
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Mouse Model Transforming Growth Factor-β
Habashi • Science 2006
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Aortic Root Dilatation in Marfan Syndrome •
In these 18 pediatric patients, the rate of yearly aortic expansion was 3.5 mm per year
•
Under treatment in this trial, the rate of yearly expansion dropped to 0.5 mm per year Brooke NEJM 2008
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Aortic Growth in 2 MFS Children Treated with Losartan Root Dimension (mm)
32
38
Losartan
30 28
Losartan
36 34
β-blocker
26
β-blocker 32 ACE
24
30
22
28
20
26
0
10
20
Age (months)
30
0
20
40
60
Age (months) Basel Ramlawi, MD Bramlawi@TMHS.ORG
Bicuspid Aortic Valves
• NOTCH1 mutation Elastin abnormality and decreased tensile strength.
Image Fedak 2002
• Incidence 1-2% of population. M:F 2:1
Congenital Bicuspid
Cardiovascular Risk Factors
• Risk of ascending aortic dissection • Hypothesis of turbulent blood flow
• Hemodynamic stress on ascending aortic wall leads to dilatation or dissection Functional Bicuspid Basel Ramlawi, MD Bramlawi@TMHS.ORG
Surgical Indications
Basel Ramlawi, MD Bramlawi@TMHS.ORG
2010 ACCF/AHA/AATS/ACR/ASA/ SCA/SCAI/SIR/STS/SVM Guidelines for the Diagnosis and Management of Patients with Thoracic Aortic Disease Developed in partnership with the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, American Association for Thoracic Surgery, American College of Radiology, American Stroke Association, Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, Society of Interventional Radiology, Society of Thoracic Surgeons, and Society for Vascular Medicine. Endorsed by the North American Society for Cardiovascular Imaging.
Size Matters‌
Davies, RD, Annals Thor Surg, 2006
RISK OF COMPLICATIONS BASED ON SIZE
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Elefteriades. Natural history of thoracic aneurysms: Aortic Surgery Symposium VIIII. Ann thorac surg 2002;74:S1877–80
Key Points • Symptomatic TAA must be resected regardless of size. • Asymptomatic patients with diameter is 5.5 cm or greater. • Patients with BAV, genetic disorders, or familial history should undergo elective operation at smaller diameters (4.0 to 5.0 cm.) • Growth rate of more than 0.5 cm/year. • Patients undergoing cardiac surgery with ascending/root >4.5cm. • Imaging recommended for: • First-degree relatives of patients with TAA and/or dissection. • Second-degree relatives if first-degree relatives are affected..
OPERATIVE TECHNIQUES AORTIC ROOT REPLACEMENT
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Approaches • Modified Bentall Procedure – AVR with Replacement of aortic root with Dacron Graft – Re-implantation of coronaries – Options: • • • • •
Mechanical valve conduit Constructed stented/stentless tissue valve conduit Homograft Aortic Root Bioprostheses (e.g. Medtronic Freestyle) Autograft / Ross
• Valve-sparing root replacement (VSRR) – i.e. David / re-implantation procedure
Basel Ramlawi, MD Bramlawi@TMHS.ORG
BENTALL PROCEDURE
•
Replacement of root and proximal ascending aorta with a tube graft containing a prosthetic valve and reimplantation of the coronary arteries into the graft.
•
In original Bentall procedure native aorta as an external wrap to reduce bleeding related due to porosity of the graft or anastomosis.
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Mechanical vs. Bio (STS Database) Use of Mechnical vs. Bioprosthetic Mitral Valves STS Adult Cardiac Surgery Database Pts undergoing MV surgery including cases with concomitant procedures
100% 90% 80% 70%
Percent
60% 50% 40% 30% 20% 10% 0%
1994-1996
1997-1999
2000-2002 Mechanical
2003-2005 Bioprosthetic
2006-2007
Basel Ramlawi, MD Bramlawi@TMHS.ORG
The Society of Thoracic Surgeons National Adult Cardiac Surgery Database, 2007
• Conduit Construction – 27mm Edwards Magna in 30mm VALSALVA graft – 7 minute construction time
Basel Ramlawi, MD Bramlawi@TMHS.ORG
MODIFIED BENTALL OPERATION WITH BIOPROSTHETIC VALVED CONDUIT No Coumadin!
Figure 2
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Basel Ramlawi, MD Bramlawi@TMHS.ORG
HYBRID TOTAL AORTIC ARCH REPLACEMENT
Selective antegrade cerebral perfusion is instituted for the graft to innominate and the distal aortic anastomoses.
The proximal graft is then clamped and full CBP flow re-instituted.
The proximal anastomosis is completed during the rewarming process.
The L SCA is typically ligated at the end of the procedure via the sternotomy to avoid competitive flow with the L carotid subclavian bypass.
A thoracic endograft is utilized to complete the arch replacement, using the distal aortic graft as a proximal landing zone. Basel Ramlawi, MD Bramlawi@TMHS.ORG
Hybrid Repair of Dilated Aortic Root, Ascending and Arch Aneurysm (Marfans) s/p Type 1 Aortic Dissection Repair • Modified Bentall with Mechanical Conduit • Debranching of Innominate and LCC • Carotid-Subclavian Bypass • TEVAR of aortic arch aneurysm with proximal landing zone in ascending aortic graft
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Axillary Cannulation 486 patients (Single Center) – 0.64% stroke – 1.5% morbidity • Numbness / Brachial Plexus
• STS Database: 5-8% Stroke Rate
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Valve-Sparing Procedures
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Historical Background David TE, Feindel CM: An aortic valve-sparing operation for
patients with aortic incompetence and aneurysm of the ascending aorta. Thorac Cardiovasc Surg. 1992;103:617-22 First manuscript on aortic valve-sparing operations in patients with aortic root aneurysm and/or ascending aortic aneurysm
Basel Ramlawi, MD Bramlawi@TMHS.ORG
AORTIC VALVE-SPARING • Indications – – AI due to aortic root/ascending aortic dilatation in which valvular insufficiency is due to outward displacement of the valve commissures/annulus – Transverse aortic root diameter > 5.0cm •
Procedure Tailored to Patient– – STJ downsizing with AV re-suspension– ascending aortic aneurysm (dilated STJ, normal aortic sinuses/cusps) – Remodeling aortic root (Yacoub) – aortic root aneurysm where likelihood of annular dilatation minimal – Reimplantation of aortic valve (David) – aortic root aneurysm where annular dilatation may occur (ie Marfan, annuloaortic ectasia)
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Coaptation Height
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Sinuses of Valsalva
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Repair of Aortic Cusp Prolapse Plication on Nodule Arantus
Reinforcement with Gore-Tex
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Results • Operative deaths: 4 (1.1%) Freedom from Reoperation
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Population-Matched Survival
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Freedom from Moderate/Severe AI
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Johns Hopkins Experience Freedom from Reoperation - Marfan
Patel ND, ATS 2008
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Westaby 2009 Nature CPCVM
•
•
New Guidelines? AV Cusps tend to deteriorate with larger aortic root aneurysms Prompt replacement at 5.0 cm threshold is reached may better preserve valves and allow valve sparing root replacement
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Key Points Patients with aortic root aneurysm with or without AI are candidates for aortic valve sparing operations as long as the aortic cusps are thin, pliable Not overstretched, thinned-out or large stress fenestrations
Cusp repair reduces durability of the repair Long term results seem to be excellent VSRR is an attractive alternative to aortic root replacement with mechanical or biological valve conduits
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Trends in Aortic Root Surgery • Decreased threshold for surgical intervention (50mm) – Intervene at 45 - 50mm if: • • • • •
Other cardiac surgery Connective tissue / BAV / Marfan Intention to spare valve (VSRR) Family history Sympomatic
• Increased use of VSRR and Bio-Root Replacements – ? Implications for TAVR later
• Axillary cannulation increasingly common
Basel Ramlawi, MD Bramlawi@TMHS.ORG
Thank You Questions
Basel Ramlawi, MD Bramlawi@TMHS.ORG