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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


SHA24/028003