ALLOGRAFT VALVE SURGERY P.Skillington CANBERRA April 2003

Aortic Valve Replacement Aetiology of Valvular Disease Pathology encountered Operations Available: focus on Allograft Operative Techniques Results

Aortic Valve - Aetiology Congenital: bicuspid, monocuspid age – 0-70 (peak 35-50) Degenerative: tricuspid age - >60 (peak 70-80) Rheumatic: Post rheumatic fever, uncommon in Australia age – all ages

AVR: Choice of Prosthesis Durability of Prosthesis Necessity for Warfarin- temporary or permanent Risk of Thrombo-embolism & Bleeding Re-operation rate & difficulty

Patient Related Factors Haemodynamic Performance: flow dynamics functional state achieved Biocompatibility Effect of various disease states eg: Marfans,other connective tissue diseases Possible future pregnancy Valve noise

AVR : Mechanical vs. Tissue Valve Excellent Durability 95% at 10yrs. 90% at 20yrs Low rate of re-operation. Easy to insert Warfarin, blood tests Thrombo-embolism 1-2%/pt/yr Bleeding risk 2%/pt/yr Non Cardiac Surgery hazardous Do not need warfarin Low risk of thrombo- embolism and bleeding : 0-1% Noiseless Durability variable:ie higher rate of re-operation Insertion may be more difficult Other surgery safe

Tissue Valve Durability Porcine,Pericardial: 40yrs:– 8-10 yrs 70yrs: yrs Aortic Allograft: 20yrs:- 10yrs 40-70yrs:- 15yrs Ross Procedure: On average,will last 40-50yrs (variable) Re-operation rate:- 1%/pt/yr

Stentless Porcine Valve AVR in elderly Better Haemodynamic function Larger orifice area Better resolution of Left Ventricular Hypertrophy

Aortic Allograft Insertion Human cadaveric Ao. v Cryopreserved AVR Root Replacement vs Subcoronary

Aortic Homograft (Allograft) Durability Better than Xenografts eg 50yr old: expect 15yr lifespan (vs 10 yrs ) Other Advantages Endocarditis with aortic root abcess Warfarin not required Disadvantages Not on shelf Re-operation difficult

M.O’Brien et al “The Homograft Aortic Valve:29 yrs” J. Heart V. Dis 2001;10: ,022 patients mean age 47yrs: Actuarial Survival

O’Brien et al,2001 Aortic Homograft Durability vs Age: Freedom from Re-op

Summary – Allograft AVR Best age range: 30 – 65 yrs Durability in that age range: 15yrs avge Indications: Endocarditis Not suitable for Ross Proc. Results: 78 pts over 12 yrs ( ) Early Mortality: 0 Late re-operation: 3

Ross Procedure Advantages Viable aortic valve Improved Durability cf other tissue valves No Warfarin absence T/E, ARH Disadvantages Longer operation Follow up of pulmonary valve

Ross Procedure Indications Age 20-60yrs, requiring AVR Contra-indications Bicuspid pulmonary valve(echo) Marfans Syndrome Other connective tissue disease R.arthritis/ SLE Active rheumatic heart disease Triple vessel CAD/ Mitral v. dis.

Patient Demographics (Ross P.) Time Frame : October 1992 to February 2003 No. of Patients: Age:Range (Mean 39.3) 2. :GenderM = 122 (70.9%)F = 50 (29.1%) 3. Valve Lesion: Aortic Stenosis: 68 (40%) AS/AR(Mixed): 51 (29%) Aortic Regurg: 53 (31%) 4. Aortic Valve Aetiology: Congenital: 158 (92%) Other:14 (8%) 5. Re-operation:19 (11%)

Microsoft Excel Spreadsheet – May 2002

MORTALITY & MORBIDITY 1. Early Mortality(in hosp. Or within 30 days)1 (0.6%) Myocardial Infarct 2. Early Morbidity - Re-Exploration9 (a) Bleeding7 (4.1%) (b) Graft RCA.1 ( c ) Low C.O. 1 - Retinal Embolus1 - CHB >>> Pacemaker1 - Renal Impairment4 - AMI2 - Inotropes3 - IABP1 - Respiratory Failure (Re-Intubation)1 - Pericardial Effusion1 - Arrhythmia Ventricular2 Atrial (AF) 20 -Sternal Infection 1 N=172

Late Results (n = 172) Late Death (non-cardiac) 2 1.2% Follow up 98.6% complete 735 patient years Thrombo-embolism 1 Cumulative Inc. 0.1% Bleeding(ARH) 0 0.0% Endocarditis 0 0.0% Re-operation 6 0.8% Late AR>mild 0 0.0% * 5yr freedom from re-operation = 96.2%

Ross (inclusion cylinder) Actuarial Survival: 155 patients 5yrs = 98% 7yrs = 95%

(n=155) 5yrs = 99% 7yrs = 99%

Zellner et al “Long term experience With the St.Jude Medical Valve Prosthesis” South Carolina,USA AVR 418 pts, mean age 54.8yrs Re-operation inc. 1.0%/pt/y *10yr survival 58%

Pregnancy after the Ross Procedure Seven women have under gone 11 successful pregnancies No maternal cardiac complications No problems with the passengers Favourable in contrast with mechanical valves

Durability Aortic Valve Prostheses

Pulmonary Regurgitation

AVR - Choice Prosthesis-Effect of Age yrs Ross, Mechanical, Allograft yrs Mechanical, Allograft, Porcine/Pericardial >70 yrs Stentless Porcine,Stented Pericardial, Mechanical

Results Pulmonary Allograft Insertion for Tetralogy, other Congenital Cardiac 45 patients over 12 year period zero mortality, minimal complications Beating heart surgery Do not require warfarin Quality of life very good

Conclusion 300 patients have had cardiac allograft valve replacement: Ross Procedure 177 Aortic Allograft 78 Pulmonary Allograft 45 Safe surgery: one(1) early death Excellent quality of life without anti- coagulants : young people

Standard Post-op Management Early BP(sys, mean) ; filling pressures (R+L) C. Output – depends on temperature Low CO (>37 C) Pericardial Tamponade signs of tamponade : low bp,high cvp,low urine output (usually prior bleeding) Improve CO optimal filling (+ve balance 1-2 l) vasodilators (GTN, prop., nipride) inotropes (milrinone, NOT adr,dop) noradrenaline IABP rate(80-90),rhythm

ANTICOAGULATION AVR mechanical : INR, Time to reach 2.0 pacing wire removal day 3-4 if not required porcine / pericardial : warfarin 6 weeks Ross / Allograft : aspirin 3months MVR mechanical INR 3.0,if chr.AF, clexane after 3-4 days porcine / pericardial Warfarin at least 3 months, often permanent MV Repair Warfarin 3 months

Special Situations Mitral valve surgery /PHT : pul vaso-dil,extub, sw ganz, LA line,b. gases, pht crisis AVR for AS and severe LVH AVR thin walled aorta – sys BP Ross : Sw Ganz removal Patients with poor LV sys function :early IABP TVR : pacing, cvp only for Repl. PVR : Usually no PA catheter

Stentless Tissue Valves Examples include: stentless porcine valve Aortic Allograft (homograft) Ross Proc. (pul.autograft) Features: Better haemodynamic funct. Improved resolution of left ventricular hypertrophy

Haemodynamic Function Ross (pulmonary autograft) 2-4 Stentless Porcine 5 Aortic Allograft 6 Mechanical Stented Porcine/Pericardial Residual aortic valve gradient(mmHg) *gradients at rest

MITRAL VALVE - Aetiology Myxoid Degeneration – 75% Repair Rheumatic – 95% Replacement Ischaemic – 50% Repair, 50% Replace Other – Endocarditis, SLE, Chordal Rupture

Actuarial Survival No.Patients 5 yr. 5 5yr. 97.5% 5yr.Cardiac Related 98.7%

AVR - Mortality Depends on age,cor.dis.,LV function %

Conclusions Early Mortality for AVR very low – all ages Tissue Valves favoured where possible,especially in the elderly,to avoid warfarin related problems & T- embolism If Tissue Valve used, Stentless valve is better haemodynamically In the elderly, patient will usually outlive their valve In younger patients, Ross Proc. is safe, good quality of life, low risk re-operation

ALREADY SHOWN Low Operative Mortality and Morbidity Resolution LVH Normalization LV Size and Function AIMS Late Valve Related Events Aortic Valve Function and Need For Re-Operation

AORTIC VALVE FAILURE A.R. Re-operation Moderate Aortic Regurgitation or Greater Factors Analyzed Age Sex Aortic Valve Lesion : AS/AR/Mixed Aortic Annulus Diameter Aortic Annulus Reduction Method Implantation of Autograft

TORONTO SPV CLINICAL SERIES June 1994 – May Patients Mean Age 75.5 years (61-87) Sex:Male53.3% (48) Female46.7% (42)

Results Stentless Valve Insertion Early Mortality Re-operation Hospital <30 days Total (%/pt/yr) Ross Proc (0.7%) 0.9 TSPV (2.2%) 0 Aortic Allo

Aortic Allograft :- Indications Endocarditis : Lowest risk of recurrent infection Exclusion of abcess cavities Women of child bearing age <60 yrs:-Unsuitable for Ross Procedure 60-70yrs:-Unsuitable for Mechanical device

Cardiac Surgery Modern Surgical specialty 1953: Development of the heart/lung machine (cardiopulmonary bypass) allowed intracardiac procedures to be performed on the empty heart Later improvements (cardioplegia) led to Asystolic arrest– flaccid or still heart 1960: Cardiac Valve Replacement 1968: Coronary Artery Bypass Surgery