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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.
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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
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 AVR : Mechanical vs. Tissue Valve
Tissue Valve Durability • Porcine,Pericardial: 40yrs:– 8-10 yrs 70yrs:- 12-15yrs • Aortic Allograft: 20yrs:- 10yrs 40-70yrs:- 15yrs • Ross Procedure: On average,will last 40-50yrs (variable) Re-operation rate:- 1%/pt/yr
Stentless Porcine ValveAVR in elderlyBetter Haemodynamic functionLarger orifice areaBetter 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 ) • OtherAdvantages • 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;10:334-345 1,022 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 (1990-2002) 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 : 172 1. Age: Range 16-62 (Mean 39.3) 2. :Gender M = 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%)
MORTALITY & MORBIDITY N=172 1. Early Mortality (in hosp. Or within 30 days) 1 (0.6%) Myocardial Infarct 2. Early Morbidity - Re-Exploration 9 (a) Bleeding 7 (4.1%) (b) Graft RCA. 1 ( c ) Low C.O. 1 - Retinal Embolus 1 - CHB >>> Pacemaker 1 - Renal Impairment 4 - AMI 2 - Inotropes 3 - IABP 1 - Respiratory Failure (Re-Intubation) 1 - Pericardial Effusion 1 - Arrhythmia Ventricular 2 Atrial (AF) 20 -Sternal Infection 1
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% 155 127 101 83 54 37 19 7 4
(n=155) 5yrs = 99% 7yrs = 99% 155 127 101 83 54 37 19 7
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
AVR - Choice Prosthesis-Effect of Age • 15-60 yrs • Ross, Mechanical, Allograft • 60-70 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 Residual aortic valve gradient(mmHg) • Ross (pulmonary autograft) 2-4 • Stentless Porcine 5 • Aortic Allograft 6 • Mechanical 10-20 • Stented Porcine/Pericardial 12-25 *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 5yr. 97.5% 5yr.Cardiac Related 98.7% 5 5 yr. 132 107 86 65 41 22 No.Patients
AVR - Mortality • Depends on age ,cor.dis.,LV function <70 1% 70-80 2% >80 3-5%
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 SPVCLINICAL SERIES June 1994 – May 2001 90 Patients Mean Age 75.5 years (61-87) Sex : Male 53.3% (48) Female 46.7% (42)
Results Stentless Valve Insertion Early MortalityRe-operation Hospital <30 days Total (%/pt/yr) Ross Proc. 143 0 1 1(0.7%) 0.9 TSPV 90 1 1 2(2.2%) 0 Aortic Allo. 35 0 0 0 1.5
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