ALLOGRAFT VALVE SURGERY

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:- 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 Valve

AVR 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 )

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;10:334-345 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%)

Age at Op Hosp Sex

Prev Surg

Type of Prev Surg

Pre-Op NYHA

Valve Aetiology

Valve Lesion

Aortic Valve Gradient

Cardiac Cath LVEDD LVESD

29 1 2 1 4 2 7 3 0 0 6.7 5.323 1 1 1 1 3 1 1 60 1 4.1 2.222 1 2 0 0 3 1 2 7.2 4.440 1 1 0 0 3 1 3 1 6.1 4.527 1 2 0 0 2 1 2 70 1 6 3.724 3 2 0 0 2 1 2 35 0 6.3 3.524 3 1 0 0 3 1 2 46 0 4.3 2.332 3 2 0 0 1 1 3 5 0 6.6 4.619 1 1 0 0 2 1 1 40 0 4.6 2.832 3 2 0 0 2 1 2 75 0 5.6 3.553 1 2 0 0 3 1 1 90 1 4.6 3.825 1 1 0 0 3 1 1 56 0 4.2 3.240 1 2 0 0 3 1 1 45 1 4.3 2.834 3 2 0 0 1 1 1 0 7 4.217 1 2 1 1 2 1 2 55 1 7 4.322 1 1 1 1 3 1 1 50 0 4.7 331 2 2 0 0 1 1 3 18 0 6.4 5.133 1 2 0 0 2 1 3 14 0 6 4.254 2 2 0 0 2 1 2 56 0 5.8 3.725 1 2 0 0 2 1 2 40 0 5 3.233 1 2 0 0 1 1 3 1 6.6 4.4

Microsoft Excel Spreadsheet – May 2002

MORTALITY & MORBIDITY1. Early Mortality (in hosp. Or within 30 days) 1 (0.6%)

Myocardial Infarct2. 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 2Atrial (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%

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

Durability Aortic Valve Prostheses

1 wk1 yr

2-3 yr4-5 yr

6-7 yr8-9 yr

nil or trivial

mild

moderate

severe

0

20

40

60

80

100

Percent

time post-op

Pulmonary regurgitation

nil or trivial

mild

moderate

severe

Pulmonary Regurgitation

Survival After Valve Replacement

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

• Ross (pulmonary autograft) 2-4

• Stentless Porcine 5

• Aortic Allograft 6

• Mechanical 10-20• Stented Porcine/Pericardial 12-25

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

96

97

98

99

100

101

0 1 2 3 4 5

Years

% S

urv

ival

% Survival

Actuarial Survival

132 107 86 65 41 22 No.Patients

5 yr.5

5yr. 97.5%

5yr.Cardiac Related 98.7%

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 Mortality Re-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