Indian Journal of Thoracic and Cardiovascular Surgery, 1982; 1:56-7

The First Aortic Homograft DONALD ROSS*

KEY WORDS: Homogra/t." Valre replacement; ttistory

DONALD ROSS

H I S T O R Y

In 1961 we had emerged from the era of closed heart surgery and had reached a stage where the heart-lung machine could be used with reasonable safety in simple congenital lesions.

As far as valves were concerned, mitral valvotomy still held pride of place but calcific aortic stenosis was clearly not amenable to splitting with expanding dilato,'s. Many heroic attempts were made. particularly by Lold Brock, but the results were devastating in that the massively hypertrophied left ventricles could

From National Heart Hospital, l .ondon.

not sustain the inevitable resulting aortic regurgitation.

We consequently moved into the field of open surgery on the aortic valve with coronary per- fusion and a number of successful conservative repairs and reconstructions were achieved. I

It soon became apparent that most of these valves were entirely irrepairable and that replace- ment was the only possible solution.

Hufnagel had used a ball valve in the descending aorta to palliate aortic regurgita- tion 2 and Murray had achieved the same result with a fresh homograft also in the descending aorta. Also we had news of a ball valve type of prosthesis being developed in the U.S.A. by Harken and Start.

Our inclination was towards developing a biological or naturally-occuring valve but the work of Conrad Lam of Detroit 3 had indicated that aortic homograft cusps retracted and tibrosed when inserted in the descending aorta of dogs. However, we were able to show in the dog laboratory 4 that these cusps would persist in the descending aorta of a dog pro- vided that they had a physiological work-load

in other words, provided aortic regurgitation was induced in the dog at the time of implanta- tion of the homograft.

In other bench experiments we were dissect- ing and collecting human aortic valves for

Aortic Hornogra ft 57

testing in a pulse dupl icator . The impressive feature of this work was the s t rength and resi- lience of these valves tested for up to three months in o rd ina ry unsterile tap water. Other efforts were directed towards methods of steri- l izat ion and s torage of aor t ic homogra f t vanes , and ethylene oxide plus freeze dry ing was chosen as the preferred technique.

Concur ren t with this work, Duran and Gunn ing in Oxford developed a method for sewing in homograf t valves with a single suture layer plus suspension of the commissures from the aor t ic wall. This method was published in the Lancet. 5

in early 1962 while opera t ing upon a case of calcific aor t ic stenosis in Guy ' s Hospi ta l , 1 removed calcium somewhat over enthusiast ical ly and it ended with the loss of a cusp, and no prospect of a conservat ive repair . The re- maining calcified valve was removed as com- pletely as possible and it was replaced with a stored homograf t , sewn in place with a single suture line after the method described by Gunning. 6 It was hoped that this would serve as a holding procedure while a mechanical valve was impor ted .

To our surprise and delight the pat ient did well and was out of the hospi tal within a fort- night. Very soon we realised the potent ia l of this central ly flowing non-embol iz ing valve and

well over a thousand have been inserted since. In my view it still remains one of the best aor t ic valve subst i tutes avai lable today.

As far as the first pat ient is concerned, a l though he had been in advanced left ventr i - cular failure he remained well for four years but with a minor degree of aor t ic regurg i ta t ion present f rom the t ime of surgery. At 4�89 years left ventr icular failure again developed and the pat ient died without being offered the prospec t of a second opera t ion . The homogra f t valve at au topsy was heavily calcified, as were most of the early freeze dried valves.

References

I. Ross DN. Surgical Reconstructions o] tile aortic valve. Lancet 1963; I: 571-4.

2. HUrYA(;EL CA. Aortic plastic valvular prosthesis. Bull. Georgetown Univ Med Centre 1951~ 4: 128.

3. LAM CR, ARAM HH, MONNtLL ER. An experi- mental study o f aortic valve homografts. Surg Gynec Obstet 1952; 94: 129-35.

4. BREW"IN EG. The use o f tissue transplant in the sttrgery oF cardiac valvar disease: An experimental study. Guy's Hosp Rep 1956; 105: 328-30.

5. DURA.'q CG, GUNNING AJ. Total homologous aortic valve in the sub-coronary portion. Lancet 1962; 2: 488-9.

6. Ross DN. Homograft replacement o f the aortic valve. Lancet 1962; 2: 487.