Long-Term Results of the Ross Procedure
December 1, 1997 3 minutes read
Long-Term Results of the Ross Procedure
ABSTRACT & COMMENTARY
Synopsis: In young patients (< 50 years of age), pulmonary autograft aortic valve replacement results in low rates of degeneration, endocarditis, and thromboembolism for more than 20 years.
Source: Chambers JC, et al. Circulation 1997;96: 2206-2214.
The pulmonary autograft procedure for replacing diseased aortic valves developed by DN Ross is attractive because of its autologous nature and structural similarity to the aortic valve, but concerns remain regarding its long term durability. Thus, Chambers and colleagues identified 131 hospital survivors of this procedure at the pioneering center in London who were operated on between 1967 and 1984. Most of the patients were male, and their age at operation ranged from 11 to 52 years (mean 32). Most of the operations were valve autografts with homograft pulmonic valve replacements. Survival at 10 and 20 years post-operation was 85% and 61%, respectively; freedom from reoperation was 88% and 75% for the aortic autograft and 89% and 80% for the pulmonic homograft, respectively. The three most common causes of death were heart failure, reoperation complications, and endocarditis. Infectious endocarditis occurred in 12 patients; seven early after the original operation or reoperation, and all seven were at the pulmonic site. Only three of the five late infections were on the aortic autograft. Major thromboembolic events occurred in 16 patients (11 systemic and 5 pulmonary). All but one of these 16 patients had other major risk factors for embolism such as atrial fibrillation. Autograft regurgitation was the most common indication for reoperation and was usually due to cusp prolapse; degeneration was found in only three of 30 explanted valves. Chambers et al conclude that in young patients (< 50 years of age), pulmonary autograft aortic valve replacement results in low rates of degeneration, endocarditis, and thromboembolism for more than 20 years. The major reason for reoperation is cusp malposition due to technical factors that can be surmounted with a free standing root implantation technique.
COMMENT BY MICHAEL H. CRAWFORD, MD
Biologic valves have the advantage of not requiring anticoagulation, which is ideal for young active adultsespecially women who wish to bear children. However, xenografts are plagued by a higher incidence of early degeneration and failure requiring reoperation after 7-10 years. Homografts are promising, but there are no long-term studies, and viable cells in the graft may be immunogenic and lead to early degeneration. The pulmonary autograft is ideal from a tissue point of view but did not catch on quickly because of concerns about the complexity of the surgery, the durability of the pulmonary valve in the aortic position, and the creation of pulmonic valve disease. These concerns are largely answered by this series from Ross’ group.
The duration of the pulmonary autograft at 10 and 20 years is at least as good as reports on the porcine xenograft at 12 years and is superior in the younger age groups where xenograft degeneration is more rapid. Presumably, this is because of a lack of immunologic reactions, but this hypothesis needs to be proven. An interesting downside to this procedure is that some of the surgically excised valves had developed rheumatic changes. This may be a problem in some population areas where rheumatic fever is common. In all, the Ross procedure seems to be ideal for young adults who are more likely to survive the longer surgery.
The cusp prolapse problem seems to be related to technical problems associated with sewing in the pulmonic valve into the aortic root. Because of this problem, Ross abandoned using valve tissue only in favor of a free-standing root graft in 1974. Because Chambers et al wanted a long follow-up for this series, they cut off the population at 1984, so only 20 patients had the new operation. There seemed to be less problems with autograft regurgitation requiring replacement in these 20, but a larger series will be necessary to prove this. Also, the pulmonic homograft results are likely to be better today because some of their patients had older preservation techniques that are now known to be inferior and have been abandoned. Despite these deficiencies of the operation under study, the results are excellent and support the concept that pulmonary autografts are a good choice for selected patients with aortic valve disease.
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