Does histocompatibility affect homograft valve function after the Ross procedure?

pretability of disease-specific health status assessments over time. Results: Of the 99 patients assigned to medical therapy, 59 (60%) subsequently underwent transmyocardial revascularization. By an intention-to-treat analysis, patients initially randomized to transmyocardial revascularization had 44% of their angina eliminated vs. 21% for the medical treatment group (difference⫽23%; 95% confidence interval [CI], 11% to 34%). Differences in the benefits of transmyocardial revascularization on physical limitations (33% vs. 11% in the medical arm [difference⫽23%; 95% CI, 15% to 31%]) and quality of life (47% vs. 20% in the medical arm [difference⫽26%; 95% CI, 18% to 35%]) were similarly large. These benefits were apparent at 3 months and sustained throughout the 1 year of follow-up. An efficacy analysis that excluded patients who crossed over from the medical treatment to transmyocardial revascularization arm, suggested greater treatment benefits with TMLR. Conclusion: Transmyocardial revascularization may offer a valuable palliative alternative to patients with severe limitations in health status for whom no standard revascularization options exist. Perspective: No specific medical therapies were described in this paper. As such, it is difficult to interpret the benefits of transmyocardial revascularization. RM

1980s to the 1990s, the RR of reoperation after repair of AL-MVP vs. PL-MVP did not change, but the absolute rate of reoperation decreased similarly in PL-MVP and AL-MVP (at 10 years, from 10⫾3% to 5⫾2% and from 24⫾6% to 10⫾2%, respectively; p⫽0.04). Conclusion: In severe MR due to MVP, mitral valve repair compared with MVR provides improved very long-term survival after surgery for both AL-MVP and PL-MVP, with similar rates of reoperations after both procedures. Reoperation rates are more frequent after repair of AL-MVP than for PL-MVP. Perspective: Given the excellent long-term results of mitral valve repair compared to replacement, this is the procedure of choice for patients with severe MR due to MVP. However, it is unlikely that the excellent results obtained in this study at a center with a vast experience in this surgical approach can be achieved in centers performing just a few such procedures every year. RM

Does Histocompatibility Affect Homograft Valve Function After the Ross Procedure? Bechtel JFM, Bartels C, Schmidtke C, et al. Circulation 2001; 104 (Suppl I):I-25– 8. Study Question: Is there a relationship between the degree of histoincompatibility (defined as the number of human leukocyte antigen [HLA] mismatches between valve donor and recipient) or the provoked response of the recipient (measured by alloantibodies against HLA antigen) with echocardiographic parameters of homograft valve function after the Ross procedure? Methods: Twenty-six patients (mean age 41⫾14 years; 20 males, 6 females) and the cryopreserved pulmonary homograft valves that were implanted during a Ross procedure were typed for HLA-A, HLA-B and HLA-DR and alloantibodies to HLA class was measured. Results: Anti-HLA class I antibody was detected at follow-up (mean 15⫾6 months) in 14 (54%) of the patients at panel reactive antibody levels ⬎6% (considered positive). These antibodies were shown to be donor specific in all but one patient. Alloantibody-positive patients had a significantly higher HLA-A (p⫽0.008) and HLA-B (0.025) mismatches than alloantibody-negative patients. During follow-up, there was a significant increase of the maximal (16.2⫾7.1 mm Hg) and mean (13.2⫹4.3 mm Hg) transhomograft pressure gradients while homograft regurgitation did not change. The number of HLA mismatches or antibody status was found to have no significant impact on homograft valve function. Rather the implantation of a smaller size homograft (p⫽0.001) and younger recipient age (p⫽0.044) were shown to be significantly associated with increased transhomograft pressure gradients. Conclusion: Implantation of a cryopreserved pulmonary homograft during the Ross procedure can induce a specific humoral response. Neither this nor the degree of histocom-

Very Long-Term Survival and Durability of Mitral Valve Repair for Mitral Valve Prolapse Mohty D, Orszulak TA, Schaff HV, et al. Circulation 2001;104 (Suppl I):I-1–7. Study Question: What is the very long-term durability (10 years) of repair of the mitral valve for mitral regurgitation (MR) due to anterior leaflet prolapse (AL-MVP) and posterior leaflet prolapse (PL-MVP)? Methods: Patients (n⫽917, aged 65⫾13 years, 68% male) undergoing surgical correction of severe isolated MR due to MVP (679 repairs and 238 replacements [MVRs]) between 1980 and 1995 were evaluated to assess their long-term outcomes. Results: Survival after repair was better than survival after MVR for both PL-MVP (at 15 years, 41⫾5% vs. 31⫾6%, respectively; p⫽0.0003) and AL-MVP (at 14 years, 42⫾8% vs. 31⫾5%, respectively; p⫽0.003). In multivariate analysis adjusting for predictors of survival, repair was independently associated with lower mortality in PL-MVP (adjusted risk ratio [RR] 0.61, 95% CI 0.44 to 0.85; p⫽0.0034) and in AL-MVP (adjusted RR 0.67, 95% CI 0.47 to 0.96; p⫽0.028). The reoperation rate was not different after repair or MVR overall at 19 years (20⫾5% for repair vs. 23⫾5% for MVR; p⫽0.4) or separately in PL-MVP or AL-MVP. However, the reoperation rate was higher after repair of AL-MVP than after repair of PL-MVP (at 15 years, 28⫾7% vs. 11⫾3%, respectively; p⫽0.0006). From the

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geons to develop strategies to prevent this complication. RM

patibility have any influence on the significant increase of the transhomograft pressure gradients that occurs after the Ross procedure. Perspective: The relationship of homograft size and age of the patient to the increased transhomograft pressure gradients, rather than immunologic response to the homograft, suggests the importance of mechanical factors in valve degeneration after the Ross procedure. As such, surgeons should avoid under sizing of the homograft valves to reduct risk of late valve failure. RM

Preliminary Results of Endovascular Abdominal Aortic Aneurysm Exclusion With the AneuRx StentGraft Howell MH, Strickman N, Motazavi A, Hallman CH, Krajcer Z. J Am Coll Cardiol 2001;38:1040 – 6. Study Question: What is the clinical effectiveness of the Medtronic AneuRx stent graft in patients with infrarenal abdominal aortic aneurysms (AAA)? Methods: This observational study analyzed data on 215 patients who underwent AAA exclusion with the AneuRx stent-graft. Follow-up was available in 132 patients at 6 months, 84 patients at 1 year and 22 patients at 2 years. Results: Of the patients, 192 (89%) were male, 87% had hypertension and 58.6% were American Society of Anesthesiologists grade IV or higher. The procedural success was 99.5% (unable to place the device in one patient) and free of any urgent need for surgery and procedural or 1-month mortality. One patient suffered a non–ST-elevation myocardial infarction 24 h after the procedure. The frequencies of endoleaks at discharge, 6 months and 1 year were 42%, 11.3% and 11.9%, respectively. Endoleak repair was undertaken in 22 patients that included surgical repair in three patients. There were 12 late deaths, though none due to device failure or AAA rupture. Mean hospital stay was relatively short at 1.9 days. Conclusion: This study shows that infrarenal AAA can be safely and successfully treated with the AneuRx stent-graft. Further follow-up is needed to determine the long-term efficacy of endoluminal treatment to prevent rupture and death due to AAA. Perspective: This study, like prior observational studies (including the European registry (EUROSTAR), supports the feasibility and safety of the use of stent grafts percutaneously in the treatment of infrarenal AAA. It further identifies a common problem inherent to the use of aortic stents, that is, endoleaks, and suggests that most can be treated successfully by a percutaneous approach. However, other problems seen with this technique were not reported by these investigators (graft migration, tear, etc.). As the use of this new procedure continues to grow, data from large numbers of patients are needed to identify the subgroup of patients that benefits most from this procedure. RM

Incidence, Location, Pathology, and Significance of Pulmonary Homograft Stenosis After the Ross Operation Carr-White GS, Kilner PJ, Hon JKF, et al. Circulation 2001;104 (Suppl I):I-16 –20. Study Question: What are the incidence, location, pathology and significance of pulmonary homograft stenosis after a Ross procedure? Methods: Consecutive patients (n⫽144) undergoing the Ross operation were evaluated between 1993 and 2000 with serial echocardiographic examination of the pulmonary homograft performed immediately after surgery, then at yearly intervals for a mean interval of 48 months. Patients in whom echocardiography revealed significant pulmonic stenosis (peak pulmonary gradients ⱖ30 mm Hg) underwent MRI with velocity mapping. Results: Fifteen patients showed significant pulmonic stenosis (mean gradient 46⫾18 mm Hg) with no patient showing more than mild pulmonary regurgitation. Four patients required reoperation for rapidly progressive pulmonary homograft stenosis and showed macroscopic and microscopic evidence of a pronounced chronic adventitial reaction, with perivascular infiltration producing extrinsic compression. Freedom from any pulmonary homograft stenosis at 7-year follow-up was 79.7% whereas freedom from reoperation at 7 years was 96.7%. In patients studied with MRI, there was evidence of narrowing of the whole homograft or distal suture line in 14 of 15 patients, with obvious excess surrounding tissue in 11 and peak velocity of 3.2⫾0.7 m/s. Multivariate analysis of patient, surgery and homograft-related variables did not reveal any significant predictors for development of neopulmonary stenosis. Conclusion: Pulmonary homograft stenosis after the Ross operation appears to represent an early postoperative inflammatory reaction to the pulmonary homograft that leads to extrinsic compression and/or shrinkage. Perspective: This study adds to our understanding of the anatomy of the pulmonary homograft stenosis in patients undergoing the complex Ross procedure. However, more studies with a large number of patients are needed in the future to identify clinical and operative factors associated with pulmonary homograft stenosis that will allow sur-

Modified Ultrafiltration Reduces Morbidity After Adult Cardiac Operations. A Prospective, Randomized Clinical Trial Luciani GB, Menon T, Vecchi B, Auriemma S, Mazzucco A. Circulation 2001;104 (Suppl I):I-253–9. Study Question: What is the impact of modified ultrafiltration (a technique able to remove the fluid overload and inflam-

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