Treatment of endocarditis with valve replacement: the question of tissue versus mechanical prosthesis.

BACKGROUND: It remains unknown whether there is any important clinical advantage to the use of either a bioprosthetic or mechanical valve for patients with native or prosthetic valve endocarditis. METHODS: Between 1964 and 1995, 306 patients underwent valve replacement for left-sided native (209 patients) or prosthetic (97 patients) valve endocarditis. Mechanical valves were implanted in 65 patients, bioprostheses in 221 patients, and homografts in 20 patients. RESULTS: Operative mortality was 18+/-2% and was independent of replacement valve type (p > 0.74). Long-term survival was superior for patients with native valve endocarditis (44+/-5% at 20 years) compared with those with prosthetic valve endocarditis (16+/-7% at 20 years) (p < 0.003). Survival was independent of valve type (p > 0.27). The long-term freedom from reoperation for patients who received a biologic valve who were younger than 60 years of age was low (51+/-5% at 10 years, 19+/-6% at 15 years). For patients older than 60 years, however, freedom from reoperation with a biological valve (84+/-7% at 15 years) was similar to that for all patients with mechanical valves (74+/-9% at 15 years) (p > 0.64). CONCLUSIONS: Mechanical valves are most suitable for younger patients with native valve endocarditis; however, tissue valves are acceptable for patients greater than 60 years of age with native or prosthetic valve infections and for selected younger patients with prosthetic valve infections because of their limited life expectancy.

Thoracic transplantation.

Experimental orthotopic transplantation of the heart was accomplished in 1959. Long-term survival was achieved in 1965 with a chemical immunosuppression protocol substantially different from that used for renal and hepatic transplants. Performance characteristics of the transplanted denervated heart were found to differ only slightly from normal. It appeared by the time of the Clinical Congress of the American College of Surgeons in October 1967 that clinical heart transplantation might be justified if the concept of brain death could be legally recognized. The Stanford program in clinical heart transplantation was inaugurated on January 6, 1968 and has been in continuous operation. To date, more than 1000 patients have undergone transplantation of the heart with the 5-year survival at 75%. The first long-term success in lung transplantation occurred at Stanford in 1981, with transplantation of the heart and both lungs. In 1990 the concept of living pulmonary lobar donors was introduced and is slowly finding its clinical role. The steroid-sparing capability of cyclosporine made possible both successful lung and pediatric heart transplantation. Only the donor shortage remains as a substantial barrier to widespread thoracic transplantation. Xenotransplantation is under intense scrutiny, with some encouraging experimental results. Development of the artificial heart continues to offer some relief for patients with end-stage heart disease.

Historic landmarks in clinical transplantation: conclusions from the consensus conference at the University of California, Los Angeles.

The transplantation of organs, cells, and tissues has burgeoned during the last quarter century, with the development of multiple new specialty fields. However, the basic principles that made this possible were established over a three-decade period, beginning during World War II and ending in 1974. At the historical consensus conference held at UCLA in March 1999, 11 early workers in the basic science or clinical practice of transplantation (or both) reached agreement on the most significant contributions of this era that ultimately made transplantation the robust clinical discipline it is today. These discoveries and achievements are summarized here in six tables and annotated with references.

C. Walton and F. John.

This paper is a brief biography of two of the most important contributors to the development of open heart surgery. In 1952, John Lewis performed the first successful open heart surgical procedure of any kind, repairing an atrial septal defect under general hypothermia in a 5-year-old girl. In March 1954, Walt Lillehei, utilizing controlled cross circulation, embarked on a series of 45 consecutive patients. The bubble oxygenator appeared in 1955, and open heart surgery was introduced to many of this nation's major medical centers.

Thirty years of cardiac transplantation at Stanford university.

BACKGROUND: The experience with 30 years of cardiac transplantation at Stanford University Medical Center was reviewed. A total of 954 transplants were performed in 885 patients. Patients were divided into 3 groups based on immunosuppression received: group I, no cyclosporine (INN: ciclosporin) (n = 201) (January 1968-November 1980); group II, cyclosporine (n = 248) (December 1980-June 1987); and group III, cyclosporine + OKT3 (n = 436) (July 1987-March 1998). RESULTS: The 1-, 5-, and 10-year actuarial survivals were 68%, 41%, and 24% (group I); 80%, 57%, and 37% (group II); and 85%, 68%, and 46% (group III) (I vs II, P <.01; I vs III, P <.005; and II vs III, P <.005). The 1-, 5-, and 10-year actuarial death rates from rejection were 8%, 12%, and 14% (group I); 5%, 7%, and 7% (group II); and 2%, 5%, and 5% (group III) (I vs II, P = not significant; I vs III, P <.005; and II vs III, P <.005). The 1-, 5-, and 10-year actuarial death rates from infection were 25%, 43%, and 50% (group I); 8%, 17%, and 29% (group II); and 6%, 11%, and 16% (group III) (I vs II, P <.005; I vs III, P <.005; and II vs III, P <.05). The 1-, 5-, and 10-year actuarial death rates from graft coronary artery disease were 0%, 5%, and 13% (group I); 0%, 12%, and 19% (group II); and 1%, 6%, and 9% (group III) (I vs II, P <.01; I vs III, P <.005; and II vs III, P = not significant). There have been 69 retransplants in 67 patients with 1-, 5-, and 10-year actuarial survivals of 49%, 27%, and 15%, respectively. CONCLUSIONS: The evolution of 3 decades of experience with cardiac transplantation has resulted in improved overall survival. The incidence of rejection and of death from infection and graft coronary artery disease have decreased over time, primarily as a result of improvements in immunosuppression and in the prevention and treatment of infection. Continued advances in perioperative management and the development of more specific, less toxic immunosuppressive agents could further refine this initial experience and improve the survival and quality of life of patients after cardiac transplantation.

Composite valve graft versus separate aortic valve and ascending aortic replacement: is there still a role for the separate procedure?

BACKGROUND: To ascertain if operative technique has any bearing on outcome, the surgical results after aortic root replacement using either a composite valve graft (CVG) or a separate graft and valve (GV) were analyzed. METHODS AND RESULTS: Three hundred and ninety consecutive, nonrandomized patients treated for aortic valve disease and ascending aortic aneurysm (n=278) or type A dissection (n=112 [45 acute]) between 1965 and 1995 were analyzed retrospectively. One hundred and thirty-five patients received a CVG, and 255 had separate GV replacement. Mean age was 52+/-16 years (+/-1 SD). Eighty-two patients (44% of the CVG group) had the Marfan syndrome (MFS). Follow-up (96% complete) totaled 2247 patient-years and extended to 27 years. The operative mortality rate was 10+/-3% (+/-70% confidence limits) for patients receiving a CVG and 15+/-2% for GV replacement (P=NS). The 15-year actuarial survival estimate was higher for the CVG group (53+/-14% [+/-SEM] versus 36+/-4%, P=.037). Seven patients in the CVG group required reoperation on the aortic valve or ascending aorta, as did 49 in the GV group. The probabilities of freedom from reoperation on the aortic rootwere 82+/-9% and 75+/-4% at 10 years for the CVG and GV group (P=NS). Thirty variables were analyzed in a multivariate model: pulmonary disease, higher New York Heart Association functional class, and longer cardiopulmonary bypass time were linked with higher operative mortality risk; older age, emergency operation, coronary artery disease, and liver dysfunction were independent determinants of late death. Younger age and use of a bioprosthesis were predictors of late reoperation. Type of procedure (GV versus CVG) was not a significant predictor of any outcome variable. CONCLUSIONS: The long-term results after CVG or GV were similar, which reflects proper patient selection. Use of a composite valve graft theoretically confers more protection against recurrent aortic root aneurysm, and, unless one opts for a valve-sparing aortic root replacement procedure, is most appropriate for younger patients, those with the MFS (including acute dissections), and others with marked pathological involvement of the sinuses. On the other hand, use of a separate GV should not be abandoned; in carefully selected patients (and if properly performed, eg, excision of the sinuses), GV also provides satisfactory results.

Twenty-year clinical experience with porcine bioprostheses.

BACKGROUND: For the past 25 years, porcine valves have been the most widely implanted bioprosthesis, thereby becoming the standard for comparison with newer bioprosthetic valves. METHODS: We retrospectively analyzed 2,879 patients who underwent aortic (AVR; n = 1,594) or mitral (MVR; n = 1,285) valve replacement between 1971 and 1990. Follow-up was 97% complete and extended to 20 years (total, 17,976 patient-years). Patient age ranged from 16 to 94 years; mean age in patients who underwent AVR was 60 +/- 15 (+/- standard deviation) years; that for patients who underwent MVR was 58 +/- 13 years. RESULTS: The operative mortality rates were 7% +/- 1% (70% confidence limits) for AVR and 10% +/- 1% for MVR. Actuarial estimates of freedom from structural valve deterioration at 10 and 15 years were 78% +/- 2% (SE) and 49% +/- 4%, respectively, for the AVR subgroup; and 69% +/- 2% and 32% +/- 4%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from reoperation at 10 and 15 years were 76% +/- 2% and 53% +/- 4%, respectively, for the AVR subgroup and 70% +/- 2% and 33% +/- 4%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from thromboembolism at 10 and 15 years were 92% +/- 1% and 87% +/- 2%, respectively, for the AVR subgroup and 86% +/- 1% and 77% +/- 3%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from anticoagulant-related hemorrhage at 10 and 15 years were both 96% +/- 1% for the AVR subgroup and 93% +/- 1% and 90% +/- 2%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from valve-related mortality at 10 and 15 years were 86% +/- 1% and 78% +/- 3%, respectively, for the AVR subgroup and 84% +/- 2% and 70% +/- 4%, respectively, for the MVR subgroup (p = not significant). Multivariate analysis (Cox model) showed younger age, later year of operation, and valve site (MVR > AVR) to be significant risk factors for structural valve deterioration. Younger age, later year of operation, valve site (MVR > AVR), and renal insufficiency were the significant, independent risk factors for reoperation. Multivariate analysis revealed that higher New York Heart Association functional class, longer cardiopulmonary bypass time, congestive heart failure, renal insufficiency, and longer cross-clamp time were significant risk factors for valve-related mortality. Valve manufacturer did not emerge as a factor in any analysis. CONCLUSIONS: These long-term results with porcine bioprostheses were satisfactory, particularly in older patients and those undergoing AVR. As expected, younger age was a significant risk factor for structural valve deterioration and reoperation in both groups. Surprisingly, the durability of porcine bioprosthetic valves has not improved over time, which possibly can be attributed to more enhanced postoperative surveillance and earlier reintervention. These first-generation Hancock and Carpentier-Edwards porcine bioprostheses achieved similar long-term performance.

F. John Lewis, MD: 1916-1993.

F. John Lewis performed the first successful open heart operation in 1952. He was the first full-time member of the faculty of surgery at Northwestern University. This article gives a brief biography of this great surgeon.

Surgical management of aortic dissection during a 30-year period.

BACKGROUND: Certain recent studies have demonstrated improved surgical outcome in patients with aortic dissection. We analyzed the surgical survival rates of patients with acute aortic dissections and the late prognosis of those with aortic dissection during a 30-year period. METHODS AND RESULTS: Between 1963 and 1992, 360 patients (256 men and 104 women; mean +/- 1 SD age, 57 +/- 14 years) underwent surgery for aortic dissection: 174 patients had an acute type A (AcA), 46 an acute type B (AcB), 106 a chronic type A (ChA), and 34 a chronic type B (ChB) aortic dissection. The overall operative mortality rate was 24 +/- 8% (26 +/- 3% for AcA, 39 +/- 8% for AcB, 17 +/- 4% for ChA, and 15 +/- 6% for ChB, [+/- 70% confidence limit]). The operative mortality rates for patients with acute aortic dissection (AcA or AcB) were assessed for five time "windows": 1963 to 1972 (42 +/- 8%), 1973 to 1977 (37 +/- 8%), 1978 to 1982 (15 +/- 6%), 1983 to 1987 (27 +/- 6%), and 1988 to 1992 (26 +/- 6%). Logistic regression analysis suggested that the low operative mortality rate during the 1978-to-1982 interval occurred by chance. Multivariate analysis showed earlier operative year, hypertension, cardiac tamponade, renal dysfunction, and older age were independent determinants of operative death. Actuarial survival rates (including early deaths) after 5, 10, and 15 years for AcA patients were 55%, 37%, and 24%; for AcB, 48%, 29%, and 11%; for ChA, 65%, 45%, and 27%; and for ChB, 59%, 45%, and 27%. Multivariate analysis revealed that older age and previous operation were significant predictors for late death. Freedom from reoperation for all patients was 84%, 67%, and 57% at 5, 10, and 15 years, respectively. CONCLUSIONS: Although the operative mortality rate decreased over time for patients with aortic dissection, the risk for those with acute aortic dissection during the last 10 years (1983 to 1992) is probably more realistic than that observed in the preceding 5-year interval (1978 to 1982). The operative mortality rates for patients with chronic aortic dissection have remained relatively static. Earlier diagnosis of acute aortic dissection before development of cardiac tamponade and renal impairment is critical to improve the operative salvage rate. Long-term outcome still is not optimal, which emphasizes the need for better serial postoperative aortic imaging surveillance and medical follow-up and blood pressure control.

Heart retransplantation: the 25-year experience at a single institution.

BACKGROUND: The current critical shortage of cardiac allograft donors means that the decision to offer a patient repeat heart transplantation must be carefully considered. Since 1968, a total of 66 heart retransplantation procedures (63 first-time and three second-time) have been performed in 63 patients at Stanford. METHODS: There were 52 male and 11 female patients, ranging in age from 3 to 62 years with a mean age of 41 years. Indications for retransplantation were primary allograft failure in nine patients, acute rejection in 17, graft atherosclerosis in 37, and constrictive disease in three. Six of the seventeen patients (35%) who underwent retransplantation before 1981 died in the hospital, and none are currently alive. Of the 46 patients who underwent retransplantation since 1981 treated with cyclosporine-based immunosuppression, 11 (24%) died in the hospital. Actuarial survival estimates for the whole retransplantation group at 1, 5, and 10 years were 55% +/- 8%, 33% +/- 8%, and 22% +/- 7%, respectively. RESULTS: This survival was significantly worse (p < 0.05) than that in patients undergoing primary heart transplantation (81% +/- 2%, 62% +/- 2%, 44% +/- 13% at 1, 5, and 10 years). Those patients who underwent retransplantation for graft atherosclerosis since 1981 had a significantly better 1-year survival (p < 0.05) than those who underwent retransplantation for allograft rejection (69% +/- 10% versus 33% +/- 16%), but the 5-year survival was similar in both groups (34% +/- 11% versus 33% +/- 16%). Since 1981, actuarial freedoms from infection and rejection were 22% +/- 8% and 41% +/- 9%, respectively, at 1 year, and 7% +/- 7% and 36% +/- 9% at 5 years. Patients with cyclosporine-induced renal dysfunction (serum creatinine level of greater than 2.0 mg/dl) had a high probability of requiring postoperative dialysis and also of death after retransplantation. Three patients with significant cyclosporine-induced renal dysfunction underwent simultaneous kidney transplantation and heart retransplantation, and all were alive and well at the time this article was written. Sixteen patients were also currently alive at a mean follow-up of 44 months, and 15 were in New York Heart Association functional class I. CONCLUSIONS: We continue to list carefully selected candidates with good rehabilitation potential for heart retransplantation.

The aortic valve after heart transplantation.

We studied the aortic root (wall, semilunar cusp, septal myocardium) in 37 patients (29 male and 8 female; mean age; 41 years) who died 2 to 4,380 days (mean, 398 days) after heart (n = 34) and heart-lung (n = 3) transplantation. The aim of the study was to assess tissue viability, graft-host biological interaction, and cusp mineralization with time. Study methods included gross inspection and photos of each specimen, microradiography, histology and immunohistochemistry, scanning and transmission electron microscopy, and atomic absorption spectroscopy. There were no cases of valve dysfunction; in particular, cusp tears or perforations never occurred. Only 1 valve, in place for 12 years, had a pin-point calcification visible to the naked eye. Optimal preservation of the tissue components (endothelium, fibroblasts, collagen and elastic fibers, proteoglycans, intrinsic nervous ganglia) was observed at both short and long term. Concomitant acute rejection of valve leaflets and myocardium was seen in 7, mild valve thickening in 14, myxoid degeneration in 4, and graft aortic atherosclerosis in 26. Mineralization was negligible and was not progressive with time. No linear correlation was found between mineralization and number of acute rejections. In conclusion, we observed optimal cusp viability and integrity even at long term, concomitant valve and myocardium rejection with no valvular sequelae, and negligible, non-progressive cusp calcification. Donor-recipient blood group matching, heart-beating donor, and chronic immunosuppression are the reasonable explanations of the optimal durability of the aortic valve after heart transplantation.

Durability of the Hancock MO bioprosthesis compared with standard aortic valve bioprostheses.

To compare the durability of the Hancock modified orifice (Hancock MO, model 250 [H-MO]) valve with two other commonly used standard aortic valve bioprostheses, a cohort of 1,602 patients undergoing aortic valve replacement using porcine valves between 1971 and 1990 (excluding simultaneous mitral valve replacement) was analyzed retrospectively using Cox model multivariate techniques. Five hundred sixty-one patients received a composite H-MO valve, 652 received a standard Hancock model 242 (H) valve, and 389 received a Carpentier-Edwards model 2625 (C-E) valve. Mean age was 60 +/- 15 years (+/- 1 standard deviation) (71% male). Follow-up (10,247 patient-years) extended to 15 years and was 97% complete. The main focus of this study was bioprosthetic durability, using The American Association for Thoracic Surgery/The Society of Thoracic Surgeons guidelines to define structural valve deterioration (SVD). Multivariate analysis revealed that (younger) age (p < 10(-5), liver disease (p = 0.02), and 1981 to 1985 operative period (p = 0.012) were the only significant, independent predictors of SVD. In concordance with previous reports, the SVD freedom estimate was greater than 90% at 15 years for patients older than 70 years of age. Hepatic dysfunction had an adverse effect on SVD (estimated freedom from event at 10 years was 34 +/- 17% [standard error of mean] versus 78 +/- 2% for those without liver disease), but this affected only 3% of patients. Interestingly, one operative period (1981 to 1985) was associated with a slightly higher risk of SVD compared to the three other 5-year time windows. Valve type did not emerge as a significant risk factor for SVD.(ABSTRACT TRUNCATED AT 250 WORDS)

Heart transplantation 1958-1995.

Transplantation of the heart has been a dream that began 100 years ago and now is a reality for perhaps 3,500 patients each year. The need for donors continues, and probably only about 10% of the potentially available donor supply is currently utilized. The current development of new and less toxic immunosuppressive molecules intensifies this chronic and critical shortage of donors. The use of xenografts appears still to be in the distant future, and immunological tolerance remains a beautiful dream.

Long-term results of combined heart-lung transplantation: the Stanford experience.

We assessed the long-term results of our experience with 109 patients with end-stage cardiopulmonary disease who underwent primary combined heart-lung transplantation at Stanford University Medical Center between March 1981 and January 1994. Average recipient age was 31 +/- 10 years (mean +/- standard deviation) median, 31 years; range, 1 month to 52 years. Recipient diagnoses included primary pulmonary hypertension (31%), Eisenmenger's syndrome (39%), complex congenital heart disease (8%), cystic fibrosis (14%), bronchiectasis (2%), and emphysema (3%). Immunosuppression was with cyclosporine and a tapering regimen of corticosteroids. In 1986 azathioprine was added, and since 1987 induction therapy with OKT3 has been employed. Actuarial survival rates at 1, 5, and 10 years were 68% +/- 4.6%, 43% +/- 5.4%, and 23% +/- 8.1%, respectively (mean +/- 1 standard error of the mean). Fourteen deaths occurred in the hospital for an operative mortality rate of 12.8% +/- 3.3%, and 61 deaths occurred overall. Causes of death included hemorrhage (five patients), infection (21), rejection (one), nonspecific pulmonary failure (four), graft coronary artery disease (six), and obliterative bronchiolitis (eight). Infection, rejection, and obliterative bronchiolitis were the major complications. Only 20% +/- 3.9% of patients were free from any infection 3 months after transplantation. Heart and lung rejection commonly occurred asynchronously; actuarial estimates of freedom from isolated lung rejection at 1 and 5 years were 47% +/- 5.2% and 40% +/- 5.6%, respectively. For simultaneous heart and lung rejection these estimates were 87% +/- 3.5% and 86% +/- 3.8%, and for isolated heart rejection 63% +/- 5.1% and 51% +/- 6.4%, respectively. Although graft coronary artery disease developed less frequently than in patients after isolated heart transplantation (90% +/- 4.6% of patients were free of graft coronary artery disease at 5 years), obliterative bronchiolitis remains a major long-term complication and cause of morbidity and mortality. Actuarial estimates of freedom from obliterative bronchiolitis at 1, 5, and 10 years were 71% +/- 5.1%, 51% +/- 6.1%, and 42% +/- 7.8%, respectively. These results show satisfactory early and medium-term outcome after combined heart-lung transplantation but also underscore that much progress is needed in controlling infection, rejection, and obliterative bronchiolitis, all of which remain as major impediments to long-term survival.

Surgical management of aortic dissection in patients with the Marfan syndrome.

BACKGROUND: Aortic dissection is one of the most lethal potential complications in patients with the Marfan syndrome. METHODS AND RESULTS: Among 360 patients undergoing operative treatment of aortic dissection between 1963 and 1992, 40 had the Marfan syndrome. There were 24 men and 16 women with a mean age of 35 +/- 9 years (+/- 1 SD; range, 15 to 54 years). These patients included 16 with acute type A, 2 with acute type B, 18 with chronic type A, and 4 with chronic type B aortic dissections. The aortic arch was involved in 29 cases. Preoperative complications included acute aortic valvular insufficiency in 13 patients, rupture into the pericardial space in 3, and loss of peripheral pulses in 9. The site of primary intimal tear was the ascending aorta in 25 patients, the aortic arch in 2, the descending aorta in 7, and not identified in 6. Operations included ascending aortic and aortic valvular replacement (with or without coronary artery reimplantation) in 22 patients, ascending aortic replacement alone in 5, and descending thoracic aortic replacement in 9. Four operative deaths (10 +/- 5% [+/- 70% confidence limits]) occurred in 3 acute patient-years and 1 chronic type A patient-years. Long-term follow-up (216 patient-years; range, 1 month to 22 years; mean, 5.4 years) revealed 15 late deaths, 7 from late aortic sequelae. The overall actuarial survival estimates were 71 +/- 8%, 54 +/- 10%, and 22 +/- 11% at 5, 10, and 15 years, respectively. Twenty late aortic operations were required in 14 patients. CONCLUSIONS: Despite satisfactory early results, the long-term survival of patients with the Marfan syndrome was suboptimal (albeit similar to those without the Marfan syndrome). Future progress will pivot on reducing the incidence of aortic dissection in these patients with medical therapy and/or earlier surgical intervention and enhanced postoperative serial imaging surveillance of the entire aorta.

Randomized, prospective assessment of bioprosthetic valve durability. Hancock versus Carpentier-Edwards valves.

BACKGROUND: Although the major limitation of porcine valves is their finite durability, no controlled clinical data exist regarding the relative durability of the two porcine bioprostheses implanted most commonly today, the Carpentier-Edwards (C-E) and Medtronic Hancock I (H) valves. METHODS AND RESULTS: To assess this question, 174 patients undergoing aortic (AVR) or mitral (MVR) valve replacement with a bioprosthesis between March 1980 and March 1982 were randomized to receive either a C-E or a H valve. There were 102 AVRs (54 C-E and 48 H) and 74 MVRs (39 C-E and 35 H). For both the AVR and MVR cohorts, the average patient age was 58 +/- 14 years (+/- SD). The male/female ratio was 2.2:1 for AVR and 0.57:1 for MVR. Clinical follow-up was undertaken periodically; the most recent follow-up closing interval was July through October 1992, and current follow-up was 96% complete. Cumulative follow-up totaled 1369 patient-years (mean, 7.7 +/- 3.6 years; median, 9.1 years; maximum, 12.0 years). The main focus of this analysis was bioprosthetic durability, using the AATS/STS guidelines defining "Structural Valve Deterioration" (SVD). Multivariate analysis revealed that (younger) age was the only significant (P = .024) independent predictor of SVD. Valve manufacturer (C-E versus H) and valve site (aortic versus mitral) did not emerge as significant independent risk factors for SVD. Actuarial rates (Cutler-Ederer) expressed as percent free of SVD (+/- SEM) at 10 years (n = number of patients remaining at risk) were 71 +/- 7% and 59 +/- 9% for the C-E (n = 26) and H (n = 17) groups, respectively, for the AVR cohort; for the MVR cohort, these estimates were 60 +/- 10% (n = 12) and 72 +/- 10% (n = 11), respectively, but these differences were not statistically significant (P = NS, Lee-Desu). CONCLUSIONS: After 10 years, there was no statistically significant difference in durability or other valve-related complications between the H and C-E aortic or mitral valves. Based on current information, the choice of a porcine bioprosthesis should be based on factors other than durability, including ease of implantation, hemodynamic performance, and cost.

Current trends in lung transplantation. Lobar transplantation and expanded use of single lungs.

Heart-lung transplantation remains the only therapeutic option for patients with combined end-stage cardiopulmonary disease. Because of the scarcity of heart-lung donors, we have been investigating other surgical alternatives for patients with end-stage vascular and parenchymal lung disease. From June 1989 through June 1991, 48 patients underwent pulmonary transplantation. Seventeen of the 48 patients underwent single lung transplantation. Of the 17 patients in the single lung group, eight patients had pulmonary hypertension and nine had parenchymal lung disease. Four of the 17 patients underwent repair of a cardiac defect with single lung transplantation. One-year actuarial survival was 68%. Pulmonary function has been excellent. The forced expiratory volume in 1 second was 79.6 +/- 13.6 (percent predicted), forced expiratory flow 25%-75% was 72.6 +/- 14.5 (percent predicted), and arterial oxygen tension was 82.8 +/- 10.06 mm Hg when measured at annual follow-up in a group of eight patients without obliterative bronchiolitis. Pulmonary artery pressures of systemic level or greater in the group with pulmonary vascular disease were normal at annual catheterization. Most patients had at least one episode of allograft rejection. Actuarial freedom from rejection at the end of 3 months was 30%. Three of the 17 single lung patients receiving lung lobes were children. Two children received living-related lobe transplants and one neonate received a lobe from a 2-year-old cadaver donor. Single lung transplantation is an effective therapeutic option for selected patients with vascular or parenchymal lung disease. Expanding indications will permit more individuals to receive transplants from the existing donor pool. Living-related and cadaver lobe transplantation will also increase the options available to children in need of lung transplantation.

Current approach to hypoplastic left heart syndrome. Palliation, transplantation, or both?

Over the past 3 years, 35 newborn infants have been referred for surgical management of hypoplastic left heart syndrome. Surgical palliation (first-stage Norwood) or cardiac transplantation was offered. Twenty-four families (68%) chose palliation and 11 families (32%) chose cardiac transplantation. Of the 11 infants listed for cardiac transplantation, five underwent transplantation. Because of a lack of donors after an average wait of 25 days (19 to 31), the remaining six infants underwent palliation, with no perioperative deaths. Of the 30 infants undergoing palliation, including crossovers, 20 (67%) survived the first operative stage. Among the last 19 infants undergoing palliation in 1990, the early survival was 84%. Risk factors determined for poor outcome were year of operation (p less than 0.001) and circulatory arrest time greater than 50 minutes (p less than 0.001). Among the 13 infants undergoing palliation with a circulatory arrest time of less than 50 minutes, there were 12 survivors (92%); among 12 having a circulatory arrest time of more than 50 minutes, there were four survivors (33%). At intermediate follow-up, six infants have undergone second-stage procedures (Glenn), with five survivors. There were eight late deaths, four caused by respiratory infections and four caused by cardiac problems, including a thrombosed shunt in one infant. Three of five infants are alive and doing well after cardiac transplantation. Size of aorta, tricuspid regurgitation, and ventricular wall thickness did not prove to be risk factors. Given the existing data, we believe these infants should be managed selectively on the basis of donor availability and family wishes.