Double valve endocarditis

Background. There are little data concerning surgical outcomes in patients with native valve endocarditis affecting both the aortic and mitral valves.

Methods. From 1977 to 1998, 54 patients had simultaneous aortic and mitral valve grafting for native valve endocarditis. In 78%, mitral valve involvement was limited to the anterior leaflet, suggesting a jet lesion from the aortic valve. Surgical strategies included 31 valve repairs and valve replacement with mechanical (34), bioprosthetic (34), or allograft (9) prostheses. Three hundred twenty-five patient-years of follow-up were available for analysis (mean 6.0 ± 4.8 years).

Results. There were no hospital deaths. Ten-year survival was 73%. Ten-year freedom from recurrent endocarditis was 84%, with risk peaking at 3 months, followed by a constant risk of 1.3%/yr. Choice of valvar procedure did not influence mortality or reinfection risk.

Conclusions. The most common pattern of double valve infection was a jet lesion on the anterior mitral leaflet. Surgical treatment has late survival and freedom from reinfection similar to those of patients with single heart valve infection.     

Results of reoperation for primary tissue failure of porcine bioprostheses

Results of reoperation for primary tissue failure of porcine bioprostheses were evaluated in 574 patients discharged from the hospital from 1970 to 1981. A total of 413 had undergone isolated mitral valve replacement and 161 isolated aortic valve replacement. Through March, 1984, 88 patients (15%) had required reoperation: 59 had undergone mitral and 29, aortic valve replacement. Primary tissue failure was the main cause of bioprosthetic dysfunction; it occurred in 64 patients (46 mitral and 18 aortic) at a mean postoperative interval of 93 +/- 4 months (range 34 to 158). During the same period, 11 patients required reoperation for bioprosthetic endocarditis, 11 for paravalvular leak, and two for thrombosis. These patients are not included in this review. Reoperation for primary tissue failure was performed after a mean interval of 72 +/- 6 months (range 38 to 158) for patients with aortic bioprostheses and after 101 +/- 5 months (range 34 to 153) for those with mitral bioprostheses (p less than 0.05). Overall mortality at reoperation was 12.5%: 11% for the mitral group and 16% for the aortic group. In 62 patients (45 mitral and 17 aortic) primary tissue failure was caused by calcification of the cusps, associated with severe fibrous tissue overgrowth in seven. Bioprosthetic failure was caused by an intracuspal hematoma in one patient with mitral valve replacement and by lipid infiltration of the cusps in one patient with aortic valve replacement. Actuarial freedom from bioprosthetic primary tissue failure at 12 years is 61% +/- 5% for the mitral group and 69% +/- 7% for the aortic group. On the basis of our long-term follow-up of patients after mitral or aortic replacement with a porcine bioprosthesis, we conclude: primary tissue failure is the most frequent indication for reoperation in patients with a porcine bioprosthesis; calcification of the cusp tissue is the leading cause of primary tissue failure; reoperation for primary tissue failure may be a major concern, although mortality for elective cases is low; and the limited durability of porcine bioprostheses suggests their use be restricted to selected patients.     

Cardiac valve replacement in patients on dialysis: influence of prosthesis on survival

BACKGROUND: Mechanical valves have been recommended for patients on dialysis because of purported accelerated bioprosthesis degeneration. This study was undertaken to determine time-related outcomes in dialysis patients requiring cardiac valve replacement. METHODS: From 1986 to 1998, 42 patients on chronic preoperative dialysis underwent valve replacement; 17 received mechanical valves and 25 received bioprostheses. Age was similar in both groups: 54+/-18.5 years (mechanical) and 59+/-15.5 years (bioprosthetic, p = 0.4). Sites of valve replacement were aortic (27), mitral (11), and aortic and mitral (4). Follow-up was 100% complete. RESULTS: Survival at 3 and 5 years was 50% and 33% after mechanical valve replacement, and 36% and 27% after bioprosthetic valve replacement (p = 0.3). Four patients with bioprostheses required reoperation: 3 for allograft endocarditis and 1 at 10 months for mitral bioprosthesis degeneration. One patient who received a mechanical valve required reoperation. CONCLUSIONS: Prosthetic valve-related complications in patients on dialysis were similar for both mechanical and bioprosthetic valves. Because of the limited life expectancy of patients on dialysis, bioprosthesis degeneration will be uncommon. Therefore, surgeons should not hesitate to implant bioprosthetic valves in these patients.     

心脏瓣膜病再次手术221例临床分析

目的总结既往有二尖瓣闭式扩张术、瓣膜成形术、瓣周漏及生物瓣失功能等的患者再次瓣膜手术的经验。方法自1998年1月至2005年8月,实施心脏瓣膜病再次手术221例,其中急症手术8例。其中二尖瓣闭式扩张后再狭窄105例,二尖瓣或主动脉瓣成形术后复发性瓣膜病变37例,瓣周漏29例,生物瓣衰败18例,其他瓣膜再发病变11例,人工瓣膜机械功能障碍9例,Ebstein畸形矫治术后三尖瓣关闭不全7例,人工瓣膜心内膜炎5例。再次手术方式包括二尖瓣置换、二尖瓣和主动脉瓣双瓣置换、主动脉瓣置换、三尖瓣置换。两次手术间隔时间1～21年。结果全组术后死亡19例,占8．6％。早期死亡主要原因为术后低心排综合征、恶性心律失常、多脏器功能衰竭与肾功能衰竭,其中急症手术8例中死亡3例,术前心功能Ⅳ级者手术死亡9例,病死率为14．5％（9／62例）。结论瓣膜病再次手术危险因素包括急症手术、术前心功能差、合并其他重要脏器功能不全、体外循环时间和主动脉阻断时间长等。针对这些因素积极防治,可以进一步降低这类患者手术病死率和并发症发生率。     

Aortic allografts and pulmonary autografts for replacement of the aortic valve and aortic root

Background. Extensive experience has accumulated with the use of aortic and pulmonary autografts for replacement of the aortic valve and the aortic root. Three general techniques for insertion have been used: subcoronary (free-hand) valve implantation, mini- or inclusion-root implantation, and aortic root replacement. Thirty-day mortality for elective operations with all of these techniques has not exceeded 5%. Thromboembolic episodes have been rare, and endocarditis has occurred infrequently. Early hemodynamic performance has been excellent, without significant gradients or valve regurgitation in the majority of patients.

Methods and Results. Progressive aortic regurgitation has been observed with continued follow-up, and is the most important complication of both types of valves. Leaflet failure and technical problems are the major causes of reoperation for patients receiving aortic allografts. There is some evidence to suggest that the prevalence of these complications is lower with the root replacement technique than with the intraaortic implantation methods.

Conclusions. Reoperation for regurgitation of the neo-aortic valve is the major complication of the pulmonary autograft procedure. The incidence of reoperation appears to be lowest with the root replacement technique. Certain conditions (acute rheumatic fever, juvenile rheumatoid arthritis, systemic lupus, ankylosing spondylitis, Libman-Sachs endocarditis, and possibly a dilated aortic root) may be contraindications to the use of a pulmonary autograft. Reoperation on the pulmonary allograft that is used to replace the autograft may be necessary in up to 20% of patients at 20 years.     

Advantage of autograft and homograft valve replacement for complex aortic valve endocarditis

Background. There are advantages to using homografts and autografts as aortic valve replacements, particularly in patients with infective endocarditis. To better define these advantages, we reviewed our 13-year experience with the surgical management of infective endocarditis involving the aortic valve and root.

Methods. From 1986 through 1998, 81 adults with aortic valve endocarditis underwent valve replacement (AVR). The mean age of the 65 men and 16 women was 44 ± 14 years. Sixty-three (78%) patients had active endocarditis at the time of operation. Non-native valve endocarditis was present in 29 (36%) patients, in 9 of whom the infection was a recurrence. Aortic valve replacements were performed with 46 homografts (homo-AVR), 25 autografts (Ross-AVR), and 10 prosthetic valves (prosth-AVR). Among Ross-AVR and homo-AVR patients, 11 required mitral valve replacement or repair (homo-Ross DVR). Follow-up was 90% complete within 2 years of the end of the study with a mean of 3.7 ± 3.4 years.

Results. Early mortality was 16% (13 of 81 patients). This was 12% (3 of 25 patients) for Ross-AVR, 17% (8 of 46 patients) for homo-AVR, and 20% (2 of 10 patients) for prosth-AVR. Overall late mortality was 10% (7 of 68 patients) with a valve-related late mortality of 7% (5 of 68 patients). Actuarial survival at 5 years was 88% ± 9% in Ross-AVR, 69% ± 11% in homo-AVR, and 29% ± 22% in prosth-AVR (p = 0.03). Endocarditis recurred in 12.5% (1 of 8 patients) with prosth-AVR and 3% (2 of 60 patients) in homo-Ross AVR.

Conclusions. Valve replacement in the presence of native and prosthetic endocarditis remains a formidable challenge. Autografts and homografts are the preferred replacement aortic valves for these patients even if concomitant mitral valve replacement is required, and risk of valve-related death or recurrent endocarditis is low at medium-term follow-up.     

Mitral valve replacement in the first 5 years of life

Between 1976 and 1986, 19 children aged 1 month to 5 years underwent replacement of the mitral (systemic atrioventricular) valve. Indications for valve replacement included isolated congenital mitral stenosis (n = 2), valve dysfunction associated with a more complex procedure (n = 15), and failed valvuloplasty (n = 2). Seven different valve types were used; nine were mechanical valves and ten were bioprosthetic valves. There were 6 hospital deaths (32%; 70% confidence limits, 20% to 47%). Among the 13 survivors there were 3 late deaths at a mean of 14 months after operation. The late deaths were unrelated to valve malfunction. Thromboembolic events occurred in 2 patients, both with mechanical valves. One minor bleeding complication occurred among 10 patients on a regimen of Coumadin (crystalline warfarin sodium). Five patients, all with bioprostheses, required a second valve replacement. Indications for reoperation included prosthetic valve regurgitation (n = 1) and calcific stenosis (n = 4). No early or late deaths occurred after second valve replacement. Survival was 51% +/- 12% (standard error) at 112 months after valve replacement. Analysis failed to identify age, weight, sex, previous operation, underlying cardiac lesion, or prosthesis size and type as significant risk factors for mortality. Mechanical valves had a lower reoperation rate compared with bioprostheses. These data suggest that although mitral valve replacement within the first 5 years of life is associated with a high operative and late mortality, satisfactory long-term palliation for many patients can be achieved. Mechanical valves are superior to bioprosthetic valves, and offer the best long-term results.     

Cryopreserved aortic allografts for aortic root reconstruction: a single institution’s experience

Background. An evaluation of early and long-term results of aortic root replacement with cryopreserved aortic allografts and echocardiographic follow-up of allograft valve function was performed.

Methods. From September 1989 through May 1998, 132 patients aged 17 to 77 years (mean, 50.8 ± 14.8 years) underwent freestanding aortic root replacement with a cryopreserved aortic allograft. Eighty-six (65.1%) patients had New York Heart Association class III or IV functional status before operation, and 27 (20.5%) patients underwent emergency operation. Fifty-nine (44.7%) patients had undergone previous cardiac operations. The cause of aortic disease was acute endocarditis in 63 (47.7%) patients, healed endocarditis in 15 (11.3%), degenerative in 20 (15.2%), congenital in 20 (15.2%), failed prosthesis in 10 (7.6%) and rheumatic in 4 (3.0%). Follow-up was complete, with a mean of 42 months.

Results. There were 12 hospital deaths (9.1%; 70% confidence limits [CL], 6.6% and 11.6%); 9 of them were operated on for active endocarditis (p = 0.062). Multivariate analysis determined age older than 65 years (p = 0.012) and emergency operation (p = 0.009) as independent risk factors for hospital mortality. During follow-up, 6 (5.0%; 70% CL, 3.0% and 7.0%) patients died. Cumulative survival rate for the entire group was 81.8% ± 5.4% at 8 years. Freedom from reoperation for structural valve failure was 100%, freedom from reoperation for any cause was 96.3% ± 1.8% at 8 years. Freedom from endocarditis at 8 years was 97.9% ± 1.4%. Follow-up of allograft valve function showed no or trivial aortic regurgitation in 97% of patients and absence of stenosis of the allograft in 100%.

Conclusions. Aortic root replacement with cryopreserved aortic allografts can be performed with acceptable hospital mortality and long-term results. The durability of cryopreserved aortic allografts is good, and reoperation for structural valve failure is absent at 8 years.     

Late incidence and determinants of reoperation in patients with prosthetic heart valves.

OBJECTIVES: Reoperation is a relatively common event in patients with prosthetic heart valves, but its actual occurrence can vary widely from one patient to another. With a focus on bioprosthetic valves, this study examines risk factors for reoperation in a large patient cohort. METHODS: Patients (N=3233) who underwent a total of 3633 operations for aortic (AVR) or mitral valve replacement (MVR) between 1970 and 2002 were prospectively followed (total 21,179 patient-years; mean 6.6+/-5.0 years; maximum 32.4 years). The incidence of prosthetic valve reoperation and the impact of patient- and valve-related variables were determined with actual and actuarial methods. RESULTS: Fifteen-year actual freedom from all-cause reoperation was 94.1% for aortic mechanical valves, 61.4% for aortic bioprosthetic valves, 94.8% for mitral mechanical valves, and 63.3% for mitral bioprosthetic valves. In both aortic and mitral positions, current bioprosthesis models had significantly better durability than discontinued bioprostheses (15-year reoperation odds-ratio 0.11+/-0.04; P<0.01 for aortic, and 0.42+/-0.14; P=0.009 for mitral). Current bioprostheses were significantly more durable in the aortic position than in the mitral position (14.3+/-6.8% more freedom from 15-year reoperation; (P=0.018)). Older age was protective, but smoking was an independent risk factor for reoperation after bioprosthetic AVR and MVR (hazard ratio for smoking 2.58 and 1.78, respectively). In patients with aortic bioprostheses, persistent left ventricular hypertrophy at follow-up and smaller prosthesis size predicted an increased incidence of reoperation, while this was not observed in patients with mitral bioprostheses. CONCLUSIONS: These analyses indicate that current bioprostheses have significantly better durability than discontinued bioprostheses, reveal a detrimental impact for smoking after AVR and MVR, and indicate an increased reoperation risk in patients with a small aortic bioprosthesis or with persistent left ventricular hypertrophy after AVR.     

Prosthetic valve replacement in children

Between 1975 and 1998, 27 patients aged 3 months to 14 years underwent replacement of the aortic, mitral, tricuspid, and pulmonary valves. Five different types of prosthetic valves were used; three were mechanical valves and two were bioprosthetic valves. There were 3 hospital deaths. Among the 24 survivors there were 4 late deaths. Arrhythmia requiring pacemaker implantation occurred in 2 cases after AVR and TVR. Thromboembolic events occurred in 3 patients, all with mechanical valves in pulmonary position. Infective endocarditis occurred in 1 patient after PVR with a mechanical valve. No bleeding complication occurred among the patients on a regimen of Coumadin and Dipyridamole. Two patients, both with Hancock bioprosthesis, required a second valve replacement on account of severely calcified changes. Mechanical valves in left side heart had a satisfactory long-term performance. One patient who had undergone MVR for congenital parachute mitral valve received reoperation for growth. A larger sized prosthetic valve should be used at the first replacement, and special procedures including supra-annular positioning or annular augmentation are recommended for MVR or AVR respectively.     

Acute endocarditis treated with radical debridement and implantation of mechanical or stented bioprosthetic devices

BACKGROUND: Operation for active infective endocarditis carries high mortality and morbidity rates, especially when the annulus is involved. Overall the literature favors the use of autograft and homograft valves because of better resistance to infection. In our clinic during the last 5 years we used an aggressive surgical approach to infective endocarditis in combination with implantation of mechanical or stented bioprosthetic devices. METHODS: From 1994 to 1999, 50 adults with aortic and/or mitral valve endocarditis underwent valve replacement. The median age of the 36 men and 14 women was 58 years (range, 17 to 78 years). All patients had active endocarditis at the time of operation. Native valve endocarditis was present in 48 patients and prosthetic valve endocarditis was present in 2 patients. The aortic valve was affected in 24 patients, the mitral valve in 21 patients, and both the aortic and mitral valves in 5 patients. Two of the patients with mitral endocarditis also had infection of the tricuspid valve. Annular destruction was present in 24 patients (48%). The patients were treated with radical excision of all infected tissue. The annular defects were closed, if possible, with direct sutures. Otherwise, a reconstruction was performed. Follow-up was 100% complete with a median follow-up period of 45 months (range, 6 to 66 months). RESULTS: The procedures were performed without lethal bleeding complications. Early mortality was 12% and the actuarial survival at follow-up was 80%. In none of the patients who died was death related to the prosthetic valve or recurrence of the endocarditis. Only 1 patient (2%) developed recurrence of the infective endocarditis and was reoperated with a Ross procedure. Three and a half years later the patient developed severe valve insufficiency of the autograft and was operated again with implantation of a mechanical device. CONCLUSIONS: Native and prosthetic valve endocarditis can be treated successfully with aggressive surgical debridement and implantation of mechanical or stented bioprosthetic devices with a low risk of recurrent endocarditis.     

Long-term results of bioprosthetic valves mounted on flexible stent]

From April, 1984 to April, 1989, 104 heart valve replacements were performed in 103 patients. The atrio-ventricular valves (97 mitral and 7 tricuspid valves) were replace by bioprosthetic valves mounted on the flexible stent made of Elgiloy. They included 91 porcine aortic valves and 13 bovine pericardial valves. Only 74 patients recovered and discharged from the hospital because of high operative mortality of re-replacement and double valve replacement (19 and 30 patients, respectively). These patients were followed-up for 8 to 68 months with a total follow-up period of 297 patient-years. Two patients developed cerebral embolism and two developed bacterial endocarditis. The incidence of the two complications was 0.67%/patient-year. No valve failure occurred. Long-term results of bioprosthetic heart valves mounted on flexible stent were better than those mounted on rigid stent.     

Is There an Advantage to Repairing Infected Mitral Valves?

Background. The therapy for native mitral valve endocarditis is in evolution. Antibiotics have significantly improved survival rates, but patients with complications of endocarditis may require surgical treatment.

Methods. Between January 1985 and December 1995, 146 patients underwent surgical therapy (repair or replacement) for native mitral valve endocarditis. All patients had documented bacterial endocarditis. Univariate and multivariate analyses were performed to determine predictors of hospital death, long-term event-free survival, and probability of repair. Patients were evaluated in three groups: all patients, patients with acute endocarditis, and patients with chronic endocarditis.

Results. There were ten hospital deaths (6.8%). Patients undergoing repair had a lower hospital mortality rate (p = 0.008) then those having replacement. Event-free survival was improved after mitral valve repair in the overall group (p = 0.02) and in the group with healed (chronic) endocarditis (p = 0.05). Although the acute endocarditis group demonstrated an improved event-free survival rate after mitral valve repair versus replacement (74% versus 20% at 6 years), this did not reach statistical significance.

Conclusions. We conclude that mitral valve repair is preferable to mitral valve replacement when possible, in patients with complications of endocarditis, as repair results in a lower hospital mortality and an improved long-term survival.     

An eight-year experience with porcine bioprosthetic cardiac valves

A total of 589 porcine bioprostheses were implanted in 509 patients from January, 1976, through December, 1983. Of the valves implanted, 390 were Hancock and 199 were Carpentier-Edwards. A total of 1,633 patient-years was accrued, with a mean follow-up of 38 months per patient. Two hundred eight patients had aortic valve replacement, 209 had mitral valve replacement, and 79 had multiple valve replacements, of which 46 were aortic and mitral replacements. The mortality for isolated aortic valve replacement was 5.8%; for isolated mitral replacement, 8.6%, and for all patients, 10.9%. Late mortality was 3.9% per patient-year. The actuarial survival rate at 5 years was 79% for aortic, 68% for mitral, and 76% for aortic-mitral valve replacement. There were 12 thromboembolic events (0.73% per patient-year). Two episodes occurred in patients with an aortic bioprosthesis, nine in patients with a porcine mitral valve, and one in a patient with mitral and tricuspid bioprosthetic valves. The probability of remaining free of thromboembolism at 5 years was 99% for the group having aortic valve replacement, 93% for those having mitral replacement, and 100% for the group having aortic-mitral valve replacements. Thirteen episodes of endocarditis occurred (0.8% per patient-year). Seven of the 13 patients died as a direct result of endocarditis. The probability of remaining free of prosthetic endocarditis at 5 years was 97% for the aortic valve replacement group, 95% for the mitral group, and 97% for the aortic-mitral group. There were 20 instances of xenograft failure (1.2% per patient-year). The probability of remaining free of valve failure at 5 years was 96% for the aortic valve replacement group, 93% for the mitral group, and 93% for the aortic-mitral replacement group. Primary tissue failure of a prosthesis occurred in seven patients, all with Hancock valves (0.43% per patient-year). As yet there has been no primary tissue failure of the Carpentier-Edwards prosthesis. There also appears to be a lower incidence of thromboembolism (Edwards, 0.3% per patient-year; Hancock, 0.8% per patient-year) and endocarditis (Edwards, 0.6% per patient-year; Hancock, 1.0% per patient-year). The low incidence of complications with the porcine bioprosthetic valve, especially the Carpentier-Edwards, encourages us to recommend its continued use, especially in situations in which anticoagulation is contraindicated.     

Active Native Valve Endocarditis: Determinants of Operative Death and Late Mortality

Background. In this report, we reviewed 247 patients who underwent operation by our team for active native valve endocarditis between January 1979 and December 1993.

Methods. There were 201 male and 46 female patients (mean age, 45.4 ± 6 years). The aortic valve was involved in 163 cases, the mitral valve in 36 cases, both mitral and aortic valves in 44 cases, and the tricuspid valve alone in 4 cases. The most common microorganisms were streptococci. Univariate Pearson (χ² test) and multivariate (stepwise logistic regression [BMDPLR]) analyses were used to identify significant predictors of operative mortality, reoperation, and recurrent endocarditis. Cox proportional hazards regression model was used to study late survival.

Results. Operative mortality was 7.6% (n = 19). Increased age, cardiogenic shock at the time of operation, insidious illness, and greater thoracic ratio (>0.5) were the predominant risk factors; the length of antibiotic therapy appeared to have no influence. Two hundred thirteen patients were followed up. Median follow-up time was 6 years (range, 2 to 19 years). Overall survival rate (operative mortality excluded) was 71.3% ± 3.8% at 9 years. Increased age, preoperative neurologic complications, cardiogenic shock at the time of operation, shorter duration of the illness, insidious illness before the operation, and mitral valve endocarditis were the predominant risk factors for late mortality. The probability of freedom from reoperation (operative mortality included) was 73.3% ± 4.2% at 8 years; risk factors were younger age and aortic valve endocarditis. The rate of prosthetic valve endocarditis was 7%. No significant risk factor was found.

Conclusions. Increased age, insidious illness, and hemodynamic failure are the main risk factors for operative mortality. Long-term survival is good except for patients with preoperative neurologic complications and mitral valve endocarditis.     

Reoperative surgery for degenerated aortic bioprostheses: predictors for emergency surgery and reoperative mortality.

OBJECTIVE: The long-term outcome of patients with aortic bioprosthetic valves could be improved by decreasing the reoperative mortality rate. METHODS: Predictors of emergency reoperation and reoperative mortality were identified retrospectively in 172 patients who had the first bioprosthetic aortic valve replacement between 1975 and 1988 (mean age 46+/-13 years) and were subjected to replacement of the degenerated bioprostheses between 1978 and 1997 (mean age 56+/-14 years). Emergency reoperation had to be performed in 31 patients (18%). RESULTS: The operative mortality was 5.2% (9/172), 22.6% for emergency (odds ratio 11.17; 95%-confidence limit 4.33-28.85) and 1.4% for elective replacement of the degenerated aortic bioprosthesis (P<0.0001; OR=20.3). Patients who died at reoperation had higher transvalvular gradients before the primary aortic valve replacement (P=0.007), received smaller bioprostheses at the first operation (P=0.03), had later recurrence of symptoms after the first aortic valve replacement (P=0.04), a higher pre-reoperative New York Heart Association (NYHA) class (P=0.02), and a higher incidence of coronary artery disease (P=0.001) and pulmonary artery hypertension (P=0.009). Endocarditis before the primary aortic valve replacement (P=0.004), postoperative pneumonia at the first operation (P=0.005), pulmonary hypertension (P=0.0004) acquired during the interval, later recurrence of symptoms (P=0.04) after the first operation, a lower ejection fraction at the time of reoperation (P=0.03) and acute onset of bioprosthetic regurgitation (P=0.00002) were predictors for emergency surgery. Higher transvalvular gradients at the primary aortic valve replacement (P=0. 006), coronary artery disease (P=0.003) acquired during the interval, the need for concomitant coronary artery revascularization (P=0. 001), sex (P=0.02) and size (P=0.05) and type of the bioprostheses used (P=0.007) were incremental predictors for reoperative mortality which were independent of emergency surgery. CONCLUSIONS: Elective replacement of failed aortic bioprostheses is safe. Patients undergoing emergency reoperation have a considerably higher mortality. They can be identified by a history of native aortic valve endocarditis, higher transvalvular gradients at primary aortic valve replacement, smaller bioprostheses, and pulmonary hypertension or coronary artery disease acquired during the interval. A failing bioprosthesis must be replaced at its first sign of dysfunction.     

Eight-year results of aortic root replacement with the freestyle stentless porcine aortic root bioprosthesis

Background. Stentless porcine aortic valves offer several advantages over traditional valves. Among these are superior hemodynamics, laminar flow patterns, lack of need for anticoagulation, and perhaps improved durability.

Methods. One hundred four patients were operated on from September 17, 1992, to October 31, 1997, as part of a multicenter worldwide investigation of the Medtronic Freestyle stentless porcine bioprosthesis. All patients received a total aortic root replacement. The patients were evaluated postoperatively at discharge, at 3 to 6 months, and yearly by clinical examination and color flow Doppler echocardiography.

Results. Operative mortality was 3.9%. No patient experienced structural valve deterioration, nonstructural deterioration, perivalvular leak, or unacceptable hemodynamic performance. At 8 years, survival was 59.8%. Freedom from thromboembolic complications was 83.3%. Freedom from postoperative endocarditis was 96.9%. Freedom from reoperation was 100%. Mean systolic gradients did not change over the time period studied. They were 6.4 ± 3.8 mm Hg at 1 year and 6.7 ± 2.6 mm Hg at 8 years. Correspondingly, effective orifice area was 1.9 ± 0.7 cm² at 1 year and 1.8 ± 0.8 cm² at 8 years. The incidence of any aortic insufficiency also did not change over the length of follow-up. At 1 year, 98% of patients had no or trivial aortic insufficiency and 2% had mild aortic insufficiency. At 8 years, 100% of patients evaluated were free of any aortic insufficiency.

Conclusions. The Medtronic Freestyle aortic root bioprosthesis can be used safely to replace the aortic root or aortic valve for aortic valve and aortic root pathology. Total root replacement allows optimal hemodynamic performance with no significant aortic regurgitation. Results up to 8 years show excellent survival and no signs of degeneration. Further follow-up is still needed to determine valve durability.     

Aortic valve replacement for active infectious endocarditis in 108 patients. A comparison of freehand allograft valves with mechanical prostheses and bioprostheses.

A total of 108 patients hospitalized with active (acute) endocarditis on either a native aortic valve (n = 66) or a previously inserted replacement device (n = 42) underwent aortic valve replacement because they were too ill for hospital discharge. A nonstented aortic allograft valve was used in 78 patients and prosthetic (mechanical or bioprosthetic) valves in 30 patients. The survival rate was 82% at 1 months, 73% at 1 year, 64% at 5 years, and 36% at 15 years. It was better in patients with native valve endocarditis than prosthetic valve endocarditis. The incremental risk factors for death in the early phase postoperatively were older age at operation, higher New York Heart Association functional class, and a larger number of previous aortic valve procedures. There were 13 episodes of recurrent endocarditis, giving an actuarial freedom of 80% at 10 years. The hazard function for recurrent endocarditis had only a low constant phase when allograft valves were used, which contrasted with the existence of a high peaking early phase (in addition to the constant phase) when prosthetic devices were used. No risk factors for recurrent endocarditis were found in patients receiving a prosthesis, and "localized" versus "extensive" endocarditis was the only risk factor when an allograft was used. Reoperation was performed in 24 patients for a variety of reasons, and freedom from reoperation was 61% at 10 years. It is concluded that the allograft valve is the valve of choice when aortic valve replacement is required for active endocarditis.     

Repeat heart valve surgery: risk factors for operative mortality.

BACKGROUND: Patients undergoing repeat heart valve operations are a diverse population. We assessed risk factors for operative mortality in patients undergoing a first heart valve reoperation. METHODS: A retrospective review of hospital records was performed for 671 patients who underwent first repeat heart valve operations between 1969 and 1998. Univariable and multivariable analyses were performed. RESULTS: Operative mortality was 8.6%. Mortality fell each decade to 4.8% in the most recent period (adjusted chi(2) for linear trend P <.0005). Mortality increased from 3.0% for reoperation for a failed repair or reoperation at a new valve site to 10.6% for prosthetic valve dysfunction or periprosthetic leak and to 29.4% for endocarditis or valve thrombosis. Concomitant coronary artery bypass grafting was associated with a mortality of 15.4% compared with 8.2% when it was not required. Mortality for aortic valve replacement was 6.4%, mitral valve replacement 7.4%, aortic and mitral valve replacement 11.5%, tricuspid valve replacement 25.6%, periprosthetic leak repair 9.1%, and isolated valve repair 2.2%. Among 336 patients requiring replacement of prosthetic valves, mortality was 26.1% for replacement of a mechanical valve compared with 8.6% for replacement of a tissue valve (P <.0005). Multivariable analyses identified year of reoperation, age, coronary artery bypass grafting, indication, and replacement of a mechanical valve rather than a tissue valve as significant explanatory variables for operative mortality. CONCLUSIONS: Heart valve reoperations can be performed with an acceptable operative mortality. However, we have identified several categories of patients in whom reoperation carries an increased risk.     

复杂性感染性心内膜炎的外科治疗

目的评价瓣周脓肿、心肌脓肿以及瓣膜严重毁损等复杂性感染性心内膜炎手术治疗的近、远期疗效.方法回顾性分析1988年12月至2002年6月手术治疗的复杂性心内膜炎患者57例临床资料,均为原发性心内膜炎,其中感染侵犯主动脉瓣25例、二尖瓣16例、二尖瓣和主动脉瓣16例.术中发现瓣叶严重毁损32例、主动脉瓣周脓肿19例、主动脉根部环形脓肿导致左心室-主动脉连接破坏4例、二尖瓣后瓣环脓肿11例、心肌脓肿6例、瓣膜赘生物形成55例.脓肿清除后遗留残腔采用间断褥式缝合6例、自体心包片修补19例、牛心包片修补6例、聚四氟乙烯膨体补片修补4例;施行以带瓣管道作升主动脉根部替换和左、右冠状动脉移植术4例,主动脉瓣替换术21例,二尖瓣替换术16例,主动脉瓣及二尖瓣双瓣替换术16例.结果早期死亡6例(11%),死亡主要原因为低心输出量综合征、人造心脏瓣膜性心内膜炎和多脏器功能衰竭.随访4个月至14年,平均(5.93±0.20)年.晚期死亡5例,晚期主要并发症为人造瓣膜性心内膜炎.术后1年心功能恢复NYHA分组Ⅰ～Ⅱ级占96%(44/46);5年再手术免除率为(84±3)%,5年实际生存率为(61±9)%.结论复杂性心内膜炎局部组织破坏较多,应限期手术或急症手术,清创后残腔的处理是影响手术本身能否成功以及术后近、远期效果的关键.