心脏瓣膜术后心室辅助治疗

目的 总结瓣膜病变术后重症心衰病人置入心室辅助(VADs)装置时,心脏瓣膜或人工瓣膜处理方法及围术期抗凝管理的经验.方法 回顾1994年1月到2008年6月,宾夕法尼亚大学附属医院心脏中心157例置入VADs病人中,10例为瓣膜术后重症心衰者.对于二尖瓣和三尖瓣病变,无论成形或置换,置入VADs时均未处理原瓣膜或人工瓣膜(环).5例主动脉瓣病变病例置入VADs时,2例用生物瓣膜取代了原机械瓣膜,1例未处理原来生物瓣膜,1例未处理原机械瓣膜,1例取出机械瓣膜,用牛心包封闭主动脉根部.结果 所有病人置入VADs术后应用抗凝治疗.10例病人中,停VAD出院和VAD姑息治疗各1例;转心脏移植4例;4例死亡,3例为多器官衰竭,1例为血栓栓塞事件.结论 瓣膜病变术后置入VADs总的生存率是60%,与非瓣膜病心衰病人置入VADs相比,未增加手术风险.

Abstract：

Objective An increasing number of patients requiring ventricular assist devices (VAD) have had previous valvular corrections,including valve repair,and valve replacement with mechanical or bioprosthetic valves.The operative and peri-operative management of these patients has been varied.Methods A retrospective study of VADs between Jan 1994 and June 2008 revealed 10 patients with previous prosthetic valves requiring management during and after VAD placement.Three patients were supported post-cardiotomy after valve surgery.Two patients were supported due to cardiogenic shock postopera-tively.Four patients were supported as a bridge to transplantation.One patient was supported as a destination therapy.Results The mitral valve was left untreated during VAD implantation regardless of valve repair or replacement.For aortic valves,the mechanical aortic valve was replaced with tissue valve in two patients and left untreated in one case.One patient had tricuspid valve repair previously and was left untouched.All patients with prosthetic valves in aortic,mitral and tricuspid position during VAD support received anticoagulation therapy.There were 4 deaths,and 4 went on to transplantation.One patient weaned from VAD and discharge from hospital.One patient received HeartMate Ⅰ as destination therapy.The most common causes of death were multisystem organ failure and sepsis.One patient had a thromboembolic event.Conclusion The survival rate of 60% is encouraging when compared to overall survival rates.The most common cause of death was multisystem organ failure.Patients with prosthetic valves may be safely managed during VAD support.     

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.     

Management of Prosthetic Valves during Ventricular Assist Device Implantation

Abstract Background: An increasing number of patients requiring ventricular assist devices (VAD) have had previous valvular corrections, including valve repair and valve replacement with mechanical or bioprosthetic valves. The operative and peri‐operative management of these patients has been varied. Methods: A retrospective study of VADs between January 1994 and June 2008 revealed 10 patients with previous prosthetic valves requiring management during and after VAD placement. Three patients were supported postcardiotomy after valve surgery. Two patients were supported due to cardiogenic shock postoperatively. Four patients were supported as a bridge to transplantation. One patient was supported as a destination therapy (DT). Results: The mitral, valve was left untreated during VAD implantation regardless of valve repair or replacement. For aortic valves, the mechanical aortic valve was replaced with tissue valve in two patients and left untreated in one case. One patient had tricuspid valve repair previously and was left untouched. All patients with prosthetic valves in aortic, mitral and tricuspid position during VAD support received anticoagulation therapy. There were four deaths, and four went on to transplantation. One patient was weaned from VAD and discharged from the hospital. One patient received HeartMate I as DT. The most common causes of death were multisystem organ failure (MSOF) and sepsis. One patient had a thromboembolic event. Conclusions: The survival rate of 60% is encouraging when compared to overall survival rates. The most common cause of death was MSOF. Patients with prosthetic valves may be safely managed during VAD support. (J Card Surg 2010;25:601‐605)     

Ventricular assist device in patients with prosthetic heart valves

Ventricular assist device (VAD) support inpatients with a prosthetic heart valve had previously been considered a relative contraindication due to an increased risk of thromboembolic complications. We report our clinical experience of VAD implantation in patients with prosthetic heart valves, including both mechanical and bioprosthetic valves. The clinical records of 133 consecutive patients who underwent VAD implantation at a single institution from January 2002 through June 2009 were retrospectively reviewed. Six of these patients had a prosthetic valve in place at the time of device implantation. Patient demographics,operative characteristics, and postoperative complications were reviewed.Of the six patients,four were male.The mean age was 57.8 years (range 35–66 years). The various prosthetic cardiac valves included a mechanical aortic valve (n = 2), a bioprosthetic aortic valve (n = 3), and a mechanical mitral valve (n = 1).The indications for VAD support included bridge to transplantation (n = 2), bridge to recovery (n = 1), and postcardiotomy ventricular failure(n = 3). Three patients underwent left ventricular assist device placement and three received a right ventricular assist device. Postoperatively, standard anticoagulation management began with a heparin infusion (if possible)followed by oral anticoagulation.The 30-day mortality was50% (3/6). The mean duration of support among survivors was 194.3 days (range 7–369 days) compared with 16.0 days(range 4–29 days) for nonsurvivors. Of the three survivors,two were successfully bridged to heart transplantation and one recovered native ventricular function.Among the three nonsurvivors,acute renal failure developed in each case, and two developed heparin-induced thrombocytopenia. This study suggests that VAD placement in patients with a prosthethic heart valve, either mechanical or bioprosthetic,appears to be a reasonable option.     

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.     

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.     

Comparison of outcomes after mitral valve replacement with a mechanical versus a bioprosthetic valve in patients between forty and sixty years of age

Background  The American College of Cardiology/American Heart Association (ACC/AHA), guidelines for choice of prosthetic valve based on patients’ age are difficult to apply to the developing world because of a lower life expectancy and difficulty in maintaining correct levels of anticoagulation for a variety of reasons. While there is general agreement on the choice of prosthetic valves for patients below 40 years of age (mechanical) and above 60 years of age (biologic), the 40 to 60 age group remains a grey zone. The goal of our study was to compare outcomes after mitral valve replacement with a mechanical versus a bioprosthetic valve in patients between forty and sixty years of age. Methods  From Jan 2003 to July 2008, 250 patients between the ages of 40 and 60, undergoing mitral valve replacement at our institution were randomized to receive either a mechanical or a bioprosthetic valve. Outcomes in the form of incidence of valve thrombosis and thromboembolism, bleeding complications, incidence of prosthetic valve endocarditis and survival were compared in the two groups. Results  Out of 250 patients, 135 patients received mechanical valve and 115 patients were implanted with a bioprosthetic valve. Patients were followed up for a mean period of 3 years (range 6 months to 4.8 years). The incidence of valve thrombosis was higher in mechanical valve as compared to bioprosthetic valve (6% vs. 0.9%, p= 0.04). Similarly there was a higher incidence of thromboembolism in mechanical valves as compared to bioprosthetic valves (4.5% vs. 0%, p=0.03). Bleeding complications occurred more frequently in mechanical than bioprosthetic valve (6% vs. 0.9%, p=0.04). There was no significant difference in the incidence of prosthetic valve endocarditis (2.2% vs. 2.7%, p >0.05) or survival at three years (96.2% vs. 97.2%, p > 0.05) in the two groups. Conclusions  Patients in the age group of 40 to 60 years undergoing mitral valve replacement with a mechanical valve have a higher incidence of thrombotic and bleeding complications as compared to bioprosthetic valve, even though short term survival is similar. This favours implantation of a bioprosthetic valve in this age group.     

Thrombotic and bleeding complications of prosthetic heart valves

A review of articles published since 1979 indicates that thrombotic and bleeding complications account for about 50% of valve-related complications in patients with bioprosthetic aortic and mitral valves and for approximately 75% of the complications in patients with mechanical valves. Although compromised by lack of standard definitions and by variability in reporting and follow-up, the data suggest that the linearized rate of both thrombotic and bleeding complications in patients with aortic bioprostheses is approximately half that for aortic mechanical prostheses (2% versus 4%), but is approximately equal for both bioprostheses and mechanical valves in the mitral position (approximately 4%), and for mechanical and bioprosthetic aortic and mitral valves in combination. However, linearized rates for fatal thrombotic and bleeding events are two to four times higher in patients with mechanical prostheses. The adequacy of warfarin anticoagulation is the most important factor affecting thrombotic and bleeding complications in patients with mechanical valves and over shadows the dubious importance of other phenomena such as atrial fibrillation and left atrial thrombus. Short-term warfarin anticoagulation or the use of long-term platelet inhibitors, or both, do not appear to reduce the incidence of thrombotic complications in patients with aortic bioprostheses but increase bleeding. For mitral bioprostheses, the postoperative use of warfarin for three months or aspirin indefinitely is as effective in preventing thromboembolism as long-term warfarin. Acute prosthetic valve endocarditis is associated with a 13 to 40% incidence of thrombotic complications. Likewise, the recurrence rate of cerebral emboli is high (20-30%) in patients with prosthetic valves who are not anticoagulated. Bioprostheses are strongly preferred for women who wish to bear children; fetal wastage occurs in 25 to 30% of pregnant women with mechanical heart valves who receive either warfarin or heparin, or a combination of the two. Heparin, however, greatly increases the risk of maternal bleeding. In children, the efficacy of platelet inhibitors without warfarin anticoagulation is unproven; nearly all serious strokes occur when warfarin is omitted; and permanent disability from warfarin-related bleeding is rare. All prosthetic cardiac valves initiate coagulation and affect the dynamic equilibrium between activated procoagulants and endogenous anticoagulants. Warfarin is the only available oral exogenous anticoagulant.(ABSTRACT TRUNCATED AT 400 WORDS)     

Prosthetic replacement of tricuspid valve: bioprosthetic or mechanical

BACKGROUND: Tricuspid valve replacement is one of the most challenging operations in cardiac surgery. Selection of the suitable prosthesis is still debatable. METHODS: In our institution, between January 1980 and December 2000, 129 tricuspid valve replacements were performed in 122 patients (14.7%). Bioprosthetic valves were used in 32 patients, whereas 97 patients had mechanical valve implantation. Twenty-two percent of replacements were done on men. Mean age was 35.27+/-11.56 years. In all patients, initially an annuloplasty technique was tried. Tricuspid valve replacement was performed when annuloplasty was not sufficient. In most of the cases, tricuspid valve interventions were done under cardiopulmonary bypass and on a beating heart. RESULTS: Early mortality was 24.5%. Patients were followed for 2 to 228 months. Seven patients underwent reoperation because of tricuspid valve dysfunction (7.6%). Nine patients died during the follow-up period. Late mortality was 9.7%. Actuarial estimates of survival in 20 years of follow-up for all tricuspid prosthetic valves, mechanical valves, and bioprosthetic valves were 65.1%+/-9.3%, 68.3%+/-10.6%, and 54.8%+/-12.1%, respectively. For the bioprosthetic valve group, freedom from structural valve degeneration was 90%+/-5.5%; for the mechanical valve group, freedom from deterioration, endocarditis, and leakage was 97.8%+/-4.2%, and freedom from thromboembolism was 92.6%+/-6.9%. CONCLUSIONS: We found that there was no statistically significant difference between the two groups in terms of early mortality, re-replacement, and midterm mortality (p > 0.05). Nevertheless, we recommend low profile modern bileaflet mechanical valves for prosthetic replacement of the tricuspid valve, due to their favorable hemodynamic characteristics and durability.     

Enlarged coronary sinus thrombosis after repair of Ebstein's anomaly

A 58-year-old woman was referred to our hospital with progressively increasing breathlessness. She reported a history of bioprosthetic valve implantation for tricuspid valve replacement and direct closure of an atrial septal defect for Ebstein's anomaly, 31 years before presentation. Transthoracic echocardiography revealed prosthetic valve failure, an enlarged coronary sinus, and severe mitral regurgitation. Computed tomography revealed a giant coronary sinus with thrombosis and persistent left superior vena cava. She underwent successful mitral and tricuspid valve replacement; however, severe hemodynamic deterioration necessitated mechanical ventilatory support with extracorporeal membrane oxygenation.     

Observation of the right atrial wall suture line after tricuspid valve supra-annular implantation

Strength of the right atrial wall suture line after tricuspid valve supra-annular implantation (TVSI) is controversial. We observed the right atrial supra-annular position of a 63-year-old male during his third mitral operation who underwent mitral valve replacement (MVR) and TVSI 15 years ago. Eight years later, he received the second MVR and removal of the bioprosthetic valve from the tricuspid position due to primary tissue failures. The annular size of the tricuspid valve had decreased enough to be fixed by tricuspid annuloplasty (TAP) and re-TVSI was not needed at that time. In this operation, 7 years following bioprosthetic valve removal, the circularly bulging atrial wall still remained and seemed to have enough strength for holding the prosthetic valve. This finding may support the conclusion that the right atrial wall has enouth strength for holding a prosthetic valve in position.     

Discrepancies Between Labeled and Actual Dimensions of Prosthetic Valves and Sizers

A bstract Background and aims : The hemodynamic performance of a mechanical or stented bioprosthetic valve is primarily determined by the diameter of its orifice. Thus, in aortic or mitral valve replacement, assessment of the native annular size and selection of the correspondingly sized prosthetic valve is necessary to achieve maximum hemodynamic performance. The purpose of this study was to determine the actual dimensions of aortic and mitral valve sizers and their corresponding prostheses, and to determine whether they differed from their marked dimensions. Methods : Mechanical and stented bioprosthetic valves and sizers were obtained from the manufacturers (CarboMedics, St. Jude, Medtronic-Hall, Starr-Edwards, Carpentier-Edwards, and Medtronic-Hancock), and the diameters were measured. Results : For the mechanical models, both aortic and mitral sizers were larger than their marked size by 0.5 mm to 1.0 mm. The aortic valves were all smaller than their corresponding sizers, but the relationship of the mitral valves to corresponding sizers varied with the manufacturer. For the bioprosthetic models the aortic and mitral sizers were true to marked size, the aortic valves were close to marked size and the mitral valves were smaller than marked size. Conclusions : These differences make optimal sizing difficult at best, particularly if more than one manufacturers' product is used in an institution. These differences may or may not impact valve performance in an individual surgeon's hands. However, the wide range of variations across prosthetic type and manufacturer obligate the surgeon to be aware of these variances to achieve maximum hemodynamic performance for each patient.     

Transatrial transcatheter tricuspid valve-in-valve implantation of balloon expandable bioprosthesis

Transcatheter valve-in-valve implantation into failing mitral and aortic bioprosthetic valves have been reported. This strategy avoids performing high-risk repeat cardiac surgery in elderly patients with multiple comorbidities. Tricuspid valve-in-valve implantation has not been described. We report a case of failing bioprosthetic tricuspid valve in a 48-year-old woman with carcinoid syndrome. We attempted a transatrial transcatheter approach and we successfully deployed a 26-mm Edwards Sapien balloon expandable bioprosthesis (Edwards Lifesciences, Irvine, CA) into a severely stenotic tricuspid bioprosthesis. This case demonstrates the technical feasibility and safety of this approach. Therefore, tricuspid valve-in-valve implantation may be a viable treatment alternative in carefully selected patients.     

Biological versus mechanical valves. Analysis of 1,116 valves inserted in 1,012 adult patients with a 4,818 patient-year and a 5,327 valve-year follow-up

All surviving patients between 18 and 88 years of age receiving biological or mechanical prosthetic heart valves at the Yale-New Haven Hospital from January 1974 through January 1985 were analyzed for thromboembolism, anticoagulation-related hemorrhage, endocarditis, perivalvular leak, valve failure, need for reoperation, late cardiac death, and valve-related death. The rates of these events were analyzed in linear and actuarial terms over the 11 year period. A total of 533 patients received 606 biological valves (328 aortic, 252 mitral, 24 tricuspid, and two pulmonary, consisting of 482 Carpentier-Edwards, 108 Hancock, 15 Ionescu-Shiley, and one other), with a mean follow-up of 2,571 patient-years and 2,935 valve-years. They were compared with 479 patients with 510 mechanical valves (330 aortic, 175 mitral, and five tricuspid, consisting of 178 Starr-Edwards, 166 St. Jude Medical, 164 Bj?rk-Shiley, and two others), which were implanted for 2,247 patient-years and 2,392 valve-years. We found a significantly increased incidence of thromboembolism (p less than 0.001) and reoperation for perivalvular leak (p less than 0.05) in the mechanical valves compared with the biological valves, but a significantly increased rate of valve failure (p less than 0.001) in the biological valves compared with the mechanical valves. The overall analysis comparing total morbidity and valve-related mortality significantly (p less than 0.01) favored the biological valves in the first 5 years of the study and the mechanical valves (p less than 0.001) in the second 5 years of the study. However, the net 10 year results showed no significant difference between the two types of valves. In summary, we found little direct evidence to strongly support the generalized use of one type of valve over another.     

Long-term results of porcine bioprosthetic heterograft; a 13-years' experience

One hundred and ninety-four patients underwent valve replacements with the glutaraldehyde-preserved porcine bioprostheses (133 Hancock valves, 39 Angell-Shiley valves, 22 Carpentier-Edwards valves and 3 other valves) from 1974 through 1979. There were 105 women and 89 men, whose age ranged 18 to 62 (mean 38.8) years. One hundred and eighty-two patients had mitral bioprosthetic valve replacement (BVR)s, of which 52 had combined aortic mechanical valve replacements, 8 had aortic BVR's, 3 had tricuspid BVR's and 3 had multi-BVR's. Operative mortality was 10.8%. Only one patient was lost to follow-up. Cumulative duration of follow-up is 1421 patient-years. Linearized rate of anticoagulant related hemorrhage, thromboembolism (TE), prosthetic valve endocarditis (PVE), primary tissue failure (PTF) and valve dysfunction (VD) were 0.07, 1.62, 0.49, 2.74 and 3.66% per patient-year. Actuarial freedom from TE, PVE, PTF and VD were 87.0 +/- 2.7%, 95.6 +/- 1.5%, 65.2 +/- 4.9% and 56.9 +/- 5.6% at 13 years. Actuarial survival rate was 67.4 +/- 4.0% at 13 years. Long term follow-up after valve replacement with porcine bioprosthetic valve confirms low thrombogenicity. But primary tissue failure was the chief cause of valve dysfunction and represent a major problem. At this time, we are going to use porcine bioprosthetic valve in the selected patients, that is in the situations in which anticoagulation is contraindicated.     

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.     

Selection of prosthetic heart valves for adult patients by age

The use of bioprosthetic heart valves has dramatically increased over the last decade. In 2004, the ratio was 52% for mechanical and 48% for bioprosthetic valves in a survey by the Japanese Association for Thoracic Surgery. This increase in the use of bioprosthetic valves is related to evidence demonstrating the durability of such valves over the last 20 years. The guidelines of the Japanese Circulation Society recommend selection of prosthetic heart valves by considering the patient's age. In patients who received a mechanical valve in previous cardiac surgery, selection of another mechanical valve is inevitable. The age of 65 years is when patients are separated into groups receiving either mechanical (<64 years) or bioprosthetic (> or =65 years) valves. However, the evidence that a bioprosthetic valve is better for patients in their 60s is somewhat questionable, particularly in Japanese with a long life expectancy. Anticoagulation with warfarin in patients with mechanical valves leads to a higher incidence of hemorrhagic complications compared with bioprosthetic valves, although the incidence of thromboembolism is the same. Thus patients with contraindications to warfarin or a low risk of thromboembolism who are more than 65 years old are reasonable candidates for a bioprosthetic valve. It is also recommended that women of childbearing age receive bioprosthetic valves after being informed of the possibility and risks of reoperation. In addition to the information in the guidelines and physicians' preference for valve selection, factors such as the patient's lifestyle, wishes, cardiac function, other complications, and longevity must always be considered when selecting a valve prosthesis.     

Tricuspid valve replacement: an analysis of 25 years of experience at a single center

BACKGROUND: Tricuspid valve replacement is seldom used in clinical practice, but the choice between mechanical and biologic prostheses remains controversial. METHODS: Between 1977 and 2002, 97 patients underwent tricuspid valve replacement and were followed at the Montreal Heart Institute Valve Clinic. Patients underwent replacement with bioprostheses (n = 82) and mechanical valves (n = 15). RESULTS: Patients with bioprosthetic tricuspid replacements averaged 53 +/- 13 years of age compared with 48 +/- 11 years in those with tricuspid mechanical valve replacements (p = 0.2). Isolated tricuspid valve replacement was performed in 11 patients (73%) in the mechanical valve group compared with 31 patients (38%. p = 0.01) in the bioprosthetic replacement group. In patients undergoing bioprosthetic tricuspid replacement, 51 (62%) underwent multiple associated valve replacements. The 5-year survival after tricuspid replacement averaged 60% +/- 13% in the mechanical valve group and 56% +/- 6% in the biologic replacement group (p = 0.8). The 5-year freedom rate from tricuspid valve reoperation averaged 91% +/- 9% in patients with mechanical valves and 97% +/- 3% in those with biologic valves (p = 0.2). CONCLUSIONS; Patient survival after tricuspid valve replacement is suboptimal but related to the clinical condition at operation. The use of biologic prostheses for tricuspid valve replacement remains a good option in young patients because of limited life expectancy unrelated to the type of tricuspid prostheses at long-term follow-up.     

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.     

Paraprosthetic leak: a complication of cardiac valve replacement

Paraprosthetic leak (PPL) is a rare but potentially serious complication of cardiac valve replacement. Between 1974 and 1988, 1175 prosthetic valves were implanted in 1026 patients by one cardiac surgeon at St. Thomas' Hospital, London. Of these 539 (52.5%) were aortic (AVR), 334 (32.6%) mitral (MVR), 7 (0.7%) tricuspid, and 144 (14%) AV and MV double valve replacements (DVR). There were only 2 triple valve replacements. The prosthetic valves implanted were the Starr-Edwards (7%), Bjork Shiley (11.8%), Lillehei-Kaster (23%), Carpentier-Edwards bioprosthesis (35.2%), Duromedics bileaflet (16.4%) and a variety of other mechanical and bioprosthetic valves (6.6%). Over the 15 year period there were a total of 82 (7%) valve failures of which PPL was diagnosed in 29 (2.5%) valves in 24 patients. Presenting features included cardiac decompensation in 72%, bacterial endocarditis in 12% and haemolytic anaemia in 12%. One patient (4%) had no symptoms. Nineteen patients underwent re-operation. Median time to re-operation was 15 months (range 1-65 months) with a re-operative mortality of 22%. Clinical evidence of prosthetic valve infection was found in 79% of MVR and 67% of AVR. A heavily calcified aortic annulus, found in 47% of patients, may also have contributed to PPL after AVR.