Mitral valve replacement in the pediatric age group- a single institution experience

Background  Mitral valve replacement in pediatric patient is a difficult surgical task, with many intraoperative and post-operative considerations. We conducted this study to evaluate the indications and early results of mitral valve replacement in children. Methods  From January 2003 to July 2008, fifty-four children under the age of fifteen years underwent mitral valve replacement at our institution. All children received a mechanical bi-leaflet or tilting disc prosthetic valve. All of them underwent valve replacement on the basis of preoperative echocardiography and intraoperative assessment of valve pathology. Results  Preoperatively 65% of the children were in New York Heart Association (NYHA) class III and 35% of them were in NYHA class IV. The cause of mitral valve disease was chronic rheumatic valve disease in 97% of cases and congenital in 3% of the cases. In the rheumatic group 66% of them had severe mitral regurgitation as predominant lesion. The mean diameter of the implanted valve was 27.17mm. There was no hospital or 30 day mortality. The mean follow-up period was 3.6 years. One patient died after 2 years from a stuck valve. Two other patients required thrombolysis for stuck valves. 53 patients are doing well at last follow up. Conclusions  Mitral valve replacement in children is a safe alternative to valve repair when the morphology is not suitable for repair, with acceptable immediate and early outcomes.     

Mitral valve repair and replacement for rheumatic disease

OBJECTIVES: Mitral valve repair may be technically feasible in patients with suitable anatomy, but the appropriateness of repair for rheumatic disease remains controversial. We evaluated our late outcomes after mitral repair and replacement for rheumatic disease. METHODS: Five hundred seventy-three patients underwent mitral valve surgery for rheumatic disease at our institution from 1978-1995. Follow-up was 98% complete (mean, 68 +/- 46 months). Survival and morbidity were evaluated by Kaplan-Meier analysis and Cox regression, including propensity score analysis. RESULTS: Mean age was 54 +/- 14 years, 55% of patients had congestive heart failure, 22% were undergoing redo mitral valve surgery, and 9% also underwent coronary bypass. Mitral stenosis was present in 53%, regurgitation in 15%, and both in 32%. Valve repair was performed in 25%, bioprosthetic replacement was performed in 28%, and a mechanical valve was placed in 47%. Patients undergoing repair were younger and less likely to be undergoing reoperation or to have atrial fibrillation than those undergoing replacement (P =.001). The operative mortality rate was 4. 2%. Better late cardiac survival was independently predicted by valve repair rather than replacement (P =.04) after adjustment for baseline differences between patients. Freedom from reoperation was greatest (P =.005) but that from thromboembolic complications was worst (P <.0001) after mechanical valve replacement. Twenty-three patients underwent reoperation after initial repair, with no operative deaths. CONCLUSIONS: Mechanical valves minimize reoperation but limit survival and increase thromboembolic complications. Patients undergoing valve repair had improved late cardiac survival independent of their preoperative characteristics. Rheumatic mitral valves should be repaired when technically feasible, accepting a risk of reoperation, to maximize survival and reduce morbidity.     

Mitral valve repair with aortic valve replacement is superior to double valve replacement

OBJECTIVES: Double valve replacement has been advocated for patients with combined aortic and mitral valve disease. This study investigated the alternative that, when feasible, mitral valve repair with aortic valve replacement is superior. Patients and Methods: From 1975 to 1998, 813 patients underwent aortic valve replacement with either mitral valve replacement (n = 518) or mitral valve repair (n = 295). Mitral valve disease was rheumatic in 71% and degenerative in 20%. Mitral valve replacement was more common in patients with severe mitral stenosis (P =.0009), atrial fibrillation (P =.0006), and in patients receiving a mechanical aortic prosthesis (P =.0002). These differences were used for propensity-matched multivariable comparisons. Follow-up extended reliably to 16 years, mean 6.9 +/- 5.9 years. RESULTS: Hospital mortality rate was 5.4% for mitral valve repair and 7.0% for replacement (P =.4). Survivals at 5, 10, and 15 years were 79%, 63%, and 46%, respectively, after mitral valve repair versus 72%, 52%, and 34%, respectively, after replacement (P =.01). Late survival was increased by mitral valve repair rather than replacement (P =.03) in all subsets of patients, including those with severe mitral valve stenosis. After repair of nonrheumatic mitral valves, 5-, 10-, and 15-year freedom from valve replacement was 91%, 88%, and 86%, respectively; in contrast, after repair of rheumatic valves, it was 97%, 89%, and 75% at these intervals. CONCLUSIONS: In patients with double valve disease, aortic valve replacement and mitral valve repair (1) are feasible in many, (2) improve late survival rates, and (3) are the preferred strategy when mitral valve repair is possible.     

Evaluation of clinical treatment of atrial fibrillation associated with rheumatic mitral valve disease by radiofrequency ablation.

OBJECTIVES: The aim of this clinical study was to evaluate the effectiveness and advantages of the radiofrequency ablation maze procedure in the treatment of atrial fibrillation associated with rheumatic mitral valve disease. METHODS: We developed one kind of modified Cox III maze procedure with the use of radiofrequency ablation in the treatment of atrial fibrillation associated with rheumatic mitral valve disease and compared the outcome of 96 patients of atrial fibrillation associated rheumatic mitral valve disease who underwent radiofrequency ablation maze procedure plus mitral valve replacement with that of 87 patients with atrial fibrillation associated rheumatic mitral valve disease who had mitral valve replacement during the same interval by the same surgeon. The patients in the two groups were similar in age, gender, preoperative New York Heart Association class and duration of preoperative atrial fibrillation. RESULTS: No operative deaths occurred in the study group and the control group. Duration of cardiopulmonary bypass (137.63 +/- 10.82 vs. 90.95 +/- 7.65 min, P<0.01) and duration of aortic crossclamping (56.96 +/- 6.19 vs. 32.66 +/- 3.55 min, P<0.01) were prolonged in the study group. Blood loss from chest tubes was similar in the two groups (494.06 +/- 100.44 vs. 476.09 +/- 115.84 ml, P=0.263). Freedom from atrial fibrillation in the study group was 77% 3 years after the operation compared with 25% in the control group (P<0.01). CONCLUSIONS: The addition of the radiofrequency ablation maze procedure to mitral valve replacement is safe and effective in the treatment of atrial fibrillation associated with rheumatic mitral valve disease.     

IL-10 and ET-1 as biomarkers of rheumatic valve disease

Objective

To evaluate the immunological profile and gene expression of endothelin-1 (ET-1) in mitral valves of patients with rheumatic fever originated from a reference service in cardiovascular surgery.

Methods

This was a quantitative, observational and cross-sectional study. Thirty-five subjects (divided into four groups) participated in the study, 25 patients with chronic rheumatic heart disease and ten control subjects. The mean age of the sample studied was 34.5 years. Seventeen of them (48.58%) were male and 18 (51.42%) were female. Inflammatory cytokines (TNF-α, IL-4 and IL-10) were measured and ten mitral valves of patients who underwent first valve replacement were collected for determination of gene expression of endothelin-1 by real time PCR.

Results

Among the groups studied (patients vs. controls), there was a statistically significant difference in IL-10 levels (P=0.002), and no differences in other cytokines. Expression of endothelin-1 was observed in 70% of samples. Quantitatively, average of ET-1 expression was 62.85±25.63%.

Conclusion

Inflammatory cytokine IL-10 participates in the maintenance of chronicity of rheumatic fever in patients who underwent valve replacement and those who are undergoing medical treatment. The expression of endothelin-1 in heart valve lesions in patients undergoing mitral valve replacement confirms its association with inflammatory activity in rheumatic fever.     

Calcific stenosis of the porcine heterograft.

We have encountered two cases of late calcification of the porcine heterograft. A patient in chronic renal failure died of sepsis and endocarditis fifteen months after replacement of the mitral and tricuspid valves. At postmortem examination, both heterograft valves exhibited severe calcification and thrombosis. A second patient with rheumatic heart disease and sickle cell disease underwent mitral valve replacement for severe regurgitation. Thirty months later, cardiac catheterization revealed prosthetic valve stenosis. The valve was replaced successfully, and the excised heterograft exhibited severe calcification with restriction of leaflet motion. Although calcification of the porcine heterograft is known to occur in patients with infection or disorders of calcium metabolism, dysfunction of the heterograft is rare in our experience.     

二尖瓣主动脉瓣三尖瓣同时置换治疗重症风湿性瓣膜病

目的　总结二尖瓣主动脉瓣三尖瓣同期置换治疗重症风湿性心脏瓣膜病的手术疗效。方法　 1999年 6月至 2 0 0 1年 6月 94 1例病人进行瓣膜置换术 ,其中 2 4例同期进行二尖瓣、三尖瓣和主动脉瓣置换 ,占瓣膜置换病人的 2 5 5 %。 2 4例病人中女 17例 ,男 7例 ;年龄 18～ 5 9岁 ,平均 36岁 ;体重 37～ 5 6kg。其中 8例曾行二尖瓣闭式扩张术、11例合并左房血栓、16例病人合并有肝肿大 (肋下 2～ 8cm)和下肢水肿、8例合并有腹水。X线胸片示心胸比率为 0 6 6～ 0 91。超声检查示三尖瓣均有严重反流 ,反流面积为 4 2～ 34 0cm2 ,平均 (16 8± 9 3)cm2 。术前心功能III级 9例 ,VI级 15例。 6例病人因药物不能控制心衰而行急诊换瓣手术。结果　死亡 1例 ,死亡率为 4 2 %。术后 1周、3、6个月复查超声心动图示各心腔内径较术前明显缩小。出院者均得到随访 ,随访时间 2 0～ 36个月 ,平均 2 6 4个月。术后心功能I～II级2 0例 ,III级 4例。术后 3～ 12个月复查超声心动图未见机械瓣功能障碍及血栓形成。结论　对于联合瓣膜病变 ,三尖瓣有严重器质性病变的病人 ,在进行二尖瓣主动脉瓣置换的同时进行三尖瓣置换 ,有利于术后右心功能的恢复 ,能更好地改善心脏的血流动力学特性 ,改善心功能 ,并有利于术后病人的康     

Long-term results after surgical repair of incomplete endocardial cushion defects

Since 1964, 56 children (mean age, 6.7 years) underwent repair of incomplete endocardial cushion defects. Forty patients had isolated ostium primum defects. Additional congenital defects were present in 17 patients (30%). All patients underwent patch closure of the ostium primum defect and 47 of 56 patients (84%) underwent mitral valvuloplasty. Hospital mortality was 1.8% (one death). Arrhythmias developed in 7 other patients in the early postoperative period, of which six were transient and resolved completely. One patient required early pacemaker placement for complete heart block. Cumulative follow-up was 378 patient-years. There were three late deaths (5.7%), and additional operations were required in 12 patients (22.6%). Seven of these 12 patients required mitral valve replacement for severe mitral regurgitation. The mean interval between initial repair and mitral valve replacement was 4.2 years, with only three valves needing replacement within 12 months. There was a significant correlation between the severity of mitral regurgitation before initial repair and subsequent need for mitral valve replacement. Late onset atrial arrhythmias have developed in 6 patients. Current functional status has been evaluated in 50 of 52 surviving patients and 88.5% are in NYHA class I, with the remainder in class II.     

2349例心脏瓣膜置换术早期死亡原因分析

目的 分析2349例心脏瓣膜置换术病人的死亡原因,以期进一步提高治疗水平.方法 1995年1月至2007年12月,2349例心脏瓣膜病病人接受人工心脏瓣膜置换手术.其中二尖瓣置换术(MVR)1333例,主动脉瓣置换术(AVR)271例,二尖瓣、主动脉瓣同期置换术(DVR)736例,三尖瓣置换术(TVR)9例.结果 早期病死率1995年至1999年6.81%,2000年至2004年3.22%,2005年至2007年2.82%.全组总早期病死率3.40%.结论 心脏瓣膜置换术早期死亡的原因主要是低心排血量综合征、肾功能衰竭、心律失常、肺部感染、脑血管意外、左室破裂和多器官系统功能衰竭等.     

60例感染性心内膜炎的临床诊断与外科治疗

目的总结感染性心内膜炎的临床诊断和外科治疗经验。方法回顾分析2000年1月～2006年8月在我院接受手术治疗的60例感染性心内膜炎患者的临床资料,其中男46例,女14例;年龄9～58岁,平均年龄34.3岁。术前血培养60例,阳性25例(41.7%),其中链球菌12例,葡萄球菌6例,其他细菌7例。超声心动图提示有心内膜赘生物或瓣膜穿孔42例,其中累及二尖瓣9例,主动脉瓣26例,二尖瓣主动脉瓣同时受累6例,三尖瓣1例。合并原发心脏疾病28例,其中先天性心脏病16例,风湿性心脏病9例,二尖瓣脱垂3例。对60例患者全程采用大剂量敏感抗生素治疗。择期手术55例,急诊手术5例。手术中清除所有感染灶,同期矫治心内畸形16例,行心瓣膜置换术41例,三尖瓣修复成形术1例。结果术后早期死亡3例。随访51例(89.5%),随访时间5～71个月,无心内膜炎复发,心功能恢复至级38例,级13例。结论早期诊断,掌握适当的手术时机,联合内科治疗和外科手术,可取得较好的治疗效果。     

Ross procedure in rheumatic aortic valve disease.

OBJECTIVE: To assess the results of aortic valve replacement with the pulmonary autograft in patients with rheumatic heart disease. METHODS: From October 1993 through September 2003, 81 rheumatic patients with aortic valve disease, mean age 29.5+/-11.9 years (11-56 years) underwent, the Ross procedure with root replacement technique. Forty patients were 30 years of age or below (young rheumatics). Associated procedures included mitral valve repair (n=19), open mitral commissurotomy (n=15), tricuspid valve repair (n=2), and homograft mitral valve replacement (n=2). RESULTS: Early mortality was 7.4% (six patients). Mean follow-up was 92.3+/-40.9 months (7-132 months, median 109 months). Sixty of the 73 patients whose follow-up was available (82%) had no significant aortic regurgitation. Re-operation was required in seven (8.4%) patients for autograft dysfunction with failed mitral valve repair (n=3), autograft dysfunction alone (n=2) and failed mitral valve repair alone (n=2). No re-operations were required for the pulmonary homograft. There were six (7.5%) late deaths. Actuarial survival and re-operation-free survival at 109 months were 84.5+/-4.1% and 90.5+/-3.7%, respectively. Freedom from significant aortic stenosis or regurgitation was 78.4+/-5.2% and event-free survival was 64.6+/-5.8%. When compared to rheumatics above 30 years of age, the relative risk of autograft dysfunction was high in the young rheumatics. CONCLUSION: The Ross procedure is not suitable for young patients with rheumatic heart disease. However, it provides acceptable mid-term results in carefully selected older (>30 years) patients with isolated rheumatic aortic valve disease.     

Long-term results of reoperative mitral valve surgery in patients with rheumatic disease

BACKGROUND: Reoperative (redo) mitral valve surgery is still a continuing challenge to surgeons. The aim of this study was to detect the factors that affect late mortality or morbidity after redo mitral valve surgery in patients with rheumatic disease. METHODS: Between May 1983 and February 2003, 92 patients who underwent redo mitral valve surgery for rheumatic disease were enrolled. Risk factors influencing survival or cardiac events were investigated with univariate analysis and a Cox model. RESULTS: Operative mortality rate was 4.2%. Kaplan-Meier actuarial analysis demonstrated an 84.7% 5-year, a 69.5% 10-year, and a 65.9% 15-year survival. Multivariate analysis demonstrated that age at surgery and preoperative New York Heart Association (NYHA) class were found to be independent predictors of late deaths, and that higher age, advanced NYHA class, and previous mitral valve replacement were independent predictors of cardiac events. CONCLUSIONS: Redo mitral valve surgery can be achieved with low early mortality. However, long-term results of redo mitral surgery are not necessarily satisfactory in patients with preoperative advanced NYHA class or with a previous mechanical heart valve, and especially in 60 years or older age.     

老年风湿性二尖瓣病变行二尖瓣修复术与生物瓣膜置换术中期效果比较

目的比较60岁以上老年患者风湿性二尖瓣修复(MVP)与生物瓣膜置换(MVR)的中期效果。方法选取2014年1月至2016年1月北京安贞医院瓣膜外科诊疗中心行风湿性二尖瓣修复或生物瓣置换手术的60岁以上老年风湿性二尖瓣病变患者,包括同期行三尖瓣修复术及房颤射频消融术患者;排除合并主动脉瓣手术、冠状动脉旁路移植手术、二次手术患者,最终纳入患者82例。根据二尖瓣手术方式分为二尖瓣修复组(MVP组,25例)和生物瓣置换组(MVR组,57例)。采用Kaplan-Meier法进行生存分析并绘制曲线,通过Log Rank方法比较两组患者5年生存率的差异。结果围手术期全组患者平均年龄(66.37±4.41)岁。54.9%的患者心功能(NYHA分级)Ⅲ级。两组患者在体外循环时间(P=0.99),主动脉阻断时间(P=0.88),术后住院时间(P=0.76)差异均无统计学意义。MVR组3例患者住院期间死亡,病死率5.3%;MVP组无住院期死亡(P=0.24)。随访5年,最长随访63个月,平均随访47.03个月。MVR组6例死亡,其中4例死于心脑血管不良事件,2例死于非心脑血管不良事件。MVP组无死亡。两组均无再手术病例。结论风湿性二尖瓣病变的老年患者采用二尖瓣修复手术治疗能够获得较好的中期效果。     

More than ten years' follow-up of the Hancock porcine bioprosthesis in Japan.

From February 1975 through October 1981, 256 Hancock porcine bioprostheses (Johnson & Johnson Cardiovascular, King of Prussia, Pa.) (60 aortic, 169 mitral, and 27 pulmonary/tricuspid position) were implanted in 220 patients (104 male and 116 female, aged 9 to 67 years; mean 43.3) at Kyushu University Hospital in Japan. The procedures include 41 aortic valve replacements, 121 mitral valve replacements, 4 pulmonary valve replacements, 6 tricuspid valve replacements, and 48 combined valve replacements (31 aortic plus mitral, 13 mitral plus tricuspid, and 4 aortic plus mitral plus tricuspid). Hospital mortality was 6.4%. Follow-up was 98% during 8 to 14 (mean 10.5) years. Cumulative follow-up was 1836 patient-years and 2078 valve-years. At 10 years the overall actuarial survival rate, including hospital morality, was 70% +/- 3%, and freedom from valve-related mortality with sudden death was 87% +/- 3%. More than half of the current survivors required no anticoagulant therapy. Freedom from thromboembolism or anticoagulant-related hemorrhage (or both) and prosthetic valve endocarditis was common. Freedom from structural valve failure and reoperation declined more than 9 years after replacement of left-sided heart valves but not after replacement of right-sided heart valves. Sixty-seven patients underwent 68 repeat operations, and there were four deaths (5.9%). The rate of freedom from overall valve-related complications at 10 years was 62% +/- 8% for aortic valve replacement, 53% +/- 5% for mitral valve replacement, 80% +/- 13% for pulmonary/tricuspid valve replacement, and 42% +/- 9% for combined valve replacement. There was a significant difference between pulmonary/tricuspid valve replacement and combined valve replacement (p less than 0.05). The Hancock bioprosthesis is suitable for the replacement of valves in the right side of the heart but not for combined valve replacement.     

Mitral valve repair in children with rheumatic heart disease

OBJECTIVE: The purpose of this study was to assess the long-term results of mitral valve repair in children with chronic rheumatic heart disease. METHODS: From January 1988 through December 2003, 278 children (153 male children) underwent mitral valve repair. Mean age was 11.7 +/- 2.9 years (range, 2-15 years). One hundred seventy-three children (62%) were in the New York Heart Association functional class III or IV. Congestive heart failure was present in 24 (8.6%). Reparative procedures included posterior collar annuloplasty (n = 242), commissurotomy (n = 187), cusp-level chordal shortening (n = 94), cusp thinning (n = 71), cleft suture (n = 65), and cusp excision or plication (n = 10). Associated procedures included atrial septal defect closure (n = 22), aortic valve repair/replacement (n = 13), and tricuspid valve repair (n = 3). RESULTS: Early mortality was 2.2% (6 patients). Preoperative left ventricular dysfunction was associated with greater mortality. Median follow-up was 56.5 months (mean, 58.9. +/- 32.3 months; range, 5 to 180 months). One hundred seventy-seven survivors (65%) had no or trivial mitral regurgitation. Sixteen patients (6%) required reoperation for valve dysfunction. There were 7 late deaths (2.6%). Actuarial, reoperation-free, and event-free survivals at a median follow-up of 56.5 months were 95.2% +/- 1.5%, 91.6% +/- 2.2%, and 55.9% +/- 3.5%, respectively; at 15 years, they were 95.2% +/- 1.5%, 85.9% +/- 5.9%, and 46.7% +/- 4.7%, respectively. CONCLUSION: Mitral valve repair in children with chronic rheumatic heart disease is feasible and provides acceptable long-term results.     

Triple valve repair for rheumatic heart disease

The onset of the clinical expression of rheumatic heart disease (RHD) is variable. Exercise or other states that necessitate increased cardiac output often precipitate symptoms. Mitral stenosis (MS) is present in 25% of patients with RHD, and 40% of patients have concomitant MS and mitral regurgitation. About two third of patients with MS have concurrent aortic insufficiency. Pulmonary and tricuspid insufficiency may occur from rheumatic involvement of these valves, or secondary to dilatation of valve annuli from pulmonary hypertension secondary to mitral and/or aortic valve disease. Pregnancy is associated with many hemodynamic changes including expanded intravascular volume, tachycardia, increased intracardiac dimensions, and valvular regurgitation. We report a case of a young female who developed flash pulmonary edema during parturition and was found to have abnormal rheumatic involvement of her aortic, mitral, and tricuspid valves. Successful triple valve repair was performed in a single operation. A review of rheumatic valvular abnormalities, and literature supporting multivalvular repair for rheumatic heart disease is provided.     

Heart valve replacement in children

Twenty children with heart valve disease were operated upon and underwent heart valve replacement between 1965 and 1968. Thirteen were girls and seven boys. At the time of operation their ages ranged from 3 to 16 years. All the patients were in classes III or IV prior to operation. Three children suffered from congenital valvular lesions and 17 from rheumatic lesions. In each patient left and/or right heart catheterization and angiographic studies were performed. Six patients underwent aortic valve replacement, 11 mitral, 1 tricuspid, and 2 double valve replacement. Mitral annuloplasty was performed in addition to aortic valve replacement in two patients, and tricuspid annuloplasty in addition to mitral valve replacement in another patient. In 19 patients a prosthetic valve was used and in one an aortic heterograft (pig). Two patients died in the early postoperative period (10%), and two later, two and nine months after surgery (10%). Postoperative thromboembolism occurred in four patients (20%). All have completely recovered. All the surviving 16 patients have been followed for a period of one to four and a half years and all showed significant clinical improvement; all children of school age have returned to school and/or other normal actitivies. The overall result has been encouraging and might justify a more aggressive approach in the management of valvular diseases in this specific group of patients.     

Pediatric valve replacement, 15 years experience in Oman

Background Despite improving surgical techniques, treatment of heart valve disease in children remains controversial. Somatic growth and adequate anticoagulation are of concern when children undergo valve replacement. We conducted this study to evaluate the performance of valves in this age group. Methods 42 children under the age of 13 years who underwent valve replacement were included in this study. Totally, 50 valves were implanted in 42 patients: 48 were mechanical prostheses, two were bioprosthetic both in pulmonary position. 37 (74%) valves were implanted in mitral position, 10 (20%) in aortic position, 1 (2%) in tricuspid position and 2 (4%) in pulmonary position. Preoperatively, 14 (33,3%) patients were in New York Heart Association (NYHA) class IV, while 27 (64.2%) were in NYHA class III. Results There were 2 (4.7%) hospital deaths and 2 (4.7%) late deaths while 2 (4.7%) patients were lost to follow up. The mean follow up period was 9.4 yrs. 35 (83.3%) patients are in NYHA Class I and free of all medications except warfarin. 3 (7.1%) patients have undergone 5 successful pregnancies. The median INR was 2.23. Major thrombo-embolic episode occurred in 1 (2.3%) patient. Conclusions In view of the problems of sizing, anticoagulation and need for re-operation at an early age, there is a reluctance to replace valves in children. This study shows that despite these problems, valve replacement can be undertaken safely and successfully in children, when repair has failed or not technically feasible.     

Valve replacement in children

Between May 1979 and September 1998, 202 children underwent surgical treatment for valvular heart disease. Of these 23, who ranged in age from 25 days to 15 years, underwent valve replacement, including 1 reoperation. The valve replacement consisted of the aortic valve in 5 patients, the mitral valve in 3, the tricuspid valves in 9, including 5 systemic atrioventricular valves for atrioventricular discordance, the pulmonary valve in 6, 5 bioprostheses and 18 mechanical prostheses. There were 4 operative deaths, 1 hospital death and 3 late deaths. At the 10-years follow-up, the actual survival rate was 67.8%, the event free rate was 76.1% and the freedom from reoperation rate was 86.2%. Valve re-replacement was performed in only 1 patient due to a thrombosed tricuspid valve. These results suggest that there is a small risk of major complications and reoperation in children who undergo valve replacement, whether a bioprosthetic valve or a mechanical valve. The long-term results of younger patients should be followed more closely according to their growth.     

Failure of Hancock xenograft valve: importance of valve position (4- to 9-year follow-up)

To evaluate long-term durability of Hancock valves, we reviewed our results in 107 hospital survivors (120 valves) who were operated on during 1974 through mid-1979. Mitral valve replacement was done in 63 patients, aortic valve replacement in 20, and mitral valve replacement combined with other procedures in 24. The 7-year survival was 84 +/- 4% (standard error of the mean) for 91 patients and 97 valves. During a follow-up of 590 patient-years, 15 (12 mitral and 3 aortic) of 120 valves at risk (87 mitral, 32 aortic, 1 tricuspid) were removed from 14 patients. Six valves (3 mitral and 3 aortic) were removed because of bacterial endocarditis. One mitral valve was removed because of thromboembolism. Eight mitral valves were removed because of valve structural failure, which occurred at a mean follow-up of 42 months. These valves showed extensive calcification, leaflet perforation, or cusp tear. Structural failure was unrelated to valve size, year of implantation, or valve shelf-life. Structural failure was not seen after aortic valve replacement. Results show that structural failure of the Hancock xenograft valve in the mitral position is related primarily to valve position. After aortic valve replacement, valve failure is predominantly due to endocarditis. Although medium-term (mean, 6-year) durability of this xenograft valve compares satisfactorily with prosthetic valves, its high failure rate in the mitral position indicates the necessity for improvement in valve mounting, design, and preservation.