Patch Enlargement of the Aortic and the Mitral Valve Rings with Aortic-Mitral Double-Valve Replacement

In 1 patient, patch enlargement of the aortic valve ring was accomplished by extending the aortic incision into the anterior mitral leaflet. The pericardial patch broke from the aortic leaflet of the mitral valve on the fourth postoperative day. The resultant acute mitral incompetence necessitated mitral valve replacement also. An aortic-mitral double-valve replacement with attendent enlargement of both the aortic and mitral valve rings ensued. To our knowledge, enlargement of the aortic and mitral valve rings with aortic-mitral double-valve replacement has not been described in the literature.     

Patch enlargement of the aortic valve ring by extending the aortic incision into the anterior mitral leaflet. New operative technique.

This communication describes a new surgical procedure of enlarging the narrow aortic valve ring by extending the aortic incision through the fibrous origin of the aortic leaflet of the mitral valve into this leaflet. A fusiform patch is sutured to the V-shaped defect in the aortic leaflet of the mitral valve and in the aortic anulus. This procedure permits the replacement of the aortic valve by a suitable prosthesis. Between June of 1976 and February of 1978, eight patients underwent this surgical procedure. At the time of operation the patients were between 8 and 50 years old. The estimated enlargement of the aortic root ranged from 10 to 25 mm. The operative technique is described, peculiarities of this method are discussed, and the results are reported. Six to 27 months following operation, the clinical condition of six patients is good. Four patients show no impairment of mitral valve function. In one case, preoperatively diagnosed mitral incompetence persists. In another patient the pericardial patch broke from the aortic leaflet of the mitral valve, so that the valve had to be replaced on the fourth postoperative day. One patient died of myocardial necrosis because of insufficient myocardial protection during operation. One child with acute aortic insufficiency caused by staphylococcal endocarditis and congestive heart failure died of septicemia 3 months postoperatively. Mitral incompetence was not detectable in this child.     

Mitral Stenosis in Association with Aortic Valvular Disease

In a series of 47 consecutive patients with pure mitral stenosis in association with aortic valvular disease, 25 patients underwent closed mitral commissurotomy in addition to aortic valve replacement, whereas combined aortic and mitral valve replacement was performed in 22 patients. The pathology of the stenosed mitral valve and resultant left atrial stasis were more pronounced in the latter group. Valve replacements were performed under generalized hypothermia to 30°C and selective coronary artery perfusion. The advantages and disadvantages of commissurotomy in comparison with mitral valve replacement were evaluated. Commissurotomy with aortic valve replacement involved a markedly higher mortality rate, which was closely related to early and late complications from the closed mitral commissurotomy per se. The reduced risk of thrombo-embolism following preservation instead of replacement of the mitral valve hardly outweighs this excessive mortality. The late haemodynamic improvements, although slight, were definite and similar in the two groups of patients. Diminished pressure levels in the left atrium and pulmonary artery were observed both at rest and during exercise in all the 19 patients who underwent recatheterization. Three patients showed signs of slight mitral restenosis (or residual stenosis), while another required mitral valve replacement due to mitral restenosis with incompetence. Commissurotomy remains clearly indicated if the commissures split up completely and the valve leaflets, chordae tendineae and papillary muscles are in unquestionably good condition. Unfortunately, this type of mitral stenosis, particularly in association with aortic valvular disease, is seldom encountered in Sweden nowadays. Mitral valve replacement seems to be mandatory when surgery is performed for restenosis and if uncertainty exists about the immediate result of commissurotomy.     

重症心脏瓣膜病的外科治疗

目的总结重症心脏瓣膜病的外科治疗结果,探讨提高早期生存率的措施。方法自2000年6月至2005年7月,对78例重症心脏瓣膜病患者施行瓣膜替换术。其中单纯二尖瓣置换12例,二尖瓣置换 三尖瓣成形22例,单纯主动脉瓣置换8例,二尖瓣 主动脉瓣置换 三尖瓣成形35例,二尖瓣置换 冠状动脉旁路移植术1例。结果死亡6例,其中术后并发低心排血量5例,心室颤动治疗无效死亡1例,死亡率7.69%。随访53例,平均随访2.5年,死亡5例。结论对重症心脏瓣膜病患者,注重改善术前心功能,掌握手术时机,尽量保留瓣下组织,选择合适瓣膜,重视围手术期处理,可提高手术成功率。     

Double valve replacement for acute spontaneous left chordal rupture secondary to chronic aortic incompetence

A 54 years old male with undiagnosed chronic calcific degenerative aortic valve incompetence presented with acute left anterior chordae tendinae rupture resulting in severe left heart failure and cardiogenic shock. He was successfully treated with emergency double valve replacement using mechanical valves. The pathogenesis of acute rupture of the anterior chordae tendinae, without any evidence of infective endocarditis or ischemic heart disease seems to have been attrition of the subvalvular mitral apparatus by the chronic regurgitant jet of aortic incompetence with chronic volume overload. We review the literature with specific focus on the occurrence of this unusual event.     

Heart valve replacement with the Sorin tilting-disc prosthesis. A 10-year experience.

From 1978 to 1988, 697 patients with a mean age of 48 +/- 11 years (range 5 to 75 years) received a Sorin tilting-disc prosthesis; 358 had had aortic valve replacement, 247 mitral valve replacement, and 92 mitral and aortic valve replacement. Operative mortality rates were 7.8%, 11.3%, and 10.8%, respectively, in the three groups. Cumulative duration of follow-up is 1650 patient-years for aortic valve replacement (maximum follow-up 11.4 years), 963 patient-years for mitral valve replacement (maximum follow-up 9.9 years) and 328 patient-years for mitral and aortic valve replacement (maximum follow-up 9.4 years). Actuarial survival at 9 years is 72% +/- 4% after mitral valve replacement, 70% +/- 3% after aortic valve replacement, and 50% +/- 12% after mitral and aortic valve replacement, and actuarial freedom from valve-related deaths is 97% +/- 2% after mitral valve replacement, 92% +/- 2% after aortic valve replacement, and 62% +/- 15% after mitral and aortic valve replacement. Thromboembolic events occurred in 21 patients with aortic valve replacement (1.3% +/- 0.2%/pt-yr), in 12 with mitral valve replacement (1.2% +/- 0.3% pt-yr), and in seven with mitral and aortic valve replacement (2.1% +/- 0.8%), with one case of prosthetic thrombosis in each group; actuarial freedom from thromboembolism at 9 years is 92% +/- 3% after mitral valve replacement, 91% +/- 3% after aortic valve replacement, and 74% +/- 16% after mitral and aortic valve replacement. Anticoagulant-related hemorrhage was observed in 15 patients after aortic valve replacement (0.9% +/- 0.2%/pt-yr), in 9 after mitral valve replacement (0.9% +/- 0.3%/pt-yr), and in 6 with mitral and aortic valve replacement (0.9% +/- 0.5%/pt-yr); actuarial freedom from this complication at 9 years is 94% +/- 2% after aortic valve replacement, 91% +/- 4% after mitral valve replacement, and 68% +/- 16% after mitral and aortic valve replacement. Actuarial freedom from reoperation at 9 years is 97% +/- 2% after mitral and aortic valve replacement, 92% +/- 4% after mitral valve replacement, and 89% +/- 3% after aortic valve replacement, with no cases of mechanical fracture. The Sorin valve has shown a satisfactory long-term overall performance, comparable with other mechanical prostheses, and an excellent durability that renders it a reliable heart valve substitute for the mitral and aortic positions.     

Creation of an atrial septal defect for acute postperfusion right ventricular failure

Acute postperfusion right ventricular failure following mitral and aortic valve replacement in a patient with severe double-valve incompetence secondary to endocarditis is presented. The situation was reversed by creating an atrial septal defect that decompressed the right ventricle and increased left ventricular filling pressure.     

Use of the Carpentier-Edwards porcine bioprosthesis: assessment of a patient selection policy.

The Carpentier-Edwards bioprosthesis was implanted in 369 patients (414 valves) between May 1977 and December 1987 (age 67.2 +/- 0.5 years); 242 had aortic valve replacement, 80 had mitral valve replacement, 44 had multiple valve replacement, of which 41 were aortic and mitral valve replacement, 2 had isolated tricuspid valve replacement, and 1 had a pulmonary valve replacement. The selection criteria were the following: shorter life expectancy (253 patients) or contraindications to anticoagulants for organic (113 patients) or psychologic (38 patients) reasons, or both. The early mortality rate was 11.1% (aortic valve replacement, 9.1%; mitral valve replacement, 12.4%; aortic and mitral valve replacement, 23.1%). Total cumulative follow-up was 1456 pt-yr (mean 4.4 years, range 1 to 148 months), and the patient evaluation was 99.5% complete. Late mortality was 4.9%/pt-yr. Five-year survival was 70.4% +/- 2.7% overall, 74.3% +/- 3.2% after aortic valve replacement, 60.9% +/- 6.2% after mitral valve replacement (p < 0.03), and 60.7% +/- 8.1% after aortic and mitral valve replacement. Eight patients were reoperated on for primary tissue failure, and freedom from reoperation for structural valve deterioration was 97.5% +/- 1.2% at 5 years and 95.6% +/- 1.8% at 8 years. Failing aortic bioprostheses were explanted in four patients (0.4%/pt-yr) and mitral bioprostheses in seven (1.6%/pt-yr). No patient whose valve was inserted after the age of 70 had to be reoperated on for structural valve dysfunction. The probability of freedom from thromboembolism after 5 and 8 years of follow-up was 93.1% +/- 1.6% and 92.2% +/- 1.8%, respectively. The prevalence of anticoagulant-related hemorrhage was 0.8%/pt-yr (major 0.6%, minor 0.2%). Anticoagulants had to be maintained in 16.3% of the patients: 5.9% after aortic valve replacement, 35.7% after mitral valve replacement, and 45.8% after aortic and mitral valve replacement, while 80.0% were on a regimen of antiplatelet drug therapy. Prosthetic valve endocarditis happened in five patients (0.3%/pt-yr). Freedom from all valve-related morbidity and mortality, including hospital deaths, was 71.0% +/- 2.7% at 5 years and 58.6% +/- 4.6% at 8 years and was significantly better in the aortic valve replacement group (61.3% +/- 6.6% at 8 years) compared with the mitral valve replacement group (54.4% +/- 7.7% at 8 years; p = 0.04). This study confirms the satisfactory performance of the Carpentier-Edwards valve after aortic valve replacement in elderly patients.(ABSTRACT TRUNCATED AT 400 WORDS)     

Combined valve replacement and myocardial revascularization

Combining valve replacement with coronary artery bypass (CABG) for significant concomitant disease remains a controversial subject. To determine the operative results following combined valve replacement and CABG, we evaluated 201 patients seen consecutively between July 1977 and June 1982. CABG for vessels with greater than 70% stenosis was performed with aortic valve replacement in 106 patients, with mitral valve replacement in 82, and with aortic and mitral valve replacement in 13. There were 143 men and 58 women; the mean age was 67 years. Nine operative deaths (8.5%) occurred with aortic valve replacement and CABG: 5 of 25 (20%) when cardioplegia was not used and 4 of 81 (4.9%) with cardioplegia (p less than 0.01). The operative mortality rate for isolated aortic valve replacement without coronary disease during the same period was 5.9% (10 of 168). The late actuarial survival rate is similar for aortic valve replacement alone or aortic valve replacement and CABG. There were no operative deaths among patients having undergone aortic and mitral valve replacement and CABG; the rate was 15% (9 of 60) in patients having undergone aortic and mitral replacement and CABG. The operative mortality rate was 21.9% for mitral valve replacement and CABG (18 of 82). Rheumatic disease was present in 14 of these patients, two of whom had early deaths (14.3%), both after repeat mitral operations; 11 mitral valve replacements and CABG were done for degenerative mitral regurgitation with no deaths, and the remaining 57 patients had ischemic mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)     

What are the limits for the Ross operation?

The Ross operation is physiologically the best approach for aortic valve replacement. At the Hospital de Santa Cruz 22 consecutive pulmonary autograft operations have been performed in patients with a mean age of 49 (range 17–65) years. Six patients had mitral valve disease, two had aortic aneurysms and one had a ventricular septal defect. Subcoronary implantation of the autograft was performed in 20 patients. A partial inclusion aortic root replacement technique was used in one and the aortic root was replaced in another. There were no hospital or late deaths. Two patients required autograft replacement at 3 and 9 months postoperatively because of regurgitation. One of these cases was caused by an abnormality of the pulmonary valve and since then echocardiographic assessments of this valve have been performed routinely and have detected significant pulmonary incompetence in four patients who otherwise would have been operated on using the Ross procedure. Copyright 2 1996 The International Society for Cardiovascular Surgery.     

Current surgical treatment for acquired valvular heart disease

We discuss the current status of surgical treatment for acquired valvular heart disease. Mitral valve repair for organic and functional mitral regurgitation is the first choice instead of valve replacement. It is important that surgery for functional mitral regurgitation restores the geometry of the left ventricle and mitral valve. The reduction of mitral valve tethering for functional mitral regurgitation is a current topic of discussion. At present, the surgical procedure for both aortic stenosis and aortic regurgitation is valve replacement in most cases, although aortic valve repair has been attempted for aortic regurgitation in recent years. The early results of aortic valve repair are excellent, but the long-term results have not been clarified. The durability of valve repair in both the mitral and aortic position is a future issue and it may be improved by revising the indications for valve repair and using new surgical techniques.     

Replacement of ascending aorta with aortic valve reimplantation: midterm results

Objective: Aneurysms of the aortic root lead to aortic valve incompetence due to dilatation of the sinotubular junction and annuloaortic ectasia. Reimplantation of the native, structurally intact aortic valve within a Dacron tube graft corrects annular ectasia as well as dilatation of sinotubular junction and aortic sinuses. Durability of this valve repair with respect to increased mechanical stress on valve cusps is discussed controversially and is yet unknown. Methods: Since 7/93, replacement of the ascending aorta with repair of the aortic valve was performed in 48 patients (34 male, 14 female; 47±20 years) with aortic insufficiency and aneurysm of the aortic root. Fifteen patients (31%) had Marfan's syndrome and five patients (10%) had an aortic dissection type A (two acute, three chronic). In 11 patients (23%), concomitant replacement of the aortic arch was necessary utilizing elephant trunk technique in two patients. Additionally, one patient required mitral valve repair and two other patients coronary artery bypass grafts. Clinical and echocardiographic follow-up was performed in 6–12 month intervals for a cumulative study period of 100 patient years. Results: There were no operative deaths. Two patients (4%) died 5 and 20 months postoperatively. One additional patient experienced a TIA within the first postoperative week. Three patients (6%) with an early postoperative aortic insufficiency (AI)>1 required aortic valve replacement after 9, 11, and 14 months due to progressive AI. In these patients, distortion of the aortic root geometry led to valve incompetence. All other patients have no or mild aortic insufficiency. The repair now remains stable for up to 63 months (mean 25±18 months). Other valve related complications did not occur. Conclusions: Our results demonstrate that this type of aortic valve repair achieves excellent results in selected patients. Perfect coaptation of valve cusps during the repair with no or only trace AI at initial echocardiography seems to be essential for durability.     

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.     

Mitral valve replacement with aortic heterografts in humans

The complications associated with the implantation of prosthetic valves and the experimental attempts to graft the mitral valve are described. Because of the disadvantages connected with the use of artificial valves and as the experimental methods of grafting the mitral valve did not prove satisfactory for clinical use, the authors developed a technique for mitral valve replacement using heterologous aortic valves—reinforced by a semirigid Teflon ring—placed above the mitral annulus inside the atrial cavity. The technique of collecting, preparing, and inserting these grafts is described in detail. Using this method, seven patients with mitral incompetence or mitral disease were operated upon between February and April, 1967. One patient died five weeks after the operation from bacterial endocarditis in a period of severe hospital infection with staphylococcus. The other six patients had a very good clinical result immediately after surgery. At the present time they are symptom-free and have normal heart sounds. Clinical and experimental data are discussed concerning the long-term fate of aortic heterografts in the mitral position.     

Ten years' experience in heart valve replacement with artificial prostheses: immediate and long-term results in 1812 cases.

A ten year follow up of 1,812 patients who underwent heart valve replacement with artificial prothesis between October 1963 and December 1973 is reported. Hospital mortality was 8.5% for aortic valve replacement; 13.6% for mitral valve replacement and 19.3% for multiple valve replacement. Late mortality was 13.3% for aortic valve replacement; 25.7% for mitral valve replacement and 25.9% for multiple valve replacement. The survival rate of the different groups of patients were actuarially determined. The survival rates following replacement of the aortic valves was 81% after 9 years. The main late complications are embolism and valve leakage. All surviving patients show a clinical improvement, particularly in the groups of isolated aortic a mitral valve replacement. The heart size reduction after operation has been measured. This is more evident 6 months after surgery: the average reduction was 23% after aortic valve replacement and 20% after mitral valve replacement.     

Cardiac Valve Replacement with Heterologous Aortic Valves1

Eighty-six formalin-prepared heterologous aortic valves have been used to replace the human aortic valve over a three-year period, with encouraging clanical resuts. In a more recent ten-month pertoct, similarly prepared valves mounted in a suitable frame have been usea as a mitral valve prosthesis tn 11 patients without any operative mortality. Clinical and hæmodynamic follow-up has shown excellent long-term function in the aortic valve replacement group, although one-third of patients have developed some evidence of valve incompetence. Only four patients have had severe incompetence, and in two this was shown to be due to dehiscence of the implanted valve from the host tissues and related to late infection. Pathological studies have shown no evidence of degenerative changes in the valves after implantation, the coliagen and elastic tissue remaining histologically near normal.     

The Carpentier-Edwards standard porcine bioprosthesis. A first-generation tissue valve with excellent long-term clinical performance

The Carpentier-Edwards standard porcine bioprosthesis was implanted in 1190 patients (1201 operations, 1303 valves) between January 1975 and June 1986; most implants were before 1982. The mean age of the patients was 57.2 years (range 8 to 85 years). The early mortality was 7.6% (aortic valve replacement 5.1%, mitral valve replacement 8.8%, and multiple valve replacement 15.3%). Late mortality was 3.9% per patient-year (aortic valve replacement 3.6%, mitral valve replacement 4.2%, and multiple valve replacement 3.8%). The total cumulative follow-up period was 6737 years. Thromboembolism was 1.5% per patient-year (fatal 0.4% per patient-year) (minor 0.6%, major 0.9%); antithromboembolic therapy-related hemorrhage was 0.5% (fatal 0.1%); prosthetic valve endocarditis was 0.6% (fatal 0.2%); nonstructural dysfunction was 0.5% (fatal 0.2%); and structural valve deterioration and/or primary tissue failure was 1.5% per patient-year (fatal, 0.2% per patient-year). Thromboembolism and structural valve deterioration were the significant complications, structural valve deterioration occurring primarily between the sixth and 10th year of evaluation. The overall patient survival was 65.0% for aortic valve replacement and 54.8% for mitral valve replacement (p less than 0.05) at 10 years. The patients were classified as 92.9% New York Heart Association functional classes III and IV preoperatively and 92.3% classes I and II postoperatively. Freedom at 10 years from thromboembolism was 84.3% for aortic valve replacement and 76.5% for mitral valve replacement (p = 0.05); structural valve deterioration was 78.6% for aortic valve replacement and 71.6% for mitral valve replacement (p less than 0.05); reoperation was 74.4% for aortic valve replacement and 67.1% for mitral valve replacement (p less than 0.05). Freedom from all valve-related complications at 10 years was 58.9% for aortic valve replacement and 46.8% for mitral valve replacement (p less than 0.05); valve-related mortality was 89.5% for aortic valve replacement and 82.6% for mitral valve replacement (p = not significant); mortality and reoperation was 58.9% for aortic valve replacement and 46.8% for mitral valve replacement (p less than 0.05); mortality and residual morbidity (treatment failure) was 87.2% for aortic valve replacement and 75.1% for mitral valve replacement (p = not significant); mortality, residual morbidity, and reoperation were 66.3% for aortic valve replacement and 54.9% for mitral valve replacement (p less than 0.05). The standard Carpentier-Edwards porcine bioprosthesis has provided satisfactory clinical performance and has afforded patients excellent quality of life.     

Reduction in left ventricular volume following aortic valve replacement does not predict improved ventricular function

Background  Aortic valve replacement in rheumatic disease is one of the procedures that clearly prolonged the life expectancy of adult patients. Our study objectives are to assess the mortality and morbidity associated with aortic valve replacement, and study the effects of successful, valve replacement on ventricular volume and performance in aortic stenosis and in aortic incompetence. Methods  Between January 1997 and December 2001, 148 patients underwent aortic valve replacement at our institution. The records of these patients were evaluated retrospectively. A total of 136 survivors were followed up both actively and passively. Results  There were 9 deaths (6.07%) with an early mortality at 30 days of 4.05% and valve related mortality of 4.05%. Bleeding events and operated valve endocarditis occurred infrequently (0.03% and 0.04% / patient year). 2 patients had nonstructural valve dysfunction (paravalvular leak) (0.02% / patient year). Following successful valve replacement, ventricular volume decreased substantially, while there was no significant increase in ventricular performance in aortic stenosis, and aortic incompetence. Conclusion  Aortic valve replacement can be performed today with a low mortality and morbidity. Although the ventricular volume and cardiac size reduced substantially following valve replacement, the ventricular performance remained unchanged in aortic stenosis, and aortic incompetence because of the impaired ventricular function pre-operatively and because the ejection fraction tends to over estimate contractile function in aortic regurgitation. Low preoperative ejection fraction is therefore an important risk factor for postoperative left ventricular dysfunction.     

Conservative surgery for mitral valve disease: clinical and echocardiographic analysis of results

Eighty-five patients underwent mitral valve reconstruction by the Carpentier method from January 1976 to December 1981. Concomitant procedures were performed in 30 patients (aortic valve replacement in 23, coronary revascularisation in six, and tricuspid valve repair in seven). Before operation 76 patients (89%) were in clinical class II or III (New York Heart Association) and atrial fibrillation was present in 50. Thirty-six patients had valvular incompetence, while 26 had pure stenosis. The aetiology was rheumatic in 57 cases and dysplastic in 21. The patients were assessed for clinical improvement, durability of valve repair, thromboembolism, and survival. There was one death, an operative mortality rate of 1.2%, and 63 of 74 patients followed for one to six years were in clinical class I after operation. The actuarial survival was 92% with a 93% incidence of freedom from thromboemboli at five years. Six patients had embolic episodes, four of whom had aortic valve replacement. Three patients had a repeat operation 16-20 months later, a valve failure rate of 6.7%. Nineteen patients with ruptured chordae had postoperative echocardiographic assessment of myocardial and mitral valve functions; the peak rates of dimension changes of the left ventricular cavity (indicative of flow across the mitral valve) fell to normal in most patients, and the left ventricular end-diastolic dimensions decreased significantly from 6.4 (1.53) to 5.09 (1.31) cm (mean and SD)--p less than 0.05. Our results confirm that reconstructive mitral surgery is able to restore and maintain normal valve function in addition to providing satisfactory relief of symptoms.     

The Hancock pericardial xenograft: incidence of early mechanical failures at a medium-term follow-up

The Hancock pericardial xenograft has been used in our Institution since August 1981 as an alternative to porcine bioprostheses. Up to July 1984, 97 Hancock pericardial xenografts have been implanted in 84 patients; of 76 operative survivors with a mean age of 55.2±13 years (range 13–75 years), 50 had undergone aortic valve replacement, 16 mitral valve replacement and 10 mitral-aortic valve replacement. Follow-up ranged from 0.5 to 5.2 years with a cumulative duration of 239 patient/years and is 99% complete. Actuarial survival is 92%±4% for patients with aortic valve replacement and 84%±10% for patients with mitral valve replacement at 5 years, and 77%±14% for those with mitral-aortic valve replacement at 4 years. Thromboembolic episodes occurred in 2 patients (1 after aortic and 1 after mitral valve replacement). The actuarial freedom from emboli is 100% for patients with mitral-aortic valve replacement at 4 years, and 96%±3% for patients with aortic and 93%±6% for patients with mitral valve replacement at 5 years. Reoperation was performed in 13 patients (9 aortic, 2 mitral and 2 mitral-aortic valve replacements), because of endocarditis in 3 (2 aortic and 1 mitral valve replacement), paravalvular leak in 1 (aortic valve replacement), and primary tissue failure in 9 (6 aortic, 1 mitral and 2 mitral-aortic valve replacements). Actuarial freedom from primary tissue failure is 72%±9% for aortic and 83%±8% for mitral Hancock pericardial xenografts at 5 years. Eleven xenografts explanted because of primary tissue failure were studied pathologically. All showed commissural tears with gross regurgitation; calcium deposits were severe in 2, mild but unrelated to the tears in 2 and absent in 7. Collagen disarray was observed at the site of cusp rupture while the collagen was well preserved in the intact areas of the leaflets. Our results show that: 1) Hancock pericardial xenografts have a high rate of early primary tissue failure, 2) primary tissue failure is caused by cusp rupture at the commissures and can be considered fatigue-induced, 3) tissue calcification does not influence the durability of pericardial xenografts which do not represent a valid alternative to porcine bioprostheses.