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PubMed1998

[Late-occurrence hemolytic anemia after mitral valve bioprosthesis. 2 cases].

The authors report the cases of two patients admitted to hospital for investigation of haemolytic anaemia. Both had undergone, 10 and 12 years previously, mitral valve replacement with a Ionescu-Shiley bioprosthesis. In both cases, in the absence of signs of cardiac failure, Doppler echocardiography showed mitral regurgitation. The association of haemolytic anaemia and dysfunction of the bioprosthesis led to redux valve replacement and correction of the anaemia. Haemolytic anaemia was the presenting sign of bioprosthetic valve dysfunction requiring replacement of the prosthesis. This complication is common with mechanical valve prostheses but much more rare in bioprosthetic valves.

Aged↗
PubMed2002

Clinical experience with Sorin Bicarbon valve in patients with tight mitral valve stenosis and elevated pulmonary hypertension (early and mid-term results).

BACKGROUND: The results of mitral valve replacement (MVR) with Sorin mechanical valves in patients who had tight mitral stenosis with high pulmonary artery pressure were reviewed. METHODS: During a period of two years, from August 1998 to May 2000, a mitral valve replacement with a Sorin Bicarbon mechanical valve was performed in 51 patients with a diagnosis of tight mitral stenosis associated with severe pulmonary hypertension (preoperative mean systolic pulmonary artery pressure was 72+/-12 mmHg, range from 60 to 105 mmHg). There were 37 women and 14 men; mean age was 47.2+/-12 years. Forty-eight patients (94.12%) were in NYHA functional class III or IV. All the patients discharged from the hospital were submitted to a clinical follow-up program. A 100% follow-up was obtained with a mean of 12.6+/-6.4 months (range 2 to25 months). RESULTS: Operative mortality was 3.9%, 2 patients who had concomitant CABG died due to low cardiac output. Twelve patients (23.5%) needed an inotropic pharmacological support during the postoperative time. In one patient a re-exploration for bleeding was necessary, and in another one a cerebrovascular accident occurred 3 days after the operation. After 6 months, one patient was reoperated on because of mechanical valve dysfunction due to pannus formation. All survivors underwent a postoperative echocardiographic assessment. The systolic PAP decreased from a mean preoperative value of 72+/-12 mmHg to 39.9+/-12 mmHg. NYHA functional status significantly improved and 86% of the patients were in NYHA functional class I or II. CONCLUSIONS: The mitral valve replacement with Bicarbon mechanical valve prosthesis shows excellent results in patients with mitral valve stenosis associated with a severe pulmonary hypertension.

Female↗
PubMed2002

A temporarily stented, autologous pericardial aortic valve prosthesis.

BACKGROUND AND AIM OF THE STUDY: A new bioprosthesis has been developed that is: (i) constructed from glutaraldehyde-treated autologous pericardium due to its lack of antigenicity and low cost; (ii) easily constructed in the operating room; (iii) stentless but easy to implant by using a temporary stent that is removed once its function is no longer necessary; and (iv) implanted with a single proximal suture and three commissural stitches. METHODS: This prosthesis was implanted in the subcoronary aortic position of six sheep. The mean prosthesis size was 19.7 +/- 3.5 mm, and manufacturing time 16 +/- 3 min. Cardiopulmonary bypass and cross-clamp times were 142.5 +/- 26.7 min and 100.2 +/- 28.8 min, respectively. Three sheep were euthanized at three, seven, or 27 days, and the remainder at five months postoperatively. RESULTS: In all cases the valve was competent and the single commissural stitches were well-anchored. The pericardium was pliable in all cases, but one animal had obvious endocarditis (at 27 days). Small calcific nodules were found at the commissures in valves explanted at five months. Histology showed an intact collagen and elastin structure, and neointimal growth was seen covering the basal quarter of the leaflets and commissures. CONCLUSION: This new bioprosthesis might offer a particularly attractive alternative for the young patient population of the developing world. The simplicity of construction, low cost, and absence of any need for anticoagulation makes this prosthesis close to the ideal aortic valve substitute.

Animals↗
PubMed2006

[Long-term results of conventional aortic valve replacement for small aortic annulus].

We studied cardiac function, clinical outcome and quality of life (QOL) long after aortic valve replacement for pure aortic stenosis. Forty-four patients in small group [St. Jude Medical (SJM) 17 HP, 19 A], and 69 patients in non-small group (19 HP, 21 A, 23 A) operated on from 1984 to 2004 were enrolled in this study. We assessed the clinical data, aortic pressure gradient, left ventricular mass index (LVMI), and ejection fraction (EF) by preoperative and postoperative echocardiography. Moreover to evaluate QOL after the operation, we performed SF-36 used for the evaluation of health and QOL worldwide. Mean follow-up is 7.1 +/- 4.8 years in small group, and 6.8 +/- 4.6 years in non-small group. There were 2 hospital deaths in small group, and 1 in non-small group. The actual survival rate at 10-year were 89.2% in small group, and 85.6% in non-small group. There was no significant difference in hospital mortality, LVMI, long-term survival rate, and the scores of SF-36 between the 2 groups. The use of small sized prosthetic valves in patients with small aortic annulus might be justified when there is no patient-prosthesis mismatch.

Aged↗
PubMed2005

Long-term outcomes of tricuspid valve replacement in the current era.

BACKGROUND: Regardless of the indication, tricuspid valve replacement (TVR) has historically been associated with high mortality and morbidity. We report the results of our experience in a high-risk patient population with an emphasis on operative mortality, long-term survival, and valve related events according to the type of prosthesis. METHODS: Between 1985 and 1999 TVR was performed in 81 patients (isolated n = 25, combined with valve surgery n = 44, combined with CABG or other n = 12). The mean age was 61 years old (range 19-83 years old). Risk factors included New York Heart Association functional class III/IV (n = 73, 90%), reoperation (n = 58, 72%), urgent/emergent indication (n = 62, 76%), and hepatic dysfunction (n = 13, 16%). Mean pulmonary artery pressure was 34 mmHg. Etiology of tricuspid regurgitation was classified as functional (n = 18, 22%) or organic (n = 52, 64%), or failed previous tricuspid valve surgery (n = 11, 14%). RESULTS: Tricuspid valve replacement was performed with either a bioprosthetic (n = 34, 42%) or mechanical valve (n = 47, 58%). The overall operative mortality was 22% (n = 18). Risk factors for mortality included urgent/emergent status, age greater than 50 years old, functional etiology, and elevated pulmonary artery pressure. Of the 60 survivors, 26 (43%) died during follow up. After univariate analysis, organic etiology was the only predictor of late death (p = 0.01). Kaplan-Meier survival at 2.5, 5, and 10 years was 80%, 60%, and 45% for bioprosthetic, and 84%, 69%, and 59% for mechanical valves, respectively. CONCLUSIONS: Patients requiring TVR are typically high-risk with a high-percentage of reoperations, concomitant cardiac procedures, and end-stage functional class. Operative and overall mortality remains high. Heart failure was the predominant cause of early and late deaths, emphasizing importance of timely referral before the development of end-stage cardiac impairment.

Adult↗
PubMed2004

The mitral pulmonary autograft: assessment at midterm.

BACKGROUND: There is a dire need, especially in emergent societies, for a mitral substitute that does not require anticoagulation, and is not affected by early degeneration. METHODS: Between 1997 and 2003, 80 patients had successful mitral valve replacement with a pulmonary autograft. Fifty-five patients were female, and the mean age was 39.3 years. Seventy-eight patients had rheumatic mitral disease and 2 congenital. The autograft was placed inside a rigid Dacron tubing for support, and the right ventricular outflow was reconstructed with a xenograft or a homograft. Recently we have used microwave energy to ablate atrial fibrillation when present. RESULTS: Intraoperative transesophageal echocardiography revealed adequate mitral valve areas (mean area 2.76 cm2) and acceptable mitral gradients (mean 4.3 mm Hg) in all 80 patients. There was no mitral regurgitation or trace amounts in 61 patients, and mild regurgitation in 19. Operative mortality was 5.0%, and late mortality clearly related to the procedure 6.25%. Follow-up was complete except for 2 lost patients, with a mean of 25 months, and echocardiographic findings were generally stable during follow-up. One patient developed uncritical mitral stenosis and another uncritical stenosis and insufficiency during 4 to 5.5 years. Four more patients had progression of mitral regurgitation from "mild" to "moderate" over a period from 8 months to 3 years. Uncritical xenograft pulmonic stenosis developed in 2 patients. Most of the surviving patients (83%) remain in class I status. CONCLUSIONS: We believe the pulmonary autograft is a good mitral substitute at the disposal of cardiac surgeons, especially when patients are young and when life anticoagulation is contraindicated or impractical.

Adolescent↗
PubMedDate not supplied

Acute mechanical valve thrombosis of the St. Jude medical prosthesis.

From 1986 to 1996, 2585 patients underwent valve replacement with the St. Jude medical prosthesis. Sixty experienced mechanical valve thrombosis. Seventeen of 60 patients (28.3%) had isolated aortic valve replacements, 33 had isolated mitral valve replacements (55%), and 10 had double valve replacements (16.7%) (aortic and mitral valve replacement). All patients who underwent reoperation for mechanical valve thrombosis were functional Class III or IV. Against medical advice, systemic anticoagulation with warfarin sodium had been discontinued or used only intermittently. Thus, anticoagulant activity was not adequate. The diagnosis of thrombosis was made by clinical examination, laboratory findings, and echocardiography and cineradiography. Of the 60 patients, 9 patients died early after surgery or before discharge. Most of the deaths were attributed to low cardiac output. The overall hospital mortality was 15%. The overall 10-year actuarial survival rate was 82.8+/-1.6%. In our study, reoperation for thrombosed mechanical prosthesis was not an independent parameter determining mortality. Age was the only statistically important hospital mortality predictor. Of this group, 90% suffered mechanical valve obstruction within the first 5 years after operation. These results suggest that valve re-replacement appears to be a suitable surgical treatment for thrombosis of mechanical prosthetic valves, especially in the young. In these patients subsequent anticoagulation management is necessary.

Adolescent↗
PubMed2005

[Surgical treatment of aortic stenosis: which prosthesis for which patient?].

The long-term evolution following aortic valve replacement depends on the specific clinical context for each patient, but also on the type of prosthesis used. The increased hemorrhagic risk with mechanical prosthesis has to be weighed against the long-term risk of structural failure of bioprostheses. The patient's age will be a key determinant in the choice of the best suited prosthesis. Usually, bioprostheses are preferred after 70 years of age, while mechanical prostheses are chosen in patients under 65.

Age Factors↗
PubMed2003

Unexpected durability of Smeloff-Cutter aortic ball valve prosthesis.

We report a case in which replacement of a Smeloff-Cutter aortic ball prosthesis was required 28 years after initial implantation. A 57-year-old woman underwent aortic valve replacement with a 21-mm Smeloff-Cutter ball prosthesis and open mitral commissurotomy for aortic stenosis, aortic regurgitation, and mitral stenosis in 1973. Severe aortic regurgitation occurred in April 2001, and aortic valve reoperation combined with mitral valve replacement was successfully performed. The patient's aortic ball valve was nearly intact with perivalvular leakage probably causing the aortic regurgitation. Our experience documents longer durability for the Smeloff-Cutter prosthesis than has been reported to date.

Aortic Valve↗
PubMed1998

Discrepancies between sizer and valve dimensions: implications for small aortic root.

BACKGROUND: Precise labeling of sizer and valve diameters is crucial for optimal valve selection especially in the small aortic root. This study examines the accuracy of manufacturers' markings on small aortic prostheses and sizers. METHODS: Sizer and valve dimensions of 22 different mechanical aortic prostheses (19 to 23 mm) were evaluated by caliper micrometer measurements. RESULTS: Nearly all sizers exceeded their marked dimensions by up to 1.0 mm. Measured tissue annulus diameters for 19-mm-labeled valves varied between 18.3 and 19.6 mm, for 21-mm valves from 20.5 to 21.6 mm, and for 23-mm valves from 22.4 to 23.5 mm, respectively. The orifice areas ranged from 1.5 to 2.06 cm2 for 19-mm valves, from 2.0 to 2.55 cm2 for 21-mm valves, and from 2.4 to 3.09 cm2 for 23-mm valves, respectively. CONCLUSIONS: Actual sizer dimensions and tissue annulus diameters of various small mechanical aortic prostheses varied considerably from their marked diameters. These differences should be considered to ensure the optimal prosthesis selection for each patient.

Aortic Valve↗
PubMed2000

Aortic valve replacement with concomitant annular enlargement for small aortic annulus of less than 19 mm.

Three female patients with aortic stenosis associated with a severely small annulus underwent aortic valve replacement. In intraoperative measurements, a 19-mm obtulator could not pass through the aortic annulus in each case. We therefore concluded that it would be difficult to implant an appropriate-sized prosthesis in a routine fashion, so we performed an annular enlargement in a modified Nicks procedure. By using a wide teardrop-shaped patch for enlargement and slightly tilting insertion of a prosthesis, a 21 mm bileaflet mechanical prosthesis could be inserted into the enlarged annulus. Despite being a simpler method than other enlarging procedures, a two- or three-sizes larger prosthesis than the native annulus can be inserted with relative ease. Thus, the use of a 19 mm mechanical prosthesis may be avoidable in most adult cases.

Aged↗
PubMed2003

Does the type of prosthesis influence early left ventricular mass regression after aortic valve replacement? Assessment with magnetic resonance imaging.

BACKGROUND: Debate exists regarding selection of the prosthesis type most likely to maximize early left ventricular (LV) mass regression after aortic valve replacement (AVR) for stenotic valvular disease. The aim of this study was to compare the degree of LV mass regression measured by MRI 6 months after prospectively randomized valve implantation for two biological prostheses, stented and stentless, and for two mechanical valves, tilting disc and bileaflet. METHODS: Thirty-nine consecutive patients with predominant aortic stenosis accepted for elective AVR were studied. Twenty patients requiring a tissue prosthesis were randomly assigned to receive either a Freestyle or Mosaic valve. The remaining 19 patients in whom mechanical prosthesis was indicated were randomly assigned to receive either an Ultracor or an ATS valve. RESULTS: There was no difference in valve size implanted between the compared groups. LV mass measurements were performed with MRI (1.5-T Vision, Siemens, Germany) immediately before and 6 months after surgery. All valve types produced significant postoperative reduction in LV mass compared with preoperative values (P <.01). Percent change in LV mass regression was similar between the two porcine valve types, Mosaic (24.4% +/- 11.1%) and Freestyle (21.1% +/- 16.7%), and between the two mechanical valve designs, Ultracor (19.3% +/- 9.5%) and ATS (26.3% +/- 10.8%), respectively. CONCLUSIONS: Significant LV remodeling occurs early after AVR for aortic stenosis. The degree of regression in LV mass is independent of prosthesis type implanted.

Adult↗
PubMed2003

[Anticoagulation of valvular prostheses].

Prosthetic valve replacement has transformed the outcome of patients with severe or poorly tolerated valvular heart disease. Between the two main families of prostheses, only mechanical prostheses require indefinite anticoagulant therapy to lower the thromboembolic risk. National and international guidelines have been published within the past decade. They have outlined how anticoagulation, essentially oral anticoagulant therapy and transient heparin, should be used. The intensity of anticoagulation depends on the type of prosthesis, its position, the presence of atrial fibrillation and the individual's risk of thromboembolism. Monitoring is based on the INR. Temporary recourse to heparin therapy is necessary for all situations in which the risk of major hemorrhage requires more flexible treatment (postoperative period, extracardiac surgery, stroke, severe hemorrhage) or when warfarin is contraindicated because of its risk of inducing malformation (pregnancy). Low molecular weight heparins are not yet authorized for use in prosthesis bearers. Nonetheless, they are being prescribed by more-and-more teams, seduced by the facility of their use, their more stable action and, usually, no need for biological monitoring. And their use is supported by the most recent guidelines, several favorable publications, and the excellent results obtained with them in treating other thromboembolic pathologies. Indispensable to lower the rate of thromboembolic events, anticoagulant therapy bears a hemorrhagic risk that is higher for prolonged and marked anticoagulation. On the other hand, despite effective anticoagulation, the occurrence of thromboemboli can lead to considering the adjunction, in certain cases, of anti-platelet aggregating agents, particularly favored in North America, and recommended in Europe for patients with a predilection for atheromas.

Adult↗
PubMedDate not supplied

Is aortic valve replacement with bileaflet prostheses still contraindicated in the elderly?

BACKGROUND: Prolonged survival in the Western world has increased the number of elderly patients referred for open-heart surgery during the last decade. Aortic valve disease is the most common heart valve disease in aged patients. Which aortic valve substitute is best employed in the elderly is still a debated matter. The main concern is about the thromboembolic and hemorrhagic risks related to mechanical valves and anticoagulation. OBJECTIVE: The study aimed at reviewing clinical results after isolated aortic valve replacement with bileaflet prostheses in patients over 70 years and at retrospectively comparing them with those of a group of otherwise comparable patients under 50 years of age who underwent isolated aortic valve replacement with a mechanical device. METHODS: The study population included 118 consecutive elderly patients (group A) operated on between January 1988 and January 1999 and 122 young patients (group B) who underwent aortic valve replacement during the same time period. Patients with associated coronary artery disease, mitral stenosis or regurgitation, type A aortic dissection, and infective endocarditis were excluded from the study. Preoperative clinical data, early and late postoperative mortality, all valve-related complications, and all data concerning the anticoagulation status - including the mean international normalized ratio (INR) and the mean time interval between each INR assay - were compared between the two groups. RESULTS: The hospital mortality was significantly lower in group B (2.45%) than in group A (9.3%; p = 0.022). The mean follow-up period was 50.98 +/- 2.23 months. The 12-year actuarial survival was significantly lower (69.6 +/- 0.08%) in group A than in group B (94.4 +/- 0.02%; p < 0.001). No significant difference was found in terms of valve-related and anticoagulation-related complication rates and actuarial freedom as well as mean interval between consecutive INR checks (p = 0.219) and mean INR value (p = 0.914). CONCLUSIONS: Bileaflet prostheses in elderly patients can achieve excellent early and late clinical results, with a low incidence of anticoagulation-related complications and an extremely low risk of a reoperation. Older age can no longer be considered a contraindication to bileaflet prosthesis implantation in the aortic position.

Adult↗
PubMed2005

Technique and outcome of mitral valve replacement in dogs.

Eight dogs with naturally occurring severe mitral regurgitation underwent mitral valve replacement with a mechanical valve prosthesis during cardiopulmonary bypass. Dogs received warfarin orally after surgery to maintain a prothrombin time-based international normalized ratio from 2.5 to 3.5. Seven dogs survived surgery. Left ventricular diastolic volume index decreased significantly from 206 +/- 91 mL/m2 before surgery to 121 +/- 47 mL/m2 after surgery. Left atrium-to-aorta ratio decreased significantly from 2.66 +/- 0.4 before surgery to 1.73 +/- 0.65 after surgery. Left ventricular systolic volume index was not significantly different after surgery (56 +/- 36 mL/m2), compared with before surgery (40 +/- 32 mL/m2). Median survival after surgery was 4.5 months (range, 0.75 months to 5.25 years). Six dogs died of confirmed or suspected thrombosis of the valve prosthesis. Dogs with severe mitral regurgitation tolerated mitral valve replacement well, but a high incidence of prosthetic valve thrombosis limited long-term outcome.

Animals↗
PubMed2003

[Surgical treatment of mitral valve regurgitation: which method for which patient?].

The surgical treatment of mitral regurgitation has been completely revamped in the last years. The development of reproducible and durable plasty techniques has made mitral valve replacement less and less frequent. The virtual disappearance of rheumatic valve disease in developed countries has made degenerative disease the most frequent etiology of mitral insufficiency. Furthermore the outlook of this pathology has been modified by the early surgical treatment. The following article presents the surgical techniques available today and their indications in the different types of mitral insufficiency.

Heart Valve Diseases↗