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PubMed2006

[Evaluation of aortic valve replacement involving small severely calcified aortic annulus in elderly patients].

We performed aortic valve replacement in 24 patients aged over 70 with small calcified valves. The surgical management of such patients remains controversial as the extensive calcification compromises implantation. Hence, we used an ultrasonic debridement instrument to remove calcium and selected a small prosthesis with the largest possible orifice without enlargement of the aortic annulus. Echocardiography showed significant reductions in left ventricular mass index compared with preoperative values. Early and mid-term prognosis has been relatively good.

Aged↗

PubMed2004

Influence of valve prosthesis type on the recovery of ventricular dysfunction and subendocardial ischaemia following valve replacement for aortic stenosis.

BACKGROUND: Long-standing aortic stenosis (AS) causes significant progressive left ventricular (LV) dysfunction and may result in subendocardial ischaemia. Following aortic valve surgery, LV function may improve and this may be accompanied by reversal of ischaemia. There is debate about the differential effects of valve substitutes. METHODS: We studied 33 patients with significant AS and impaired LV systolic function. Patients underwent trans-thoracic Doppler echocardiography and 12-lead electrocardiography pre-operatively, prior to discharge from hospital and at 2.5 (range 1.5-3) years follow-up. RESULTS: Twenty patients received a stentless valve and 13 a stented valve. No patient had significant aortic regurgitation, other valvular disease or coronary artery disease. LV fractional shortening (FS) increased from 19+/-6% to 26+/-7% post-operatively and to 33+/-12% at follow-up in the stentless group (p<0.001). In the stented group, no significant change was seen in the post-operative FS, although it improved at follow-up and at this point did not differ from the stentless group. LV mass fell from 338+/-72 to 265+/-64 g post-operatively and to 170+/-77 g at follow-up (p<0.001) in the stentless group, whereas in the stented group a significant fall was seen only at follow-up (329+/-51 g pre-operatively, 304+/-68 g post-operatively, 166+/-28 g at follow-up, p=0.01). LV free wall excursion increased from 0.8+/-0.3 to 1.1+/-0.4 cm (p=0.05) and to 1.4+/-0.3 cm (p=0.02 compared with pre-operative values) in the stentless group. In the stented group, values were 1.0+/-0.4, 1.0+/-0.3 and 1.3+/-0.2 cm (p=0.05 compared with pre-operative) at the three time points, respectively. QRS duration fell from 113+/-36 ms pre-operatively to 99+/-12 ms at follow-up in the stentless group and from 117+/-28 to 99+/-19 ms in the stented group, p=0.01 for both comparisons. QT interval fell from 385+/-54 ms pre-operatively to 366+/-39 ms at follow-up (p=0.04) in the stentless group with no significant change in the stented group (387+/-52 and 375+/-33 ms, p=0.24). There was reversal of LV strain pattern in 11 (55%) of the stentless group and 6 (46%) of the stented group and normalisation of the inverted U wave in two thirds of patients. CONCLUSION: In patients with AS and severe LV dysfunction, there is a more rapid improvement in LV function following aortic valve replacement with a stentless prosthesis. Improvements in those receiving stented valves appear delayed, although there were no differences between the groups in LV function or mass at follow-up. Normalisation of LV free wall systolic behaviour, narrowing of the QRS complex and a reduction in the QT interval suggest that AS is associated with subendocardial ischaemia that reverses following valve replacement.

Aortic Valve↗

PubMed2006

Survival advantage and improved durability of mitral repair for leaflet prolapse subsets in the current era.

BACKGROUND: Factors predicting long-term survival and reoperative risk after mitral valve repair for subsets with prolapse involving the anterior leaflet in the current era are unclear. METHODS: Between January 1, 1980 and December 31, 1999, surgical correction of mitral regurgitation was performed in 2,219 patients. We analyzed a subset of 1,411 patients with isolated mitral regurgitation due to leaflet prolapse undergoing mitral repair or replacement (+/- coronary bypass). RESULTS: Mean age was 64 years, and 1,003 (71%) were men. Mitral repair was performed in 1,173 (83%) patients. Factors independently predicting overall long-term survival included valve repair, younger age, better functional class, and the absence of significant coronary artery disease. After adjusting for these, smaller preoperative left ventricular end-systolic dimension and greater preoperative ejection fraction were associated with superior survival. Mitral reoperation occurred in 97 patients (75 repairs, 22 replacements), at a mean of 4.8 years after initial procedure. Cumulative risk of reoperation was similar for patients having valve repair or replacement. Factors predictive of need for reoperation after initial repair were younger age, anterior leaflet prolapse, chordal shortening, no leaflet resection, no prosthetic annuloplasty, greater than mild residual mitral regurgitation, and coronary artery disease. After valve replacement, the sole determinant of reoperation was use of a biological prosthesis. The durability of repair for prolapse of the anterior leaflet improved significantly during the second decade of the study. CONCLUSIONS: Mitral repair affords superior long-term survival, with permanence comparable with mechanical valve replacement. In all categories of mitral leaflet prolapse, durability of valve repair has improved over the past decade.

Age Factors↗

PubMed2005

Hemodynamic evaluation of the Sorin Soprano bioprosthesis in the completely supra-annular aortic position.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the clinical and hemodynamic performance of the Sorin Soprano bioprosthesis in the aortic position. METHODS: Rest and stress echocardiography were performed at six months after surgery in 57 patients who underwent aortic valve replacement with the stented Soprano bioprosthesis. The exercise protocol included workloads of 25, 50, 75 and 100 W, each of 2 min duration. RESULTS: Thirty-day mortality was 1.8% (n = 1). Due to malperfusion of the coronary arteries, two Soprano prostheses had to be replaced by a different prosthesis, and one patient received coronary artery bypass grafts. One patient developed bacterial endocarditis of his prosthesis at seven months postoperatively and died as a result of a fulminant sepsis. There were no other prosthesis-related adverse events. Mean pressure gradients (MPG) ranged from 7.8 to 15.9 mmHg, effective orifice areas (EOA) from 1.25 to 2.98 cm2, EOA index (EOAI) from 0.79 to 1.43 cm2/m2, and EOA fraction from 34 to 45%. Stress echocardiography showed no significant increase in MPG up to 50 W, and MPGs did not exceed 35 mmHg at 75 and 100 W. CONCLUSION: Initial hemodynamic results showed low MPGs during rest and exercise. The EOAI was large due to completely supra-annular placement of the Soprano valve. The difficulty of complete supraannular placement is that the prosthesis is positioned relatively high, especially in narrow aortic roots, and this may handicap coronary artery perfusion. Patient selection with suitable aortic root anatomy is crucial to achieve the benefit of completely supra-annular implantation without coronary ostium deterioration.

Aged↗

PubMed1998

Carpentier-Edwards supraannular porcine bioprosthesis evaluation over 15 years.

BACKGROUND: The Carpentier-Edwards supraannular porcine bioprosthesis experience during 15 years has been evaluated to determine the incidence of structural valve deterioration by valve position in various age groupings. METHODS: From 1981 to 1995, 2,943 patients older than 20 years had the prosthesis implanted in 3,024 procedures. The mean age of the population was 65.5+/-11.9 years (range, 21 to 89 years). Aortic valve replacement was performed in 1,657 patients (54.8%); mitral valve replacement, 1,092 (36.1%); multiple valve replacement, 253 (8.3%); pulmonary valve replacement, 2 (0.1%); and tricuspid valve replacement, 20 (0.7%). Concomitant procedures were performed in 1,332 patients (45.3%), and 352 (12.0%) had previous procedures. RESULTS: The early mortality was 8.9% (270), only 0.4% (11) valve-related. The total follow-up was 17,471 years (mean, 5.9+/-4.1 years). The late mortality was 5.2%/ patient-year (901) with the valve-related component 1.0%/patient-year (171). The reoperation rate was 2.1%/ patient-year (369) with 4.3% mortality (16). The linearized rate of structural valve deterioration was 2.0%/patient-year (341), and overall complications, 5.9%/patient-year (1,019). The overall survival, at 15 years, was 31.1%+/2.8% (p < 0.05; aortic valve replacement greater than mitral valve replacement or multiple valve replacement). The freedom from structural valve deterioration for aortic valve replacement was, at 12 years, for patients older than 70 years, 95.3%+/-2.7%; 61 to 70 years, 92.9%+/-2.1%; 51 to 60 years, 70.1%+/-5.3%; 41 to 50 years, 60.0%+/-8.8%; and 21 to 40 years, 75.7%+/-7.3%. The freedom from structural valve deterioration for mitral valve replacement was, at 12 years, for patients older than 70 years, 66.1%+/-9.7%; 61 to 70 years, 53.1%+/-4.7%; 51 to 60 years, 52.6%+/-5.5%; 41 to 50 years, 39.3%+/-6.9%; and 21 to 40 years, 42.1%+/-9.4%. CONCLUSIONS: The prosthesis is recommended for aortic valve replacement for patients older than 70 years and for patients 61 to 70 years (when extended longevity is not anticipated) and for mitral valve replacement for patients older than 70 years (when extended longevity is not anticipated).

Adult↗

PubMed1998

Aortic root replacement in adolescents and young adults: composite graft versus homograft or autograft.

BACKGROUND: Aortic root replacement (ARR) is a technically demanding procedure that can be performed using a variety of prosthetic devices. Root replacement in the young, but grown-up, patient poses unique problems in terms of the long-term outcome and active lifestyle that must be guaranteed by this operation. To identify the "ideal" substitute for ARR in the young, clinical results in teenagers and young adults (<35 years) operated on in the past two decades were reviewed. METHODS: Thirty-eight patients younger than 35 years underwent ARR between January 1980 and December 1996. Eighteen patients, aged 30+/-5 years, had ARR with composite graft (group 1), whereas 20 patients, aged 28+/-6 years, had ARR with aortic homografts or pulmonary autografts (group 2). Primary indication for the operation was aortic insufficiency with anuloaortic ectasia (12 of 18) in group 1 and aortic insufficiency with or without anuloaortic ectasia (16 of 20) in group 2. Urgent ARR was required in 3 (17%) group 1 patients and 1 (5%) group 2 patient (p = 0.01). RESULTS: Operative deaths were 2 (11%) in group 1, caused by hemorrhage and low output, and none in group 2. There were 4 (25%) late deaths in group 1, caused by embolism (2), hemorrhage, and myocardial infarction, and 1 (5%) in group 2, caused by arrhythmia. Survival was 81% +/- 9%, and 55%+/-18% at 2 and 10 years in group 1 versus 94%+/-5% at 2 years in group 2 (p = 0.04). Freedom from valve-related events was 93%+/-6% and 62%+/-18% at 2 and 10 years in group 1 versus 100% at 2 years in group 2 (p = 0.02). Freedom from reoperation in group 1 was 75% +/- 22% at 10 years, whereas no reoperations were done in group 2. Seven (58%) group 1 patients versus 1 (5%) group 2 patient were on cardiac medications (p = 0.001), and 11 (92%) group 1 patients versus no group 2 patients were on warfarin therapy at follow-up. All survivors were back to school or prior employment. CONCLUSIONS: Survival early after ARR does not differ depending on the type of prosthesis. Valve-related events are common, and reoperation may be needed late after ARR with composite grafts. Despite limited follow-up with biologic devices, the prevalence of complications with composite grafts makes homograft or autograft ARR preferable in adolescents and young adults.

Adolescent↗

PubMed1999

Eight year experience with the CarboMedics bileaflet valvular prosthesis.

Two hundred and two patients (97 female and 105 male; mean age: 45. 5+/-9 years) received CarboMedics bileaflet valves during a period of eight years. Ninety-one patients received mitral, 72 aortic and 39 aortic+mitral valve prosthesis. Tricuspid plasty and coronary artery bypass surgery were the concomitant operations in 17 and 12 patients, respectively. The mean follow-up period was 24.7 months and the ratio was 91%. Overall operative mortality was 3.96% (8 patients); 2.78% for aortic valve replacement (AVR), 3.29% for mitral valve replacement (MVR) and 7.7% for double valve replacement (DVR). The late mortality rate was 2.89% for AVR, 2.2% for MVR and 8. 3% for DVR. The main cause of mortality was low cardiac output. The overall survival rate was 91.5% in 2 years. The actuarial freedom from thromboembolism in 2 years was 97% for AVR, 95% for MVR and 84% for DVR. No mortality due to heamorrhagic events was observed. CarboMedics prosthetic heart valves may be used satisfactorily with a low incidence of valve-related morbidity and mortality.

Actuarial Analysis↗

PubMed2006

Percutaneous implantation of the CoreValve self-expanding valve prosthesis in high-risk patients with aortic valve disease: the Siegburg first-in-man study.

BACKGROUND: The morbidity and mortality of surgical aortic valve replacement are increased in elderly patients with multiple high-risk comorbid conditions. Therefore, a prospective, single-center, nonrandomized study was performed in high-risk patients with aortic valve disease to evaluate the feasibility and safety of percutaneous implantation of a novel self-expanding aortic valve bioprosthesis (CoreValve). METHODS AND RESULTS: Symptomatic high-risk patients with an aortic valve area <1 cm2 were considered for enrollment. CoreValve implantation was performed under general anesthesia with extracorporeal support using the retrograde approach. Clinical follow-up and transthoracic echocardiography were performed after the procedure and at days 15 and 30 after device implantation to evaluate short-term patient and device outcomes. A total of 25 patients with symptomatic aortic valve stenosis (mean gradient before implantation, 44.2+/-10.8 mm Hg) and multiple comorbidities (median logistic EuroScore, 11.0%) were enrolled. Device success and procedural success were achieved in 22 (88%) and 21 (84%) patients, respectively. Successful device implantation resulted in a marked reduction in the aortic valve gradients (mean gradient after implantation, 12.4+/-3.0 mm Hg; P<0.0001). The mean aortic regurgitation grade was unchanged. Major in-hospital cardiovascular and cerebral events occurred in 8 patients (32%), including mortality in 5 patients (20%). Among 18 patients with device success surviving to discharge, no adverse events occurred within 30 days after leaving the hospital. CONCLUSIONS: Percutaneous implantation of the self-expanding CoreValve aortic valve prosthesis in high-risk patients with aortic stenosis with or without aortic regurgitation is feasible and, when successful, results in marked hemodynamic and clinical improvement.

Aged↗

PubMed2006

[Aortic valve replacement for the small aortic annulus].

Aortic valve surgery for the small aortic annulus is still challenging for surgeons. Recently, the new types of high performance prosthesis have been developed and the chance of an aortic root enlargement (ARE) is decreasing. In this study, we propose the ideal strategy of the aortic surgery for the small aortic annulus. We analyzed the clinical records of 158 patients who underwent aortic valve replacement from August 1999 to October 2005 in our institution. The small aortic annulus was observed in 38 patients (24%). Fourteen patients of this group underwent ARE. Patient-prosthesis mismatch (PPM) was less frequently observed in patients with ARE compared to those without ARE. The additional time required for ARE was not considerable, and neither ischemic time nor cardiopulmonary bypass time was significantly prolonged by ARE. In conclusion, we have to select a prosthesis with sufficient orifice area to avoid PPM, otherwise we should choose an option of ARE. For this consideration, we definitely need the chart that demonstrates the relationship between the nominal size of various types of prostheses and the size of a patient's annulus that those prostheses actually fit.

Aged↗

PubMed1999

Predictors of the long-term outcome after combined aortic and mitral valve surgery.

BACKGROUND: The influence of preoperative clinical, hemodynamic, and surgical procedures on long-term prognosis after combined aortic and mitral valve surgery is not well known. METHODS AND RESULTS: One hundred seventy patients (mean age, 50.5 years; 102 men and 68 women) who underwent surgery for chronic combined aortic and mitral valvular disease between 1975 and 1989 were followed up for an average of 10.6 years. Additional repair of tricuspid valve was performed in 29 patients (17%), and aortocoronary bypass graft surgery was performed in 7 patients (4.1%). The perioperative mortality rate was 4%, and 10- and 20-year survival rates were 61% and 33%. Only 12 of 94 deaths (11%) were non-cardiac related. At 10 and 20 years, 57% and 21% of patients were free of reoperation, respectively. The main predictors of late survival in univariate analysis were age at surgery (P=0.0002), preoperative left ventricular ejection fraction (P=0.002), cardiac index (P=0.007), tricuspid surgery (P=0.03), pulmonary vascular resistance (P=0.03), NYHA class (P=0.04), and additional aortocoronary bypass graft surgery (P=0.04). Duration of symptoms, gender, cause of valvular disease, and type of prosthesis were not predictive of postoperative outcome. In multivariate stepwise Cox analysis, ejection fraction (P=0.0008), age at surgery (P=0.0011), and tricuspid surgery (P=0. 007) were independent predictors of late survival. CONCLUSIONS: In combined aortic and mitral valve disease, preoperative myocardial function is the main predictor of long-term survival. Low operative mortality rates and good late outcome make valve replacement mandatory before deterioration of myocardial function occurs. Additional tricuspid valve disease requiring surgery significantly decreases the late survival rate.

Aortic Valve↗

PubMed1998

Replacement of aortic root with valved tubular prosthesis in a ten-year-old child with infective endocarditis--a case report.

Aortic root abscess, aneurysm of sinus Valsalva, severe aortic valve insufficiency, and a fragile aortic wall caused by infective endocarditis were found in a 10-year-old child. Aortic valve replacement was intended as a preoperative strategy, but one of modifications of Cabrol had to be used urgently because of aortic root rupture between right atrial and aortic connection just after pericardiotomy.

Aorta↗

PubMed2005

Long-term follow-up after aortic valve replacement with a small aortic prosthesis.

UNLABELLED: Although aortic valve replacement (AVR) is an effective treatment for patients with aortic valvular disease, the implantation of a small aortic prosthesis may result in residual left ventricular outflow stenosis and transvalvular gradient. In this study, the outcome in the long-term period of patients treated with a small aortic prosthesis was analyzed retrospectively. Twenty-four patients with AVR were divided into two groups, group A and group B. Group A consisted of 16 patients with 21 mm-sized prosthetic valves, and group B consisted of 8 patients with 19 or 16 mm-sized prosthetic valves. There were no significant differences in preoperative cardiac function or operative procedure in the two groups. The mean follow-up period (months) was 55.0 in group A and 51.3 in group B. RESULTS: One patient died of cerebral infarction in group A. There were no significant differences in cardiothoracic ratio (CTR), left ventricular ejection fraction (LVEF), and left ventricular mass index (LVMI) between the two groups. Postoperative physical activity according to the New York Heart Association (NYHA) classification showed no significant differences in the two groups. Despite using a small prostheses for AVR, the postoperative course was good in the long-term period, although careful follow-up is necessary.

Aged↗

PubMed2000

Disruption of the silver and non-silver coated sewing cuff of a new generation bileaflet valve prosthesis during aortic valve replacement: report on four cases.

OBJECTIVES: New generation bileaflet valve prostheses with a silver-coated sewing cuff like the St Jude Medical (SJM((R)) Regent) model are designed to offer a larger valvular orifice as well as a better resistance to postoperative prosthetic endocarditis, at the expense of a smaller sewing cuff. METHODS AND RESULTS: We report on four cases of aortic valve replacement where during the implantation procedure the fixation cuff disrupted, leading to the exchange of all four valve prostheses. This happened three times with silver- coated sewing cuffs and after withdrawal of the silver- coated cuff prostheses from the market, once with a non silver- coated sewing cuff. This was due to the arbitrary cutting of the cuff fixation suture at the ventricular side of the prosthesis, although the implantation was performed according to the recommendations of the company. This problem didn't occur previously, using other models of the same manufacturer, although the sewing cuff had been fixed in the same technique. CONCLUSION: Fixation of smaller sewing cuffs of mechanical valve prostheses with a critically exposed fixation suture at the ventricular side of the prosthesis represents a significant risk for disruption during the implantation process through cut off by chance. We recommend meticulous inspection of the sewing cuff for signs of disruption before seating the valve into position. During follow-up particular attention should be paid to valve dislodgement and leakage. The company was informed and advised by us to modify the fixation of the prosthetic annulus of the SJM((R)) Regent valve, which has led to an alternative cuff design, called the SJM Flex cuff.

Aortic Valve↗

PubMed2003

Prospective study of hemodynamic performances of standard ATS and AP-ATS valves.

BACKGROUND AND AIM OF THE STUDY: Following aortic valve replacement (AVR), a residual transprosthetic gradient can develop which has detrimental long-term effects, especially with regard to left ventricular mass regression and subsequent mortality. The Advanced Performance-ATS valve (AP-ATS) was developed to overcome this potential patient-prosthesis mismatch. In the present study, the early postoperative transprosthetic gradient was determined after AVR with ATS valves 18 to 25, to confirm the promise of superior hemodynamic performance of the AP series and to define respective indications. METHODS: This prospective study included 302 consecutive patients operated on for AVR between December 1997 and December 2000. In all patients, body surface area (BSA), associated with mean transprosthetic gradient and paravalvular leaks (measured echocardiographically) was monitored, between the 5th and 8th postoperative days. RESULTS: A significantly lower mean transprosthetic gradient was found for size 22 and 24 valves, compared with size 23 and 25 valves. Results for size 18 and 20 valves were in concordance with those obtained for size 22 and 24 valves. For size 23 valves the mean gradient was significantly higher when the BSA was >1.9 m2, but the use of size 22 valves in these patients overcame this potential patient-prosthesis mismatch. No patient was reoperated on for paravalvular leakage, and no greater degree of paravalvular leakage was found with AP-ATS than with Standard ATS valves. CONCLUSION: These results confirm the global good hemodynamic performances of Standard ATS and especially of the AP-ATS valves. However, the significantly lower mean gradient found in the AP-ATS valves recommends their use in patients with larger BSA.

Adolescent↗

PubMed2006

Intracardiac echo guided valvuloplasty of a stenotic tricuspid prosthetic valve in a patient with idiopathic hypereosinophilic syndrome.

A 52-year-old male with idiopathic hypereosinophilic syndrome (HES) was transferred to our institution following the development of acute respiratory failure and shock. He had previously undergone tricuspid valve replacement with bioprosthetic valves on two occasions: the initial surgery for severe native tricuspid valve stenosis and the redo surgery for severe prosthetic valve stenosis and regurgitation. Conventional imaging assessment using transoesophageal echocardiography was suboptimal and comprehensive assessment of prosthetic valve function was aided by the use of intracardiac echocardiography (ICE). ICE provided high quality 2D imaging of the prosthesis demonstrating thrombus-like material coating the inner surfaces of the prosthetic valve stents effectively forming a tunnel-like obstruction. Unusual hemodynamics secondary to severe tricuspid stenosis were demonstrated by CW Doppler with intermittent "signal fusion" resulting from blunted respiratory variation in the markedly elevated right atrial pressure relative to right ventricular pressure. Successful balloon valvuloplasty was performed with ICE proving highly valuable in guiding balloon position as well as monitoring the efficacy of the subsequent inflations.

Cardiac Output, Low↗

PubMed2005

Percutaneous implantation of an aortic valve prosthesis.

Recently, percutaneous aortic valve implantation has become an alternative technique to surgical valve replacement in patient at high risk for surgery. Our animal experimentation evaluated the technical feasibility of aortic valve replacement using a bovine pericardium valve sutured on a self-expandable stent in a sheep model. Precise implantation with satisfactory attachment on the adjacent tissues and absence of migration was obtain in 8 out of 14 animals. This study confirmed the feasibility of the endovascular implantation of a pericardium valve sutured on a self-expandable stent in a sheep model.

Animals↗

PubMed1998

[Aortic valve prosthesis implantation from a mini approach].

The authors share their experiences with performing the first in Russia operation of making the aorta valve prosthetics from a mini-access--transverse sternotomy. It is concluded that operations through such accesses are safe for the patient and relatively easy for the surgeon. Its main advantage consists in quick surgical rehabilitation of the patient and good cosmetic effect.

Adult↗

PubMed1999

Reoperations for acute prosthetic thrombosis and pannus: an assessment of rates, relationship and risk.

OBJECTIVE: Mechanical valvular prostheses have the advantage of longevity but carry a risk of thrombosis which is dependant on valve design, materials and host-related interface. While pannus is common to both biologic and mechanical valves, acute prosthetic thrombosis is mostly a complication of mechanical valves; therefore we investigated to find rates and risk of these obstructive complications. METHODS: Between 1/1/70 and 31/12/97, 2680 patients received at least one mechanical prosthesis in the aortic or mitral or tricuspid position and a total of 3014 operations were performed. Follow-up included 18523 years and was 98% complete. Incidence rates, Kaplan-Meier estimates, modeling of the hazard and multivariate analysis in the hazard domain were used in the analysis. RESULTS: Overall survival was 76%, 64%, 51%, 38.5% and 29% at 5, 10, 15, 20 and 25 years, respectively. It was significantly better in aortic than in mitral than in double prosthesis. 290 patients received a single reoperation, 37 a second, six a third and one a fourth reoperation. Two-hundred and fifty-one of these reoperations were exclusively due to malfunction of mechanical prosthesis, nine to malfunction of both mechanic and biologic prostheses. Most frequent reoperative indications was dehiscence (133), pannus (48) and thrombosis (29). The linearized rate of reoperations for pannus was 0.24%/patient per year, for valvular thrombosis 0.15%/patient per year. The shape of the thrombotic hazard was constant (at random) and the relative risk 12 times higher for tricuspid prosthesis, seven times higher for mitral prosthesis. Multivariate analysis controlling for prosthetic position, age, sex and prosthetic size, showed a 67% risk reduction with larger prosthesis (>27 mm), a 69% risk reduction with the Sorin tilting disk prosthesis and an 83% risk reduction with the bileaflet prosthesis. Pannus hazard shows a delayed exponential rise and was two times higher in tricuspid and three times higher in mitral position. Multivariate analysis showed a 50% risk reduction with larger prosthesis, an 11 times higher hazard of old (caged-disk, caged ball) prosthesis and a three times higher hazard of Lillehei-Kaster prosthesis. Reoperation for thrombosis has a 62% perioperative (30 days) survival compared to 92% survival of pannus reoperation. CONCLUSIONS: Mechanical valves have a low incidence of reoperation, mostly for prosthetic dehiscence. Pannus development is the next frequent complication increasing with time since implant, therefore in this series it was related to old valvular models and tilting disk prosthesis, with longer follow-up. Acute thrombosis occurs significantly earlier than pannus formation. Despite shorter follow-up we are therefore confident that bileaflet prostheses are less prone to this complication and pannus is a rare early etiologic factor. Thrombosis has very high operative risk as compared to pannus, justifying the present trend to thrombolysate selected cases.

Acute Disease↗