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PubMed1989

[Staphylococcal endocarditis on a heart valve prosthesis. Apropos of 28 cases].

The purpose of this retrospective study of 28 cases of staphylococcal endocarditis on cardiac valve prosthesis was to evaluate the prognosis of that disease and the possible causes of its recent improvement. Between March 1977 and May 1987, 69 patients were treated for bacterial endocarditis on cardiac valve prosthesis. Among these, 28 patients (19 men, 9 women, mean age 53.2 +/- 14.3 years) had staphylococcal endocarditis (Staph. epidermidis in 18 cases, Staph. aureus in 10 cases) of early (10 cases) or late (18 cases) onset. Complications were present in no less than 27 out of 28 patients, the most frequent being heart failure, embolism or neurological disorders. The mortality rate was high (61 p. 100). Among the clinical variables studied, only a state of shock seemed to be predictive of death. Mortality was higher in the group treated medically (100 p. 100) than in the group treated surgically (50 p. 100). Since 1984, however, a significant decrease of mortality was noted; it coincided with the systematic use of vancomycin but also with surgical treatment in all cases. As a result of this study, we suggest that all patients with staphylococcal endocarditis on cardiac valve prosthesis should be operated upon and that this should be done as soon as possible, before the end of the classical antibiotic therapy period.

Adolescent↗
PubMed1991

[Ultrastructural analysis of myocardial condition during cardioplegic protection in heart valve prosthesis].

The article deals with the results of ultrastructural study of the myocardium at three stages of cardiosurgical operations: preischemic, ischemic, and during reoxygenation. A statistically significant difference was revealed in the condition of the cardiomyocyte organelles in each of these stages, and the degree of their intraoperative destruction was determined. It is concluded that ischemia of more than 90 minutes redoubles the progress of irreparable changes of the cardiomyocytes, particularly in patients with severe damage to the myocardium in the preischemic stage. The search for means of cardioprotection for these patients must be continued.

Adult↗
PubMed1985

Two years' experience with the duromedics bileaflet heart valve prosthesis.

The new Duromedics Bileaflet Cardiac Valve prosthesis has a special moving hinge mechanism for its two leaflets to wash the critical articulation area and thus reduce thrombus formation. Between October 1983 and June 1985, we implanted 278 of these prostheses in 254 patients. We did 114 aortic valve replacements, 109 mitral valve replacements, 34 double valve replacements, and two tricuspid valve replacements. Nearly 20% of the patients had had previous cardiac procedures. The hospital mortality was 5.9%. Follow-up was started with 214 surviving Austrian patients, and up to the present time, we have a follow-up period of 1704 patient months. Five patients died late after the operation (3.5 per 100 patient years). We observed 10 valve-related complications in nine patients (7 per 100 patient years). There were three cases of prosthetic endocarditis (2.1 per 100 patient years), two paravalvular leaks, and four bleeding episodes (2.8 per 100 patient years). The mechanical hemolysis was minimal, and the postoperative hemoglobin value averaged 15 g%. The LDH increased from 230 IU to 307 in the aortic valve replacements, 406 in the mitral valve replacements, and 435 in the double valve replacements. Intraoperative pressure gradients and postoperative Doppler echocardiography showed good hemodynamic performance. We conclude that good clinical results and a low complication rate can be achieved with the Duromedics Valve.

Journal Article↗
PubMed1979

Ten years' experience with the Björk-Shiley tilting disc valve.

More than 10 years of clinical experience with 1,800 consecutive valve replacements with the Björk-Shiley tilting disc valve were focused on improving its durability, flow dynamics, thromboresistance, and in vivo functional control. Although the original Delrin disc functions excellently after 10 years in the human circulation, the durability of the prosthetic valve was further prolonged by the introduction of pyrolytic carbon as disc material. The opening mechanism was also reinforced by integrating the bearing struts with the valve ring. No other presently available heart valve prosthesis shows such a low resistance to flow for a given tissue diameter. The disc was equipped with a ring-shaped radiopaque marker that permitted noninvasive functional control. The 5 year survival rates were 82% after aortic, 66% after mitral, and 66% after mitral and aortic valve replacements, including the operative mortality rates. The incidence of systemic emboli was 0.7% per year after aortic, 4.2% per year after mitral, and 2.2% per year after mitral and aortic valve replacements with anticoagulation treatment. The incidence of obstruction by thrombosis was 0.3% per year for aortic, 1.3% per year for mitral, and 2.3% per year tricuspid prostheses. The new convex-concave model decreases the stagnation zone behind the disc, decreases emboli from 4.2% to 1.2% per year after mitral valve replacement, and has a lower gradient.

Aortic Valve Stenosis↗
PubMedDate not supplied

Future horizons in surgical aortic valve replacement: lessons learned during the early stages of developing a transluminal implantation technique.

The aim of this study was to develop a heart valve prosthesis that could be transluminally inserted through the infrarenal aorta in pigs and the femoral artery in humans. Therefore, this valve prosthesis had to be foldable to a diameter of approximately 8 mm, self-expandable when released in the vascular system, and equipped with an anchoring mechanism. For implantation, a suitable catheter delivery system for insertion via the abdominal aorta in pigs also was designed. Furthermore, an operation method, including positioning of the catheter delivery system and deployment of the valved stent under fluoroscopic and echocardiographic control, was developed. A series of different prototypes of the valved stents and catheter delivery systems was produced to optimize design and handling. These prototypes were tested in vitro in a circulation model, and those showing satisfying hemodynamic properties were implanted in pigs as in vivo studies afterwards. The valved stents had a good hemodynamic function in vitro and in vivo with no more than a mild regurgitation or stenosis. Valve movements were satisfying, and the design proved to be generally feasible. However, positioning and anchoring were still difficult; some stents were tilted in the lumen or migrated after implantation.

Animals↗
PubMed2000

Does the Ross operation fulfil the objective performance criteria established for new prosthetic heart valves?

BACKGROUND AND AIM OF THE STUDY: Objective Performance Criteria (OPC) were established to compare a new heart valve prosthesis with fixed standards of linearized complication rates for morbid events: thromboembolism, thrombosis, hemorrhage, leakage and endocarditis. Although the pulmonary autograft operation provides optimal hemodynamic performances, the morbidity of both the autograft and homograft remain topics of controversy. METHODS: Valve-related morbid events and echocardiography in 109 patients who have undergone the Ross operation since 1991 were evaluated at annual follow up examination (mean 2.8 years; range: 1 month to 8 years). Linearized rates (number of events per 100 years patient exposure) were calculated to establish the safety and efficacy of this operation (288.7 years cumulative patient-years). RESULTS: Three patients died perioperatively (2.8%); two patients were reoperated due to autograft incompetence (1.8%, both valve repairs). No patient is currently on anticoagulation therapy, and no events of thromboembolism, valve thrombosis or bleeding were observed during follow up. Two patients had homograft endocarditis but were asymptomatic with moderate incompetence at the last follow up examination. There was no significant increase in aortic incompetence (AI) or pulmonary incompetence (PI) between discharge and follow up (AI, 0.4 +/- 0.5 versus 0.6 +/- 0.6; PI, 0.2 +/- 0.4 versus 0.4 +/- 0.6). In comparing the OPC (events per patient-year) for the Ross operation with those for tissue and mechanical valves, the results were: thromboembolism 0% (tissue 2.5%, mechanical 3%), valve thrombosis 0% (0.2% and 0.8%), all bleeding 0% (1.4% and 3.5%), major bleeding 0% (0.9% and 1.5%), all leakage 0.7% (1.2% and 1.2%), major leakage 0.7% (1.2% and 1.2%) and endocarditis 0.7% (1.2% and 1.2%). CONCLUSION: The pulmonary autograft procedure provides optimal hemodynamics and echocardiographic performance, and low valve-related complication rates; thus, the OPC for tissue and mechanical heart valve prostheses can be fulfilled by this technically demanding operation. These results confirm that the autograft is an ideal aortic valve replacement device.

Adolescent↗
PubMed2001

Long-term results with the Xenomedica porcine bioprosthesis in the mitral position.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate our clinical experience with the Xenomedica heart valve prosthesis, a low-pressure glutaraldehyde-preserved porcine aortic valve with low-profile mounting. METHODS: Between January 1983 and July 1990, 242 consecutive patients (75 men, 167 women; mean age 59.8+/-8.0 years; range: 32-77 years) underwent mitral valve replacement with the Xenomedica prosthesis. Preoperatively, patients were in NYHA classes III (66%) and IV (26%); 94 patients (39%) had undergone previous cardiac surgery and 201 (83%) had chronic atrial fibrillation. Etiology was rheumatic in 51%, myxomatous in 7%, ischemic in 1%, endocarditis in 2%, and due to dysfunction of a previously implanted device in 39%. In total, 115 (47%) patients underwent an associated procedure. Mean follow up was 142+/-24 months (range: 2-181 months); total follow up was 2,627 patient-years. RESULTS: Early mortality was 8.2% (14 patients with low-output syndrome, three with multi-organ failure, one with stroke and two with major bleeding, 2). Late mortality was 45% (3.8%/pt-year) (84 cardiac deaths, 38 being valve-related). Actuarial survival at 5, 10 and 15 years was 69+/-3%, 52+/-3% and 38+/-4%, respectively. Actuarial estimates of freedom from structural valve deterioration (SVD) at 5, 10 and 15 years were 93+/-2%, 64+/-4%, and 25+/-9%; in almost all cases SVD occurred in progressive fashion. At 5, 10 and 15 years, estimates of freedom from thromboembolism were respectively 90+/-2%, 83+/-3% and 83+/-3%, for anticoagulant-related hemorrhage 96+/-1%, 88+/-3% and 88+/-3%, for endocarditis 96+/-1%, 94+/-2% and 94+/-2%, and for reoperation 93+/-2%, 67+/-4% and 54+/-6%. Estimates of freedom from all valve-related mortality at 5, 10 and 15 years were 87+/-2%, 80+/-3% and 75+/-4%. Multivariate analysis (Cox model) showed younger age to be a significant risk factor for reoperation. CONCLUSION: Long-term results with the Xenomedica device implanted in the mitral position appear in line with those achieved for other first-generation bioprostheses. However, incidence of primary tissue failure within 10 years was unsatisfactory. Although sudden dysfunction of the device never occurred, close monitoring of survivors is warranted.

Actuarial Analysis↗
PubMed2005

Fifteen years' clinical experience with the CarboMedics prosthetic heart valve.

BACKGROUND AND AIM OF THE STUDY: The CarboMedics bileaflet prosthetic heart valve was first implanted as part of a prospective clinical study at the authors' institution in November 1987. The patient cohort included was part of a multicenter trial set up by the manufacturer for an FDA application. The present report details findings over a 15-year period, with a continuous follow up on this patient cohort. METHODS: Between November 1987 and August 1990, 132 patients (68 males, 64 females; median age 56 years; range: 12-74 years) received a CarboMedics heart valve prosthesis. All patients were included in the study, whether surgery was elective or emergency, first time or reoperation. There were 69 aortic, 49 mitral and 12 double (aortic and mitral) valve replacements. Two patients had isolated tricuspid valve replacement. Concomitant surgery was performed in 15 patients. Anticoagulation with warfarin was started on postoperative day 1. After discharge, patients were examined regularly as outpatients for up to five years. Subsequent follow up was obtained prospectively by questionnaires to the patients' general practitioners and with telephone calls to the patients. Actuarial estimates of survival and freedom from morbid events were calculated using the Kaplan-Meier method; 95% confidence limits for the distribution function were calculated according to the Greenwood formula. RESULTS: Complete follow up information was available on 94% of the patients; total follow up was 1,270.3 patient-years (pt-yr). Actuarial survival at 15 years was 51+/-4.9% overall; 56+/-6.2% for single aortic, 51+/-8.0% for single mitral, and 30+/-15.9% for double valve replacements. Actuarial rates of freedom from complications were: valve thrombosis 100%, embolism 89+/-3.3%, and all anticoagulant-related bleeding 76+/-4.5%. The linearized rates per 100 pt-yr were: embolism 0.94 (aortic 0.74, mitral 1.25); anticoagulant-related bleeding 2.28; paravalvular leakage overall 0.24 (aortic 0.29); prosthetic valve endocarditis overall 0.24 (aortic 0.29, mitral 0.21). There was no hemolysis, prosthetic valve dysfunction, or structural deterioration. CONCLUSION: Over a 15-year time frame, the CarboMedics prosthetic heart valve has proven to be a highly reliable device with no structural failures and a low incidence of valve-related complications.

Adolescent↗
PubMed2001

Twelve years' clinical experience with the CarboMedics prosthetic heart valve.

BACKGROUND AND AIM OF THE STUDY: The CarboMedics bileaflet prosthetic heart valve was first implanted as part of a prospective clinical study at the authors' institution in November 1987. The patient cohort included was part of a multicenter trial set up by the manufacturer for an FDA application. The present report details findings over a 12-year period, with a continuous follow up on this patient cohort. METHODS: Between November 1987 and August 1990, 132 patients (68 males, 64 females; median age 56 years; range 12-74 years) received a CarboMedics heart valve prosthesis. All patients were included in the study, whether surgery was elective or emergency, first time or reoperation. There were 69 aortic, 49 mitral and 12 double (aortic + mitral) valve replacements. Two patients had isolated tricuspid valve replacement. Concomitant surgery was performed in 15 patients. Anticoagulation with warfarin was started on postoperative day 1. After discharge, patients were examined regularly as outpatients for up to five years. Subsequent follow up was obtained prospectively by questionnaires to the patients' general practitioner, or by telephone calls. Actuarial estimates of survival and freedom from morbid events were calculated using the Kaplan-Meier method; 95% confidence limits for the distribution function were calculated according to the Greenwood formula. RESULTS: Complete follow up information was available for 94% of the patients; total follow up was 1,014.3 patient-years (pt-yr). Actuarial survival at 12 years was 62 +/- 0.5% overall (61 +/- 6.5% for aortic; 66 +/- 7.5% for mitral; 65 +/- 14.0% for double valve replacements). Actuarial rates of freedom from complications were: valve thrombosis 100%, embolism 92 +/- 2.8%, and anticoagulant-related bleeding 77 +/- 5.6%. The linearized rates per 100 pt-yr were: embolism 0.89 (aortic 0.74, mitral 1.30); anticoagulant-related bleeding 2.56; paravalvular leakage overall 0.20 (aortic 0.37); prosthetic valve endocarditis overall 0.20 (aortic 0.37). There was no hemolysis, prosthetic valve dysfunction or structural deterioration. CONCLUSION: Over a 12-year time frame, the CarboMedics prosthetic heart valve has proven to be a highly reliable device with no structural failures, and a low incidence of valve-related complications.

Adolescent↗
PubMed2002

Prosthetic heart valves with silver-coated sewing cuff fabric: early morphological features in two patients.

BACKGROUND: The current generation of prosthetic heart valves are excellent examples of engineering that work well, for long periods of time. Unfortunately, host-related problems and consequent valve failure continue to occur, including infective endocarditis. St Jude Medical Inc introduced a new model of mechanical heart valve prosthesis with silver-treated fabric to try to reduce the incidence of infective endocarditis. Two cases of failure of this prosthesis, with a clinical diagnosis of infective endocarditis, are presented. MATERIALS AND METHODS: Of the 176 St Jude Medical Silzone-coated prostheses implanted, two were explanted in the first half of 1998. The clinical status of the patients was reviewed, and a detailed gross, histological and stereomicroscopic examination of the prosthetic valves was undertaken. RESULTS: Clinically, both patients developed symptoms of infective endocarditis. The first patient developed features of a stroke and two months later underwent a second valve replacement. The prosthesis showed pannus and thrombus. A paravalvular leak was revealed in the second patient, who underwent a second valve replacement six months after the initial surgery. Blood and tissue cultures were negative in both cases. CONCLUSIONS: The new model St Jude Medical Silzone mechanical heart valve prosthesis, designed to prevent infective endocarditis, was associated with clinical features of endocarditis in these two cases. Significant pannus and thrombus were seen on both prostheses, which likely led to emboli and stroke in the first case. The cause of the paravalvular abscess in the second case has not yet been established. The early failure of these prostheses suggests that patients with this prosthesis be followed up carefully.

Endocarditis, Bacterial↗
PubMed1980

Clinical results of valve replacement by the Starr-Edwards prosthesis.

Heart valve replacement has initiated special research efforts and has led to debate among surgeons from different surgical services. It is in this area of cardiac surgery that complications are frequent. This paper is a summarized review of the problems related to valve replacement by the Starr-Edwards prosthesis at the University of Sao Paulo Medical School Heart Institute. It describes the difficulties which led the authors to abandon its use in 1971. Clinical experience is from July 1958 to January 1974.

Aortic Valve↗
PubMed1998

[Surgery of the heart valves: prosthetic replacement versus repair (1)].

The surgical management of valvular heart disease nowadays includes the use of various valvular substitutes and sophisticated reparative surgical techniques. Characteristics and indications of these different surgical options are discussed and the objective criteria that justify the use of a given technique in a given clinical situation are provided.

Aortic Valve↗
PubMed1965

SIMULTANEOUS CORRECTION OF MULTIVALVULAR CARDIAC LESIONS.

Cardiac surgery, once confined to pure and isolated mitral stenosis, can now be carried out on all valvular lesions irrespective of their number or complexity. At the Montreal Heart Institute, simultaneous surgical correction of multivalvular lesions was carried out in 16 instances and 13 patients survived. All of the survivors have remained almost asymptomatic. However, if significant associated valvular lesions were not corrected at the same operation, the survival rate dropped to 28%. Moreover, such survivors have required constant medical therapy.This experience emphasizes the necessity of correcting completely and simultaneously all significant valvular malfunctions. Extrapleural median sternotomy appears to be the best single approach for all cases of valve replacement.

Cardiac Surgical Procedures↗