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Tirone E David

Publications and source records attributed to Tirone E David.

71 records · Page 4Linked to original sources
PubMed2002

Reoperative mitral valve replacement: importance of preservation of the subvalvular apparatus.

BACKGROUND: Preservation of the subvalvular apparatus has been demonstrated to be beneficial during first-time mitral valve replacement (MVR), but has not been fully examined in reoperative (redo) MVR. The purpose of this study was to analyze outcomes in a large cohort of redo MVR patients, focusing on the effect of subvalvular preservation on mortality. METHODS: We undertook a review of prospectively gathered data on patients undergoing MVR, with or without concomitant cardiac procedures, at our institution from 1990 to 1999. Predictors of mortality were determined by stepwise logistic regression. RESULTS: A total of 1,521 consecutive MVR patients were analyzed, of which, 513 (34%) had undergone one or more previous MV procedures. In-hospital mortality occurred in 6.9% of first-time MVR patients versus 9.0% in redo patients (p = 0.13). The number of prior MV operations ranged from one to five in redo MVR patients, with 115 patients (22% of redos) having two or more. In redo MVR patients, preservation of the native posterior subvalvular apparatus was performed in 103 patients (21%), whereas native anterior and posterior preservation was performed in 31 patients (6%). Gore-Tex neochordal construction was performed in 135 redo MVR patients (26%). Perioperative mortality occurred in 3.6% of redo MVR patients with a preserved subvalvular apparatus (native tissue and/or Gore-Tex reconstruction) versus 13.3% of redo patients without preservation (p < 0.001). Independent predictors of mortality in redo MVR patients were (in decreasing order of magnitude) failure to preserve the subvalvular apparatus, preoperative renal failure, previous stroke/transient ischemic attack, left ventricular dysfunction (left ventricular ejection fraction <40%), and urgent timing. CONCLUSIONS: Redo MVR can be performed with an acceptable risk of mortality. Although preservation of the subvalvular apparatus may increase operative complexity, we recommend subvalvular preservation in order to decrease the risk of early mortality.

Adult↗
PubMed2002

Aortic valve-sparing operations in patients with aneurysms of the aortic root or ascending aorta.

BACKGROUND: Aortic valve-sparing operations are an alternative to aortic root replacement in patients with aortic root aneurysms, or aortic valve replacement and supracoronary replacement of the ascending aorta in patients with ascending aorta aneurysms and dilated sinotubular junctions with consequent aortic insufficiency. METHODS: From 1988 to 2001, 230 patients underwent aortic valve-sparing operations for aortic root aneurysms (151 patients) or ascending aortic aneurysms with aortic insufficiency (79 patients). Two types of aortic valve-sparing operations were performed in patients with aortic root aneurysms: reimplantation of the aortic valve and remodeling of the aortic root. Mean follow-up was 3.8 +/- 2.8 years. RESULTS: Patients with aortic root aneurysms were younger, had less severe aortic insufficiency, less extensive vascular disease, and better left ventricular function than patients with ascending aorta aneurysms. The 8-year survival was 83% +/- 5% for the first group and 36% +/- 14% for the second. The freedom from aortic valve reoperation at 8 years was 99% +/- 1% for the first group and 97% +/- 2% for the second. In patients who had aortic root aneurysms, 3 developed severe aortic insufficiency (AI), and 15 developed moderate AI, for an 8-year freedom from significant AI of 67% +/- 7%. But freedom from AI was 90% +/- 3% after the technique of reimplantation, and 55% +/- 6% after the technique of remodeling (p = 0.02). In patients with ascending aortic aneurysms, the freedom from AI greater than 2+ at 8 years was 67% +/- 11%. CONCLUSIONS: The long-term results of aortic valve sparing for aortic root aneurysms are excellent, and reimplantation of the aortic valve may provide a more stable repair of the aortic valve than remodeling of the aortic root.

Adult↗
PubMed2002

Aortic valve replacement with the Toronto SPV: long-term clinical and hemodynamic results.

OBJECTIVE: Long-term durability and hemodynamics of stentless valves are unknown. Therefore, this study was undertaken to evaluate long-term clinical and echocardiographic outcome after aortic valve replacement with the Toronto stentless porcine valve (SPV) bioprosthesis at our institution. METHODS: Between 1991 and 1998, the Toronto SPV was implanted in 255 patients (mean age, 63+/-11 years, range 22-83 years, 181 males and 74 females). Preoperative diagnoses were aortic stenosis (76%), aortic insufficiency (12%) and mixed lesion (12%). New York Heart Association class III and IV were present in 49% (126/255) of the patients preoperatively. Mean valve size implanted was 26.5+/-2.1mm and in addition 34% (86/255) of the patients had coronary artery bypass surgery. RESULTS: Early mortality was 0.8% (2/255). Actuarial survival at 7 years was 90+/-3%. At 7 years, the freedom from cardiac death was 98+/-2%; from valve-related death, 99+/-1%; from valve reoperation, 97+/-2%; from structural valve degeneration, 97+/-2%; from thromboembolism, 95+/-2%; and from endocarditis, 99+/-1%. At 7 years of follow-up, the transvalvular peak and mean pressure differences across the aortic valve measured with Doppler echocardiography was 9.6+/-5.1 and 3.6+/-2.0 mmHg, respectively. CONCLUSIONS: The Toronto SPV has provided excellent clinical and hemodynamic results up until 7 years of follow-up.

Adult↗
PubMed2002

Intraoperative transesophageal echocardiography accurately predicts mitral valve anatomy and suitability for repair.

Mitral valve (MV) repair is the procedure of choice for MV prolapse or flail. However, valve repair is more technically demanding and requires a precise definition of MV morphology to determine the timing, complexity, and feasibility of repair. We prospectively examined 170 consecutive patients with MV prolapse or flail referred for MV repair. The MV valve was systematically assessed by intraoperative transesophageal echocardiography. MV anatomy was independently assessed at the time of operation. Accuracy of transesophageal echocardiography in identifying MV segments ranged from 90% to 97%, and was best for the middle segment/scallop of either anterior or posterior leaflet. MV repair was successful in 91% of patients. Success rate was the lowest (78%) in the presence of extensive bileaflet disease involving at least 2 segments of each leaflet. Independent predictors of unsuccessful repair were central jet of mitral regurgitation, calcification or severe dilatation of the mitral annulus, and extensive leaflet disease with involvement of at least 3 segments.

Adult↗
PubMed2002

Late hemodynamic and clinical outcomes of aortic valve replacement with the Carpentier-Edwards Perimount pericardial bioprosthesis.

OBJECTIVES: The aim of this study was to investigate the long-term clinical and hemodynamic outcomes after aortic valve replacement with the Carpentier-Edwards Perimount bioprosthesis (Edwards Lifesciences, Irvine, Calif), which has been used in our institution since 1984. METHODS: From January 1984 to December 1995, the Carpentier-Edwards pericardial bioprosthesis was used for aortic valve replacement in 254 patients (male/female ratio 117:137) with a mean age of 71 years (range 25-87 years). Before the operation, 216 patients (85%) were in New York Heart Association functional class III or IV. The predominant diagnosis was aortic stenosis (n = 219, 86%). Associated surgical procedures included coronary artery bypass grafting in 130 cases (51%), mitral valve replacement in 11 cases (4%), and tricuspid or mitral valve repair in 12 cases (5%). Previous cardiac operations had been performed in 36 cases (14%). Follow-up was 100% complete at a mean of 60 +/- 31 months. Univariate estimates of time-related cumulative probabilities were calculated by the Kaplan-Meier method. Multivariable adjustment was performed by Cox proportional hazards regression. Echocardiography was performed in 61% of long-term survivors. RESULTS: There were 11 early deaths (4%) and 58 late deaths. Actuarial survivals at 5, 10, and 12 years were 80% +/- 3%, 50% +/- 8%, and 36% +/- 9%, respectively. At 12 years the freedom from cardiac death was 73% +/- 7%, the freedom from valve-related death was 84% +/- 11%, the freedom from valve reoperation was 83% +/- 9%, the freedom from primary tissue failure was 86% +/- 9%, the freedom from thromboembolism was 67% +/- 13%, and the freedom from endocarditis was 98% +/- 1%. Echocardiography was performed on long-term survivors (mean follow-up 67 +/- 25 months) and showed that transvalvular peak and mean pressure differences measured with Doppler echocardiography were 23.2 +/- 9.6 and 12.3 +/- 4.8 mm Hg, respectively. Aortic regurgitation was found by Doppler echocardiography to be none or trivial, mild, moderate, and severe in 64%, 30%, 3%, and 1% of patients, respectively. Mean left ventricular mass index was 107.2 +/- 35.3 g/m(2) (118.9 +/- 40.2 g/m(2) in men and 98.8 +/- 28.8 g/m(2) in women) at late follow-up. One third of all patients, regardless of sex (n = 26/64 women and n = 14/45 men), had evidence of left ventricular hypertrophy. However, our analyses indicate that the residual left ventricular hypertrophy was not caused by valve mismatch but was probably multifactorial. CONCLUSION: The Carpentier-Edwards Perimount bioprosthesis has provided satisfactory clinical and hemodynamic outcome. However, at long-term follow-up about one third of the patients being investigated still had left ventricular hypertrophy examined by echocardiography.

Aged↗
PubMed2002

Performance of the Carpentier-Edwards SAV and Hancock-II porcine bioprostheses in aortic valve replacement.

BACKGROUND AND AIMS OF THE STUDY: Extended experiences of the Carpentier-Edwards Supra-Annular Valve (CE-SAV) and the Hancock II (H II) porcine bioprostheses were evaluated to determine the freedom from structural valve deterioration (SVD) by reoperation in the aortic position. METHODS: Between 1981 and 1994, 1,524 procedures (mean patient age 67.6+/-11.2 years) with the CE-SAV, and 670 procedures (mean patient age 65.2+/-12.1 years) with the H II were conducted at the University of British Columbia and University of Toronto, respectively. The patient populations were differentiated by mean age, gender and valve size, but not by concomitant coronary artery bypass. The analyses included actuarial and actual freedom from SVD and evaluation of predictors of SVD. RESULTS: Actuarial freedom from SVD at 15 years for patients aged > or =65 years was 91.5+/-2.9% for CE-SAV, and 100% for H II (p = NS), while the actual freedom was 96.4+/-1.0% and 100%, respectively. For the patient population aged 66-70 years, the actuarial freedom from SVD was 87.0+/-6.0% for CE-SAV and 100% for H II (p = NS), while the actual rates were 93.6+/-2.3% and 100%, respectively. For the population aged >70 years, the actuarial freedom from SVD was 96.9+/-1.5% for CE-SAV, and 100% for H II (p = NS), while the actual freedom was 98.8+/-0.5% and 100%, respectively. In the patient population aged <65 years, the actuarial freedom from SVD at 15 years favored the H II (p = 0.04), and the actual freedom showed the same outcome. The valve type was not predictive of SVD for age groups < or =60 years, >60 years, 61-70 years and >70 years, but was predictive for the overall population (p = 0.03), as was age and previous valve replacement. CONCLUSION: The CE-SAV and Hancock II both provide satisfactory clinical performances, with a low incidence of SVD, and no significant difference in SVD was shown in patients aged > or =65, 66-70, or >70 years. There is a trend to less SVD by actual analysis for the Hancock II in patients aged <65 years. This evaluation must be considered as work-in-progress because of the limited number of patients at risk at 15 years, especially with the Hancock II prosthesis.

Adolescent↗
PubMedDate not supplied

Morphological findings in explanted Toronto stentless porcine valves.

BACKGROUND: Stentless porcine valves have many documented advantages over stented valves. Since its introduction in 1991, the Toronto stentless porcine valve (T-SPV) has shown excellent hemodynamic performance. METHODS: A total of 332 T-SPVs have been implanted at our institution up to December 2003, 25 of which have been explanted at surgery. Herein, we report a study of 30 explanted T-SPVs seen at our institution over a 5-year period. RESULTS: The mean patient age at explant was 61.2+/-11.8 years with a mean implant duration of 100.7+/-27.8 months (after excluding one valve removed early postoperatively for infective endocarditis). Twenty-seven of 30 valves (90%) showed structural deterioration characterized by tissue degeneration, cusp tears, calcification, and lipid insudation. Eight valves (26.7%) showed evidence of calcification on gross inspection and a total of 23 valves (76.7%) showed at least one microscopic focus of calcification, located primarily in the basal and commissural regions of the cusp. Twenty valves (66.6%) showed cusp tears. Pannus was visible grossly on the surface of 27 of 30 valves (90%), while histologically, at least some degree of pannus was observed on both the inflow and outflow surfaces of all but two valves. Twelve T-SPV (40.0%) showed calcification in the porcine aortic tissue, four of which involved calcification of the porcine muscle shelf in the right coronary cusp. Two T-SPV showed no significant structural deterioration. Their clinical reason for explantation was incompetence or infective endocarditis. CONCLUSION: With a freedom from reoperation of about 87.0% at up to 10 years, the T-SPV shows excellent durability. The majority of explanted valves show structural valve deterioration similar to that seen in other porcine heart valves.

Animals↗
PubMedDate not supplied

A giant coronary artery aneurysm in the right coronary artery.

Aneurysms of the coronary arteries are uncommon occurrences that usually develop secondary to atherosclerosis and are often asymptomatic. They are usually diagnosed incidentally during investigation for ischemic heart disease or at autopsy for sudden death. We present a case of a "giant" right coronary artery aneurysm (CAA) discovered incidentally at surgery. Pathological examination confirmed that this was a true aneurysm showing marked thinning of the media and fibrocalcific plaques with small, multifocal areas of lymphocytic infiltrates.

Atherosclerosis↗
PubMedDate not supplied

Ruptured synthetic expanded polytetrafluoroethylene chordae tendinae.

Synthetic sutures are used for mitral valve repair and as synthetic chordae tendinae to resuspend the mitral valve. The sutures soon get covered with connective tissue and work well for long periods. We report the first instance (in the literature) of rupture of a synthetic (PTFE) chordae tendinae. The synthetic suture (PTFE) was associated with calcification.

Aged↗
PubMedDate not supplied

Aortic root replacement in patients with previous heart surgery.

OBJECTIVE: The objective was to review the operative risk and outcomes of redo aortic root replacement. PATIENTS AND METHODS: From July 1990 to December 2001, aortic root replacement was performed in 165 patients who had at least one previous cardiac operation. Their mean age was 49 +/- 16 years and 78% were men. Twenty-eight patients had a previous aortic root replacement. The principal indication for surgery was prosthetic aortic valve dysfunction. All the patients had a dilated, calcified, ruptured, or some other abnormality of the aortic root. The follow-up was complete and extended from 0 to 12.5 years, mean of 3.8 years. RESULTS: There were 12 operative (7%) and 20 late deaths (12%). The survival at 8 years was 68%+/- 6%. The principal cause of death was cardiovascular related. Age at increments of 5 years (risk ratio: 1.2; CI: 95%; 1.1 to 1.4) and preoperative New York Heart Association functional class IV (risk ratio: 2.2; CI: 95%: 1.1 to 4.7) were the only two independent predictors of death. Two patients had a stroke and died; two patients developed three episodes of prosthetic valve endocarditis and died. Three patients were reoperated on because of endocarditis in one, bioprosthetic valve failure in one, and dehiscence of a prosthetic mitral valve in one. The freedom from reoperation at 8 years was 93%+/- 5%. CONCLUSIONS: Redo aortic root replacement can be done with low operative mortality in elective patients and the risk increases in those who need emergent surgery and are older. The long-term results are satisfactory and similar to those for patients who have aortic root replacement for the first time.

Adult↗
PubMedDate not supplied

Artificial chordae tendinae: long-term changes.

BACKGROUND AND AIM: We present the clinical and pathological findings of a patient who underwent mitral valve repair, with synthetic chordae, for rheumatic disease 13 years earlier. METHODS: Echocardiographic, pathologic, and histologic examination of a previously repaired mitral valve using artificial chordae tendinae. RESULTS AND CONCLUSIONS: Extensive fibrosis and thickening, consisting of fibroblasts and mature collagen, in time surrounds the artificial chorda rendering it indistinguishable from its native counterparts on gross examination and even during echocardiography.

Chordae Tendineae↗