Biomedical subjects
Publications and source records attributed to M A Sarsam.
Candida parapsilosis endocarditis in association with prosthetic heart valves is rare. We report the first two cases of C. parapsilosis endocarditis on the Toronto stentless porcine valve (TSPV) and the first reported case of successful elimination of infection without lifelong antifungal therapy.
A 61-year-old man with angina had a lesion in the left upper lobe of his lung on chest roentgenogram. Coronary angiography revealed a dominant circumflex lesion. Combined coronary artery bypass grafting (CABG) and left upper lobectomy was performed through left posterolateral thoracotomy without the use of cardiopulmonary bypass. Off-pump CABG abolishes the complications of cardiopulmonary bypass, while posterolateral thoracotomy provides a direct access to the circumflex vessels and is ideal for lung resection.
We present a case of acute endocarditis involving the posteromedial commissure and both leaflets of the mitral valve, including a vegetation on and perforation of the anterior leaflet, in a young man with active Crohn's disease. Repair was performed using glutaraldehyde-treated bovine pericardium. Competence of the valve was achieved with no recurrence of endocarditis. This case demonstrates that extensive destruction of both leaflets of the mitral valve does not prohibit repair.
BACKGROUND: Our objective was to compare long-term results of mechanical and bioprosthetic valve replacement in patients older than 70 years. METHODS: Patients older than 70 years who had either a St. Jude Medical (SJM) mechanical prosthesis or any bioprosthesis (BP) implanted between January 1977 and December 1997 were identified. Alive patients were interviewed by telephone during a closing interval of 130 days. RESULTS: Complete follow-up was achieved with a total follow-up of 2,264 patient years. A total of 547 patients had 448 aortic valve replacements (199 SJM and 249 BP) and 99 had mitral valve replacements (76 SJM and 23 BP). A further 30 patients had double valve replacement. One hundred ninety of the 577 patients (33%) had coronary artery bypass grafting in addition to the valve replacement. Survival analysis showed no advantage for either mechanical or bioprosthetic valves. There was also no difference in thromboembolic rates, paravalvular leaks, structural dysfunction, and endocarditis rates. However, patients with mechanical valves had a significantly greater risk of major (p < 0.0001) and minor bleeding (p = 0.002) events. CONCLUSIONS: Bioprosthetic valves do not offer a survival advantage over mechanical valves among the elderly. However, anticoagulant-related mortality and morbidity is statistically higher for patients with mechanical valves.
BACKGROUND: Patients undergoing repeat heart valve operations are a diverse population. We assessed risk factors for operative mortality in patients undergoing a first heart valve reoperation. METHODS: A retrospective review of hospital records was performed for 671 patients who underwent first repeat heart valve operations between 1969 and 1998. Univariable and multivariable analyses were performed. RESULTS: Operative mortality was 8.6%. Mortality fell each decade to 4.8% in the most recent period (adjusted chi(2) for linear trend P <.0005). Mortality increased from 3.0% for reoperation for a failed repair or reoperation at a new valve site to 10.6% for prosthetic valve dysfunction or periprosthetic leak and to 29.4% for endocarditis or valve thrombosis. Concomitant coronary artery bypass grafting was associated with a mortality of 15.4% compared with 8.2% when it was not required. Mortality for aortic valve replacement was 6.4%, mitral valve replacement 7.4%, aortic and mitral valve replacement 11.5%, tricuspid valve replacement 25.6%, periprosthetic leak repair 9.1%, and isolated valve repair 2.2%. Among 336 patients requiring replacement of prosthetic valves, mortality was 26.1% for replacement of a mechanical valve compared with 8.6% for replacement of a tissue valve (P <.0005). Multivariable analyses identified year of reoperation, age, coronary artery bypass grafting, indication, and replacement of a mechanical valve rather than a tissue valve as significant explanatory variables for operative mortality. CONCLUSIONS: Heart valve reoperations can be performed with an acceptable operative mortality. However, we have identified several categories of patients in whom reoperation carries an increased risk.
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BACKGROUND AND AIM OF THE STUDY: By providing a superior hemodynamic profile, the stentless valve design allows ventricular remodeling and may improve patient survival after aortic valve replacement (AVR). Compared with stent-mounted prostheses, implantation is more complex and requires a longer ischemic time; this may adversely affect surgical risk, especially if patients are elderly or require a concomitant procedure. The mid-term clinical and hemodynamic performance of the Toronto SPV bioprosthesis in a predominantly elderly patient group was analyzed. METHODS: A total of 123 patients (median age 72 years) underwent AVR with the Toronto SPV. Concomitant procedures (mainly coronary artery bypass grafting, CABG), were performed in 60 patients (49%). Clinical details were recorded, with 100% follow up (total 317 patient-years). Hemodynamic evaluation, by serial echocardiography, was performed at four and 18 months after implantation. RESULTS: The early mortality rate was low (0.8%). Mean (+/- SD) actuarial survival at 53 months was 78 +/- 5.9%, with most patients (91%) in NYHA classes I and II. Freedom from valve-related complications were: endocarditis 93.8 +/- 2.3%, thromboembolism 90.3 +/- 3.7% and bleeding 95.8 +/- 1.8%; there were no structural failures. The valve hemodynamic profile was excellent for all sizes: peak gradient 8.8 +/- 4.3 mmHg, effective orifice area 1.9 +/- 0.54 cm2 with significant improvement in left ventricular fractional shortening. CONCLUSION: In this patient population the Toronto SPV was a suitable choice. Advanced age, a requirement for concomitant procedures and increased ischemic times did not adversely affect surgical risk. AVR with the Toronto SPV provided an excellent hemodynamic profile, and improved both left ventricular function and NYHA functional class.
A single-stage procedure for repair of the whole thoracic aorta via median sternotomy is described. The procedure is based on exposure of the descending aorta, posterior to the pericardium in the oblique sinus, or exposure of the aorta in the supracoeliac region and the placement of an endoprosthesis as an intraluminal graft. The ascending aorta and arch repair can be carried out as usual. The procedure has been performed in five patients with either dissection or aneurysm in the period between 1992 and 1997.
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We describe an alternative technique for orthotopic cardiac transplantation (bicaval Wythenshawe technique), which maintains the right and left atrial anatomy. We compared the new bicaval technique with the conventional (Lower and Shumway) technique of orthotopic cardiac transplantation to identify any beneficial physiologic and clinical outcomes resulting from maintaining the normal anatomy. Seventy-five patients were randomized on an alternate basis to two groups: group A (n = 40) had orthotopic cardiac transplantation with the bicaval technique and group B (n = 35) had conventional orthotopic heart transplantation. All patients were studied with transthoracic echocardiogram, endomyocardial biopsies, and measurement of intracardiac pressures 1, 4, and 12 weeks after transplantation. There were no statistically significant differences in the demographic profile, ischemic time, bypass time, implantation time, transpulmonary gradient, or pulmonary vascular resistance between the two groups. The hemodynamic data were collected in the absence of histologic signs of rejection. In group A right atrial pressure (mean 3.6 mm Hg) was significantly lower (p < 0.03) than in group B (mean 8.8 mm Hg). The right atrial a wave was recorded in 38 patients in group A compared with seven patients in group B (p = 0.041). Atrial tachyarrhythmias occurred in two patients in group A compared with 11 in group B (p < 0.016). Temporary pacing was required in 10 patients in group A and 16 patients in group B (p = 0.034). Four cases of mitral regurgitation (all mild) were detected in group A in comparison with 12 cases (10 mild, 2 severe) in group B (p = 0.008). The mean ejection fraction in the first week after transplantation was 58% in group A and 46% in group B (p = 0.5). In the first 3 months the need for diuretics was less in group A (mean dose 80.8 mg furosemide daily) than in group B (mean dose 134 mg furosemide daily in the first week increasing to 160 mg furosemide daily). Hospital stay was shorter in group A (mean 23 days) than in group B (mean 27 days) (p < 0.015). There were no early deaths as a result of right ventricular failure in group A (n = 0/40) compared with four (n = 4/35; 9%) in group B (p < 0.034). This difference suggests that bicaval orthotopic cardiac implantation is associated with a lower right atrial pressure, a lower likelihood of atrial tachyarrhythmias, less need for pacing, less mitral incompetence, a lower diuretic dose, and a shorter hospital stay.(ABSTRACT TRUNCATED AT 400 WORDS)
Injury to the internal mammary artery (IMA) during harvesting or the construction of sequential anastomosis can be troublesome and may force the surgeon to abandon the use of this valuable conduit. Since July 1991, we have utilized a simple technique for repair of a damaged IMA anywhere along its length. This involves leaving the IMA as a pedicled in situ graft and anastomosing a small piece of vein graft to an arteriotomy at the site of injury. The IMA is then used as originally planned, usually to the left anterior descending, and the vein graft can be used for a second vessel or simply tied. The technique was used in 12 patients, all of whom had an uncomplicated postoperative course.
Over a period of 22 years, chylothorax developed in 9 of 1,800 patients who underwent pneumonectomy. Two groups were identified. In group I (n = 5), accelerated opacification of the pneumonectomy space was noted, but the mediastinum remained shifted to the pneumonectomy site. No hemodynamic problems developed and their course was no different from that of other patients who had undergone pneumonectomy. In the second group (group II; n = 4), rapid opacification of the pneumonectomy space was accompanied by mediastinal shift away from the pneumonectomy site and by major hemodynamic and respiratory embarrassment. All 4 patients required surgical intervention to control the chylous leak.
Currently, three techniques are used for reimplantation of coronary arteries following the insertion of a composite aortic valve graft: Bentall, aortic button, and Cabral interposition graft. We have utilized an alternative technique based on the creation of an inverted U-shaped flap, which is then reflected and sutured to an appropriately sized coronary button. The technique is simple, obviates the needs for coronary mobilization, and assures a tension-free anastomosis and accessible suture line.
A technique of aorto-aortic shunt using ordinary non-heparin-bound tubing was used in 21 patients. The proximal limb of the shunt was introduced via the left ventricular apex and advanced through the aortic valve into the ascending aorta, thereby avoiding the difficulty of cannulating the ascending aorta and offering a superior alternative to positioning the proximal limb in the left ventricular cavity.
Forty patients underwent orthotopic cardiac transplantation at Wythenshawe Hospital between May 1991 and November 1992. Twenty patients had transplantation using an alternative technique that preserves the shape of the left atrium and leaves the right atrium intact (group A). The remaining twenty had conventional transplantation using the technique described by Lower and Shumway (group B). The patients were randomized to either the new or the conventional technique on an alternate basis. There was no mortality in group A, but two patients in group B developed right ventricular failure and died. Two patients in each group developed nodal rhythm and all four recovered sinus rhythm. Echocardiography and Doppler velocimetry at the transvalvular level confirmed normal atrial function in group A with erratic atrial contraction wave in group B. There was also slightly lower incidence of mitral and tricuspid valve regurgitation in group A than in group B. The improved atrial function in group A may play a part in the prevention of right sided failure following cardiac transplantation.
Isolated aortic valve regurgitation that results from disease that primarily affects the aortic wall can be repaired by remodeling of the aortic anulus to restore its normal geometry. This involves excision of the aortic wall to within 2 to 3 mm of the leaflet attachments, detachment of the coronary ostia, reshaping of the anulus with the aid of a Dacron graft, and then reimplantation of the coronary arteries. Increases in the surface area of the leaflet that are caused by root dilatation are often present and can be accommodated in the repair procedure. In this study we describe our experience with 10 patients with annuloaortic ectasia who underwent the remodeling procedure at the National Heart Hospital and the Royal Brompton Hospital from 1982 to 1990.