Biomedical subjects
Publications and source records attributed to B J Amsel.
Because of the current donor shortage, organ selection criteria are being progressively liberalized. We present a case of carbon monoxide poisoning in a multiorgan donor that led to primary cardiac allograft failure. A biventricular assist device was used as a bridge to recovery.
BACKGROUND: To investigate the feasability and results of endoscopic vein harvesting (EVH) using the Vasoview Uniport system (Guidant Corporation, Menlo Park,CA). Can this technique be used as a standard technique for vein harvesting in coronary artery bypass surgery (CABG) or is it too time consuming? Do smaller incisions result in less morbidity and discomfort? METHODS: From October 1998 to May 1999, 158 patients who underwent CABG with venous grafts, in addition to arterial grafts, formed the study population for EVH. In group A (n=131) the vein was harvested with the Vasoview Uniport System. In group B (n=27) the vein was harvested by a conventional open technique with interrupted incisions because of unavailability of the equipment. Recordings were made on vein length, harvest time, length of incision, and complications. RESULTS: In none of the patients in group A was a conversion to the open technique necessary. In 72/131, pure EVH was used. In 59/131 an additional incision below the knee was used for harvesting extra vein length. Mean harvested vein graft length (cm) was 35.9 (range 18-56) in group A and 30.6 (range 16-51) in group B, and mm of vein harvested/min was 77 and 71 in group A and B. Mean time for harvesting and closing (min) was 56.1 (range 14-120) SD 20.4 and 78.3 (range 37-129) SD 26 for a mean length of incision (cm) of six (range 2-19) and 27 (range 12-54). Wound complications at postoperative day three at discharge, and after six weeks were seen in 30 (23%), 27 (20%) and four (4%) patients of group A, and in five (18%), five (18%) and four (23%) of group B. CONCLUSIONS: Despite a learning curve in using endoscopic techniques, the total procedural time for EHV is acceptable and even shorter than open harvesting. Most of the time is gained in closure of the wound. Hematoma formation is the most common peroperative complication, but diminishes with experience. The absence of postoperative edema after EVH is striking. Despite the higher costs for disposable material, we have adopted EVH as a standard technique since patient and surgeon satisfaction have improved substantially.
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The Bernoulli equation relates the pressure exerted on a fluid to its flow velocity and its density, in addition to its flow acceleration and its viscous friction loss. When flow velocity increases at a narrowing, the local pressure decreases proportionally. It has been wrongfully assumed that pressure lost distal to a stenosis can never recover. It is, however, the energy content of the fluid, equal to the kinetic plus the potential energy, which can not increase. When flow slows distal to a narrowing and little energy is lost to friction, pressure does actually increase. Pressure recovery has been well demonstrated to exist in a variety of pathophysiological states. Bicuspid aortic valve prostheses such as the St. Jude valves can produce quite remarkable pressure recovery. This causes a great discrepancy between pressure drop calculations based on continuous wave doppler on the one hand and true pressure drop across the prosthesis on the other. Reliance on doppler measurements only might wrongfully lead one to conclude that the prosthesis was malfunctioning. Less extreme pressure recovery is possible across a stenotic native aortic valve, but interpretation of the flow velocity across the valve might make the difference between recommendations to replace or to retain the valve. When interpreting doppler signals across narrowings the phenomenon of pressure recovery should be kept in mind.
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Severe heart failure in acute rheumatic myocarditis is rare. It may be rapidly reversible with treatment, so maximal medical treatment and, if necessary, mechanical support should be given before heart transplantation is considered.
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To assess the efficacy and safety of the use of a high-dose regimen of aprotinin in routine cardiac operations, a placebo-controlled randomized double-blind study was conducted in 93 adult patients undergoing cardiopulmonary bypass. Aprotinin-treated patients (group A, n = 46) received 2 x 10(5) Kallikrein Inactivating Units (KIU) of aprotinin before incision, 2 x 10(6) KIU in the priming solution and 5 x 10(5) KIU/h during CPB. Control patients (group B, n = 47) received the same volume of normal saline. Mean postoperative blood loss in ml after six hours and in total until removal of thoracic drains decreased significantly from 752 and 1933 in controls, to 358 and 1051 in treated patients (p < 0.001). Mean total transfusion needs were 2.6 (A) and 4.8 (B) units per patient. Adverse events were evenly distributed between both groups and could not be attributed to aprotinin use. We, therefore, recommend the use of a high-dose regimen of aprotinin for routine cardiac operations despite its cost.
Native valve endocarditis normally presents with fever and only later in its course demonstrates dysfunction of the affected valve. We describe a case of endocarditis due to Neisseria subflava, a Gram-negative diplococcal saprophyte of the oral cavity, which was unsuspected clinically and found unexpectedly during a mitral valve operation performed for symptomatic prolapse with regurgitation.
Right-to-left shunting through a foramen ovale complicating acute right ventricular infarction and resulting in severe arterial hypoxemia has been described eight times before. Treatment strategies have often aimed at reducing the shunt. Four patients died. Less attention has been paid to attempts at revascularization and, despite a high incidence of atrioventricular conduction disturbances, to temporary dual-chamber pacing. We describe herein two patients with postcardiac surgical right ventricular infarction complicated by severe right-to-left interatrial shunting. Treatment strategy was aimed at improving right ventricular function, and right-to-left shunting ceased. All efforts should be directed at treating right ventricular dysfunction, which is the cause of the clinical picture, and not at reducing the shunt, which is a secondary phenomenon.
Atrial flutter occurring after cardiac operations normally responds well to atrial overdrive pacing through epicardial atrial pacing wires and medication. When this fails, transvenous atrial overpacing offers an attractive alternative. We performed the procedure 29 times in 25 patients. Sinus rhythm returned acutely after 25 procedures in 21 patients and persisted with medication in 20 patients at follow-up. The procedure was well tolerated by all.
137 patients with a mean age of 77.3 years (Group A) who underwent isolated coronary artery bypass grafting (CABG) were compared to 137 patients with a mean age of 55.6 years (Group B) who also underwent isolated CABG on the same or the adjacent day as the Group A patients. Group A patients were more commonly women, and had a significantly higher incidence of unstable angina, emergency operations, extensive coronary disease, peripheral vascular disease, and multiorgan debility. However, their left-ventricular function and the extent of revascularisation was similar to Group B patients. They also had significantly more operative mortality (7.2% vs 1.45%, p < 0.001). cardiac and non-cardiac complications, and longer hospital stay (14.2 vs 8.8 days, p < 0.001) than group B patients. At a mean follow-up of 29.8 months, no significant differences were noted in Group A versus Group B patients in terms of long-term survival (95% vs 94%), freedom from angina (82% vs 81%), cardiac readmission (10% vs 12%), or in the incidence of new myocardial infarction or new CABG. Actuarial survival at 4 years was 76.9% in Group A patients and 90.1% in Group B patients. Severe angina due to extensive coronary disease commonly makes urgent surgery unavoidable in this growing population of very old patients, but the operative mortality is modest and survivors do enjoy several years of life, remaining as free of angina, etc., as similar but younger patients.
21 studies reporting on at least 100 elderly patients were reviewed to assess the influence of patient age on outcome of isolated coronary artery bypass surgery. Elderly patients were variously defined as being older than 64, 69 or 74 years of age. They had significantly higher incidences of female sex, unstable angina, urgent surgery, extensive coronary disease, peripheral vascular disease and other risk factors, but left ventricular function was similar to younger patients. The number of grafts inserted and operation times were also similar. Operative mortality and multiorgan morbidity were significantly higher with advancing age. Late survival and relief of angina were generally good.
Over the last three decades, heart valve replacement has become a safe and routine surgical procedure, but replacement devices are still far from ideal. Despite improvements in materials and design, life-long anticoagulation remains mandatory for mechanical valves. The major shortcoming of the less thrombogenic bioprosthetic valves is early tissue failure. Parallel to the decrease in operative mortality after heart valve replacement, the potential quality of life for survivors has been becoming increasingly important in evaluating the late results and in selecting the appropriate device for the given patient. All factors that determine the quality of life are strongly affected by the operation due to the usually dramatic improvement both in subjective status and objective parameters postoperatively. The patient, thus, can return to normal activities, maintain self-esteem and keep normal relationships at work, in the community and at home. Psychoneurologic dysfunction was also found to decrease greatly within six months, although more than a quarter of patients were depressed preoperatively because of their disease. Overall, the experience was generally satisfying.
Two cases of brief left ventricular fibrillation concurrent with a beating right ventricle during cardiopulmonary bypass are described. Although no left or right ventricular dysfunction was detected postoperatively, this regional electrical heterogenicity suggests inhomogeneous myocardial protection during at least a short period of time. The precise mechanisms concerned are not clear and limited clinical and animal experimental analogies can be found in the literature.
We report a 14-year-old girl who sustained a syncope followed by cardiac arrest. She was kept alive for three days by full cardiocirculatory support using left and right ventricular assist devices, but subsequently died in multiple organ failure. Autopsy revealed an anomalous origin of the left coronary artery (LCA) from the right sinus of Valsalva (RSV) and a major left anterior wall infarction. A cyclo-ergometric stress test performed two years before having been negative, we discuss its value in preventing sudden death due to coronary anomalies.
Bullets which enter a sufficiently large vein may embolize to the right ventricle. This finding is usually determined after the bullet has been removed from the heart. A chest x-ray study cannot, however, differentiate with certainty between localization in the right ventricular cavity, the right ventricular wall, or the pericardium. We recommend echocardiography to document bullet localization in the right ventricular cavity prior to surgical removal.