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Biomedical subjects

N H Fishman

Publications and source records attributed to N H Fishman.

At least 19 recordsLinked to original sources
PubMed1995

Arterial conduits in emergency coronary artery surgery.

The internal thoracic artery (ITA) is considered to be the conduit of choice for coronary bypass (CABG), but there has been some reluctance to utilize the ITA for revascularization in emergency situations. In a 9-year retrospective analysis from 1986 through 1993, 484 patients had emergency CABG, 237 were not associated with failed PTCA (noninstrumented) and 247 were within 24 hours of PTCA (instrumented). About 62% of noninstrumented and 49.3% of instrumented patients received one or more ITA grafts, the others receiving only saphenous vein grafts (SVGs). Those who received an ITA graft tended toward male sex, better ejection fraction, and a generally lower clinical risk score. Instrumented patients tended toward a lower incidence of diabetes and left main coronary disease, higher ejection fraction, and lower clinical risk score than noninstrumented patients. The postoperative results were not significantly different between ITA and SVG groups with respect to new Q waves, need for reexploration, sternal wound infection, respiratory complications, or stroke. However, ITA patients more often had an event-free postoperative course, received fewer blood transfusions, and experienced fewer cardiac deaths (2.7% vs 9.4%, p < 0.01). There were few obvious differences in postoperative results between instrumented and noninstrumented patients. These results indicate that the ITA can be used for emergency CABG in selected patients with good results.

Aged↗
PubMed1987

The significance of bundle branch block in the immediate postoperative electrocardiograms of patients undergoing coronary artery bypass.

Three hundred sixteen consecutive patients undergoing coronary artery bypass were studied for postoperative electrocardiographic conduction disturbances. Fifty-five of these 316 patients had postoperative bundle branch block (Group 1). This group had a higher incidence of left main coronary stenosis, together with previous inferior myocardial infarction, than patients without postoperative conduction disturbances (Group 2). Perioperative myocardial infarction, low cardiac output, and death were significantly more common in Group 1 than in Group 2: 7.3% versus 1.9% for perioperative myocardial infarction, 16.4% versus 2.7% for low cardiac output, and 5.5% versus 0.8% for death. Analysis of the type of conduction disturbances indicates that the presence of a new complete left bundle branch block postoperatively in a patient undergoing coronary artery bypass is a sign of intraoperative myocardial damage. This damage is potentially lethal, especially in a patient with left main coronary stenosis and previous inferior myocardial infarction.

Bundle-Branch Block↗
PubMed1986

Infant coarctation: a spectrum in clinical presentation and treatment.

Between 1975 and 1985, 125 infants 2 to 365 days old (majority, 30 days old or less) with coarctation of the aorta underwent surgical repair. Forty-seven patients (38%) had severe congestive heart failure (CHF), metabolic acidosis, and poor systemic perfusion. The predominant operative technique was synthetic patch aortoplasty (100 patients); the remaining 25 had an end-to-end anastomosis. There were no operative deaths. Perioperative complications were minimized with the synthetic patch technique (less than 15%). For patients surviving at least 3 months after repair, the arm-leg systolic blood pressure gradient was relieved in 82% (71/87) of the patients having patch aortoplasty versus 65% (15/23) of the patients with end-to-end anastomosis. Although the rate of reoperation between the two groups was similar (patch, 5 [6%]; end-to-end, 3 [13%], two of the reoperations in the patch group were for preexisting hypoplastic transverse aortic arch. Late deaths (20 patients, 16%) were due to other major associated cardiac anomalies. Patch aneurysms have not occurred. Expedient use of synthetic patch aortoplasty has decreased perioperative complications, relieved coarctation gradients for CHF, increased early survival even in the presence of complex or associated cardiac anomalies, and has an acceptable rate of recurrent coarctation (6 to 13%).

Aortic Coarctation↗
PubMed1986

Preparation of oxygenated cold crystalloid cardioplegic solution.

The value of oxygenated, aqueous, cold cardioplegic solutions is being evaluated at several centers. The theoretical advantages of such a solution are counterbalanced in part by the complexity and expense of the preparation and delivery systems that have been used. A simple method is described that effectively achieves satisfactory levels of oxygenation of the cardioplegic solution within its original vinyl container.

Potassium↗
PubMed1982

Reconstructive surgery for obstructing lesions of the intrathoracic trachea in infants and small children.

This is a report of ten infants and small children with congenital obstructive lesions of the distal trachea and main bronchi. Four were successfully resected. One with a distal segment stenosis required tracheal resection at age 6 wk, another with stenosis of the distal half of the trachea at age 18 mo, and 2 (1 with distal stenosis and 1 with tracheal hamartoma) at age 4 yr. All 4 are presently free of symptoms and their anastomoses have grown without stricture. A child with coil-spring mucosal stenosis of the left main bronchus developed an excellent airway following bronchoscopic removal of the folds, and a baby with tracheomalacia was successfully treated with a rib splint on a segment of distal tracheomalacia, but she died later of associated cyanotic congenital heart disease. Four babies died with airway obstruction in the newborn period. Two with critical distal stenoses died before tracheal reconstruction could be performed. Two died following emergency resections in which all of the congenital stenosis could not be removed. In both, stenotic trachea remained despite operation. All of these infants had complete cartilage rings the entire length of the trachea. Congenital lesions of the distal trachea may become suddenly life-threatening at birth or during the onset of a respiratory infection. An abrupt or insidious onset of airway symptoms requires an expeditious diagnostic evaluation to define the tracheobronchial anatomy, and the operating team has to be prepared for emergency tracheal reconstruction.

Abnormalities, Multiple↗
PubMed1981

Uniform myocardial protection by cold potassium-induced cardioplegia for coronary artery bypass.

Cold potassium solution (4 C) is used to induce cardioplegia during coronary artery bypass surgery. When 1,000 ml of the cold solution are introduced through the root of the aorta, the temperature of the myocardium drops to about 7 C within a few minutes. At this level of hypothermia, ischemia can be tolerated for at least 2 h, the surgical field is rendered quiet and dry, and the safety and precision of the procedure are increased. This method, however, does not provide uniform cooling of the myocardium and some areas remain less protected than others. The temperatures in the different areas of the myocardium are measured directly with needle thermistors and the "warm" areas are cooled in turn, in descending order of myocardial temperature. Saphenous vein grafts are anastomosed to the arteries in these warm areas and additional cold solution is instilled through the graft until the temperature drops to 7 C. The coronary artery bypass, and any other required surgical procedure, is then performed. To maintain hypothermia, small amounts of cold solution are infused at intervals through the root of the aorta and through the appropriate graft. With this method of cooling, the operative mortality rate in a series of 200 high-risk patients with coronary artery disease in whom there was at least one factor predisposing to perioperative mortality and/or infarction was only 3%.

Coronary Artery Bypass↗
PubMed1978

Cardiac valve replacement in patients over 65 during a 10-year period.

From 1967 through 1976, 754 adult patients were subjected to open heart procedures for acquired valvular disease at the University of California, San Francisco, 104 of whom were 66 years of age or over (mean = 70 years). The operative mortality of 15.0% in the elderly group did not differ significantly from that of 14.3% in the entire adult series for the 10-year period. Mortality was consistently higher in combined procedures (multiple valve replacement and valve replacement with coronary grafting). Since the introduction, in 1973, of hypothermic hyperkalemic coronary washout for intraoperative protection of the ischemic myocardium, the hospital mortality rate has decreased to 8.1% overall, 6.0% for isolated aortic valve replacement and 0% for isolated mitral valve replacement in patients over 65. Moreover, the long-term survival following aortic and mitral valve replacement in this series appears to approximate the survival curve of the normal population of the same age. This experience suggests that cardiac surgery has become safer for all patients during the past 10 years and that operative mortality is related primarily to the type and severity of disease rather than to age.

Age Factors↗
PubMed1978

Combined treatment methods for carcinoma of the esophagus.

From 1950 to 1973, 129 patients received irradiation for esophageal squamous-cell carcinoma at the University of California, San Francisco. From this group, 26 received surgical and irradiation treatment. Twelve did not receive irradiation until recurrence became evident and among them were no 5-year survivors. Among the other 14 were six 5-year survivors (43%). The authors believe that planned sequential irradiation and surgery offer the best chance for cure in squamous-cell carcinoma of the esophagus. Selection factors, treatment details, and therapeutic regimens are presented and a management plan proposed for this group of operable patients.

Aged↗
PubMed1978

Models of congenital heart disease in fetal lambs.

Intracardiac flow patterns were chronically altered by partially obstructing left ventricular (LV) inflow or outflow in midgestational fetal lambs. Physiological measurements of the fetal circulation were made serially through indwelling catheters and the use of radioactive microspheres. With LV inflow obstruction, mean LV output (LVO) decreased to 30% of control (P less than 0.01). Within seven days, the LV/right ventricular (RV) weight ratio decreased to 70% of control (P less than 0.01), and the mean LV/RV chamber volume decreased to less than one-half of control (P less than 0.001), simulating an early form of the hypoplastic left heart syndrome. With LV outflow obstruction, mean LVO decreased to 64% of control (P less than 0.05). Mean LV/RV wall thickness doubled (P less than 0.0001) and mean LF/RV chamber volume decreased to less than one-half of control (P less than 0.0001). Within four to ten days after increasing LV afterload, a large increase in LV mass occurred, which was demonstrated by morphometric analysis to be due to hyperplasia of ventricular myocytes. LV chamber volume decreased somewhat, simulating moderately severe congenital aortic stenosis. Over the long term (30--36 days), the mean LV/RV weight ratio decreased and the LV chamber was nearly obliterated, simulating very severe congenital aortic stenosis. The results suggest that by varying preload and afterload in both ventricles of the fetus, various forms of congenital heart disease may be simulated.

Animals↗
PubMed1977

The application of radionuclide infarct scintigraphy to diagnose perioperative myocardial infarction following revascularization.

To evaluate the application of radionuclide infarct scintigraphy to diagnose myocardial infarction after revascularization, we obtained postoperative technetium 99m pyrophosphate myocardial scintigrams, serial electrocardiograms and CPK-MB isoenzymes in ten control and 51 revascularized patients. All control patients had negative electrocardiograms and scintigrams, but eight had positive isoenzymes. Eight revascularized patients had positive electrocardiograms, images and enzymes and two had positive scintigrams and enzymes with negative electrocardiograms. Thirty-four patients with negative electorcardiograms and scintigrams had positive isoenzymes; in only seven patients were all tests negative. Our data suggest radionuclide infarct scintigraphy is a useful adjunct to the electrocardiogram in diagnosing perioperative infarction. The frequent presence of CPK-MB in postoperative patients without other evidence of infarction suggests that further studies are required to identify all factors responsible for its release.

Adult↗
PubMed1977

Myocardial protection with cold, ischemic, potassium-induced cardioplegia.

A total of 204 patients, ages 3 months to 84 years, underwent open-heart surgery with the aid of cardiopulmonary bypass with moderate hypothermia. For protection of the myocardium, cardioplegia was induced by washing out the coronary arteries with an iced, buffered, isoosmolar, potassium-based infusate. After aortic cross-clamping, the aortic root or individual coronary arteries were perfused with 500 to 2,000 c.c. of an aqueous solution (at zero to 4 degrees C.) containing 20 mEq. of potassium. Periods of ischemic arrest as long as 208 minutes have been well tolerated, with only two of the eleven hospital deaths considered heart related. Defibrillation occurred spontaneously in 41 per cent and after one shock in 47 per cent of patient, without apparent correlation between duration of ischemia and restoration of effective rhythm.

Cardiac Surgical Procedures↗