Postcardiotomy shock: clinical evaluation of the BVS 5000 Biventricular Support System.

This prospective trial evaluated the safety and efficacy of a new pulsatile, temporary ventricular assist device, the BVS 5000. Patients were eligible for treatment if they were hemodynamically unstable despite maximal pharmacologic and intraaortic balloon pump therapy, were free of concomitant complications, and were less than 6 hours from the first attempt to separate from cardiopulmonary bypass. Fifty-five postcardiotomy patients were enrolled; 31 met all selection criteria and the remainder failed to meet criteria (n = 15) or were not successfully supported (n = 9). The BVS 5000 effectively restored hemodynamics: Mean arterial pressure increased (77.1 +/- 8.0 mm Hg on-support versus 50.1 +/- 15.3 mm Hg presupport; p = 0.0001). Cardiac index increased (2.3 +/- 0.3 L.min-1.m-2 on-support versus 1.6 +/- 0.6 L.min-1.m-2 presupport; p = 0.0013). Left ventricular filling pressure decreased (11.9 +/- 4.5 mm Hg on-support versus 23.8 +/- 8.7 mm Hg presupport; p = 0.0030). The most frequent complication was bleeding in 42 patients (76%). Of the patients meeting all criteria, 17 (55%) were weaned from support and 9 (29%) were discharged. Survival was significantly influenced by presupport cardiac arrest events. Survival among patients not experiencing arrest was 47%. Eight patients are long-term survivors and were asymptomatic in New York Heart Association class I or II at 1-year follow-up. The BVS 5000 restored hemodynamics, permitted myocardial recovery, and improved survival in a group of patients who would have otherwise died.

Lesser saphenous vein as an alternative conduit of choice in coronary bypass operations.

Dissatisfaction with the use of the greater cephalic vein and the ease of harvest and overall excellent quality of the lesser saphenous vein have caused us to consider this as our alternate conduit of choice when complete revascularization cannot be obtained with the internal mammary artery and greater saphenous vein. We describe our experience with this conduit and our harvesting technique and review the anatomy of this vein.

Effect of nitroglycerin and aortic occlusion on myocardial blood flow.

To better characterize the cardiac and peripheral effects of nitroglycerin during aortic occlusion, we measured myocardial blood flow in 43 normal and pentobarbital (PB)-depressed dogs (groups I to VII). PB was continuously infused in groups IV to VII to maintain reduced cardiac output and contractility. In groups VI and VII nitroglycerin was administered at 2 micrograms/kg/min. Sequential injections of radioactive microspheres (10 micrometers) and hemodynamic measurements were performed during 2-hour occlusions of the infrarenal aorta. The hearts were divided into endocardium, midmyocardium, and epicardium; total and regional blood flows and the ratio of endocardial to epicardial blood flow (endo/epi) were calculated. The results (mean +/- SEM) were subjected to analysis of variance. Normal dogs that underwent aortic occlusion had predictable increases in peripheral vascular resistance. Coronary vascular resistance fell (P less than 0.05) and endo/epi ratios were maintained above 1. Following PB administration, the myocardial blood flow uniformly fell (1.08 +/- 0.34 to 0.55 +/-0.09 ml/min/gm, P less than 0.001), and the animals not treated with nitroglycerin demonstrated decreased endo/epi ratios (1.11 +/- 0-.07 to 0.83 +/- 0.08, P less than 0.001). Although nitroglycerin did not prevent decreases in total myocardial blood flow, endo/epi ratios were maintained above 1 in treated animals (group VI, 1.04 +/- 0.08; group VII, 1.18 +/- 0.17). Furthermore, the increases in left ventricular end diastolic pressure in the untreated animals were significantly greater than those in animals receiving nitroglycerin (P less than 0.01). Despite severe cardiac depression, nitroglycerin maintained normal transmural distribution favoring the endocardium. Since coronary and peripheral vascular resistances were not altered, this benefit most probably reflects decreased ventricular wall tension secondary to preload reduction.

Nonpenetrating trauma to the thoracic aorta.

Twenty-seven patients underwent surgical repair for nonpenetrating injuries of the thoracic aorta. Emergency operation was performed in 19 patients with acute aortic injury and there were 12 survivors. Left heart bypass (LHB), external shunts, and simple aortic cross-clamping were methods employed during repair. All operative deaths occurred in the left heart bypass group. Morbidity, hospital stay, operative time, and blood loss all were markedly less in patients repaired with an external shunt or simple cross-clamping. Systemic heparinization related adversely to mortality and morbidity. Eight patients had repair of chronic post-traumatic descending aortic aneurysms. One of these had previous repair elsewhere with paraplegia and subsequent mycotic aneurysm at the graft repair site. He presented to us with massive hemoptysis. Surgical correction in the chronic group was performed using either left heart bypass, external shunt, or simple aortic cross-clamp with graft interposition. The only death occurred in a patient repaired on left heart bypass.