George J. Motsay

Traumatic right coronary arterial-right atrial fistula

A healthy 25 year old man presented with a machinery murmur and a history of a penetrating thoracic injury. Hemodynamic and angiographic evaluation demonstrated a fistula from the right coronary artery to the right atrium that was later successfully repaired. This case and similar reported cases indicate that fistula formation is a late complication of penetrating thoracic injuries. The onset of the murmur occurs with enlargement of the fistula and typically is delayed for several weeks to months after the initial injury.

Iliac Vein Trauma With Pelvic Fracture

Major injury of an iliac vein was the principal cause of fatal hemorrhage in six patients with pelvic fractures. Clearly in some cases of pelvic fracture early surgical intervention is necessary to control bleeding. Hypogastric artery ligation will succeed in most instances but first the surgeon must make sure that the bleeding is not coming from a vein.

Experimental auxiliary liver allotransplantation with special reference to biliary duct obstruction and hepatic arterial blood restriction of host liver

Abstract Auxiliary liver allotransplantation accompanied by various adjuvant procedures was performed in dogs. The auxiliary liver was supplied with all the splanchnic blood in addition to arterial flow. The host liver was damaged by (1) deprivation of portal flow and obstruction of the common bile duct and (2) restriction of hepatic arterial blood flow in some cases. In dogs with deprivation of portal flow and obstruction of the common bile duct, four of thirteen survived forty days or more with a functioning graft. Three animals are still alive at 61, 112, and 135 days and have normal serum bilirubin levels. The bilirubin level was found to be a good index for evaluating a rejection crisis. In this group two dogs showed a reduction in the size of the allograft in the absence of any occlusion of the aortic or arterial supply of the grafts. In dogs with restriction of hepatic arterial blood flow, three of ten dogs survived fifty-four days or more. However, a thrombus developed in the graft portal vein in two dogs and there was marked reduction in size of the allograft. In this series of experiments, atrophy of the graft could be prevented for at least three months; however, one dog, still living at 157 days, is showing gradual diminution in the size of the allograft although the portal vein and hepatic arterial anastomosis of the graft are open. Control dogs with portacaval shunts in which the common bile duct was tied and azathioprine given showed high enzyme levels in the absence of an hepatic allograft. This indicates that elevation of enzymes is not a specific indicator of graft rejection. The combination of technetium 99m radioactive scans and serum bilirubin levels is the best indicator of graft function when the common bile duct of the host is tied.

Retrograde Perfusion as a Method for Myocardial Revascularization

Retroperfusion of the superficial coronary venous system was studied in 44 canine fibrillating in vivo, normothermic preparations, with exclusion of the systemic circulation using cardiopulmonary bypass techniques in order to assess its value as a method of myocardial revascularization. Perfusion of either the isolated aortic arch via a brachiocephalic cannula or of the coronary sinus through the free end of a vein anastomosed to the atrial rim of the sinus was performed for 1 h at 100 cm3/min in groups II-IV following 30 min of anoxia. Oxygen uptake, vascular resistance, venous outflow and venous enzyme levels (CPK, GDH) were studied. Group I controls (antegrade perfusion, no anoxia) showed continued aerobic metabolism in contrast to group II (antegrade perfusion) and III (retrograde perfusion) which displayed negative lactate balance. Oxygen consumption was greater in group III than II (p less than 0.01) with a higher oxygen extraction in III (p less than 0.005). Group IV, which was given intravenously 30 mg/kg methylprednisolone prior to anoxia and then retroperfused, showed continued aerobic metabolism with low GDH venous levels and adequate oxygen consumption. Three dogs were then subjected to aortoatrial rim coronary sinus vein grafts with ligation of the left common coronary artery at its bifurcation with distal left circumflex and anterior descending artery-internal mammary vein anastomoses for venous drainage. The right coronary artery was left intact. Arterial inflow into the coronary sinus was associated with a left ventricular pressure of 70-80 mm Hg for up to 1.5 h while regular sinus rhythm was maintained. We conclude that retroperfusion of the coronary sinus represents a surgically feasible technique for providing oxygen delivery to the ischemic myocardium.

The effects of alpha stimulation and alpha blockade on pulmonary vascular segment resistance in canine cardiogenic shock

Abstract We used an isolated lung perfusion technique to examine the effect of alpha stimulation and alpha blockade on the pulmonary precapillary ( R a ) and postcapillary ( R v ) resistances of cardiogenic-shocked dogs. Five groups of dogs (10/group) were used: (1) controls, (2) cardiogenic-shock, (3) cardiogenic shock treated with a continuous infusion of norepinephrine to maintain the arterial blood pressure, (4) cardiogenic-shock treated with 1 mg/kg of phenoxybenzamine, and (5) cardiogenic shock in dogs previously made tolerant to lethal injections of epinephrine (1 mg/kg). All cardiogenic-shock dogs were studied 3 hr after closed-chest coronary artery microsphere embolization. Precapillary ( P a ) and postcapillary ( P v ) pressures were monitored, and the capillary pressures at constant lobe weight ( P c i ) were measured by the stopflow technique. Precapillary and postcapillary resistances were calculated using R a = ( P a - P ci )/ Q and R v = ( P ci - P v )/ Q . The ratio of postcapillary to precapillary resistance was calculated as an index of capillary pressure. Both the precapillary and postcapillary resistances were increased 3 hr after cardiogenic shock. This increase indicated that pulmonary vascular reactivity exists even without an intact nerve supply. The ratio of postcapillary to precapillary resistance was increased with cardiogenic shock which indicated an elevated capillary pressure. The postcapillary resistance was not significantly lowered with alpha stimulation, whereas both precapillary and postcapillary resistances were significantly lowered with alpha blockade. The ratio of postcapillary to precapillary resistance was increased with alpha stimulation and decreased with alpha blockade. An increase in the ratio of postcapillary to precapillary resistance is associated with an increase of capillary pressure and could lead to pulmonary congestion and edema on a mechanical basis. These data may explain the pulmonary congestion and poor survival in cardiogenic-shocked dogs treated with alpha stimulation and the increased survival in cardiogenic-shocked dogs treated with alpha blockade.

Clinical Cardiogenic Shock. Vasopressor Versus Corticoid Therapy.

Excerpt Ninety-five patients in clinical cardiogenic shock (Group I: cardiac index, ≤ 2 litre/min·m2body surface area; systolic blood pressure, ≤ 90 mm Hg) and 20 in impending cardiogenic shock (Gr...

Pulmonary isogravimetric capillary pressures in canine cardiogenic shock: Effect of alpha adrenergic stimulation and blockade

Abstract An isolated lung preparation was utilized to determine the isogravimetric capillary pressure ( P c c ) in five groups of dogs subjected to cardiogenic shock by the microembolization technique: (1) Controls; (2) cardiogenic-shocked controls; (3) cardiogenic shock treated with continuous infusion of norepinephrine to maintain a systolic arterial blood pressure of 90 mm Hg; (4) cardiogenic shock treated with 1 mg/kg phenoxybenzamine; and (5) cardiogenic shock in dogs previously made epinephrine tolerant. Three hours following shock the left lower lobe of the lung was excised and perfused with venous blood from the same animal at high flows with low venous pressures. Those pressures opposing net capillary filtration, isogravimetric capillary pressures, were determined in each lobe by altering arterial inflow and pulmonary venous outflow to maintain a constant weight. Isogravimetric capillary pressure in cardiogenicshocked dogs was elevated above controls 3 hr following cardiogenic shock. Treatment of cardiogenic-shocked dogs with an alpha adrenergic stimulating drug caused an increase in isogravimetric capillary pressure, whereas, treatment with an alpha adrenergic blocking drug and tolerance lowered the isogravimetric capillary pressure to values lower than cardiogenic shock. An elevated isogravimetric capillary pressure in the lung is associated with an increase in interstitial fluid formation. Alpha adrenergic blockade in cardiogenic shock could prevent this accumulation of interstitial fluid and thus the rise in isogravimetric capillary pressure. Possible mechanisms of pulmonary edema formation and elevated isogravimetric capillary pressures in cardiogenic-shocked dogs are discussed.

Diastolic hypertension corrected by operation: A review

Abstract Most patients with diastolic hypertension will eventually be diagnosed as having “essential hypertension.” However, a small but important percentage will have a condition which can be corrected by a specific operative technique. The more common etiologies amenable to operation are coarctation of the aorta, Cushings syndrome, pheochromocytoma, primary aldosteronism and renal artery stenosis. In view of the gratifying outcome in the lesions lending to correction, a systematic screening of all hypertensive patients should be conducted prior to the use of a nonspecific antihypertensive drug program.

The Minnesota system for cardiorespiratory assistance: Test of a new system on dogs

Abstract Venoarterial extracorporeal partial bypass, with asynchronous and synchronous pulsatile perfusion with aortic arch coagulation, was studied in 17 sedated male dogs for up to 24 h, and they were followed up for i month. A specially developed preperfusion drug protocol is described, which allowed the use of homologous blood for both prime and fluid replacement. Five animals survived long-term asynchronous bypass, which was characterized by a reduction in mean aortic and peak left ventricular pressures, left ventricular work index, and tension-time index. Cardiac index was maintained throughout the bypass interval. Viscerocutaneous blood flow was increased and systemic arterial oxygenation was improved. Damage to formed elements of the blood or to coagulation factors was minimal. Synchronized pumping at flows 1200–2000 ml/min resulted in successful augmentation of diastolic pressure. Aortic root pressure curves indicated the presence of ‘ejection phenomenon’ in early diastole and an elastic recoil pressure wave in late diastole. As a result of these studies, we are now developing a mobile cardiorespiratory assistance unit which combines synchronous pulsatile perfusion with membrane oxygenation and monitoring sensors.