Distal Arterial Bed Research Articles

Current Status of Vascular Grafts

All of the vascular grafts currently available perform satisfactorily in a high flow, low resistance location. Patency rates diminish when any of these grafts are placed in locations with progressively smaller diameters of recipient arteries or limited distal arterial beds. Additional improvement in the patency rates of prostheses placed in such locations may come about through pharmacological modification of the phenomena associated with graft–recipient artery healing.

Surgical correction of chronic postembolic obstructions of the pulmonary arteries

Following episodes of pulmonary embolism, the presence of thrombi in the pulmonary arteries leads to severe respiratory insufficiency and chronic right heart failure. We have operated upon 16 such patients, nine men and seven women from 23 to 68 years of age. All had severe dyspnea, 14 had chronic cor pulmonale, six had mental disturbances with syncope, and four had severe cardiac failure. The presence of clots was demonstrated by pulmonary angiography, and the permeability of the distal arterial bed was ascertained by selective injection of the bronchial arteries. In all cases but two a lateral thoracotomy was used so that the obstructed arterial branches could be approached distally. The inferior vena cava was always ligated to prevent recurrences. There were six operative deaths, three from cardiac failure, one from acute pulmonary edema, one from hemothorax, and one following a pyothorax. Ten patients are surviving after 6 months to 10 years. One is still limited because of significant pleuropulmonary sequelae. Six are enjoying good results with marked improvement in their functional limitations, a significant drop in the pulmonary artery pressure, and radiological permeability of previously obstructed arteries. Three are excellent condition--completely asymptomatic.

Pulmonary Arteriovenous Fistulae with Bidirectional Shunting

Pulmonary arteriovenous fistulae and cardiomegaly in a patient with Rendu-Osler-Weber disease is reported with hemodynamic data. Indicator dye dilution curves showed the expected right-to-left shunt and also revealed the unusual coexistence of a probable bronchial artery to distal pulmonary arterial bed fistula, in effect establishing a bidirectional shunt. The cardiomegaly was considered to be secondary to the left-to-right shunt Partial resection of the fistulae ten years prior to this admission failed to relieve cyanosis and symptoms. Diffuse pulmonary involvement prevented further surgical therapy and medical treatment was recommended. Pulmonary arteriovenous fistulae and cardiomegaly in a patient with Rendu-Osler-Weber disease is reported with hemodynamic data. Indicator dye dilution curves showed the expected right-to-left shunt and also revealed the unusual coexistence of a probable bronchial artery to distal pulmonary arterial bed fistula, in effect establishing a bidirectional shunt. The cardiomegaly was considered to be secondary to the left-to-right shunt Partial resection of the fistulae ten years prior to this admission failed to relieve cyanosis and symptoms. Diffuse pulmonary involvement prevented further surgical therapy and medical treatment was recommended.

Reconstruction of small arteries with an arteriovenous fistula; an experimental study.

PROSTHETIC grafts have not been successful when used to reconstruct small arteries. 1,2,3 The inevitable clotting seems to be directly related to low flow rates through the graft resulting from the small capacity of the arterial bed that the graft supplies. 4,5 Flow through the reconstruction can be increased with a distal arteriovenous fistula. Dean and Read used a femoral arteriovenous fistula to prevent thrombosis in a proximal iliac graft in dogs. 6 However, this type of reconstruction may deprive the distal arterial bed of blood flow so that the tissue it supplies is compromised to preserve graft patency. Root and Cruz used an arteriovenous fistula in dogs to maintain patency of a distally ligated superficial femoral artery and concluded that this helped maintain viability of the limb. 7 In the present experiment the value of arteriovenous fistulae in maintaining function of plastic grafts anastomosed to small arteries was studied.

Studies in regional heparinization. I. The use of simultaneous neutralization with protamine; preliminary studies.

REGIONAL heparinization is a technic whereby heparin is infused into an artery at such a rate that the coagulation time of the blood is prolonged in the area supplied by that artery, but the clotting time in the rest of the body remains normal owing to dilution of the heparinized blood. The technic has been applied primarily after operations on an artery, such as endarteriectomy, in which there is a considerable possibility that postoperative thrombosis will result in obstruction of the vessel. This danger is particularly great when the distal arterial bed is partially obstructed by atherosclerosis. A number of . . .