Lester R. Sauvage

The effect of predetermined thrombotic potential of the recipient on small-caliber graft performance

This study was designed to establish the influence of the recipients thrombotic potential on the patency of small-caliber prostheses and to evaluate the subsequent improvement of graft performance by medicinally altering the prostaglandin balance in subjects predisposed to graft occlusion. Mongrel dogs were pretested and classified as low and high responders according to their thrombotic potential, measured as prostaglandin metabolite balance and platelet aggregability. High responders were randomly divided into two groups. Those assigned to serve as the medicated subjects were pretreated 1 week before surgery with a single oral daily administration of combined dazmegrel (UK-38,485) and aspirin in equal dosages of 3 mg/kg. Medication was continued throughout the experiment. Dacron grafts were implanted bilaterally in the carotid artery site in all subjects. Following a 3-week implantation period, the patency rate for the group with low thrombotic potential was 100%. In the animals with high thrombotic potential the patency rate was 10% for nonmedicated subjects and 100% for medicated subjects. These data support the concept that the thrombotic potential largely determines the capacity of the recipients blood to thrombose small-caliber prostheses. Effective medicinal alteration of prostaglandin balance results in exceptionally increased patency of synthetic grafts.

Radical Enlargement of the Aortic Root and Outflow Tract to Allow Valve Replacement

A method of radical enlargement of the aortic root and outflow tract is described. The technique consists of incising the aortic annulus, the anterior mitral leaflet, and the superior aspect of the left atrium. Valve replacement is then possible, with patch reconstruction of the resulting defects.

Differential effect of the retropleural and retroperitoneal environments on healing of the inner wall of porous fabric prostheses in the thoracic and abdominal aorta of the same dog

Healing of the inner wall of the same preclotted knitted Dacron arterial prostheses was compared in the descending thoracic aorta (DTA) and the abdominal aorta (AA) of the same dog. Each of 16 dogs received this dual implantation with study periods of 4 weeks for five dogs, 8 weeks for five dogs, and 16 weeks for six dogs. Healing was studied with light microscopy, scanning electron microscopy, transmission electron microscopy, and immunocytochemistry identification. The outer capsule was firmly adherent to the Dacron framework of all grafts implanted in the DTA; advanced healing of the inner wall of all thoracic grafts was present by 4 weeks, nearly complete healing by 8 weeks, and complete healing by 16 weeks. In contrast, the outer capsule was either not attached or only loosely adherent to the Dacron framework in eight AA grafts (50%), and in these implants no healing of the inner wall occurred beyond the limited perianastomotic pannus zone. In the other eight implants in which the outer capsule was firmly adherent to the Dacron framework, healing was roughly comparable to that in the grafts implanted in the DTA. This study demonstrated that (1) DTA grafts heal faster and more completely than AA grafts, (2) healing and endothelialization are related to the tightness of the outer capsule, (3) there is a high incidence of loose tissue attachment in the AA, and (4) healing of aortic grafts is site specific.

Severe Left Main Coronary Arterial Stenosis With Right Coronary Arterial Occlusion: Results of Bypass Graft Surgery

A detailed study was made of preoperative, operative and postoperative data from 69 patients with severe (70 percent or greater) luminal narrowing of the left main coronary artery and occlusion of the right coronary artery who underwent bypass surgery from December 1970 through December 1978. Preoperatively, 40.6 percent of patients were in functional class III and 55.1 percent in class IV. Ninety-six percent of those tested had a positive electrocardiographic treadmill test. Coronary bypass grafting was accomplished using standard techniques in all patients. An average of 2.7 grafts/patient were placed. The hospital mortality rate was 4.3 percent, and an additional 4.3 percent died before the end of 1 year. A history of congestive heart failure was a significant predictor (p less than 0.05) of postoperative mortality. An intraaortic balloon pump was not inserted in 64 patients, and our experience suggests that it was a necessary preoperative adjunct. A postoperative treadmill test was negative in 92 percent of those patients tested. Of those surviving 1 year postoperatively, 89 percent were in functional class I and 8 percent in class II. This study demonstrates a surgical mortality rate comparable with that of patients with left main coronary stenosis alone and a significantly better survival rate than that of similar patients treated medically.