Faculty Bibliography

The hospital records of 870 consecutive patients undergoing elective biliary tract operations during an eight year period were reviewed. Bacteriologic cultures of the biliary tract obtained on 451 patients were correlated with specific biliary tract abnormalities and with postoperative complications. The incidence of positive biliary tract cultures was higher in patients with common duct disease than in those with chronic gallbladder disease without common duct disease. Choledocholithiasis and partial obstruction of the common duct are viewed as important factors in causing a high incidence of postive biliary tract cultures. Eighty-eight per cent of patients who had undergone previous biliary tract decompression procedures had positive cultures. There was no difference in the yield of postive cultures taken from the gallbladder wall and the gallbladder bile. Forty-nine per cent of patients with common bile duct disease and positive biliary tract cultures had no history of clinical cholangitis. Postoperative wound infections were more common in patients with common duct disease. The microorganism responsible for postoperative cholangitis and septicemia can usually be cultured from the biliary tract at operation. Antibiotics significantly decreased the incidence of postoperative cholangitis and septicemia

The ability of coronary collateral vessels to supply an adequate volume of blood to the subendocardium during the resting state and during periods of stress was studied. Regional myocardial blood flow was determined by the radioactive microsphere technique. Ameroid constricting devices were placed around the left circumflex coronary artery in 22 adult mongrel dogs. Three months later, regional myocardial blood flow was measured in a normal area of the left ventricle as well as in the area supplied entirely by coronary collateral vessels. Collateral blood flow was sufficient in the resting state to prevent myocardial ischemia distal to a gradually occluded coronary artery. However, in 10 animals (Group I) without aorta-coronary bypass grafts (ACBG), a selective underperfusion of the collateralized subendocardium occurred during periods of stress. In 12 animals (Group II), this selective underperfusion of the collateralized subendocardium with stress was abolished by placing ACBG's distal to the site of the coronary artery occlusion

The evolution and transmural distribution of coronary collateral blood flow in acute myocardial infarction was determined in 24 trained, unanesthetized dogs by injection of radioactive microspheres into the coronary circulation. Acute coronary artery occlusion resulted in a greater decrease in subendocardial flow than subepicardial flow in both the central and marginal zones of the infarct. Coronary collateral blood flow was distributed primarily to the marginal zone and to the subepicardium of the central zone of the infarct. The greatest increase in collateral flow occured between 12 and 18 hours after coronary artery occlusion. By 24 hours after coronary occlusion, blood flow to all areas of the infarct except the subendocardium of the central zone had returned to near control levels. This dispropotionate distribution of coronary collateral blood flow during the early stages of myocardial ischemic injury helps to explain the apparent lack of protection of the subendocardium by collateral flow