Biomedical subjects
D S Zimmon
Publications and source records attributed to D S Zimmon.
The biliary tract: imaging for the 1990s.
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Alternatives to cholecystectomy and common duct exploration.
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Injection pistol for volume control of contrast injection during endoscopic retrograde cholangiopancreatography.
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New bile duct interventions: critique and caveats.
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The management of common duct stones.
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Pathogenesis of precirrhotic portal hypertension in alcohol-fed baboons.
To study mechanisms and anatomic correlates of precirrhotic portal hypertension, we measured portal pressure either at laparotomy (in the portal vein) or by hepatic vein catheterization (wedge pressure) in 24 pairs of baboons fed 50% of energy either as ethanol or isocaloric carbohydrate (controls) for 4 mo-9 yr. On liver biopsy 7 had simple fatty liver; none had portal pressure exceeding the control range (2.7-13.0 cmH2O). The remaining 17 alcohol-fed baboons had fibrous tissue deposition around the terminal hepatic venules and adjacent sinusoids. The mean portal pressure was significantly increased (15.0 +/- 1.4 cmH2O) compared with the value in baboons with fatty liver (9.6 +/- 0.9 cmH2O) and in controls (8.0 +/- 0.6 cmH2O), with 8 animals exceeding the control range. Estimated hepatic blood flow was unchanged. Alcohol feeding resulted in increased hepatocyte size in both the fatty liver and fatty liver with fibrosis group; however, portal pressure did not correlate with alterations of cell size, liver volume, hepatic triacylglycerol, and protein contents. By contrast, for veins of comparable size, there was a significant correlation (r = 0.6666, p less than 0.01) between the thickness of the perivenular fibrous rim and portal pressure. Perivenular fibrosis was commonly associated with adjacent perisinusoidal fibrosis and this lesion also correlated with portal pressure. Furthermore, if one postulates that increased cell size causes enhanced pressure with secondary fibrosis, the latter should have first occurred "upstream," in the mid and portal zones. Sequential biopsy specimens, however, showed that fibrosis first appeared in the perivenular areas, suggesting that, in most instances, increased pressure is in fact secondary to the perivenular fibrosis.
Devices and techniques for endoscopic sphincterotomy.
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Investigation and management of biliary tract disease.
Evolution in the diagnosis and non-surgical management of biliary tract disease is outlined and analyzed. The relative roles of endoscopic and percutaneous techniques are weighed in terms of risk, technical difficulty and clinical value. Initial diagnosis and treatment should be by endoscopic retrograde cholangiopancreatography (ERCP) when feasible because of lower diagnostic and treatment risk. When technical or clinical circumstances dictate, a prompt shift to percutaneous techniques is indicated. The complimentary roles of endoscopic, percutaneous and surgical methods are emphasized. Therapy by nonsurgical methods is closely linked to diagnosis by direct cholangiography. Close coordination reduces hazard and improves likelihood of successful resolution in these difficult clinical problems.
Endoscopic stents and drains in the management of pancreatic and bile duct obstruction.
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Effect of portal venous blood flow diversion on portal pressure.
To anticipate the hepatic vascular response to portacaval anastomosis, we studied portal pressure during diversion of portal blood through a temporary extracorporeal umbilical vein to saphenous vein shunt. The relationship of portal pressure to shunted flow was approximately linear. In five schistosomiasis patients (controls) portal diversion to 1,250 ml/min gave portal pressure-shunted flow curve slopes ranging from 0.13 to 0.57 cm water/100 ml per min (0.31+/-0.18, mean+/-SD). In 17 cirrhotic patients with portal hypertension a continuum of slopes was observed from within mean+/-2 SD of control (type A) to larger slopes (type B) indicating failure of portal pressure regulation. When portal flow was augmented by shunting from saphenous vein to portal vein, cirrhotic patients who had slopes less than mean+/-2 SD of controls during diversion (type A) exhibited a compliant system with small increases in portal pressure, whereas type B patients had significantly greater pressure increases. Selective investigations suggested that changes in portal pressure provoked compensatory changes in hepatic arterial blood flow that tended to maintain portal pressure at a set point. Type B patients demonstrated failure of this mechanism to varying degrees.After end-to-side portacaval shunt, seven type A cirrhotic patients maintained residual intrahepatic venous pressure unchanged from prior portal pressure, whereas six type B patients had a significant decrease. Residual intrahepatic venous pressure was measured after portacaval shunt in 40 cirrhotic patients who were followed for as long as 9 yr (median survival 4.0 yr). The 13 patients who developed chronic encephalopathy had significantly lower pressure (21.1+/-4.4 cm, mean+/-SD) and shorter survival (median 0.6 yr) than the other 27 patients (32.6+/-5.3 cm, 5.0 yr). The preoperative estimation of portal pressure-diverted portal flow curve slope anticipates the hepatic vascular response to portacaval anastomosis and identifies a group of patients in whom loss of portal blood flow results in a low residual intrahepatic venous pressure that is associated with early death and chronic encephalopathy.
Acute abdominal pain, vasculitis, and hepatitis B antigenemia.
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Endoscopic diagnosis and management of biliary and pancreatic disease.
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Advances in the management of bile duct obstruction: percutaneous transhepatic cholangiography and endoscopic retrograde cholangiopancreatography.
Jaundice can be diagnosed anatomically and frequently histopathologically without laparotomy by radiologic and endoscopic techniques, combined with biopsy or cytology. Benign and malignant causes of bile duct obstruction can be managed by endoscopic and radiologic methods with reduced morbidity and mortality, displacing abdominal operation for many entities. Even unresectable or inoperable lesions can be effectively palliated by these new techniques.
Visualization of the bile ducts.
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Percutaneous pancreatography: case report and presentation of technique.
A case of traumatic pancreatitis with a radiopaque calculus producing pain by obstructing the distal pancreatic duct is presented. Preoperative ductal anatomy was defined by a percutaneous pancreatogram that established the presence of mechanical duct obstruction as the cause of pain, and the potential for operative relief of duct obstruction. A remission from pain resulted from pancreatic duct decompression by a lateral pancreaticojejunostomy. The potential value of percutaneous pancreatography is discussed.
Radiology of papilla of Vater stenosis.
The radiographic characteristics of the terminal pancreatic and biliary ducts were analyzed by endoscopic retrograde cholangiopancreatography in 25 patients with documented benign stenosis of the papilla of Vater. Demonstration of marked hypertrophy of the distal sphincter, mucosal hyperplasia or mucosal redundancy of the distal common bile duct, dilatation of the ducts, and prolonged retention of contrast media suggest papillary stenosis. The diagnosis of benign papillary stenosis, however, ultimately depends on physiologic measurements and response to therapy.