David S. Zimmon

The portal pressure-blood volume relationship in cirrhosis

Portal pressure-blood volume curves were derived in 13 cirrhotic patients with portal hypertension and oesophageal or gastric varices by measuring portal pressure at two levels of blood volume. Portal pressure varied directly with blood volume. In seven patients where portal pressure was measured at three levels of blood volume separated by 500 ml or more the portal pressure-blood volume relationship was found to be approximately linear.

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.

Endoscopic Retrograde Cholangiopancreatography (ERCP) in the Diagnosis of Pancreatic Inflammatory Disease

The clinical value of endoscopic retrograde cholangiopancreatography (ERCP) was evaluated in 63 patients by comparing the initial clinical diagnosis with pancreatographic findings. ERCP was of considerable diagnostic value and permitted early and precise differentiation of pancreatic inflammatory disease.

Endoscopic retrograde cholangiopancreatography in the dog: a model for training and research

A canine model for training and research in endoscopic retrograde cholangiopancreatography is proposed. Similarities to human endoscopic appearance and anatomy allowed successful cannulation of duodenal papillae in 4 of 10 dogs.

Choledochocele: Radiologic diagnosis and endoscopic management

A case of choledochocele, missed during exploratory laparotomy but managed by endoscopic biliary surgery, is presented.

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.

Repetitive endoscopic accidents and instrument malfunction

The retroflexed tips of peroral endoscopes became impacted on passage into the esophagus in 4 patients. In 3 instances, the impacted endoscope could be advanced to the stomach, straightened, and withdrawn; in 1 instance the retroflexed tip could only be firmly extracted, resulting in a cervical esophageal perforation. The cause of these misadventures was found to be laxity in the tip-control mechanism. The likelihood of such complications may be minimized by regular inspection and maintenance of endoscopic instruments.

The Future of Endoscopic Retrograde Cholangiopancreatography (ERCP) as a Clinical and Research Tool

The initial reception of endoscopic retrograde cholangiopancreatography (ERCP), particularly in North America, was tinged with pessimism and skepticism (1,2). In the short span of two years, a spate of reports documenting experiences at centers throughout the world testifies to the rapid development of individual skill in the technique and to the value of ERCP in the clinical management of pancreatic and biliary tract diseases (3,4,5,6,7). Therefore, it seems appropriate to venture an estimate of the future clinical and research value of this tool so that individuals and institutions will be encouraged to invest the time and treasure necessary to master the technic. The opinion expressed here results from experience gained through more than 400 attempts at endoscopic retrograde cannulation of the papilla of Vater.

7134 Measurement of portal pressure by endoscopic observation of varix collapse or doppler ultrasound during esophagogastric balloon tamponade.

Under an IRB approved protocol we compared the tamponade pressure required to collapse esophageal varices observed endoscopically or by Doppler ultrasound and wedged hepatic vein pressure as a surrogate for portal pressure in patients with cirrhosis and esophageal varices. Endoscopic esophagogastric balloon tamponade utilizes a unique tamponade device with a 12mm lumen deployed over a standard endoscope with minimum conscious sedation. After deployment balloon inflation to specified volume yields 50mmHg tamponade pressure. The 12mm lumen and 4mm control bridle allow normal deglution without pain or discomfort during tamponade. The 6cm diameter gastric balloon is held in place by a 3cm diameter esophageal balloon without traction and blocks portal blood at the diaphragm to decompress esophageal varices. Free communication between esophagus and stomach through the 12mm tamponade lumen limits the influence of endoscopic air inflation and esophageal peristalsis on visible varix collapse. Endoscopic evaluation of varix collapse during tamponade in 6 patients approximated portal pressure but was cumbersome, difficult to reproduce and requires continued sedation. During therapeutic tamponade in 4 patients this method allows adjustment of tamponade pressure to control variceal hemorrhage particularly in a patient with a portal pressure greater than 50mmHg. Alternatively a 20mH doppler ultrasound sensor glued to the tamponade with wires carried parallel to the tamponade bridle was used to signal the cessation of varix blood flow as tamponade pressure was increased to exceeded portal pressure. On tamponade deflation the Doppler signal returns confirming the initial measurement. By changing the signal depth the doppler probe records blood flow of either periesophageal or paraesophageal varices. The Doppler signal is recorded on audio tape for study. One of two patients studied by Doppler probe showed identical portal Doppler tamponade pressure and wedged hepatic vein pressure of 30mmHg. In the second patient background noise prevented identification of the Doppler signal. This initial experience suggests that the Doppler tamponade method may provide a simple and accurate method for measuring portal pressure at endoscopy. Endoscopic observation of varix collapse is crude but useful in therapeutic situations for estimating portal pressure before pharmacotherapy and setting tamponade pressure to collapse varices and control varix hemorrhage.

Nonsurgical biliary drainage in cancer

The rapid evolution of nonsurgical techniques for drainage of the biliary tree first by the percutaneous route and more recently by the use of endoscopic retrograde cholangiopancreatography (ERCP) has raised important issues and questions. We now have three competing techniques for the diagnosis and management of patients with actual or incipient bile duct obstruction due to cancer. What is the role of each technique? In what way do they compliment or compete with each other? Can an algorythm for their use be developed? Can we balance the risk versus the benefits of these various techniques?