Experimental Reflux Pancreatography after Intubation of the Duodenum Per Os

Abstract

Doubilet and Mulholland initially reported the use of contrast media for pancreatography in 1951 (3). Since then numerous attempts have been made, with and without the use of pharmacological agents, to devise a nonsurgical, reflux method of pancreatography (4, 5, 7). The use of Xylocaine locally and aminophylline systemically to relax the opening of the pancreatic duct into the duodenum in dogs has been reported previously (9). In that study balloons were placed in the duodenum, after surgery, to isolate the duodenal segment containing the pancreatic-duct and biliary-duct openings. More recently, reflux pancreatography has been performed in monkeys, also at the time of laparotomy, with secretin and cholecystikinin-pancreozymin used to promote reflux (2). The problems inherent in the reflux method have been discussed elsewhere (10). This report outlines a method of reflux pancreatography after intubation of the duodenum per os. Method and Results Intubation of the duodenum is virtually impossible in the nonanesthetized dog. Most of the common general anesthetics lead to gastric hypotony or atony, however. We have found that gastric peristalsis, which facilitates passage of a double balloon intestinal tube2 into the duodenum (Fig. 2), will return after the use of a short-acting intravenous barbiturate (thiopental 20 mg per kg). The animal is maintained on succinylcholine given as required intravenously in 5–10 mg increments and N2O: O2 (3:1) by inhalation until the tube has passed into the duodenum. Anesthesia is maintained thereafter with intravenous pentobarbital given pro re nata to maintain light general anesthesia. We have used adult mongrel dogs in the 45–65 pound class in these studies. Following placement of the duodenal tube, the balloons are inflated to isolate the segment of the duodenum containing the pancreatic-duct opening, and the duodenal loop is filled with 2 per cent Xylocaine for thirty to forty minutes. The Xylocaine is preheated to a temperature of 37–40° centigrade. Five hundred milligrams of aminophylline is given slowly intravenously over the course of fifteen to twenty minutes, while the Xylocaine is in the isolated loop. Amyl nitrite, by inhalation, has been used in some cases in an attempt to augment relaxation of the smooth muscle around the pancreatic-duct opening. Although this appears to be helpful, it is not mandatory, nor will it work alone. The Xylocaine is replaced with 50 per cent Hypaque. The pressure, as measured at the head of the column of Hypaque, is in the 100–110 mm Hg range. The pressure of the duodenal balloons against the side wall, as measured by the method of Nathan and Kohen (8), is usually 20–40 mm Hg, although pressures up to 120 mm Hg have been recorded. Damage to the duodenum has not been a problem. Using this method, we have been able to get opacification of the ducts of both the proximal and distal lobes (Figs. 4 and 5).