Behrns, K.E.

The aims of this study were to determine the effects of duodenal and jejunoileal nutrient infusions on small intestinal motor patterns and intestinal contractions in neurally intact and neurally isolated small bowel. Fifteen dogs were prepared with duodenal and jejunal infusion and manometry catheters and a diverting jejunal cannula. Ten of the dogs underwent in situ neural isolation of the jejunoileum. A mixed nutrient meal (0.5 kcal/ml) was infused into the duodenum or jejunum at 3 ml/min for 5 h. Control experiments involved infusion of a balanced salt solution. Manometric data collected on-line to a microcomputer were analyzed for direction, distance, and velocity of spread of single pressure waves (SPW) and clustered contractions. Isolated duodenal and jejunoileal nutrient infusions inhibited the fasting motor pattern in neurally intact and neurally isolated small bowel. Motor activity (motility index) increased slightly during nutrient infusion within groups, but there were few differences between groups. Neither neural isolation nor nutrient infusion had a consistent effect on spread of SPW or migration of clustered contractions. Isolated duodenal and jejunoileal nutrient infusions in the dog inhibit fasting motor patterns and increase motor activity slightly but have little effect on characteristics of individual and clustered contractions. Extrinsic innervation to the jejunoileum or intrinsic neural continuity of the jejunum with the duodenum had little effect on single or grouped contractions. Although the changes in motor activity demonstrated in this study appear small, alterations in intestinal transit and absorption may still occur and may be of importance physiologically.

Our aim was to determine the effect of in situ neural isolation of the jejunoileum (extrinsic denervation and disruption of enteric neural continuity with the duodenum) on the spread of single pressure waves (SPW) and clustered contractions (CC) in response to increasing rates of isolated duodenal and jejunoileal nonnutrient infusions. Ten dogs were prepared with duodenal and jejunal infusion and manometry catheters and a diverting proximal jejunal cannula. Five of the dogs also underwent in situ neural isolation of the entire jejuno- ileum A noncaloric solution was infused at 0-15 ml/min into proximal duodenum or jejunum while manometric data were collected. Alterations in direction, distance, and velocity of spread of SPW and CC with increasing rates of intestinal infusion were analyzed by linear regression of responses to increasing infusion rates. Neural isolation of the jejunoileum did not markedly alter characteristics of duodenal or jejunal SPW or CC under conditions of no intestinal infusion. After neural isolation of jejunoileum, increasing rates of jejunal infusion decreased both the proportion and distance of antegrade spread of SPW in duodenum. These findings suggest that extrinsic innervation to the jejunoileum and enteric neural continuity with the duodenum do not regulate jejunal SPW or CC. Increasing rates of nonnutrient intestinal infusions do not alter local motor patterns in the innervated or neurally isolated jejunum, but after neural isolation of the jejunoileum, these infusions do alter characteristics of duodenal SPW by mechanisms independent of neural pathways.

Abstract Occasionally pancreatoduodenectomy is performed for clinically suspected pancreatic malignancy only for the surgeon to find that a benign aetiology accounts for the pancreatic mass. The aim of this study was twofold: to determine the incidence of pancreatoduodenectomy performed for a misdiagnosis of pancreatoduodenal malignancy and to identify potentially avoidable errors in preoperative and intraoperative judgement. Between 1956 and 1990, radical pancreatoduodenectomy was performed in 603 patients at the Mayo Clinic; 29 (5 per cent) underwent pancreatoduodenectomy for a diagnosis made before and during surgery of primary pancreatic or periampullary malignancy that was later proven histopathologically to be either unsuspected subacute or chronic pancreatitis (22 patients), benign fibrous common bile duct stricture (two), and penetrating duodenal ulcer, metastatic melanoma, ampullary adenoma, intrahepatic drug-induced cholestasis and pseudocyst (one each). No patient had a preoperative diagnosis of chronic pancreatitis. Weight loss, pain and/or jaundice were present in 27 of the 29 patients. Objective imaging tests, such as computed tomography, ultrasonography and/or endoscopic retrograde cholangio-pancreatography, were performed in 25 patients. Potential errors in judgement may be avoided by a more aggressive attempt at biopsy in selected patients; in others, resection for presumed malignancy may be unavoidable.