Akihito Enjoji

Role of bile acids in duodenal migrating motor complexes in dogs

Previous studies have suggested thatenterohepatic circulation of bile acids is essential forregular cycling of duodenal migrating motor complexes(MMCs). The present study was an attempt to clarify the role of bile acids in the enterohepaticcirculation system in initiating duodenal MMCs. Sevendogs underwent total external biliary diversion thatresulted in the loss of MMCs originating from theduodenum. Sodium ursodeoxycholate (6 mg/kg/hr) was thengiven either through the portal vein or a peripheralvein, and motility of the gastrointestinal tract wasserially recorded. When sodium ursodeoxycholate was given either through the portal vein or aperipheral vein during external biliary diversion,duodenal MMCs restarted. The cyclic change in plasmamotilin levels during an MMC cycle as induced by sodium ursodeoxycholate was almost the same as in anormal MMC cycle. Total bile acid concentration in theportal vein changed cyclically with MMC cycles when bileflow was intact but did not change cyclically with MMC cycles restarted by intravenous bilesalt infusion. Bile acid stimulation of putativereceptors existing between the portal vein andintrahepatic bile ducts may be involved in initiatingnormal duodenal MMC cycles.

Changes in colonic motility in dogs after a resection of the inferior mesenteric ganglion and plexus.

In a curative resection for advanced sigmoid or rectal cancer, an extensive dissection of the regional lymph nodes is generally required. This often necessitates the removal of the autonomic nerves around the inferior mesenteric artery. The present study was done in an attempt to clarify the influence of a neurectomy around the inferior mesenteric ganglion and plexus on the motility of the colon. In eight dogs, we resected the ganglion and plexus around the inferior mesenteric artery, together with an implantation of strain gauge force transducers in various parts of the colon, and 7–10 days later, colonic motility was examined. The percentage of contractile states and contractile forces increased at both the distal colon in fasting dogs, as well as at the middle colon in the late postprandial period. At the distal colon, contractile forces were noted in the early and late postprandial periods. These contractile abnormalities at the middle and distal colon may thus explain the frequent bowel movements or diarrhea often observed after extensive surgery in patients with sigmoid or rectal cancer.

Situs ambiguous with gastric cancer: report of a case.

Situs ambiguous is an unpredictable anomaly characterized by disorder of the organ arrangement in the chest and abdomen. We report a case of situs ambiguous found incidentally in a 73-year-old man with gastric cancer. Preoperative imaging showed polysplenia, a bridging liver, a midline gall bladder, and pancreatic divisum. The vessels around the stomach were clearly shown by computed tomography with multiplanar reconstruction (MPR). Computed tomography with MPR proved a good diagnostic tool for identifying both the abdominal vessels and the location of the organs. Based on a precise evaluation of this unusual anatomy, we performed distal gastrectomy with dissection of the regional lymph nodes.

Experience of gastric cancer in a patient who had received a living-donor liver transplantation

A 57-year-old woman had previously undergone a living-donor liver transplantation (LDLT) for end-stage liver disease related to hepatitis B virus. The liver graft had been donated by her husband. Her postoperative course had been uneventful. In the course of postoperative surveillance, she was incidentally found to have gastric cancer by an endoscopic examination 2 years after the liver transplantation. A gastric resection was the treatment choice, and the results were successful. The tumor, which was moderately differentiated adenocarcinoma, was limited to the mucosal layer, with no metastasis. In addition, a Helicobacter pylori infection was observed. This is the first reported case of a gastric cancer after LDLT. We report this case because of its importance regarding the need to carry out close surveillance in transplant recipients who are treated with immunosuppressive drugs, in order to make a timely identification of the occurrence of common malignancies.

Cyclic motor activity of the gallbladder maintained in a pylorus-preserving gastrectomy in dogs

The gallbladder has cyclic motor activity (CMA), which is impaired after a conventional gastrectomy. We conducted experiments to determine whether or not a pylorus-preserving gastrectomy (PPG) could maintain gallbladder CMA. Six strain gauge force transducers were implanted into the gastrointestinal tract and gallbladder of six dogs, respectively. The motor activity of the gastrointestinal tract and gallbladder was recorded as a control. PPG was then carried out. The phasic contractions of the gallbladder, which were correlated with the antral contractions in the control state, were synchronized with contractions of the pylorus after PPG. Intravenous administration of CCK-OP (40 ng/kg) induced phasic contractions of the gallbladder at 4.6±0.2c/min in 3 of the 6 dogs with gastric contractions. After PPG, the gallbladder had phasic contractions (4.5±0.2c/m), which were synchronized with the contractions of the pylorus in all dogs regardless of the contractions in the remnant stomach. These findings suggest that gallbladder CMA has a closer relationship with the CMA of the pylorus than with the remnant stomach after PPG. Thus, a preservation of the pylorus at the time of gastric surgery will help in maintaining gallbladder function and coordination with the remnant stomach.

Cyst formation of duodenal heterotopic pancreas accompanied by pancreas divisum.

Heterotopic pancreas and pancreatic divisum are wellknown anatomic anomalies of the pancreas (1). Although heterotopic pancreas is usually asymptomatic, it may become clinically evident with any symptoms related to complications, including ulceration, bleeding, hyperinsulinism, obstructive jaundice, and gastric outlet obstruction (2). In addition, cystic degeneration is an uncommon and serious complication of heterotopic pancreas (3–5). In this article, we report an unusual case of cyst formation in duodenal heterotopic pancreas accompanied by pancreas divisum.

A second primary esophageal cancer developing 7 years after chemoradiotherapy for advanced esophageal cancer

We report a rare case of advanced carcinoma and a second primary carcinoma of the esophagus, both of which were successfully cured by chemotherapy and operation at different times. In 1991, a 38-year-old Japanese man was diagnosed with advanced esophageal cancer, which was unresectable because of the bronchial invasion of the tumor. He was given chemotherapy with cisplatin (CDDP), combined with radiotherapy. During a 4-year follow-up, neither regrowth of the primary tumor nor distant metastasis occurred. In 1995, esophagoscopy demonstrated a lugol-unstained region located 3 cm distal from the area of radiation to the primary lesion shown by esophagography. Histological examination of a biopsy specimen showed the mucosa to be normal. Nevertheless, yearly surveillance by endoscopy and histological examinations showed that the mucosa of the esophagus gradually began to demonstrate mild dysplasia, followed by severe dysplasia; in 1998, a diagnosis of squamous cell carcinoma was made. Esophagectomy with lymph node dissection was performed. Microscopic examination revealed that there had been pathologic complete response for the original advanced esophageal cancer.