A functional description of the canine choledochoduodenal flutter valve

Postprandial sphincter of Oddi myoelectric activity and gallbladder emptying

Feeding initiates gallbladder emptying and bile delivery into the duodenum. It is not yet defined how the sphincter of Oddi regulates flow of bile into the duodenum during gallbladder emptying. The aim of this study was to assess postprandial spike burst activity in the sphincter of Oddi, while quantitating gallbladder emptying with noninvasive radioisotope imaging. Six adult opossums were prepared with bipolar electrodes in the sphincter of Oddi. After 2 weeks of recovery the animals were fasted overnight and positioned under a gamma camera, and myoelectric recordings were begun. After two cycles of the migrating motor complex (MMC), 2 mCi 99Tc-HIDA was infused intravenously and permitted to concentrate in the gallbladder for a period of 30 min. Subsequently, a 30-ml liquid meal, containing 0.9 g protein, 3.5 g carbohydrate, and 3.3 g fat, was instilled into the stomach. Sphincter of Oddi myoelectric activity (spike bursts/min) and gallbladder emptying (expressed as percentage of original 99Tc counts in the gallbladder) were measured at intervals for 120 min following feeding. Feeding resulted in prompt gallbladder emptying. Sphincter of Oddi spike burst activity was not altered significantly in the first 30 min after feeding, suggesting that motor activity in the sphincter of Oddi does not initially influence bile flow. Subsequently, spike burst activity increased progressively, suggesting that sphincter of Oddi motor activity may accelerate bile delivery into the duodenum during later phases of gallbladder emptying.

Common bile duct pressure in dogs after opiate injection--epidural versus intravenous route

The effect on the common bile duct pressure of epidurally injected morphine and fentanyl, was compared with that of intravenous injections of the same drugs in 12 mongrel dogs. Intravenous injection of morphine (0.1 mg X kg-1) or fentanyl (0.01 mg X kg-1) significantly elevated the common bile duct pressure from 10.48 +/- 0.37 to 21.68 +/- 0.33 cm H2O and from 9.66 +/- 0.33 to 14.14 +/- 0.21 cm H2O respectively. These increases occurred within 4-15 minutes after injection and lasted for about 2-3 hours. When the narcotics in identical dosages were injected epidurally, the common bile duct pressures were unchanged during the four hours of investigation. Further studies are planned to determine whether this beneficial effect of epidural narcotics applies also in the human clinical situation.

A hydraulic behavior of the mucosal structure of the intramural common bile duct. An experimental study

In the intramural portion of the common bile duct in the dog, the lumen is occluded by the mucosal folds which are pointed to the direction of the ductal orifice. Luminal occlusion by the folds becomes more marked from the halfway of the portion as judged from the duodenal muscle layers. A pressure study using the pressure ramp apparatus suggested that the mucosal structure plays some role in generating the passage resistance to bile floow and in the prevention of regurgitation of duodenal content.

Reimplantation of the ampulla of Vater after total pancreatectomy for nesidioblastosis

Total pancreatectomy is often required to control hypoglycemic seizures in infants with nesidioblastosis. If duodenal devascularization results, reconstruction is difficult because standard biliary-intestinal anastomoses may reflux, or, in infants, become strictured. Therefore, surgeons are loath to perform such procedures. To avoid these complications, the common bile duct and the ampulla of Vater were implanted into the reconstructed duodenum.