[Thoracic epidural anesthesia improves the gastric microcirculation during experimental gastric tube formation]

We studied the effects of gastric tube formation and thoracic epidural anaesthesia (TEA) on gastric microcirculation, hemodynamic and bowel motility changes. The experiments were performed on pentobarbital-anesthetized, mongrel dogs. Mean arterial pressure (MAP), gastric and mesenteric blood flow (Transonic Systems Inc.) and small bowel motility changes (strain gauge technique) were monitored. The stomach was prepared according to the method of Akiyama. TEA was induced by injecting Bupivacain 1 mg/kg. Orthogonal polarization spectral imaging (OPS) technique (Cytoscan A/R, Cytometrics, PA, USA) was used to observe in vivo microcirculatory changes. The gastric pull-up caused significant decrease in intramucosal pH and red cell velocity (RBCV) in terminal arterioles of the upper part of gastric tube both on the mucosal and serosal side. After TEA the RBCV returned to baseline level and the intestinal motility index significantly increased. Functional capillary density of the mucosa or subserosa did not change during the experiments. MAP was significantly reduced by 30%, while the arterial blood flow in gastric and mesenteric arteries was significantly increased. TEA significantly improves microcirculation of the distal portion of the gastric tube and increases intestinal motility. These results show that epidural anaesthesia is favourable and should be recommended during reconstructive oesophageal surgery.