Ileocecal Interposition Graft As Substitute For Pylorus After Subtotal Distal Gastrectomy

Objective: To investigate the feasibility of ileocecal interposition graft as substitute for pylorus after conventional distal gastrectomy. To observe the changes of glucose tolerance, gastric emptying, electrogastrogram and intragastrical environment of Bama minipigs after operation so as to offer an ideal digestive tract reconstruction procedure for the clinic that avoids dumping syndrome and reflux gastritis.Methods: Twenty-one Bama minipigs were randomized into 3 groups (n=7 in each group). Group 1: sham laparotomy group; group 2: Billroth I procedure after subtotal distal gastrectomy; group 3: ileocecal interpostion graft after subtotal distal gastrectomy. The following tests for each group were performed at 2, 4, 6 months after operation.(1) Gastric emptying in each pigs were quantified by using quick testing blood sugar paper dipped with marginal ear vein blood to detect blood sugar levels before and at 30, 60, 90, 120 min after the glucose intake.(2) Gastric emptying was assessed by radionuclide gastric emptying test with SPECT, ant the half-emptying time (T1/2) were recorded and compared among 3 groups.(3) Electrogastrogram was recorded by BL-410 biologic experiment enginery system for 60 min. The mean frequency of slow wave and the index of abnormal slow wave were calculated and compared.(4) The pH of gastric juice was determined with pH paper.(5) The total bile acid concentration of gastric juice was determined by the gallbladder acid standard curve methods.(6) The bacteria in gastric juice were cultured in vitro, and the clonal formation units were counted and compared, and the bacteria species were detected and compared. At 6 months postoperatively, all pigs were sacrificed and the gastric mucous membrane was collected, fixed and observed under the microscope and scanning electron microscope.Results:(1) The recovery of the experimental pigs The pigs in group 1 all survived withoutabnormal symptoms. In. group 2, the wound all cicatrized, and the vomitirvg of grade 1-2 occurred in two pigs, loss of appetite (grade 2-3) in all pigs at the early period postoperatively, and body weight lost significantly at 4, 6 months postoperatively. In group 3, all pigs survived, and the vomiting of grade 1-2 occurred in two pigs, loss of appetite (grade 1-2) in all pigs at early period postoperatively, and the symptoms above disappeared at 4, 6 months postoperatively and systemic conditions as well as body weight recovered to normal levels before operation.(2) The results of oral glucose tolerance test At 2 months postoperatively, the blood glucose concentration in 3 groups showed no significant differences during limosis. After oral glucose intake, the blood glucose concentration in group 1 increased slowly, while that in groups 2 and 3 increased quickly. As compared with group 1, groups 2 and 3 showed significant difference (P<0.01), but the difference between group 2 and group 3 was of no significance. At 4 months postoperatively, the blood glucose concentration in 3 groups showed no significant differences during limosis. After oral glucose intake, the blood glucose concentration in groups 1 and 3 increased slowly, while that in group 2 increased quickly. As compared with group 2, groups 1 and 3 showed significant difference (PO.01), while the difference between group 1 and group 3 was significant (P<0.05). At 6 months postoperatively, the situation was the same with that at 4 months, with the only exception for no difference between group 1 and group 3.(3) The results' of radionuclide gastric emptying test At 2 months postoperatively, Ti/2 of groups 2 and 3 was shorter than that of group 1 (P<0.01, group 2 vs 1; P<0.05, group 3 vs groupl), while T1/2 of group 3 was significantly longer than group 2 (P<0.05). At 4, 6 months postoperatively, T1/2 of group 3 was of no difference with that of group 1, but remarkably longer than that of group 2 (P<0.0l). The difference between group 1 and group 2 was significant (P<0.0\).(4) Electrogastrogram After operation, the mean frequency of slow wave was of no great changes and of no statistical difference. At 2, 4 months postoperatively, the index of abnormal slow wave in group 2 and group 3 was higher than that in group 1 (P<0.0\ at 2 months, P<0.05 at 4 months), while at 6 months, there was no difference among 3 groups.(5) pH and bile acid concentration of gastric juice At 2 months postoperatively, the pH and bile acid concentration in group 3 and group 2 were higher than those in group 1(PO.01, group 2 vs 1; PO.05, group 3 vs 1). At 4, 6 months postoperatively, the pH and bile acid concentration in group 3 were of no difference as compared with those in group 1, but lower than those in group 2 (PO.05).(6) Bacteria of gastric juice At 2 months postoperatively, there were aerobe and anaerobe in gastric juice in both groups 2 and 3. The amount of bacteria in groups 2 and 3 was significantly larger than that in group 1 (PO.01). The amount of aerobe and bacteria in group 3 was lower than that in group 2 (P<0.01), but no difference in amount of anaerobe. At 4, 6 months, the amount of bacteria in group 3 decreased, as compared with that at 2 months (P<0.01). There was only aerobe in group 1, whereas there were aerobe and anaerobe in groups 2 and 3. As compared with group 1, the amount of bacteria in groups 2 and 3 was higher (P<0.01). The amount of aerobe, anaerobe and bacteria in group 3 was lower than that in group 2 (PO.01).(7) Pathological observation At 6 months postoperatively, ileo-colon graft had enough blood supply, and the ostium of gastroinstetinal atium cicatrized well, and gastric mucosa was normal in group 3. In group 2, gastric mucosa had light hyper-aemia and erosion. Under optic microscope, there were scrap lymphocytes invasion into mucosa inhere layer of gastroduodenum anastomosis in local region. Limited kitchen range damages were seen in gastric mucosa by scan electron microscope. The abnormity of gastric mucosa was not seen in group 1.Conclusion: Ileocecal interposition graft as substitute for pylorus after conventional distal gastrectomy is feasible, and the postoperative recovery of group 3 is better than that of group 2. The ileocecal interposition graft can prevent dumping syndrome and reflux gastritis, furthermore, caused no changes of intragastric environment.