Preliminary Results of the Influence of Duodenojejunal Bypass in a Porcine Model of Streptozotocin-Induced Diabetes Mellitus.

BACKGROUND: Type 2 diabetic obese patients present with a normalization of plasma glucose levels shortly after most bariatric procedures, before any significant weight loss takes place. There is only scarce literature in the new field of metabolic surgery, with most experiments being performed on small animal models. AIM: Our aim is to develop a reliable large animal model for assessment of surgical correction of diabetes. METHOD: Titrated doses of streptozotocin (STZ) were used for induction of diabetes mellitus. After standardization of the surgical technique to avoid any restrictive component, three groups were created, a duodenojejunal bypass (DJB; n = 4), a gastroileal conduit (GIC; n = 3) near the ileocecal valve, and a sham (control; n = 5) group. Preoperative and postoperative glycemic curves were recorded by means of intravenous glucose tolerance tests. Body weight fluctuations were recorded as well. RESULTS: Diabetes was successfully induced with the use of STZ in all cases. Animals in the sham group remained diabetic for 3 weeks after operation. There was normalization of blood glucose levels in the operative groups during the 3-week postoperative follow-up, without significant body weight changes. The duodenojejunal group resulted in stronger positive response of glycemia. CONCLUSION: STZ-induced diabetes in swine leads to a reliable large animal model for assessment of metabolic surgical procedures. STZ is an effective but highly toxic means for inducing stable diabetes in the sensitive porcine model. Duodenojejunal bypass, although less invasive, seems to exert better antidiabetic effects than gastroileal conduit.

Laparoscopic bowel injury: role of the site and the instrument type: study with an animal model.

BACKGROUND: Unrecognized laparoscopic bowel injuries are complications that can occur during any laparoscopic procedure. These complications have variable morbidity and mortality rates, and their early clinical signs of inflammation are not typical. Therefore, a study was planned to predict the mechanical behavior of the injured bowel, taking into consideration two parameters: the size of the instrument and the site of the injury. METHODS: For this study, 78 Wistar rats were divided into eight study groups and one control group with two subgroups. Bowel injury was created using different sizes of needles and electrocautery on two different bowel sites: the jejunum and the terminal ileum. The animals were killed 48 h after surgery, followed by harvesting of the injured part of the bowel and measurement of the intraluminal pressure at which the bowel ruptured. RESULTS: The mean jejunum and terminal ileum rupture pressures on the injured bowel were significantly lower than on the intact bowel. The mean terminal ileum rupture pressures were significantly lower than those of the jejunum. CONCLUSIONS: The terminal ileum appears to be more fragile than the jejunum regardless of the size of the instrument that caused the injury. However, wider instrument tips cause more serious consequences.

Leucovorin and 5-fluorouracil versus levamisole and 5-fluorouracil as adjuvant chemotherapy in rectal cancer.

PURPOSE: To evaluate the effectiveness of 6-month therapy with leucovorin (LV)+5-fluorouracil (5-FU) versus 12-month therapy with levamisole (LVS)+5-FU, as adjuvant chemotherapy in patients with completely resected Aster-Coller stage B(2) or C(1)/C(2) rectal cancer (RC). PATIENTS AND METHODS: One hundred and fifty patients with surgically resected RC were enrolled. Seventy patients with stage B(2) and 80 with stage C were randomly assigned to adjuvant chemotherapy with 5-FU+LXx6 months or 5-FU+LVSx12 months. Patient characteristics were equally balanced between the examined groups. Adjuvant chemotherapy consisted of LV 20 mg/m(2) intravenously (i.v.) plus 5-FU 450 mg/m(2) i.v. bolus every week plus LVS tablets 50 mg t.i.dx3 days every 2 weeks for 1 year. RESULTS: After a median follow up for survivors of 8.7 years (range 1.8-10.5), all of the patients were evaluable. There were no significant differences between the two treatment groups with respect to the recurrence rates (p=0.821). Moreover, there were no significant differences between the two tratment groups in disease-free survival (DFS) (p=0.84) [B(2)(p=0.805) and C (p=0.978)] and overall survival (OS) rates for patients of either stage B(2) or C (p=0.78). Toxicities were more frequent in the 5-FU+LVS versus 5-FU+LV group: myelosuppression (grade 3 leucopenia, 12 versus 4%, p<0.04), diarrhea (grade 0, 60 versus 76%, p<0.02), and liver toxicity (increase of transaminases >3-fold, 12 patients versus 2, p<0.03.). No patient stopped chemotherapy because of toxicity, and there were no treatment-related deaths. CONCLUSION: Adjuvant chemotherapy in RC with LV+5-FU for 6 months is equally effective and less toxic than LVS+5-FU for 12 months.