[Minimum papillotomy].

AIMS: Diabetes mellitus often causes anastomotic leakage leading to severe complications after surgery. The purpose of this study was to determine whether collagen synthesis is correlated with the anastomotic strength in diabetic animals in special reference to collagen type differences. METHODS: Thirty Lewis rats weighing approximately 250 g were made diabetic by tail vein injection of streptozotocin (STZ). Laparotomy was performed through a midline incision under ether anesthesia. A colonic segment 5 cm distal to the ileocecal junction was transected then anastomosed with absorbable suture. Anastomotic strength was measured on days 3, 5, 7 and 14 postoperatively, and compared with normal rats. Collagen type I and type III mRNA together with the total collagen concentration were measured in anastomotic sites. RESULTS: Anastomotic strength in diabetic rats was significantly lower on day 7, but gradually recovered up to day 14. There was no statistical significance between the two groups in hydroxyproline concentrations. Although the expressions of mRNA of collagen type III in both groups were statistically not different, that of collagen type I in the diabetes group merely increased and was clearly less than that of the control group. CONCLUSIONS: Anastomotic integrity in diabetic rats was significantly damaged on day 7 after surgery but recovered by day 14. This is caused not by the total contents of collagen accumulation but by the decrease of newly formed collagen type I contents.

Anastomosis, Surgical↗

PubMed2004

Evaluation of platelet deposition and neointimal hyperplasia of heparin-coated small-caliber ePTFE grafts in a canine femoral artery bypass model.

INTRODUCTION: Bypass graft failure due to acute thrombosis and intimal hyperplasia remains a major challenge in small-diameter vascular prosthetic graft reconstruction. Heparin has been shown to prevent thrombus formation and inhibit intimal antithrombotic in animal studies. In this study, we evaluated the effect of small-caliber heparin-coated expanded polytetrafluoroethylene (ePTFE) grafts on platelet deposition and intimal hyperplasia in a canine model of femoral artery bypass grafting. METHODS: Nine adult greyhound dogs underwent placement of bilateral femorofemoral artery bypass grafts with ePTFE grafts (4 mm diameter and 7 cm long). In each animal, a heparin-coated ePTFE graft was placed on one side while a noncoated graft was placed on the contralateral side which served as the control. Platelet deposition was measured by autologous (111)indium-labeling and scintillation camera imaging analysis in 24 h. The graft patency was assessed at 4 weeks following the bypass. The effect of intimal hyperplasia was assessed with histological and morphometric analysis. RESULTS: Platelet deposition on the heparin-coated grafts at 24 h was significantly reduced by 72% as compared to controls (P = 0.001). The patency rate was 44% in control grafts and 89% in heparin-coated grafts. There was a significant reduction of graft intimal hyperplasia at both proximal (0.38 +/- 0.21 mm(2)) and distal (0.19 +/- 0.06 mm(2)) anastomoses in the heparin-coated grafts as compared with proximal (1.01 +/- 0.28 mm(2)) and distal (0.42 +/- 0.01 mm(2)) anastomoses in the untreated control grafts, respectively (P < 0.05). Heparin coating significantly reduced graft neointimal hyperplasia at patent graft anastomoses by 55-72% as compared to controls. CONCLUSIONS: These data demonstrate that heparin coating of ePTFE significantly reduced early platelet deposition and inhibited anastomotic neointimal hyperplasia. Moreover, small-caliber heparin-coated ePTFE graft significantly increased graft patency in a canine femoral artery bypass model. This may represent a promising treatment strategy for improving the clinical performance of small-caliber prosthetic vascular grafts.

Anastomosis, Surgical↗