Ischemic Colonic Anastomoses Research Articles

Effects of recombinant human growth hormone and nandrolone phenylpropionate on the healing of ischemic colon anastomosis in rats.

Recombinant human growth hormone and nandrolone phenylpropionate are two different anabolic agents. This study was designed to investigate the effects of these anabolic agents on the healing of ischemic colon anastomosis in rats. Seventy adult male Wistar rats were divided into five groups (n = 14). Group I was the sham laparotomy group. In the other groups, surgical procedures consisting of transsection and anastomosis were made at a distance 3 cm from the peritoneal reflection. Group II was the nonischemic control group. Ischemic colon model was produced in the remaining groups. Group III was the untreated control group. Groups IV and V received recombinant human growth hormone and nandrolone phenylpropionate, respectively. Bursting pressure and hydroxyproline levels were measured on the third and seventh postoperative days to evaluate anastomotic healing. Recombinant human growth hormone increased both collagen deposition and bursting pressure significantly at postoperative Days 3 and 7 compared with the sham and untreated control groups (P < 0.005). When compared with the untreated control, nandrolone phenylpropionate significantly increased collagen deposition at postoperative Days 3 and 7 (P < 0.005) and bursting pressure only at postoperative Day 3 (P < 0.005). Recombinant human growth hormone has more favorable therapeutic effects on the healing of ischemic colonic anastomoses than nandrolone phenylpropionate. Recombinant human growth hormone also improves healing of nonischemic colonic anastomosis.

Effects of Hyaluronic Acid-Carboxymethylcellulose Antiadhesion Barrier on Ischemic Colonic Anastomosis

Intraperitoneal adhesions may help the healing of marginally viable bowel ends. If adhesion formation is prevented by various methods, the integrity of ischemic bowel anastomosis may be compromised. Thus, we decided to study the effects of hyaluronic acid-carboxymethylcellulose, an antiadhesion barrier, on ischemic bowel anastomosis. Thirty Wistar-Albino rats were divided into three groups. In Group A (control), a well-perfused distal colonic segment was transected, and free ends were anastomosed. In Group B, an ischemic colonic segment was prepared, then divided and anastomosed. In Group C, after completion of ischemic colonic anastomosis, hyaluronic acid-carboxymethylcellulose film was wrapped around the anastomosis. In all groups, rats were killed on the seventh day. Intraperitoneal adhesions were graded by adhesion score, and healing of the anastomosis was assessed by measurement of bursting pressure and hydroxyproline levels in the anastomotic tissue. A statistically significant difference was found between hydroxyproline levels of the control group and the ischemic group (P = 0.02). HP level was also significantly higher in the hyaluronic acid-carboxymethylcellulose group than in the ischemic group (P = 0.01). There was no difference in hydroxyproline levels between the control and hyaluronic acid-carboxymethylcellulose groups. Compared with the control group, bursting pressure was lower in the ischemic group (P = 0.02). Hyaluronic acid-carboxymethylcellulose wrapping increased the bursting pressure significantly (P < 0.001). However, there was no difference in bursting pressure between the control group and the hyaluronic acid-carboxymethylcellulose group (P = 0.13). A marked increase in the adhesion score was observed in the ischemic group (P = 0.01). The difference between adhesion scores of the hyaluronic acid-carboxymethylcellulose and ischemic groups was not found to be significant, although the adhesion score in the hyaluronic acid-carboxymethylcellulose group was lower (P = 0.16). There was no difference in adhesion score between the control and hyaluronic acid-carboxymethylcellulose groups. Application of hyaluronic acid-carboxymethylcellulose in ischemic colonic anastomosis did not compromise anastomotic integrity. The adverse effect of ischemia on healing of colonic anastomosis was counteracted by hyaluronic acid-carboxymethylcellulose.

The effects of hyperbaric oxygen on normal and ischemic colon anastomoses

BACKGROUND: Leakage from colonic anastomoses is a major complication causing increased mortality and morbidity, and ischemia is a well-known cause of this event. Inadequate tissue oxygenation could be reversed by using hyperbaric oxygen. This study was designed to investigate the effects of hyperbaric oxygen on the healing of ischemic and normal colon anastomoses in the rat model. METHODS: Standardized left colon resection 3 cm above the peritoneal reflection and colonic anastomosis were performed in 40 Wistar rats divided into four groups. The control group (I) received no further treatment. To mimic ischemia, 2 cm mesocolon was ligated on either site of the anastomosis in group II and IV rats. Hyperbaric oxygen therapy was started immediately after surgery in group III and IV rats (therapeutic groups). All animals were sacrificed on the fourth postoperative day. After careful relaparotomy, in situ bursting pressure was measured. The hydroxyproline contents of the anastomotic segments in equal length were determined. RESULTS: The hydroxyproline assay revealed that rats in group II with ischemic colonic anastomosis have significantly lower levels ( P <0.05). The highest levels are in the group III rats with normal colonic anastomosis treated by hyperbaric oxygen ( P <0.05). There was no significant difference in hydroxyproline levels between group II and group IV animals ( P >0.05). Group III animals had significantly higher bursting pressures than any other group ( P <0.05). Group II rats had lowest bursting pressures ( P <0.05). Group IV animals had significantly higher levels than group II ( P <0.05). Mean bursting pressure values both in groups III and IV and hydroxyproline levels in group III were significantly increased by hyperbaric oxygen therapy ( P <0.05). CONCLUSIONS: Ischemia impairs anastomotic healing. Hyperbaric oxygen increases anastomotic healing of both normal and ischemic colonic anastomosis and reverses ischemic damage. This study demonstrated that hyperbaric oxygen improves anastomotic healing.

Healing of colonic ischemic anastomoses in the rat: role of superoxide radicals.

The aim of this study was to evaluate the role of superoxide radicals in the healing of ischemic colonic anastomoses in the rat. Adult male Wistar rats were used in a factorial design with two factors (normal or ischemic colonic anastomoses) each having two levels (treatment with saline or allopurinol). Colonic anastomoses were performed either in normal or previously devascularized colons (ischemic anastomoses) at identical locations, using the same technique. On the fourth postoperative day, animals were killed, and specimens were taken for determinations. Ischemic anastomoses displayed significant increases in superoxide radical (assayed as superoxide anion), superoxide dismutase, and glutathione peroxidase concentrations. Bursting strength and hydroxyproline levels were also significantly lower in these anastomoses. Allopurinol administration elicited a significant decrease in superoxide anions and raised both bursting strength and hydroxyproline levels only in ischemic anastomoses. Superoxide radicals are involved in the delay in healing of ischemic anastomoses. Allopurinol lowers superoxide anion production and has beneficial effects on the cicatrization of ischemic anastomoses.

Effect of a new prostacyclin analogue on anastomosis of ischemic colon in dogs.

The effect of a new prostacyclin analogue OP-41483 on ischemic colonic anastomosis was investigated in dogs. Colonic ischemia was produced by devascularization of the marginal vessels in the left colon and graded into three degrees by measuring colonic blood flow with a hydrogen gas clearance method. The agent was administered intravenously after devascularization using a continuous infusion pump. The parameters studied were colonic blood flow in the submucosal layer, rate of anastomotic leakage, beta-glucuronidase activity and protein content of the colonic mucosa, and histologic changes. After administration of the agent, blood flow increased significantly and beta-glucuronidase activity at the anastomotic site was well preserved at a relatively high level in spite of ischemic change. The anastomotic leakage rate was significantly decreased. The present study proved that administration of this new prostacyclin analogue minimizes ischemic damage, and may be of considerable importance in ischemic colonic anastomoses.