The effects of hyperbaric oxygen therapy on experimental colon anastomosis after preoperative chemoradiotherapy.

The aim of the present study was to investigate the effect of hyperbaric oxygen therapy (HBOT) on colon anastomosis after chemoradiotherapy (CRT). Sixty female Wistar-Albino rats were divided into 5 groups and underwent left colon resection and end-to-end anastomosis. CRT simulation was performed on 2 sham groups before the anastomosis, and 1 of these groups was administered additional postoperative HBOT. Two groups were administered CRT before the anastomosis, and 1 of them received additional postoperative HBOT. On postoperative day 5, all groups underwent relaparotomy; burst pressure was measured and samples were obtained for histopathologic and biochemical analysis. There was a significant weight loss in the CRT groups and postoperative HBOT had an improving effect. Significantly decreased burst pressure values increased up to the levels of the controls after HBOT. Hydroxyproline levels were elevated in all groups compared to the control group. Hydroxyproline levels decreased with HBOT after CRT. No significant difference was observed between the groups regarding fibrosis formation at the anastomosis site. However, regression was observed in fibrosis in the group receiving HBOT after CRT. Preoperative CRT affected anastomosis and wound healing unfavorably. These unfavorable effects were alleviated by postoperative HBOT. HBOT improved the mechanical and biochemical parameters of colon anastomosis in rats.

Does the type of resuscitative fluid affect healing of colonic anastomosis in experimentally induced hemorrhagic shock in rats?

OBJECTIVE: The aim of the study was to investigate the effects of different resuscitative fluids on the healing of intestinal anastomosis in a hemorrhagic-shock rat model. MATERIALS AND METHODS: Closed-colony Wistar male rats (n = 40; 8 rats per group) were subjected to volume-controlled hemorrhagic shock, followed by a 30-min shock phase. The animals were then resuscitated with one of the following fluids (which also corresponds to their respective groups): lactated Ringer's solution (LR), hydroxyethyl starch (HES), 7.5% hypertonic saline (HS) and autologous blood (AB). There was also a control group (CL), which did not experience hemorrhagic shock or receive any resuscitative fluids. All rats underwent laparotomy, segmental resection and anastomosis of the left colon. Five days later, a 2nd laparotomy was performed and the anastomotic bursting pressure was measured in vivo. Thereafter, the anastomosed segment was resected to measure the tissue hydroxyproline level and the grade of anastomotic fibrosis. RESULTS: All experimental groups (LR, HES, HS and AB) exhibited lower anastomotic bursting pressures than the CL group; however, no intergroup differences achieved statistical significance. The mean tissue hydroxyproline level and fibrosis grade also were similar across all 5 groups. CONCLUSION: In traumatic hemorrhagic shock, anastomosis safety does not appear to be affected by the type of fluid used for resuscitation. Moreover, LR, HES and HS all seemed to reinforce healing as effectively as transfused blood.

Preoperative and postoperative administration of hyperbaric oxygen improves biochemical and mechanical parameters on ischemic and normal colonic anastomoses.

Colonic anastomotic leaks are a major postoperative complication, causing increased mortality and morbidity. Tissue ischemia is one of the most important factors that disrupt anastomotic healing. It is possible to reverse inadequate tissue oxygenation by using increased atmospheric pressure and hyperoxia, which are obtained from hyperbaric oxygen treatment (HBO). Our aim was to investigate the effects of preoperative and postoperative HBO treatment on normal and ischemic colonic anastomoses in rats. Eighty male Wistar Albino rats, weighing between 180 and 240 g, were divided into 8 equal groups. A 1-cm segment of left colon was resected 3 cm proximal to the peritoneal reflection in all groups and colonic anastomosis was performed. In groups 2, 4, 6 and 8, colonic ischemia was established by ligating 2 cm of mesocolon on either side of the anastomosis. Control groups (1 and 2) received no HBO. HBO treatment was given preoperatively in groups 3 and 4, postoperatively in groups 5 and 6, and both preoperatively and postoperatively in groups 7 and 8. HBO treatment was applied for 2 days in the preoperative period and 4 days in the postoperative period. Relaparotomy was performed on postoperative day 5 and a perianastomotic colon segment 2 cm in length was excised for detection of biochemical and mechanical parameters of anastomotic healing and histopathological evaluation. HBO treatment increased tissue hydroxyproline levels in all groups, and this difference was significant in normal anastomosis groups receiving preoperative HBO compared to controls (p = .013 for group 1 vs. group 3; p = .023 for group 1 vs. group 5). This improvement was more evident in ischemic and normal groups treated by administration of combined pre- and postoperative HBO (p = .021 and p = .013). HBO treatment also increased the mean bursting pressure values in all groups, and again, a statistically significant increase was noted in the ischemic groups compared to controls (p = .002 for group 2 vs. group 6; p = .001 for group 2 vs. group 8). Histopathological evaluation of anastomotic line fibrosis was not found to show significant differences between the groups. Adequate tissue oxygenation is the main factor in wound and anastomosis healing. HBO treatment has a positive effect on biochemical and mechanical parameters of ischemic and normal colon anastomoses in rats. It is possible to see this effect more clearly with combined HBO treatment applied before and after ischemic anastomosis.

Hyperbaric oxygen enhances the efficiency of 5-aminosalicylic acid in acetic acid-induced colitis in rats.

The aim of this study was to assess the efficiency of hyperbaric oxygen alone and in combination with 5-aminosalicylic acid in the acetic acid-induced colitis model, a well-known experimental model of inflammatory bowel disease in rats. Rats were randomly divided into five groups. In the noncolitis control group, rats were given isotonic saline, while in the other groups rats were treated by intracolonic administration of 4% acetic acid. In group 2, the untreated control group, no additional therapy was applied. In groups 3, 4, and 5 hyperbaric oxygen, 5-aminosalicylic acid. and 5-aminosalicylic acid + hyperbaric oxygen therapies were applied, respectively. Administration of acetic acid caused an inflammatory response in all animals. Histopathologic score was significantly higher in group 2 than in any other group. 5-Aminosalicylic acid and hyperbaric oxygen significantly decreased the histopathologic score (P < 0.05). Myeloperoxidase activity was also reduced significantly by 5-aminosalicylic acid (P < 0.05) but not by hyperbaric oxygen. The most prominent ameliorative effect, however, was seen in group 5 and the histopathologic score and myeloperoxidase activity were significantly lower than in groups 3 (P < 0.05) and 4 (P < 0.001). Hydroxyproline level also increased significantly in group 5, but not in groups 3 and 4 (P < 0.001). These findings indicate that hyperbaric oxygen therapy is effective in reducing the extent of colitis induced by acetic acid, although it is not as potent as 5-aminosalicylic acid. The combination of hyperbaric oxygen and 5-aminosalicylic acid, however, led to a much more prominent reduction in the severity of colitis. Hyperbaric oxygen may have a promising place in the treatment of inflammatory bowel disease.

Role of anorectal myectomy in the treatment of short segment Hirschsprung's disease in young adults.

Basic pathological disorder in Hirschsprung's disease (HD) comes into being by the abnormal innervations of the aganglionic distal intestine. The nonserious forms of this congenital disease may reach the young by proceeding with chronic, obstinate constipation that does not respond to diet. Myectomy of the short segment of aganglionic part may provide diagnostic and therapeutic value. Between 1993 and 2003, anorectal posterior myectomy was performed in 19 patients diagnosed with HD. The mean age of patients was 23 years. Previous or concomitant anterior resection was added to the procedure in seven cases due to dolicomegacolon. In addition to the deficiency of anorectal inhibitor reflex (ARIR) among all patients, the frequency of defecation was 12.5 days (range, 6-30 days) before operation. Anorectal length before widening was an average of 5.5 cm (range, 2-8 cm). All pathologic specimens were found to be aganglionic. Postoperatively, the mean of first regular defecation interval was 1.5 days (range, 1-3 days). Involution of rectum was evaluated with a rectal examination and barium enema X-rays during follow-up. ARIR of patients also returned to normal. In conclusion, anorectal posterior myectomy is an effective operation in diagnosis and treatment of short-segment HD. Furthermore, colon resection annexed to this operation, in the condition of dolicomegacolon, is also used to remove obstinate constipation.

The effects of gingko biloba extract (EGb 761) on experimental acute pancreatitis.

BACKGROUND AND OBJECTIVE: Acute pancreatitis is an important and fatal disease with high mortality and morbidity. Although the pathogenesis of acute pancreatitis is poorly understood, there are many studies that suggest the role for oxygen free radicals (OFRs) in the development of pancreatitis and its complications and show beneficial effects of scavenger treatment. In the present study, we aimed to investigate whether Egb761, the standardized extract of gingko biloba, restrains the generation of OFRs and ameliorates the histopathologic findings of acute pancreatitis. MATERIALS AND METHODS: Sixty male Sprague Dawley rats were randomly assigned to one of the following experimental groups. In early and late pancreatitis and treatment groups, acute pancreatitis was induced by retrograde infusion of 3% sodium taurocholate. In treatment groups, 100 mg/kg Egb 761 was given intraperitoneally (IP) 24 h and immediately before induction of pancreatitis. Sham-operated rats received isotonic saline instead of sodium taurocholate. After observation times of 3.5 and 12 h, the pancreas was removed for light microscopy and determination of malondialdehyde (MDA) levels as a marker for OFRs-induced lipid peroxidation. Serum samples also were obtained for amylase and lipase levels. RESULTS: There was no significant difference in control and sham-operated groups in terms of histopathologic findings and serum enzyme levels. The tissue concentrations of MDA and serum enzyme levels were significantly elevated in early and late treatment groups as compared with the control group. The treatment with Egb 761 caused significant decrease in serum amylase and lipase levels and histopathologic scores as compared with early and late pancreatitis groups. CONCLUSIONS: Prophylactic application of Egb761 exerts highly beneficial influence on the course of acute pancreatitis, and this seems to be related to the oxygen radical scavenger effect of Egb761.