Effect of Vitamin C Supplementation on Colonic Anastomotic Healing in the Presence of Peritonitis- An Experimental Study in Rats.

ascorbic acid plays a critical role in wound repair and healing/regeneration process as it stimulates collagen synthesis. Its effect on jejunal and colonic anastomosis is already established. We assessed its role on colonic anastomosis healing in presence of peritonitis and without peritonitis. Assessment was done by recording bursting pressure of anastomosis and histological features of healing.METHODSThis experimental study was conducted in 48 Albino Rats (mean weight of 180 g). All rats were subjected to exploratory laparotomy with colonic resection anastomosis and were divided into six groups. Group A and B control, Group C and D were supplemented with Vitamin C in low dose i.e. 100 mg/Kg body, Group E and F high dose of Vitamin C i.e. 200 mg/Kg body wt. Vitamin C was given for seven days intra muscularly. Peritonitis was created by cecal ligation and puncture (CLP) in half the number of rats (n=24), in each group. Every rat was re-explored on 7th post-operative day and anastomotic segments were harvested for bursting pressure measurement and then sent for histopathology examination.RESULTSBursting Pressure of group D (100 mg) was significantly raised (p<0.05) as compared to group B in the presence of peritonitis. Group F (200 gm vit C) showed significantly higher bursting pressure than group D (p<0.05). The findings of analysis of variance (ANOVA) showed that the mean BP of all the groups differs significantly from each other (p<0.05). High dose vitamin C supplementation gave more strength to anastomosis than low dose even in presence of peritonitis. The average histopathological examination score was 5.24 (Group E) (p<0.05). i.e., best healing among all groups. It had better effect even in presence of peritonitis - 4.62 in Group F. Healing score in this group was greater than group A, B, C, D and less than in group E.CONCLUSIONSPresence of fecal peritonitis hampers the process of healing of colonic anastomosis by impairing reparative collagen synthesis, its deposition and anastomotic strength reflected by decreasedbursting pressure and decrease HPE score. Supplementation of systemic ascorbic acid increases intestinal anastomotic healing by increasing collagen accumulation reflected by increasedbursting pressure and increase HPE score even in presence of peritonitis. High dose ascorbic acid supplementation had better effect on intestinal anastomotic healing. Importance of ascorbic acid in colonic anastomosis healing is yet to be evaluated in human beings.

Adipose-tissue-derived Stem Cells Enhance the Healing of Ischemic Colonic Anastomoses: An Experimental Study in Rats

PURPOSE: This experimental study verified the effect of adipose-tissue-derived stem cells (ASCs) on the healing of ischemic colonic anastomoses in rats. METHODS: ASCs were isolated from the subcutaneous fat tissue of rats and identified as mesenchymal stem cells by identification of different potentials. An animal model of colonic ischemic anastomosis was induced by modifying Nagahata's method. Sixty male Sprague-Dawley rats (10-week-old, 370 +/- 50 g) were divided into two groups (n = 30 each): a control group in which the anastomosis was sutured in a single layer with 6-0 polypropylene without any treatment and an ASCtreated group (ASC group) in which the anastomosis was sutured as in the control group, but then ASCs were locally transplanted into the bowel wall around the anastomosis. The rats were sacrificed on postoperative day 7. Healing of the anastomoses was assessed by measuring loss of body weight, wound infection, anastomotic leakage, mortality, adhesion formation, ileus, anastomotic stricture, anastomotic bursting pressure, histopathological features, and microvascular density. RESULTS: No differences in wound infection, anastomotic leakage, or mortality between the two groups were observed. The ASC group had significantly more favorable anastomotic healing, including less body weight lost, less ileus, and fewer ulcers and strictures, than the control group. ASCs augmented bursting pressure and collagen deposition. The histopathological features were significantly more favorable in the ASC group, and microvascular density was significantly higher than it was in the control group. CONCLUSION: Locally-transplanted ASCs enhanced healing of ischemic colonic anastomoses by increasing angiogenesis. ASCs could be a novel strategy for accelerating healing of colonic ischemic risk anastomoses.

Effects of the histamine H2 receptor antagonist famotidine on the healing of colonic anastomosis in rats

BACKGROUND: Failure of anastomotic healing is one of the major complications in colorectal surgery. Because histamine plays an important role in immune and inflammatory reactions, we demonstrate the effects of famotidine on the healing of colonic anastomosis in rats. METHODS: Twenty-eight Sprague-Dawley rats were used in the study. Excision and end-to-end anastomosis was performed in the distal colon of the rat. The Famotidine Group received 2 mg/kg/day famotidine; the Control Group received the same amount of saline. Bursting pressure of anastomoses and hydroxyproline content of perianastomotic tissues were evaluated on the third and seventh days following surgery. RESULTS: Bursting pressures and hydroxyproline contents for the Famotidine Group were significantly lower than the equivalent parameters for the Control Group on both the third and seventh days post-surgery. CONCLUSIONS: According to our findings, famotidine exerts detrimental effects on the anastomotic bursting pressure and hydroxyproline content of perianastomotic tissues in the colon of rats.

Cicatrização de anastomoses colônicas na vigência de obstrução intestinal: Estudo experimental em ratos

INTRODUCTION: The healing of intestinal anastomosis has been studied specially the suture technique and materials used in the preparation of anastomosis, and also to the better comprehension of the effects of several factors related to healing. A considerable number of complications after anastomosis of the colon and rectum can be noticed and the colonic obstruction has been as one of the main factors. OBJECTIVE: Study the anastomotic healing in the colon of rats after intestinal obstruction. METHODS: The animals (n=39) were divided in: Group I (submitted to intestinal obstruction induced four days before of the anastomoses, n=22) and Group II (Controls, n=22). The colonic anastomosis were made by a standardized technique and, seven days later, the segments which them were reviewed, resected and analyzed for a hydroxyproline dosage. RESULTS: The complications were more usual in the animals with obstruction (11 rats: 50%) than in the controls (3 rats: 17,7%), p 0,05. The median value of hydroxyproline was higher in the Group I (975,0 x 872,0), p>0,05. CONCLUSION: The anastomosis in the rat's colon with intestinal obstruction is related to more complications. This can be explained by the following factor's: more technical difficulty in the preparation of the anastomosis caused by different diameter of the bowel, higher undernourishment, proximal faecal retention, bacterial translocation and ischaemia. The statistical similarity between the groups regarding to the dosage of hydroxyproline suggests that the healing of the rats' colonic anastomosis with intestinal obstruction, in the absence of complications, follows the same process of collagen synthesis as the controls ones.

INTRODUÇÃO: A cicatrização de anastomoses intestinais vem sendo estudada com ênfase às técnicas de sutura e materiais empregados na confecção das anastomoses, bem como à melhor compreensão dos efeitos de diversos fatores sobre a cicatrização. Observa-se número não desprezível de complicações nas anastomoses de cirurgias colorretais e a obstrução colônica é referida como um dos fatores determinantes. OBJETIVO: Estudar a cicatrização de anastomoses no cólon de ratos na vigência de obstrução intestinal. MÉTODOS: Os animais (n=39) foram divididos em: Grupo I (Submetidos à obstrução intestinal induzida quatro dias antes da anastomose, n=22) e Grupo II (Controles, n=22). As anastomoses colônicas foram confeccionadas por técnica padronizada e, sete dias após, os segmentos que as continham foram analisados e ressecados para dosagem de hidroxiprolina. RESULTADOS: As complicações foram mais frequentes nos animais com obstrução (11 ratos=50%) que nos controles (3 ratos=17,7%), p 0,05. A média dos valores de hidroxiprolina foi maior no grupo I (975,0 x 872,0), p>0,05. DISCUSSÃO: A anastomose no cólon de rato com obstrução intestinal está associada a maior número de complicações que podem ser explicadas pela presença de fatores como: maior dificuldade técnica na confecção da anastomose pela desproporção entre bocas, maior desnutrição, impactação de fezes à montante, translocação bacteriana e isquemia. A semelhança estatística entre os grupos quanto à dosagem de hidroxiprolina sugere que a cicatrização das anastomoses colônicas dos ratos com obstrução intestinal, na ausência de complicações, segue o mesmo processo de síntese de colágeno que a dos controles.