Strength Of Colonic Anastomoses Research Articles

Effect of Paclitaxel-based Hyperthermic Intraperitoneal Chemotherapy (HIPEC) on colonic anastomosis in a rat model.

Paclitaxel has been used frequently for Hyperthermic Intraperitoneal Chemotherapy (HIPEC) for ovarian carcinomatosis. Cytoreductive surgery and HIPEC are associated with high rates of morbidity being anastomotic dehiscence one of the most frequent. The objective of this study is to quantify the effect of Paclitaxel-based HIPEC on colonic anastomosis in an experimental rat model. After left colon resection and anastomosis, animals were randomized into four groups: Controls (C); Hyperthermia (H); Normothermic Intraperitoneal Paclitaxel (CP) and Paclitaxel-based HIPEC (HP). On postoperative day four, animals' peritoneal cavities were examined macroscopically, colon anastomosis burst pressures measured and specimens analyzed histologically. Thirty-nine animals were randomized and 36 were included in the analysis. H group presented the highest burst pressure 105.11 ± 22.9mmHg, which was 27% higher than C (77.89 ± 27.6mmHg). On the other hand, HP presented the lowest burst pressure 64 ± 26mmHg, 16% lower than C group and 39% lower than H, being this latter difference statistically significant (p = 0.004). There were no significant differences regarding weight loss, adhesion scores, perianastomotic abscesses and histological findings (inflammation, fibroblasts, neoangiogenesis, and collagen among groups). Strength of colonic anastomosis was improved by isolated hyperthermia and negatively affected by Paclitaxel-based HIPEC.

Mechanical Bowel Preparation Does Not Affect Anastomosis Healing in an Experimental Rat Model.

BackgroundMechanical bowel preparation before colorectal surgery is commonly performed, but its benefits are controversial. The aim of this study was to compare the effects of mechanical bowel preparation on healing of colonic anastomosis and tissue strength.Material/MethodsAfter institutional review board approval, 20 adult Wistar albino rats were randomly divided into 2 groups of 10 animals each. Mechanical bowel preparation including sodium phosphate was performed on the experimental group via a feeding tube, whereas no bowel preparation procedures were performed on the control group. Transverse colon resection and anastomosis were performed on all rats under general anaesthesia. On postoperative day 5, re-laparotomy was performed and the anastomotic areas were resected. Animals were killed, after which bursting pressure and tissue hydroxyproline concentrations were measured, histopathological examination was performed, and we evaluated and compared the results.ResultsThere were no differences between control and experimental groups in bursting pressure, tissue hydroxyproline concentrations, or histopathological examination results (P>0.05).ConclusionsOur study demonstrated no significant difference between bursting pressures, tissue hydroxyproline levels, or modified wound healing score at postoperative day 5 between rats undergoing and not undergoing mechanical bowel preparation. Mechanical bowel preparation is not essential for healing or strength of colonic anastomosis in rats.

Effects of chitosan on healing and strength of colonic anastomosis in rats

To investigate whether chitosan application over colonic anastomosis line, provide reinforcement, and subsequently improve anastomotic healing. Forty eight Wistar albino female rats were used and were randomly divided into four groups, 12 rats in each: The control groups (1 and 3) received no further treatment. The experimental groups (2 and 4) received chitosan application over the colonic anastomosis. After sacrifying rats at the end of the experiment (either on day three or on day seven, depending on the group), colonic bursting pressure, a hihydroxyproline level and histopathologic characteristics of the perianastomotic tissue were examined. At three days, chitosan and control groups had similar values for histopathologically. On day seven, chitosan group had significantly higher mean score of collagenization (p=0.007) and a significantly higher bursting pressure (p=0.038). Our study emphasizes the positive effect of chitosan in the process of collagenation in colonic anastomosis healing.

Alcohol acute intoxication before sepsis impairs the wound healing of intestinal anastomosis: rat model of the abdominal trauma patient

IntroductionMost trauma patients are drunk at the time of injury. Up to 2% of traumatized patients develop sepsis, which considerably increases their mortality. Inadequate wound healing of the colonic repair can lead to postoperative complications such as leakage and sepsis.ObjectiveTo assess the effects of acute alcohol intoxication on colonic anastomosis wound healing in septic rats.MethodsThirty six Wistar rats were allocated into two groups: S (induction of sepsis) and AS (alcohol intake before sepsis induction). A colonic anastomosis was performed in all groups. After 1, 3 or 7 days the animals were killed. Weight variations, mortality rate, histopathology and tensile breaking strength of the colonic anastomosis were evaluated.ResultsThere was an overall mortality of 4 animals (11.1%), three in the group AS (16.6%) and one in the S group (5.5%). Weight loss occurred in all groups. The colon anastomosis of the AS group didn’t gain strength from the first to the seventh postoperative day. On the histopathological analysis there were no differences in the deposition of collagen or fibroblasts between the groups AS and S.ConclusionAlcohol intake increased the mortality rate three times in septic animals. Acute alcohol intoxication delays the acquisition of tensile strength of colonic anastomosis in septic rats. Therefore, acute alcohol intoxication before sepsis leads to worse prognosis in animal models of the abdominal trauma patients.

The Effect of Butyrate on the Healing of Colonic Anastomoses in Rats

ABSTRACTBackground: Butyrate, a short-chain fatty acid (SCFA) formed by the fermentation of complex carbohydrates by the bacteria in the colon, is the main source of nutrition for colonocytes. The aim of this experiment was to investigate the effect of butyrate on the healing of colonic anastomosis in a rat model. Materials and Methods: Forty male Wistar rats were fed a fibre-free diet for 2 days. They then underwent laparotomy, transection, and anastomosis of both left and right colon, with a defunctioning caecostomy. The animals were then randomly assigned to receive butyrate or saline enemas from the third postoperative day and underwent another laparotomy on the seventh postoperative day when the bursting pressures of both anastomoses were measured. Results: Out of the 40 rats, 23 were available for the final data analysis. The mechanical strength of the anastomosis was measured by the bursting wall tension (BWT), which was calculated from the bursting pressure and the anastomotic circumference. The anastomoses in the butyrate arm showed a significantly higher BWT for both the right (48.9 s 64.71 dyne10−3/cm, p value .04) and the left (51.44 vs 72.38 dyne 10−3/cm, p value .01). Conclusion: This experiment suggests that butyrate has a significant role in increasing the mechanical strength of colonic anastomoses in rats.

Reduction of Oxygenation and Blood Flow in Pedicled Bowel Segments in the Rat and Its Consequences for Anastomotic Healing

Experimental studies indicate that perioperative hypoperfusion impairs anastomotic healing. In bowel surgery, the part of bowel that will be anastomosed is often pedicled, leaving the blood supply dependent on the marginal artery only. Little is known about the blood supply in such a segment, and whether anastomotic strength is affected when flow would be reduced. This study describes oxygenation and blood flow in pedicled bowel segments in the rat and investigates whether early anastomotic strength changes with variations in blood flow. In rats, pedicled segments were created in ileum and colon by successive ligation of the feeding arteries. Oxygenation and blood flow were measured in the distal part of this segment by use of near-infrared spectroscopy with indocyanine green as an intravascular tracer. In a second experiment, a short pedicled colonic segment was created and, after flow measurements, an anastomosis was constructed. Wound strength and hydroxyproline content were analyzed 2 and 5 days after operation. After creation of a pedicled segment, the concentration of oxygenated hemoglobin decreased significantly. Blood flow also significantly decreased to even less than 10% of baseline. A very large variation was observed between animals, in particular, after ligation of the first arteries. The strength of colonic anastomoses was not significantly correlated with the blood flow in the pedicled segment before anastomotic construction. The creation of a pedicled bowel segment greatly reduces tissue oxygenation and blood flow to its distal part. Such impaired perioperative flow does not significantly affect early wound strength after anastomotic construction.

Effects of Combined Pulse Electromagnetic Field Stimulation Plus Glutamine on the Healing of Colonic Anastomosis in Rats

An experimental study was designed to investigate the effect of combined pulse electromagnetic field (PEMF) stimulation plus glutamine administration on colonic anastomosis. Anastomosis of the left colon was performed in 28 rats, which were divided into four groups; Group 1: normal resection anastomosis plus oral 50 mg/kg/day glutamine; Group 2: normal resection anastomosis plus PEMF stimulation plus oral 50 mg/kg/day glutamine; Group 3: normal resection anastomosis plus PEMF stimulation; Group 4: normal resection anastomosis. On the seventh postoperative day, the animals were killed and the bursting pressure and tissue hydroxyproline concentration of the anastomosis were analyzed and compared. The mean anastomotic bursting pressure in Group 2 was significantly higher than in Groups 1 and 4. On the other hand, the mean anastomotic bursting pressure in Group 1 was significantly higher than in Group 4. The collagen deposition and the fibroblast infiltration were significantly increased on the seventh day in Group 3 compared the other groups. On the other hand, Groups 1 and 2 had higher scores for collagen deposition and fibroblast infiltration than Group 4. In conclusion, burst pressures, hydroxyproline, and histologic features (fibroblast infiltration and collagen deposition) were improved in the PEMF group, and both PEMF and glutamine-enriched nutrition provide a significant gain in the strength of colonic anastomoses in rats.

Intraperitoneal heated chemotherapy affects healing of experimental colonic anastomosis: An animal study

The peritoneal spread of cancer is a well-known entity carrying a dismal prognosis. A new therapeutic approach is the combination of cytoreduction with heated intraperitoneal chemotherapy (HIPC). The risk of an intra-abdominal anastomosis in the presence of such chemotherapy is recognized clinically but the experimental data on the subject are lacking. The aim of this study is to examine the influence of chemotherapy and hyperthermia on the healing of colonic anastomosis. Colonic anastomosis were performed in four groups of male Wistar rats: (1) control (operation only), (2) HIPC with saline, (3) with mitomycin C (MMC), and (4) with cisplatinum. HIPC was performed using a closed circulation system at 40 degrees C over 20 min. Anastomotic strength was tested on day 4, 7, 10, and 21. The bursting pressure of anastomoses in rats treated by HIPC was significantly lower than in controls. On day 4, it was 54.8 mm Hg, 38 mm Hg, 18 mm Hg, and 14.8 mm Hg in groups 1-4, respectively, while on day 7 it was 170 mm Hg, 188 mm Hg, 83 mm Hg, and 19 mm Hg, respectively (P < 0.01). The difference decreased on day 10 and almost vanished on day 21. HIPC with cisplatinum had the worst effect on anastomotic healing during the early postoperative period. Cytoreduction and HIPC are gaining popularity. However, the use of heated chemotherapy has a detrimental effect on the strength of colonic anastomosis, especially during the early postoperative period (until day 10). This may cause anastomotic failure and postoperative morbidity. Therefore, careful selection and avoidance of unnecessary anastomoses are mandatory.

Effect of Ulcerative Colitis in the Bursting Strength of Colonic Anastomoses in Rats

Inflammatory bowel disease may have a deleterious effect on bowel healing, but its difficult to demonstrate in clinical practice because of the association of multiple factors. An experiment was conducted in rats. They were divided in two groups: group I, a model of acetic acid induced-colitis, and group II, the control group. Both groups underwent a rectal resection and primary anastomosis. On postoperative day 7, the bursting strength of the anastomosis was evaluated. There were 44 rats in group I and 38 in group II. In 91% of group I rats there were histopathological changes compatible with inflammatory bowel disease (IBD). Mean bursting was significantly reduced in rats with acetic acid-induced IBD (142.18 ± 18.22 mm Hg in group I, and 208.85 ± 14.8 mm Hg in group II; p < .05). These results suggest a deleterious effect of IBD on bowel healing.

Strength of colonic anastomoses and skin incisional wounds in old rats - influence by diabetes and growth hormone.

The influence of advanced age on the mechanical strength of colonic anastomoses and skin incisional wounds in diabetic rats was investigated after 0 (suture binding capacity) and after 7 days of healing. Furthermore, the effects of growth hormone (GH) injections to old diabetic rats were investigated. Diabetes in old rats did not influence the strength of colonic anastomoses after 0 and 7 days. However, in these diabetic animals, the strength of skin incisional wounds was reduced by 27% after 7 days of healing (P< 0.01). GH injections administered to old diabetic rats doubled the mortality compared with that of saline-injected old diabetic rats (P< 0.01). GH injections did not influence the strength formation of either colonic anastomoses or skin incisional wounds in old normal rats. In conclusion, the healing of colonic anastomoses in diabetic rats was not compromised by old age, while the strength of skin wounds was decreased.

The Effect of Recombinant Growth Hormone on the Strength of Ileal Anastomoses in a Rat Model

In gynecologic surgery, the ileum is the primary site of bowel injury. Recombinant growth hormone (rGH) has been shown to improve the strength of colonic anastomoses in experimental models. The purpose of this study is to evaluate the effect of rGH on small bowel anastomoses, specifically in the ileum. Twenty large female rats underwent segmental ileal resections and end-to-end ileoileostomies. The rats were randomized to be treated for 7 postoperative days with either rGH (2.0 mg/kg/day) or placebo starting on the day of surgery. On the seventh postoperative day, a segment of ileum surrounding the anastomosis was resected. The anastomoses were tested for breaking strength on a tensiometer and for tissue concentrations of hydroxyproline. The ileal anastomotic breaking strength in the rGH group was 163.5 +/- 6.0 g (mean +/- standard error). In the placebo group, the breaking strength of ileal anastomoses was 125.0 +/- 3.0 g (P < .001). No significant difference was demonstrated with respect to the hydroxyproline concentration between the rGH group (15.2 +/- 2.0 micrograms/mg) and the placebo group (14.6 +/- 1.0 micrograms/mg). In an animal model, a 31% increase in ileal anastomotic breaking strength was induced by rGH administration. With further research this may translate into decreases in the surgical complications that occur in ileal anastomoses. Furthermore, these serve as preliminary data to a study that evaluates the effect of rGH on ileal anastomoses in radiation-injured bowel.

Growth hormone increases the bursting strength of colonic anastomoses

The effect of growth hormone on the bursting strength of left colonic anastomoses was investigated experimentally. Seventy-two 3 month-old female rats were randomized into two groups receiving daily injection of either saline (controls) or 2.0 mg biosynthetic human growth hormone per kg body weight per day. All injections were started 7 days before a left colonic resection and anastomosis, and continued until sacrifice at the 2nd, 4th or 6th post-operative day. The bursting strength of the anastomoses was tested in anaesthetized, living rats. The bursting pressure and the bursting wall tension of the growth hormone treated animals were increased two-fold on the second post-operative day (2p less than 0.005) and three-fold on the fourth post-operative day (2p less than 0.05), compared with controls. There was no difference in the bursting pressure or the bursting wall tension on the sixth postoperative day. The mass of the resected segment was increased by the pre-operative growth hormone treatment, whereas the hydroxyproline content was unchanged. In conclusion, treatment with biosynthetic human growth hormone increases the strength of colonic anastomoses in the early phases of healing.