Adrenomedulline improves ischemic left colonic anastomotic healing in an experimental rodent model

Neuroprotective effects of adrenomedullin in experimental traumatic brain injury model in rats

BACKGROUND

Traumatic brain injuries cause damages in the brain in several ways, which include cell death because of edema, disruption of the blood-brain barrier, shear stress, and ischemia. In this study, we investigated the effects of adrenomedullin (AM) on oxidative stress and inflammation after head traumas in a rat model.

METHODS

Eighteen male adult Wistar albino rats were randomized into three groups (n=6). No traumas were applied to the con-trol (C) group. Traumas were applied in line with Marmarau trauma model in the trauma group. The rats in the AM treatment group were treated with post-traumatic 12 μg/kg i.p. AM in addition to the trauma group. The rats were followed for 7 days in all groups and were then sacrificed. Brain tissues and blood samples were taken.

RESULTS

In the trauma group, both tissue and serum MDA, TNF-α, and IL-6 levels were significantly increased compared to the control group (p<0.05). In the AM-treated group, serum TNF-α levels were significantly decreased compared to the trauma group (p<0.05). In the trauma group, both tissue and serum GSH levels were significantly decreased compared to the control group (p<0.05). In the trauma group, serum Vitamin D3 levels were significantly decreased compared to the control group (p<0.05). In the AM-treated group, both tissue and serum GSH levels were significantly increased compared to the trauma group (p<0.05).

CONCLUSION

These results indicate that AM has neuroprotective effects on traumatic brain injury in a rat model.

Gunshot wounds to the colon: predictive risk factors for the development of postoperative complications, an experience of 172 cases in 4 years

BACKGROUND

In our study, we have defined and evaluated risk factors for the development of post-operative complications in patients with gunshot wounds to the colon. The purpose of the study is to identify the most influential risk factors.

METHODS

A retrospective study of 172 patients admitted with gunshot wounds to the colon from 17 February 2011 to 31 December 2014. Age, gender, shock upon admission defined by vital signs and haemoglobin level, blood transfusion, injured site of the colon, the colon injury score, faecal contamination, surgical procedure, colon diversion, multiple organ injuries, delay time pre-operation and duration of the operation were considered as risk factors. All patients were observed for any postoperative complications.

RESULTS

One hundred and sixty-six patients (96.5%) were males, and six (3.5%) were female. The mean age was 28.5 years. On admission 104 (60.5%) patients were in shock, 89 (51.7%) required blood transfusion. Forty-four (25.5%) patients had an injury to the ascending colon, while 53 (30.8%), 13 (7.6%), 23 (13.4%), 21 (12.2%) and 18 (10.5%) patients had an injury in transverse, descending, sigmoid, rectum and multiple colon injuries respectively. A colon diversion was used in 64 patients (37.2%). Post-operative complications documented in 67 (38.9%) patients, 35 (20.3%) required re-exploratory laparotomy, while the disability occurred in 18 (10.4%)) cases, and post-operative mortality was 12 (6.9%).

CONCLUSION

Surgeons should be aware that shock state upon admission and blood transfusion are risk factors for postoperative complications in a patient with a gunshot penetrating injury to the colon.

Effect of Alprostadil on Colorectal Anastomoses Under Relative Ischemia

BACKGROUND

Anastomotic leak after colorectal surgery, which remains a serious clinical problem that causes augmented morbidity and mortality, is usually favored by ischemia. The aim of this study was to determine whether alprostadil may improve anastomotic wound healing under ischemic condition.

METHODS

Ninety-three adult Wistar rats were randomized into three groups: control, ischemia (by devascularization along the first 2 cm at each anastomotic end), and ischemia plus alprostadil. Resection of a colonic segment at the colorectal junction and an anastomosis was performed. Animals were euthanized at 8 d. Surgical site infection, anastomotic leak, and grade of intra-abdominal adhesions using a validated scale were determined. Bursting pressure and tension were calculated and histologic examination of the anastomosis was performed.

RESULTS

The ischemic group revealed an increased anastomotic leak rate (14/31 versus 3/31) and a lower bursting pressure and tension when compared to control group, validating therefore the experimental model. After intraperitoneal injection of alprostadil, anastomotic leak rate was significantly lower (5/31) and the bursting pressure and tension were significantly increased. Histologic examination revealed a lower presence of inflammatory cells, and a significantly higher neovascularization and a higher presence of fibroblasts in treated animals when compared with the ischemic group.

CONCLUSIONS

Alprostadil may have a positive effect on colonic anastomotic wound healing under relative ischemic condition. Alprostadil administration increases anastomotic bursting pressure, decreases leak rate, and reverses most of the histological changes caused by blood flow decrease. These protective effects could be caused by vasodilation, stimulation of neovascularization, and immunomodulatory properties.

Expression of AQPs 3, 8 and 9 in the residual colonic mucosa of rats with extensive colon resection

AIM: To examine the expression of Aquaporins (AQPs) 3, 8 and 9 in the residual colonic mucosa of rats with extensive colon resection.

METHODS: Thirty-two healthy adult SD rats were randomly and equally divided into either a control group or an experimental group. Under general anesthesia, resection of about two-thirds of the colon was performed 5.0 cm from the ileocecal junction, followed by an end-to-end anastomosis with a single-layer 6/0 polypropylene suture. The animals were allowed to eat 24 h after the surgery, and the water content of feces was determined. Rats of the experimental group were killed on days 14 and 28 after surgery, and those of the control group were killed on day 28 to take colonic mucosal samples. RT-PCR was used to determine the expression of AQPs 3, 8 and 9.

RESULTS: After surgery, the water content of feces increased. The relative expression levels of AQPs 3, 8 and 9 were significantly lower in the control group (day 28) than in the experimental group (days 14 and 28) (AQP3: 0.352, 0.425 vs 0.614, both P < 0.01; AQP8: 0.425, 0.518 vs 0.733, both P < 0.01; AQP9: 0.422, 0.516 vs 0.632, both P < 0.01).

CONCLUSION: After extensive colon resection, expression of AQPs 3, 8 and 9 in the remaining colon increases, which may accelerate the absorption of water and increase the moisture of feces.

The effects of ghrelin on colonic anastomosis healing in rats

OBJECTIVES

In addition to its roles in the stimulation of growth hormone secretion and the regulation of appetite and metabolism, ghrelin exerts immunomodulatory, anti-inflammatory and antioxidant actions in several organ systems. In this study, we investigated the effects of ghrelin on the healing of experimental colonic anastomoses.

METHODS

Wistar rats were randomly divided into two groups (n = 10 in each). A segment of colon was excised, and an end-to-end anastomosis was performed in the distal colon. The Ghrelin Group received 10 ng/kg/day IP ghrelin for seven days postoperatively, whereas the Control Group received an identical volume of saline. On the seventh postoperative day, the anastomotic bursting pressures and hydroxyproline levels were measured, and adhesion formation around the anastomoses was examined. Histopathological analyses were performed to evaluate inflammatory cell infiltration, fibroblast infiltration, collagen density and neovascularization.

RESULTS

In the Ghrelin Group, the bursting pressure and hydroxyproline levels were significantly higher than in the Control Group. The adhesion formation scores were lower in the Ghrelin Group than in the Control Group. Although the inflammatory cell infiltration was diminished in the Ghrelin Group, the degrees of fibroblast infiltration, collagen density and neovascularization were not significantly different between the groups.

CONCLUSION

Our results indicate that ghrelin improves the healing of colonic anastomoses in rats.

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.