Effect of Temporary Abdominal Closure on Colonic Anastomosis and Postoperative Adhesions in Experimental Secondary Peritonitis

Experimental models of high-risk bowel anastomosis in rats: A systematic review

BACKGROUND

Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity, that negatively affect the patients’ quality of life. Experimental studies play an important role in understanding the pathophysiological background of anastomotic healing and there are still many fields that require further investigation. Knowledge drawn from these studies can lead to interventions or techniques that can reduce the risk of anastomotic leak in patients with high-risk features. Despite the advances in experimental protocols and techniques, designing a high-quality study is still challenging for the investigators as there is a plethora of different models used.

AIM

To review current state of the art for experimental protocols in high-risk anastomosis in rats.

METHODS

This systematic review was performed according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. To identify eligible studies, a comprehensive literature search was performed in the electronic databases PubMed (MEDLINE) and Scopus, covering the period from conception until 18 October 2023.

RESULTS

From our search strategy 102 studies were included and were categorized based on the mechanism used to create a high-risk anastomosis. Methods of assessing anastomotic healing were extracted and were individually appraised.

CONCLUSION

Anastomotic healing studies have evolved over the last decades, but the findings are yet to be translated into human studies. There is a need for high-quality, well-designed studies that will help to the better understanding of the pathophysiology of anastomotic healing and the effects of various interventions.

Does CO2 pneumoperitoneum in laparoscopy interfere with collagen deposition in abdominal surgical wounds?

Purpose To determine by histomorphometric analysis whether CO2 pneumoperitoneum interferes with collagen deposition in surgical wounds in the aponeurosis of rats. Methods This experiment involved 80 male Wistar rats, randomly allocated into four groups according to pneumoperitoneum period (PRE: 30 min preoperatively; POST: 30 min postoperatively; PP: 30 min pre- and postoperatively; C: control group). CO2 pneumoperitoneum was insufflated to 5 mmHg of pressure. A laparotomy was performed; 1 cm of the left colon was then resected, and an end-to-end anastomosis was performed to simulate surgical trauma, after which the abdominal wall was closed. On postoperative days 7 or 14, a sample of the abdominal wall was collected, stained with picrosirius red and observed under polarized light in an optical microscope. The amount of collagen was estimated by computerized histomorphometric analysis. Results There were no significant differences in collagen deposition between the control and experimental groups on postoperative days 7 (p=0.720) or 14 (p=0.933). The amount of collagen increased as expected in all groups between postoperative days 7 and 14 (p=0.0003). Conclusion At 5 mmHg, CO2 pneumoperitoneum does not interfere with collagen deposition in abdominal wall surgical wounds in rats.

Effects of bromopride on the healing of left colonic anastomoses in rats with induced abdominal sepsis

PURPOSE

To evaluate the effects of bromopride on the healing of left colonic anastomoses in rats with induced abdominal sepsis.

METHODS

Forty rats were divided into two groups to receive either bromopride (experimental group- E) or saline (control group- C). Each group was divided into subgroups of ten animals each to be euthanized on third (E3 and C3) or seventh day (E7 and C7) after surgery. Sepsis was induced by cecal ligation and puncture. The rats underwent segmental left colon resection and end-to-end anastomosis. Adhesion formation, tensile strength and hydroxyproline concentration were assessed. Histomorphometry of collagen and histopathological analysis were also performed.

RESULTS

On postoperative third day, anastomoses in bromopride-treated animals showed lower tensile strength (p=0.02) and greater reduction in hydroxyproline concentration (p=0.04) than in control animals. There was no statistical difference in these parameters on seventh day, and the remaining parameters were similar across subgroups. Collagen content was also similar across subgroups.

CONCLUSION

In the presence of abdominal sepsis, the administration of bromopride was associated with decreased tensile strength and hydroxyproline concentration in left colonic anastomoses in rats three days after surgery.

Study on adhesion formation and the healing of colon anastomosis in rats with induced peritoneal sepsis

PURPOSE

To evaluate the effects of abdominal sepsis on adhesion formation and colon anastomosis healing in rats.

METHODS

Forty rats were distributed in two groups containing 20 rats each for left colon anastomosis in the presence (Group S) or absence (Group N) of induced sepsis by cecal ligation and puncture. Each group was divided into subgroups for euthanasia on the third (N3 and S3) or seventh (N7 or S7) post-operative day. The amount of adhesions was evaluated and a segment of the colon was removed for histopathologic analysis, bursting strength assessment, hydroxyproline and the determination of tissue collagen.

RESULTS

The subjects which underwent cecal ligation and puncture presented a higher amount of intra-abdominal adherences in both third (p=0,00) and seventh (p=0,00) post-operatory days. Smaller bursting strengths were found in the S3 subgroup, and greater bursting strengths were found in the S7 subgroup. There was no difference in the variations on the concentrations of hydroxyproline, tissue collagen and histopathology.

CONCLUSIONS

The peritoneal infection which was developed by cecal ligation and puncture raised the amount of intra-cavitary adhesions. There was a decrease in the amount of colonic anastomosis on the third post-operatory day with a following raise on the seventh without any effects on other healing parameters.

Development of a novel method of progressive temporary abdominal closure

BACKGROUND

This paper describes our experience with a novel method of temporary abdominal closure that permits frequent reassessment of the abdominal contents and progressive reapproximation of the fascial edges without compromising definitive fascial closure outcomes.

METHODS

We developed a novel method of temporary abdominal closure, which we have named the frequent assessment temporary abdominal closure (FASTAC). The records of patients who underwent planned relaparotomy during 5 years were reviewed. The data collected included patient demographics, indication for operation, number of operations, duration of temporary abdominal closure placement, hospital duration of stay, method of definitive abdominal closure, and subsequent ventral hernia repair.

RESULTS

One hundred and thirty-three patients underwent 308 temporary abdominal closure placements, including 16 patients who had a FASTAC placed for open abdomen management. FASTAC remained in place for a significantly greater time with more frequent reassessment. Fascial closure techniques were not different in FASTAC patients. FASTAC patients had a significantly greater duration of stay, which suggests selective placement in a more complicated patient population. The materials for frequent assessment temporary abdominal closure cost only $38 compared with $350 for a large piece of Silastic.

CONCLUSION

FASTAC is a novel, cost-effective method of temporary abdominal closure that allows for frequent bedside intra-abdominal surveillance, maintains abdominal domain, and does not compromise abdominal closure outcomes in the management of the open abdomen.