Protection of intestinal anastomoses by biodegradable intraluminal bypass tubes under the condition of general peritonitis: an experimental study on the CLP model in rats

Effect of hydrogen-rich water on acute peritonitis of rat models

OBJECTIVE

To study the effect of hydrogen-rich water (HRW) on acute peritonitis with three different rat models.

METHODS

Acute peritonitis was induced by three methods including intraperitoneal injection of lipopolysaccharide (LPS), rats' feces or cecal ligation and puncture (CLP) operation. For each model, male Sprague Dawley rats were used and distributed into saline control group, HRW control group, saline plus model group, and HRW plus model group. Saline or HRW (3 ml per rat) was orally administered by gavage for 7 days beforehand and 3 days after modeling. The efficacy was tested by detecting concentrations of white blood cells (WBCs), plasma endotoxin, interleukin (IL)-6 and tumor necrosis factor (TNF)-α. The activities of malondialdehyde (MDA), myeloperoxidase (MPO) and glutathione (GSH) in visceral peritoneum tissues were also evaluated. Meanwhile, histopathology examination of visceral peritoneum was performed using hematoxylin and eosin staining. The expression and location of nuclear factor kappaB (NF-κB) in the visceral peritoneum were detected by immunohistochemistry.

RESULTS

Three models showed the same result that hydrogen-rich water had an efficient protective effect on acute peritonitis. HRW could significantly lower the levels of WBCs, plasma endotoxin and cytokines, enhance GSH activity and reduce MPO and MDA activities in the peritoneum tissue when compared with that of groups with only saline treated. Simultaneously, we found that HRW could also decrease the NF-κB expression in the peritoneum tissues.

CONCLUSION

Hydrogen-rich water could alleviate the severity of acute peritonitis, and it might perform this function by its anti-inflammation, anti-oxidation and anti-bacterial effects and reducing NF-κB expression in the peritoneum tissues.

Can intraluminal devices prevent or reduce colorectal anastomotic leakage: A review

Colorectal anastomotic leakage is a serious complication of colorectal surgery, leading to high morbidity and mortality rates. In recent decades, many strategies aimed at lowering the incidence of anastomotic leakage have been examined. The focus of this review will be on mechanical aids protecting the colonic anastomosis against leakage. A literature search was performed using MEDLINE, EMBASE, and The Cochrane Collaborative library for all papers related to prevention of anastomotic leakage by placement of a device in the colon. Devices were categorised as decompression devices, intracolonic devices, and biodegradable devices. A decompression device functions by keeping the anal sphincter open, thereby lowering the intraluminal pressure and lowering the pressure on the anastomosis. Intracolonic devices do not prevent the formation of dehiscence. However, they prevent the faecal load from contacting the anastomotic site, thereby preventing leakage of faeces into the peritoneal cavity. Many attempts have been made to find a device that decreases the incidence of AL; however, to date, none of the devices have been widely accepted.

A Novel Intestinal Anastomotic Device in a Porcine Model

The purpose of this study was to evaluate a novel, intraluminally deployed anastomotic device (AD). A survival study was conducted in 18 farm pigs. One early subject was excluded and replaced due to premature expiration. Six animals were placed in 1 of 3 cohorts, with euthanasia and AD explantation planned at 2, 4, and 6 weeks. A distal small intestinal side-side [functional end-end] anastomosis using the AD was performed via midline laparotomy. Fluoroscopy with double-contrast dilute barium and burst pressure measurements were performed in 4 animals in each group. Two animals in each cohort underwent fluoroscopy without contrast and resection for histology. Mucosal healing, inflammation, anastomotic alignment of the muscularis propria, and fibrosis were graded on a 4-point scale. All animals survived to the date of planned euthanasia except the excluded subject, who expired from causes unrelated to the device. Normal weight gain was seen in all. Sixteen of 18 devices sloughed prior to extraction without evidence of injury or obstruction during the survival period or at necropsy. Filling pressures of >200 mm Hg were reached; no leakage was seen. Mucosal healing and continuity were graded good to excellent at 2 weeks and excellent at 4 and 6 weeks. Inflammation improved with time, with moderate change at 2 weeks and mild at 6 weeks. Anastomotic fibrosis was mild at 2 weeks, mild to minimal at 4 weeks, and minimal at 6 weeks. The anastomotic alignment was 100 per cent except in 1 animal at 2 weeks with >50 per cent but <100 per cent alignment. The AD resulted in a stable, functional anastomosis without narrowing. All tested anastomoses withstood supraphysiologic insufflation pressures without evidence of disruption. The applicability of this novel device will be explored for use in other gastrointestinal and biliary anastomoses using minimally invasive deployment techniques.

Biomaterial patches sutured onto the rat stomach induce a set of genes encoding pancreatic enzymes

Asymmetric patches of polyhydroxybutyric acid with one smooth and one rough surface were produced by a dipping procedure. These patches were implanted into the rat gastrointestine and tissue samples were generated at distinct time intervals after surgery. The host's response towards the foreign material was analyzed by Differential Display and RNA profiles were compared to each other. One to two weeks after surgery a group of mRNAs encoding pancreatic enzymes was transiently present after biomaterial implantation.

Valtrac-secured intracolonic bypass device: an experimental study

PURPOSE

The intracolonic bypass tube has been used both experimentally and clinically to protect the anastomotic site. A newly designed intracolonic bypass, the Valtrac-secured intracolonic bypass, which consisted of a biofragmentable anastomosis ring (BAR) and was connected with a soft, thin vinyl tube, was used in the colon approximately 5 to 10 cm proximal to the anastomotic site. The distal end of the vinyl tube is passed through the colonic anastomosis to the anus to bypass the fecal stream.

METHODS

Eighteen piglets were divided into three groups of six each. Group A piglets underwent colon resection and rough anastomosis with large gaps between sutures, followed by Valtrac-secured intracolonic bypass. Group B piglets underwent the same procedures, but a colonic outlet obstruction also was done with pursestring sutures tied over the anus. Group C piglets underwent colon resection and rough anastomosis, but no intracolonic bypass tube was inserted (as in the control group).

RESULTS

All Group A and Group B piglets survived. Passage of the BARs occurred approximately two weeks later. As the barium enema passed through the bypass tube, it showed a patent BAR-secured tube and intact anastomosis with no leakage. In Group C, anastomotic leakage occurred in four of six piglets, three of which died. Barium enema showed leakage at the anastomotic site.

CONCLUSIONS

In the animal model we used, our new intracolonic bypass device proved to be a simple, safe, reliable means of protecting the anastomotic site and, thereby, eliminated the need for a diverting colostomy. Still we need further steps to test its potential in clinical use.