A membrane slurry reduces postoperative adhesions in rat models of abdominal surgery

Barrier materials for prevention of surgical adhesions: systematic review

BACKGROUND

Postoperative surgical adhesions constitute a major health burden internationally. A wide range of materials have been evaluated, but despite constructive efforts and the obvious necessity, there remains no specific barrier widely utilized to prevent postoperative adhesion formation. The aim of this study was to highlight and characterize materials used for prevention of postoperative surgical adhesions in both animal and human studies.

METHODS

A systematic review was performed of all original research articles presenting data related to the prevention of postoperative adhesions using a barrier agent. All available observational studies and randomized trials using animal models or human participants were included, with no restrictions related to type of surgery. PubMed and Embase databases were searched using key terms from inception to August 2019. Standardized data collection forms were used to extract details for each study and assess desirable characteristics of each barrier and success in animal and/or human studies.

RESULTS

A total of 185 articles were identified for inclusion in the review, with a total of 67 unique adhesion barrier agents (37 natural and 30 synthetic materials). Desirable barrier characteristics of an ideal barrier were identified on review of the literature. Ten barriers achieved the primary outcome of reducing the incidence of postoperative adhesions in animal studies followed with positive outputs in human participants. A further 48 materials had successful results from animal studies, but with no human study performed to date.

DISCUSSION

Multiple barriers showed promise in animal studies, with several progressing to success, and fulfilment of desirable qualities, in human trials. No barrier is currently utilized commonly worldwide, but potential barriers have been identified to reduce the burden of postoperative adhesions and associated sequelae.

Hemostatic sponge effect on adhesion prevention in a porcine model

BACKGROUND

In this work, we aimed to assess the preventive effect of an absorbable hemostatic collagen sponge (HCS) on the reduction of postsurgical gynecological adhesions in a porcine model.

MATERIALS AND METHODS

Forty female pigs were subjected to a right uterine horn myotomy and left uterine horn deserosation. They were randomly divided into two groups, HCS application and control, which were rearranged into laparotomy and laparoscopy groups. Resulting adhesions were macroscopically and microscopically semiquantitatively analyzed after a 5 mo follow-up.

RESULTS

The incidence of adhesion-free animals did not significantly differ between groups, although it increased when the HCS was placed in both laparotomy (from 10%-12.5%) and laparoscopy groups (from 20%-50%). On the contrary, a significant reduction was observed in adhesion severity when the HCS was applied in the laparotomy groups (P < 0.01). Regarding microscopic study, hemostatic sponge application significantly reduced the inflammation score in the laparoscopic approach (P < 0.01). Fibrosis, unlike inflammation, differs between both approaches. In the laparoscopic group, fibrosis was reduced with application of the HCS, whereas in the laparotomy group greater fibrosis was observed within the HCS group.

CONCLUSIONS

HCS has shown to be safe for gynecological use. Although number and extent of adhesions did not decrease with HCS, inflammation and adhesions' severity were reduced in the laparoscopic and laparotomy approaches, respectively.

Current strategies and future perspectives for intraperitoneal adhesion prevention

INTRODUCTION

The formation of peritoneal adhesions still is a relevant clinical problem after abdominal surgery. Until today, the most important clinical strategies for adhesion prevention are accurate surgical technique and the physical separation of traumatized serosal areas. Despite a variety of barriers which are available in clinical use, the optimal material has not yet been found.

DISCUSSION

Mesothelial cells play a crucial physiological role in friction less gliding of the serosa and the maintenance of anantiadhesive surface. The formation of postoperative adhesions results from a cascade of events and is regulated by various cellular and humoral factors. Therefore, optimization or functionalization of barrier materials by developments interacting with this cascade on a structural or pharmacological level could give an innovative input for future strategies in peritoneal adhesion prevention. For this purpose, the proper understanding of the formal pathogenesis of adhesion formation is essential. Based on the physiology of the serosa and the pathophysiology of adhesion formation, the available barriers in current clinical practice as well as new innovations are discussed in the present review.

A sprayable hyaluronate/carboxymethylcellulose adhesion barrier exhibits regional adhesion reduction efficacy and does not impair intestinal healing

BACKGROUND

While bioresorbable solid barriers such as Seprafilm® prevent adhesions, their efficacy is limited to sites of application. The aim of this study was to assess the effectiveness of the sprayable adhesion barrier Sepraspray® in preventing adhesions to sites of direct application and to remote sites.

METHODS

Intraabdominal adhesions were induced in 30 rats by creating three ischemic buttons on each side of a midline incision. To assess efficacy, Sepraspray (5 mg/button) or Seprafilm (1 cm(2)/button) was applied over three buttons on one side of the peritoneum. Operated control animals received no treatment. On day 7, adhesions were scored as percent of buttons with adhesions. To assess safety, 81 rats underwent a colonic transection repaired with an end-to-end anastomosis. Both barriers were applied circumferentially to anastomoses. Controls received no product. The integrity of healing anastomosed colonic wounds was assessed by burst pressure and tensile strength at days 3, 5, and 7 postoperatively.

RESULTS

The direct application of both Sepraspray and Seprafilm significantly (p < 0.001) reduced adhesion formation compared to controls. While Seprafilm had no remote effect on adhesion formation, Sepraspray significantly (p < 0.001) reduced adhesion formation to contralateral ischemic buttons. Neither barrier affected anastomotic integrity at any time point.

CONCLUSIONS

Sepraspray has widespread efficacy throughout the peritoneum in reducing adhesions without compromising intestinal healing. Furthermore, this sprayable alternative offers the potential for easier intraabdominal application.