Evaluation of the effectiveness of adhesion prevention devices in a rat model

Introduction: Adhesion formation is a frequent complication following abdomino-pelvic surgery. Despite introduction of techniques for the minimization of adhesion formation, no approach has been completely satisfying and anti-adhesion devices represent an additional Option. This study in rats ranks the adhesion prevention capability of the three market leading devices Adept® (AD), Interceed® (IC) and Seprafilm® (SF) and of 4DryField® PH (4DF), a recently introduced device, the gel of which is effective as adhesion prevention barrier. 4DF was applied in two application modes: Powder given on the respective areas and transformed into a gel in situ by dripping with saline solution and powder and saline solution premixed and afterwards applied as a gel.

Material and methods: 68 male rats had abrasion of cecum, creation of an equally sized abdominal wall defect, and approximation of both injured areas by a suture (OPAM model) and were grouped randomly: One control group without treatment (n = 10); one group each treated with SF (n = 8), IC (n = 9), or AD (n = 10) and two groups treated with 4DF using premixed gel (n = 15) or in-situ gel technique (n = 16). After 7 days the incidence of adhesions expressed as adhesion reduction rate (AR; no adhesions = 100% AR) was assessed and histologic analyses were done. ANOVA and unpaired t-tests were used for statistical analyses.

Results: SF did not reduce incidence but significantly reduced the severity of adhesions (AR: 53.7%). With IC (AR: 4.4%) and AD (AR: 16.1%) no significant adhesion reduction was achieved. 4DF significantly reduced incidence and severity of adhesions both as premixed gel (AR: 85.2%) and as in-situ made gel (AR: 100%), a comparison between these two application techniques showed no difference in efficacy. Except for inflammatory response with IC, histopathology revealed good tissue compatibility of the other devices.

Conclusion: In an experimental model known to induce severe adhesions 4DF gel significantly reduced adhesion formation. SF did not diminish incidence but significantly reduced adhesion severity, whereas AD and IC revealed no significant adhesion prevention capabilities. Due to the favorable results, 4DF gel can be recommended as a promising strategy against the burden of adhesion formation following surgery.