Lauren A Costella, Angela Pineros-Fernandez, MD, George T Rodeheaver, PhD, Michael J Danilich, PhD, Patrick S Cottler, PhD. Luna Innovations Incorporated, University of Virginia Health System Department of Plastic Surgery.
INTRODUCTION – Abdominal surgery can induce post-operative adhesion formation, which can result in significant patient morbidity including small bowel obstruction, female infertility, or chronic pain. We are developing a novel sprayable biopolymer hydrogel to act as a physical barrier between tissues during healing and protect susceptible surfaces from forming adhesions. The gel is easily applied as a two-part system in both open and laparoscopic procedures. The two components interact to form an easily-visualized gel during application and will degrade into biocompatible byproducts after healing is complete.
METHODS AND PROCEDURES – Surgical defects were created on adjacent abdominal wall and cecum surfaces in Sprague-Dawley rats. The wounds aligned upon closure such that adhesions would form in untreated control animals. The wounds in treatment animals were sprayed with the hydrogel barrier prior to closure. Adhesion analysis was performed 14 days after the procedure.
Scores were assigned to the adhesions formed between the abdominal wall and cecum injury sites. Animals received a score of 0-7 based on the extent and tenacity of the adhesions that had formed, with 0 indicating the absence of an adhesion and 7 indicating adhesion formation with significant coverage and strength. The incidence of adhesion formation and extent/tenacity scores were compared in control and spray treated animals to determine the efficacy of the treatment in preventing postoperative abdominal adhesions.
The use of the sprayable hydrogel barrier decreased the incidence of adhesion formation between the abdominal and cecum injury sites to 31.3% as compared to 87.5% of the untreated control animals. Using the Fishers Test, the decrease was determined to be statistically significant (p = 0.03).
|Incidence||Adhesion Score||Extent of Adhesion||Tenacity Score|
|Control (n=8)||7 of 8 (87.5%)||5.6 ± 2.4||70.6% ± 35.8%||2.4 ± 1.1|
|Treatment (n=16)||5 of 16 (31.3%)||1.6 ± 2.6||19.1% ± 33.0%||0.8 ± 1.2|
Additionally, the mean overall adhesion score decreased from 5.6 to 1.6, as both the extent of coverage and tenacity of adhesions formed was reduced with treatment (Table 1). These results were statistically significant (p < 0.01 using the Mann-Whitney test). No adverse reaction or foreign body response was detected in any of the treated animals.
CONCLUSIONS – The application of a novel sprayable biodegradable biopolymer hydrogel over injured tissue successfully decreased the incidence of adhesion formation 14 days after surgery. The associated extent and tenacity of adhesions decreased with treatment, as did the overall adhesion score. The gel did not interfere with injury healing and is potentially a substantial advancement in postoperative adhesion prevention. Continued development and testing for potential clinical use is warranted.