An Experimental Animal Model for Abdominal Fascia Healing after Surgery

Abstract

Background: Incisional hernia (IH) is a well-known complication after abdominal surgical procedures. The exact etiology of IH is still unknown even though many risk factors have been suggested. The aim of this study was to create an animal model of a weakly healed abdominal fascia that could be used to evaluate the actively healing fascia. Such an animal model may promote future research in the prevention of IH. Methods: 86 male Sprague-Dawley rats were used to establish a model involving six experiments (experiments A-F). Mechanical testing of the breaking strength of the healed fascia was performed by testing tissue strips from the healed fascia versus the unincised control fascia 7 and 28 days postoperatively. Results: During the six experiments a healing model was created that produced significantly weaker coherent fascia when compared with the control tissue measured in terms of mechanical breaking strength. This new animal model employed myofascial closing after a full thickness abdominal incision using a running suture with fast-absorbable suture material. This technique produced a weak myofascial layer compared with the control tissue measured in terms of breaking strength after both 7 and 28 days. Conclusion: It was possible to create a healed but weak abdominal fascia in rats with a minimum of defects after incision using a running suture technique in the fascia. In contrast to other models, regular tissue defects were absent, and the model can therefore be used to evaluate the changes, both histological and mechanical, in the actively healing fascia, which may lead to incisional herniation. Furthermore, the model may also be used to study interventions performed to promote healing. This contrasts with existing models with regular fascia defects, which are not well suited for this purpose.

Postoperative Work and Activity Restrictions After Abdominal Surgery

“…The authors believe that these findings are due to the simple, parallel orientation of collagen bundles in fascia, in contrast to the more complex 3-dimensional collagen structures that occur in dermal healing. In an animal model of hernia development, in which fascia was closed loosely after midline incision with the intention of creating an incisional hernia, it was noted that the fascia healed within the first week but then gradually weakened leading to hernia development by week 4 13 . In this study, however, the role of skin healing in hernia development was not explored.…”

“…In an animal model of hernia development, in which fascia was closed loosely after midline incision with the intention of creating an incisional hernia, it was noted that the fascia healed within the first week but then gradually weakened leading to hernia development by week 4. 13 In this study, however, the role of skin healing in hernia development was not explored.…”

A clinically relevant in vivo model for the assessment of scaffold efficacy in abdominal wall reconstruction

“…DuBay et al 57 created ‘progressive fascial failure’ on the abdominal walls of Sprague-Dawley rats by repairing laparotomy wounds using fast absorbing sutures and allowing the fascia repair to fail during the healing period. A similar model was also described by Burcharth et al 65 based on the idea of a weakly healed abdominal fascia. These techniques were able to model the abnormal wound or fascial healing environment in ventral incisional hernias.…”