Reversibility of Abdominal Wall Atrophy and Fibrosis After Primary or Mesh Herniorrhaphy

Abstract

Objective To determine whether primary or mesh herniorrhaphy reverses abdominal wall atrophy and fibrosis associated with hernia formation. Background We previously demonstrated that hernia formation is associated with abdominal wall atrophy and fibrosis after 5 weeks in an animal model. Methods Arat model of chronic incisional hernia was used. Groups consisted of uninjured control (UC, n = 8), sham repair (SR, n = 8), unrepaired hernia (UR, n = 8), and 2 repair groups: primary repair (PR, n = 8) or tension-free polypropylene mesh repair (MR, n = 8) hernia repair on postoperative day (POD) 35. All rats were killed on POD 70. Intact abdominal wall strips were cut perpendicular to the wound for tensiometric analysis. Internal oblique muscles were harvested for fiber type and size determination. Results No hernia recurrences occurred after PR or MR. Unrepaired abdominal walls significantly demonstrated greater stiffness, increased breaking and tensile strengths, yield load and yield energy, a shift to increased type IIa muscle fibers than SR (15.9% vs 9.13%; P < 0.001), and smaller fiber cross-sectional area (CSA, 1792 vs 2669 μm2; P < 0.001). PR failed to reverse any mechanical changes but partially restored type IIa fiber (12.9% vs 9.13% SR; P < 0.001 vs 15.9% UR; P < 0.01) and CSA (2354 vs 2669 μm2 SR;P < 0.001 vs 1792 μm2 UR; P < 0.001). Mesh-repaired abdominal walls demonstrated a trend toward an intermediate mechanical phenotype but fully restored type IIa muscle fiber (9.19% vs 9.13% SR; P > 0.05 vs 15.9% UR; P < 0.001) and nearly restored CSA (2530 vs 2669 μm2 SR; P < 0.05 vs 1792 μm2 UR; P < 0.001). Conclusions Mesh herniorrhaphy more completely reverses atrophic abdominal wall changes than primary herniorrhaphy, despite failing to restore normal anatomic muscle position. Techniques for hernia repair and mesh design should take into account abdominal wall muscle length and tension relationships and total abdominal wall compliance.

A Cost-Utility Assessment of Mesh Selection in Clean-Contaminated Ventral Hernia Repair

“…Despite these refinements in technique and tools, ventral hernia remains a challenge, particularly in the setting of contamination. Mesh-reinforced hernia repair is capable of restoring the functional characteristics of the abdominal wall, 38 and long-term level I data have solidified mesh-reinforced hernia repair as the standard of care. 4 However, traditional surgical teaching dictates that contamination is a contraindication to mesh use, because of the increased rate of wound infection, 39 decreased incorporation of mesh, decreased strength of repair, 15 greater risk of mesh removal, 40 and an overall increase in the risk of reoperation and recurrent hernia.…”

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

“…The deleterious effects of a weak abdominal wall musculature can be improved following repair in these models. 56 , 58 …”

Laparoscopic bridging vs. anatomic open reconstruction for midline abdominal hernia mesh repair [LABOR]: single-blinded, multicenter, randomized, controlled trial on long-term functional results

“…The possibility of muscular structure reversal after these myopathic changes have occurred is interesting [ 37 ]. Moreover, Culbertson et al demonstrated that a tension-free repair with mesh (bridging technique) in which the injured muscle is partially reloaded induces a better recovery of muscular structure in comparison with that of a simple repair with tension.…”