Prosthetic repair of large abdominal wall defects in horses and food animals

Abstract

SUMMARY Prosthetic repair of large abdominal wall defects, using either a knitted polypropylene or woven plastic mesh, was performed on 25 horses and 27 food animals. Follow-up ranging from 3 months to 8 years was available on 23 horses and 21 food animals with normal cosmetic body wall appearance and return to full function in 36 patients (82%). Two horses (4.5%) did not reherniate but had persistent incisional drainage for 6 months and 5 years, respectively, and in 2 food animals (4.5%), reherniation due to infection necessitated mesh removal. Irreversible peritonitis following mesh implantation resulted in the death of 4 animals (9%). In food animals, hernias of sufficient size to necessitate prosthetic reconstruction were most commonly caused by umbilical hernias without previous repair in older heifers, umbilical hernias that had been repaired unsuccessfuly 1 or more times, and incisional hernias following right paramedian abomasopexy or ventral midline celiotomy. In horses, traumatic hernias, ventral midline incisional hernias, and hernias associated with pregnancy (flank or prepubic area) most commonly required mesh herniorrhaphy. Careful attention to aseptic technique, hemostasis, and gentle soft tissue handling was important. Although not always anatomically possible, ideally 2 layers of mesh were placed retroperitoneally to reduce intra-abdominal inflammation and adhesions, believed to be a potential cause of major complications. An onlay fibrous hernial flap to reinforce the mesh was desirable but not essential for successful outcome. Postoperative abdominal bandaging when anatomically possible was believed to have helped reduce seroma formation. Exercise was limited to hand walking for 60 days after surgery, and each animal was confined to a clean, bedded box stall. Both types of synthetic mesh were equally effective in repairing large fascial defects. The woven plastic mesh used on 39 animals was approximately 39 times less expensive than the knitted polypropylene mesh. Also, because it was less elastic, it appears to have resulted in less abdominal wall sagging, especially when used to span large defects for which only subcutaneous tissue and skin were available to cover the mesh.