Management of ventral incisional hernias in large horses: a surgical challenge

Abstract

The report by Elce et al. (2005) in this issue describes some critical but previously undescribed problems with mesh hernioplasty in horses, which makes it a valuable contribution to the veterinary literature. Incisional complications can develop in 40% of horses that have had intestinal surgery through a ventral median incision (Wilson et al. 1995), with incisional drainage in 32–36% of horses, dehiscence in 3–5% and hernia formation in 6–17% (Gibson et al. 1989; Kobluk et al. 1989; Wilson et al. 1995). Odds of incisional hernia are 62.5 times greater for horses that had incisional drainage, and incisional drainage and herniation can have a negative association with survival (Ingle-Fehr et al. 1997). As discussed by Elce et al. (2005), an important factor associated with incisional complications is the size of the horse (Wilson et al. 1995). Hernias of ventral midline incisions typically appear months after the initial surgery as a well defined abdominal wall protrusion (Fig 1) or, more commonly, as scattered areas of attenuation along the healed body wall. The latter can be more evident on palpation than on visual inspection, do not require repair and can withstand full athletic activity and foaling. If hernia repair is indicated, it should be postponed for approximately 3–4 months after the initial surgery to allow inflammation and infection to fully resolve and the hernial ring to become firm and well organised. Timing of hernia formation in a broodmare might not allow for repair before foaling, but mares can foal uneventfully with very large hernias. However, the concern exists for conversion of a large hernia to a more complete rupture of the abdominal wall, and assisted delivery is encouraged to reduce this risk. Despite the obvious cosmetic defect, a horse can perform successfully in athletic activities, such as high-level dressage, with a large incisional hernia. Despite attempts to follow recommended guidelines for patient selection, surgical timing, technique and aftercare, the high complication and fatality rates described by Elce et al. (2005) after this procedure draw particular attention to the following observations: