Veterinary Surgery 28:456-465, 1999 Microvascular Transplantation of a Free Omental Graft to the Distal Extremity in Dogs DAREN M. ROA, DVM, RONALD M. BRIGHT, DVM, MS, Diplomate ACVS, GREGORY B. DANIEL, DVM, MS, Diplomate ACVR, MICHAEL F. MCENTEE, DVM, Diplomate ACVP, JILL E. SACKMAN, DVM, PhD, Diplomate ACVS, and TAMMY D. MOYERS, CVT Objective—To assess the survival of a free omental graft applied to an experimentally created wound on the distal extremity in dogs. Study Design—A free omental graft was evaluated as a primary method of treatment for dogs with distal extremity wounds in an experimental model. Animals or Sample Population—Five adult intact female mixed breed dogs weighing 21.8 kg to 25.0 kg. Methods—A free omental graft was harvested from the abdomen and transferred to a wound bed overlying the medial aspect of the tibia. A microvascular anastomosis was performed between the graft vessels and vessels at the recipient site. Daily clinical assessment of graft viability was performed. Angiography and 99m Technetium labeled macroaggregated albumin ( 99m Tc MAA) scintigraphic perfusion scans were performed on either day 4, 5, or 7. Postmortem collection of tissues for histopathologic analysis was performed immediately after imaging. Total operative time and graft ischemia time were evaluated for effects on graft survival. Results—Two of seven grafts survived to the end of the study, three of seven grafts failed because of ischemia, and two of seven grafts failed because of self-trauma. There was no clinically significant morbidity associated with the abdominal portion of the procedure. Because of the small number of surviving grafts, the effects of operative time and graft ischemia time could not be statistically evaluated. Conclusions—Microvascular transplantation of a free omental graft can result in a viable tissue covering of a distal extremity wound, however, the failure rate is unacceptably high. Clinical Relevance—A free omental graft may not have sufficient durability to be an acceptable wound covering by itself. Further studies combining omentum with a skin graft or other tissues may result in a clinically useful technique. ©Copyright 1999 by The American College of Veterinary Surgeons T HE GREATER OMENTUM is a versatile organ whose functions remained a mystery until the nineteenth century. It seals perforations and hernias, isolates infections, provides hemostasis, revascularizes devitalized structures, and provides lymphatic drain- age. 1-4 Thus, it has earned the nickname “the abdom- inal policeman.” 1 The omentum has been used by surgeons to improve healing of gastrointestinal and urinary tract anastomoses and repairs, to repair chest wall defects and a variety of soft tissue defects by adding bulk and blood supply, and to revascularize ischemic lower limbs and treat chronic ulcers. 2,5-16 Veterinarians have similarly used omentum as an adjunct to gastrointestinal and urinary tract anastomo- From the Departments of Small Animal Clinical Sciences and Pathology, College of Veterinary Medicine, University of Tennessee, Knoxville, TN. Supported by a Surgeon-in-Training Grant from the American College of Veterinary Surgeons, Bethesda, MD. Presented at the 32nd American College of Veterinary Surgeons Meeting, Orlando, FL, October 1997. Address reprint requests to Daren M. Roa, DVM, Chesapeake Veterinary Referral Surgery, 2138-B General’s Highway, Annapolis, MD 21401. ©Copyright 1999 by The American College of Veterinary Surgeons 0161-3499/99/2806-0007$3.00/0 456