Myoperitoneal Microvascular Free Flaps in Dogs: An Anatomical Study and a Clinical Case Report

Abstract

The purpose of the anatomical study was to identify potential myoperitoneal microvascular free flaps, in dogs, that are based on a single artery and vein. The angiosomes of the right deep circumflex iliac artery and left phrenicoabdominal (cranial abdominal) artery were evaluated in six medium-sized canine cadavers. The right deep circumflex iliac artery and left phrenicoabdominal (cranial abdominal) artery were injected with a mixture of barium and latex (equal parts). The entire right and left transversus abdominis muscles were dissected from the abdominal wall and radiographed. The angiograms of the deep circumflex iliac artery showed poor arborization of the vessels within the transversus abdominis muscle in all six cadavers. The angiograms of the phrenicoabdominal (cranial abdominal) artery showed consistent filling of the vascular bed of the cranial half of the transversus abdominis muscle flap in all six dogs. The vascular pedicle lengths and the diameter of the arteries and veins of both the deep circumflex iliac and phrenicoabdominal (cranial abdominal) myoperitoneal free flaps were found to be acceptable for microvascular anastomosis. The deep circumflex iliac flap was unacceptable because of inadequate vascular perfusion. The cranial abdominal artery had a consistent, large branch that supplied the cranial half of the transversus abdominis muscle, thereby making a myoperitoneal flap supplied by this vessel a potentially useful free flap. An 8-year-old male, neutered, mixed-breed dog was evaluated for possible repair of a large defect of the hard palate. Previous operations, using local tissue flaps, had been unsuccessful. A myoperitoneal free flap, based on the right cranial abdominal artery, and consisting of the cranial portion of the transversus abdominis muscle, was used successfully to reconstruct the hard palate. Migrating epithelium from the edges of the wound covered the myoperitoneal flap by 10 weeks after surgery. Therefore, the cranial abdominal myoperitoneal free flap can be considered for reconstruction of intra-oral defects that cannot be repaired using conventional local flap techniques.

Microvascular Free Tissue Transfer of the Rectus Abdominis Muscle in Dogs

“…Degner et al described the benefits of myoperitoneal reconstruction for oral cavity defects with primary healing of oral mucosa to the transferred peritoneal surface 10 . The human rectus abdominis muscle with its associated peritoneal lining is successfully used in intraoral reconstructive surgery.…”

“…Examples of autogenous tissues transferred using microvascular free tissue techniques in veterinary medicine include skin, bone, omentum, muscle, footpads, and various combinations of these tissues 7,[9][10][11][12] . In 1986, Fowler et al performed the first documented free tissue transfers in veterinary medicine 13 .…”

“…One-hundred percent tissue 4 4 viability was produced in all eight dogs. Free tissue transfer of the transverses abdominis muscle was then reported in a two-phase study 10 . Phase one defined the perfusion pattern of the muscle and described the dimensions of the phrenicoabdominal artery and vein, which supplied the cranial one half of the muscular body.…”

“…These include the trapezius, latissimus dorsi, caudal head of the sartorius and the transverses abdominis 10,16,20,21 .…”

Deep Circumflex Iliac Cutaneous Free Flap in Cats

“…Since then, many different free flaps have been described. Most of these flaps have been developed in dogs and include the superficial cervical cutaneous flap, saphenous fasciocutaneous flap, trapezius muscle flap, latissimus dorsi muscle flap, proximal and distal ulnar bone flaps, rectus abdominus flap, tibial vascularized cortical graft, free rib grafts, and transversus abdominus myoperitoneal flap 8–15 …”