The use of an angularis oris axial pattern flap in a dog after resection of a multilobular osteochondroma of the hard palate

An 11-year-old neutered male boxer was presented for treatment of a multilobular osteochondroma of the hard palate. The mass was surgically resected and the hard palate defect was reconstructed using an angularis oris axial pattern buccal mucosal flap. No local recurrence was reported 6 mo after surgery.     

Free tissue transfer of the rectus abdominis myoperitoneal flap for oral reconstruction in a dog

A five-month-old intact/male Boxer dog was presented 5-days following bite wound trauma to the maxillary region resulting in an oronasal fistula extending from the maxillary canine teeth to the soft palate. Multiple surgical procedures using local, buccal mucosal flaps failed to repair the oronasal fistula. Free tissue transfer of the rectus abdominis myoperitoneal flap using microvascular surgical techniques was successful in providing soft tissue reconstruction of the hard palate area. Complications of these surgical techniques included muscle contraction and subsequent muzzle distortion. Small, refractory oronasal fistulae at the perimeter of the myoperitoneal flap were repaired by primary wound closure.     

Investigation and clinical application of a novel axial pattern flap for nasal and facial reconstruction in the dog

OBJECTIVE: To describe the vascular supply to a facial skin flap based at the commissure of the lip in the dog and report on its use in four dogs. STUDY DESIGN: Experimental and prospective clinical study. Animals Five canine cadavers and four client-owned dogs. METHODS: In the cadavers, the ventral aspect of the zygomatic arch, the ventral margin of the caudal mandible and the wing of the atlas were marked as anatomical boundaries of a skin flap that was elevated from the subcutaneous tissues to the level of the medial canthus of the eye. Methylene blue dye and barium sulphate solution were independently infused through a common carotid (three dogs) or facial artery (two dogs) catheter. Distribution of dye throughout the harvested skin was assessed subjectively. After contrast infusion the flap was excised and radiographed. The technique was used to reconstruct large facial or nasal defects in four dogs after tumour or skin lesion excision. RESULTS: Cadaver dissections and contrast studies clearly demonstrated three direct cutaneous arteries, the superior and inferior labial arteries and the angularis oris artery, arborising within the base of the flap. A separate direct cutaneous branch of the angularis oris artery was identified. An arterial plexus was identified within the distal flap, within which this artery communicates with the transverse facial artery and a cutaneous branch of the masseteric artery. Dye infusion caused discolouration of the elevated skin and vasculature within the flap. The flap survived in all clinical cases with marginal distal necrosis in one dog. CONCLUSIONS: The complex facial flap described is perfused by three direct cutaneous arteries and functions reliably in clinical cases.     

Axial Pattern Flap Based on the Genicular Branch of the Saphenous Artery in the Dog

Axial pattern flaps based upon the genicular branch of the saphenous artery and medial saphenous vein were developed in eight dogs. On one hind limb of each dog, the experimental flap was raised and immediately transferred to a cutaneous defect created over the lateral aspect of the lower limb distal to the stifle. A control flap was elevated and transferred on the opposite hind limb with the genicular branches of the saphenous artery and vein ligated and divided at the base of the flap. Eighty-nine per cent of the length of the flap survived in those flaps in which the genicular vessels were left intact, whereas only 54% of the flap's length survived in the control flaps. Postoperatively, all dogs were bearing weight on the limbs normally. The genicular axial pattern flap may have special clinical application in cases of cutaneous defects involving the lateral aspect of the tibia.     

Use of Buccal Mucosal Flaps for the Correction of Congenital Soft Palate Defects in Three Dogs

Objective —To present an alternative surgical technique for the repair of soft palate defects in dogs.
Animal Population —Three Foxhound cross dogs.
Methods —Bilateral buccal mucosal flaps, based at the palatoglossal arches, were raised. One flap was rotated so that the mucosal side created the floor of the nasopharynx. The second flap was rotated so that the mucosal side formed the roof of the oropharynx. The mucosa of the remnant of the soft palate and the pharyngeal walls was incised and the flaps sutured to these free mucosal edges. The caudal ends of the two flaps were sutured to each other.
Results —Complete closure of the soft palate defect was obtained in all three dogs. The dogs were monitored for between 1.5 and 3 years postoperatively, and no long-term problems were encountered.
Conclusions —This surgical technique resulted in an excellent functional separation of the oropharynx and nasopharynx and allowed reconstruction of a large bilateral soft palate defect.
Clinical Relevance —By using the buccal mucosal flaps, as described in this report, a tension-free closure of large soft palate defects can be obtained, thereby eliminating a major cause of failure of this type of reconstructive surgery.     

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

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.     

Axial pattern flap based on a cutaneous branch of the facial artery in cats

Objective: To describe the cutaneous portion of the facial artery in cats and an axial pattern flap based on a branch of this artery. Study Design: Ex vivo study. Sample Population: Cat cadavers (n=12). Methods: The common carotid artery was identified, cannulated, and infused with methylene blue to assist in the identification of the facial artery, which was subsequently cannulated and selectively infused with methylene blue. The main trunk of the artery and its branches were dissected. The extent of blue coloration of the skin was evaluated on the contralateral side of the same specimen after infusing methylene blue into the facial artery. In 4 specimens, the flap was raised along previously defined borders and adequacy of perfusion was evaluated. Results: The area of skin perfused by the facial artery extended from the lower eyelid dorsally, to the angularis oris cranially, and the wing of the atlas caudally. Borders of the skin flap were defined on the basis of the anatomic dissection and skin coloration after selective infusion of the facial artery with methylene blue. A skin flap of 6 cm × 3.4 cm, based on the first caudally directed cutaneous branch of the facial artery was shown to be well perfused. The viability of this flap was confirmed in a clinical case. Conclusion: The facial artery flap is useful for repair of skin defects of the head in cats.     

Complications and outcome after thoracodorsal axial pattern flap reconstruction of forelimb skin defects in 10 dogs, 1989-2001

OBJECTIVE: To determine (1) the frequency and extent of complications associated with thoracodorsal axial pattern flap reconstruction of forelimb skin defects in dogs and (2) outcome after treatment of such complications. STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: Ten dogs. METHODS: Medical records for 10 dogs that had a thoracodorsal axial pattern skin flap reconstruction of a forelimb skin defect were reviewed. RESULTS: Three dogs had complete flap survival. Partial necrosis of the distal flap, ranging from an estimated 2% to 53% (mean, 21%) of the flap surface area, occurred in 7 dogs. Six dogs required surgical management of the skin necrosis, resulting in successful resolution in 5 dogs, whereas, in 2 dogs, the wound healed by second intention. Positive bacterial cultures were obtained from 3 dogs with distal flap necrosis. Seroma formation was noted in 2 dogs; the entire flap survived in 1 dog, whereas the second dog developed distal flap necrosis. Edema and bruising of the distal portion of the flap were noted in 8 dogs; distal flap necrosis subsequently developed in 7 dogs. Partial incisional dehiscence, which healed by second intention, occurred in 2 dogs. Of 6 owners available for follow-up, all were satisfied with the functional outcome, but 1 owner was not satisfied with the cosmetic appearance. CONCLUSIONS: Partial flap necrosis was a frequent complication of thoracodorsal axial pattern flap reconstruction of forelimb skin defects and required additional wound care or surgical intervention to achieve healing. CLINICAL RELEVANCE: Thoracodorsal axial pattern flaps can provide full-thickness skin coverage of extensive skin defects of the forelimb, but owners should be aware of the likelihood of local wound complications.     

Axial pattern flap based on the caudal auricular artery in dogs

An axial pattern flap that was based on the sternocleidomastoideus branches of the caudal auricular artery and vein was developed. Control flaps, which included ligation and division of the caudal auricular artery and vein, were similarly developed on the contralateral aspect of the neck. Mean survival of caudal auricular artery axial pattern flaps (85.2%), compared with control flaps (63.9%), was significantly different (P less than 0.05). On the basis of results of this study, an axial pattern flap based on the sternocleidomastoideus branches of the caudal auricular artery and vein may be a source of skin for reconstructive procedures of the head and neck.     

A vaginal mucosal pedicle flap technique for repair of rectovaginal fistula in mares

OBJECTIVE: To describe the use of a vaginal mucosal pedicle flap for repair of rectovaginal fistulae (RVF) in mares. STUDY DESIGN: Clinical case report. ANIMALS: Three mares with RVF. METHODS: After debriding the RVF, a dorsally based U-shaped mucosal and submucosal pedicle flap (2-4 mm thick) was dissected from the vaginal wall, rotated approximately 90 degrees angle to close the ventral aspect of the fistula and sutured in position with 10-13 single sutures that did not penetrate the rectal mucosa. This positioned the vaginal mucosa so that it was continuous with the rectal mucosa. RESULTS: Two RVF healed by 1st intention whereas for the 3rd RVF, 2 additional single sutures were required to repair partial dehiscence after 10 days. At 6 weeks and 6 months all RVF were healed. One mare subsequently foaled without complications. CONCLUSIONS: RVF can be closed by use of a rotation flap of vaginal tissue. CLINICAL RELEVANCE: Tension-free closure of RVF can be achieved by rotating a pedicle flap of vaginal mucosal tissue without undue wound tension, and should be considered as an alternative to conventional appositional techniques.     

The Effect of Tension on Perfusion of Axial and Random Pattern Flaps in Foals

Caudally based axial pattern and random pattern skin flaps, 5 cm x 10 cm, were raised on the abdomens of seven foals. Blood flow was measured 7.5 cm from the flap bases during incremental increases in applied tension. At tensions less than 1400 g, cutaneous blood flow was more than four times higher in axial pattern flaps than in random pattern flaps. Blood flow in axial pattern flaps at tensions up to 1500 g was greater than baseline flow in random pattern flaps. After removal of applied tension, perfusion in axial pattern flaps gradually increased but remained below baseline values. A short period of hyperperfusion after removal of tension in random pattern flaps may have been indicative of accumulation of waste products and localized acidosis. All flaps healed in their donor beds without complications.     

Assessment of a caudal external thoracic artery axial pattern flap for treatment of sternal cutaneous wounds in birds

OBJECTIVE: To assess the use of a caudal external thoracic artery axial pattern flap to treat sternal cutaneous wounds in birds. ANIMALS: 16 adult Japanese quail. PROCEDURE: A cutaneous defect in the region of the mid-sternum was surgically created in all quail. In 6 quail (group I), an axial pattern flap was created from the skin of the lateral aspect of the thorax and advanced over the sternal defect. In 8 quail (group II), a flap was similarly created and advanced but the flap vasculature was ligated. All quail were euthanatized at 14 days after surgery and had necropsies performed. Sections of the flap and the surrounding tissue were examined histologically to assess flap viability. RESULTS: All axial pattern flaps in group-I quail had 100% survival. In group II, mean percentage area of flap survival was 62.5%; mean area of necrosis and dermal fibrosis of flaps were significantly greater than that detected in group I. In flaps of group-II quail, neovascularization in the deep dermis and profound necrosis of the vascular plexus in the superficial dermis were observed. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the caudal external thoracic artery axial pattern flap could be used successfully in the treatment of surgically created sternal cutaneous defects in quail with no signs of tissue necrosis or adverse effects overall. Use of this technique to treat self-mutilation syndromes or application after surgical debulking of tumors or other masses might be beneficial in many avian species.     

Axial pattern flap based on the lateral caudal arteries of the tail in the dog: an experimental study

OBJECTIVE: To determine applicability and size limits of an axial pattern flap based on the lateral caudal arteries in dogs to reconstruct caudodorsal trunk skin defects. STUDY DESIGN: Experimental study. ANIMALS: Ten mature, mixed breed dogs. METHODS: The lateral caudal vessels of the tail were incorporated in the flaps of the treatment group (n=5) and were ligated in the control group (n=5). Flaps were rotated and placed into experimentally created caudodorsal skin defects on the trunk. The length and area of tissue that remained viable in each flap were determined. RESULTS: Mean (+/-SD) survival area (222.8+/-32.9 cm2) and length (25.1+/-4.5 cm) of vascularized flaps were significantly greater (P<.05) compared with control flaps (94.9+/-13.4 cm2 and 14.61+/-4.7 cm). Necrosis occurred in all control flaps, resulting in lower percentage flap area (48.8%) and length (47.1%) survival compared with vascularized flaps (78.1%, 77.5%). CONCLUSIONS: Axial pattern flap based on lateral caudal arteries of the tail was successfully elevated and transferred in a single procedure, with 78% survival for closure of large experimentally created caudodorsal trunk defects in dogs. CLINICAL RELEVANCE: Large cutaneous defects of the caudodorsal trunk area in dog could be reconstructed with tail axial pattern flap. Limitations in terms of size and changes in animal appearance have to be considered before flap elevation.     

Greater palatine island axial pattern flap for repair of oronasal fistula related to eosinophilic granuloma

A Greyhound presented with eosinophilic granuloma lesions of the soft palate and oronasal fistula. Since other siblings had been known to also have oral eosinophilic granuloma, it was suspected that the dog reported here had a familial predisposition to develop the disease. Preoperative medical management consisting of anti-inflammatory and immunosuppressive therapy was required before surgical repair of the oronasal fistula. Multiple surgical techniques, including a greater palatine island axial pattern flap, were used to repair the oronasal fistula.     

Axial Pattern Flap Based on the Superficial Brachial Artery in the Dog

An axial pattern flap based on the superficial brachial artery and vein (brachial axial pattern flap) was developed on the forelimbs of five dogs. The flap was immediately transferred to a distal cutaneous defect created on the antebrachium of that limb. A control flap was elevated on the opposite limb and transferred to a similar distal site after ligation of the superficial brachial artery and vein at the base of the flap. Mean brachial axial pattern flap survival (98%) was significantly more than mean control flap survival (77%) (p less than 0.05). Results of this study suggest that the brachial axial pattern flap has potential application for closure of major cutaneous defects involving the canine antebrachium above the carpus.     

Skin-fold advancement flaps for closing large proximal limb and trunk defects in dogs and cats

OBJECTIVE: To describe the use of skin-fold advancement flaps for covering large skin defects in dogs and cats. STUDY DESIGN: Clinical study. ANIMALS: Eight client-owned animals: 6 dogs and 2 cats. METHODS: Six dogs and 2 cats underwent reconstruction of soft-tissue wounds resulting from traumatic, neoplastic, or infectious lesions. Skin-fold flaps were created by division of the medial and lateral attachment to the proximal limb or the dorsal and ventral attachment to the trunk, enabling closure of adjacent defects on the trunk or proximal limb, respectively. RESULTS: Skin-fold flaps proved effective for closing defects in all animals. Necrosis of a portion of the flap occurred in 2 dogs due to technical errors, but the resultant defects remained amenable to primary closure. All wounds ultimately healed primarily, without major complications. CONCLUSION AND CLINICAL RELEVANCE: The skin-fold advancement flap is a versatile technique that lends itself to use in a variety of locations, depending on which attachments are divided. The clinical results are comparable with those reported for axial pattern and subdermal plexus flaps.     

Clinical evaluation of axial pattern skin flaps in dogs and cats: 19 cases (1981-1990).

Nineteen axial pattern skin flaps were used in 16 dogs and cats to provide skin for repair of extensive cutaneous defects. Retrospective evaluation of medical records was used to determine percentage flap survival, postoperative complications, and long-term outcome of axial pattern skin flaps. The most common indication for use of axial pattern flaps was to augment wound closure following tumor resection (n = 7). Other indications included trauma (n = 5), chronic nonhealing wounds (n = 4), urine-induced cellulitis (n = 1), idiopathic dermal necrosis (n = 1), and chronic lymphoplasmocytic dermatitis (n = 1). Mean flap survival (+/- SD) was 96% (+/- 8). Postoperative complications included wound drainage (n = 15), partial dehiscence of the sutured flap (n = 7), distal flap necrosis (n = 6), infection (n = 3), edema (n = 3), and seroma formation (n = 2). After a median follow-up time of 5 months, evaluation of animals indicated that surgery provided successful wound reconstruction with good cosmetic results. Reconstruction of large cutaneous defects is facilitated by axial pattern flap application regardless of cause of wound. Postoperative complications are common but amenable to standard wound management techniques such as drain placement and surgical debridement of devitalized distal flap skin.     

Use of skin stretchers to elongate a peninsular thoracodorsal axial pattern flap for antebrachial wound closure in a dog

Objective: To describe preoperative use of skin stretchers to elongate a peninsular thoracodorsal axial pattern flap to close a large antebrachial wound on a dog. Study Design: Case report. Animals: A 21 kg, 7‐year‐old, male intact mixed breed dog. Methods: Two skin stretchers were applied to the site of the thoracodorsal axial pattern flap 4 days before surgery. The elastic cables connecting the adhesive pads were tightened daily to increase the skin available for a peninsular thoracodorsal axial pattern flap, which was created and rotated 180° to cover an antebrachial defect to a level 2 cm proximal to the carpus. Results: The entire flap survived; there was a small amount of incisional separation at the distal margin of the flap that healed without further treatment. Conclusion: Preoperative skin stretching provided additional skin for the axial pattern flap used.     

Repair of sinocutaneous fistulae in two horses

Chronic facial defects extending into the sinuses of two mares were repaired using periosteal flaps. Partial osseous bridging was established over the defects following repair. Previous attempts to close the defects with skin alone had failed. A periosteal flap is a simple surgical technique that provides the foundations for successful repair, despite the chronicity of some fistulae.