Modification of the superficial cervical axial pattern skin flap for oral reconstruction

OBJECTIVE: To describe an extended pedicle flap based on the superficial cervical artery (SCA) for closure of oral defects in dogs. STUDY DESIGN: Anatomic study; in vivo experimental study. ANIMALS: Canine cadavers (13) and 3 dogs. METHODS: The prescapular branch of the SCA was cannulated and perfused with a lead oxide gelatin mixture. The area perfused by 1 SCA was examined as was the rostral extent of the flap. Staged implantation was performed to evaluate flap performance in vivo. In stage 1, the flap was prepared for implantation into the oral cavity. In stage 2, the flap was fully developed to include the 1 degrees, 2 degrees, and partial 3 degrees angiosome of 1 SCA pedicle. The flap was transposed by a bridging incision and a parapharyngeal tunnel into the oral cavity. The flap was used to reconstruct a partial-thickness defect created in the palate. RESULTS: The territory of the contralateral SCA was captured in all cadavers. The full flap reached the level of the canine teeth in all cadavers. In live dogs, necrosis was not observed after implantation into partial-thickness defects and dehiscence was minimal. Loss of pliability secondary to de-epithelialization and staging resulted in a limitation of rostral reach of the flap. CONCLUSIONS: Whereas the flaps did not reach as far rostrally as anticipated, they survived well in the harsh oral environment. The flap may be modified to reconstruct full-thickness palatal defects. CLINICAL RELEVANCE: The extended SCA pattern flap may be adapted for closure of oral defects.     

Use of local and axial pattern flaps for reconstruction of the hard and soft palate

There are numerous conditions that may result in defects of the hard and soft palate. Reconstruction of these defects may be difficult due to anatomical limitations and limited tissue availability. The majority of palate defects, even when large, may be closed using local and/or axial pattern flaps, while other more advanced techniques such as free tissue transfer and prosthetic implants are required in a smaller number of cases. This article describes the use of local and axial pattern flaps in the reconstruction of the hard and soft palate.     

Use of an axial pattern flap and nictitans to reconstruct medial eyelids and canthus in a dog

A 10-year-old male neutered Boxer presented with recurrence of a mast cell tumor at the right medial canthal area. Following excision including 2 cm margins, the medial one-half of the upper and lower eyelids and the medial canthus were reconstructed using an axial pattern flap based on the cutaneous branch of the superficial temporal artery. The bulbar conjunctiva of the nictitans was preserved and sutured to the medial flap edge, thus creating a conjunctival lining to the deep aspect of the flap, protecting corneal epithelium. This is a valuable surgical technique for closing a large skin defect and reconstructing the medial eyelids, thus preserving the globe.     

Standard and modified glabellar flap for medial canthus reconstruction following mass removal in three dogs and two cats

Purpose

To describe the surgical technique and clinical outcomes of the glabellar flap and its modification for the reconstruction of the medial canthus following resection of tumors in three dogs and two cats.

Methods

Three dogs (7-, 7-, and 12.5-year-old mixed breeds) and two cats (10- and 14-year-old Domestic shorthair) presented with a 7–13 mm tumor affecting the eyelid and/or conjunctiva in the medial canthal region. Following en bloc mass excision, an inverted V-shaped skin incision was made in the glabellar region (i.e., the area between the eyebrows in humans). The apex of the inverted V-shaped flap was rotated in three cases, whereas a horizontal sliding movement was performed in the other two cases to better cover the surgical wound. The surgical flap was then trimmed to fit the surgical wound and sutured in place in two layers (subcutaneous and cutaneous).

Results

Tumors were diagnosed as mast cell tumors (n = 3), amelanotic conjunctival melanoma (n = 1), and apocrine ductal adenoma (n = 1). No recurrence was noted in a follow-up time of 146 ± 84 days. Satisfactory cosmetic outcome with normal eyelids closure was achieved in all cases. Mild trichiasis was present in all patients and mild epiphora was noted in 2/5 patients, but there were no associated clinical signs such as discomfort or keratitis.

Conclusions

The glabellar flap was easy to perform and provided a good outcome in terms of cosmetic, eyelid function, and corneal health. Postoperative complications from trichiasis appear to be minimized by the presence of the third eyelid in this region.     

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.     

Use of a caudal auricular axial pattern flap in three cats and one dog following orbital exenteration

Orbital exenteration accompanied by wide eyelid excision in the cat and dog may leave a defect that cannot be closed in a primary fashion. This report describes the use of a caudal auricular axial pattern flap to effect closure following orbital exenteration in three cats and one dog. The most common complication was distal flap necrosis, which necessitated a second surgery in two patients.     

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.     

Use of a semitendinosus myocutaneous flap for soft-tissue reconstruction of a grade IIIB open tibial fracture in a dog

OBJECTIVE: To describe the clinical use of a semitendinosus myocutaneous flap for soft-tissue reconstruction of a grade IIIB open tibial fracture. STUDY DESIGN: Case report. ANIMALS: A 5-year-old castrated male Labrador retriever with a grade IIIB open tibial fracture. METHODS: A myocutaneous flap was created by elevating the origin of the semitendinosus muscle and the associated overlying skin. The flap was rotated distally based on the distal vascular pedicle into a soft-tissue defect overlying the central and distal third of the tibia. RESULTS: The flap allowed one-stage reconstruction of a severe soft-tissue defect overlying denuded bone in a grade IIIB open tibial fracture. The muscular portion of the flap survived; however, there was necrosis of 3 cm of skin extending distally beyond the muscular portion of the flap. CONCLUSION: Distal rotation of the semitendinosus muscle and overlying skin can be used in the treatment of severe soft-tissue defects of the canine crus. CLINICAL RELEVANCE: Complex soft-tissue injuries to the canine crus can be treated with a myocutaneous flap as a reasonable alternative to other reconstructive techniques.     

The use of a caudal auricular axial pattern flap for repair of a degloving pinna wound in a dog

A 3-year-old male neutered French bulldog was presented for an anatomical degloving injury of the left pinna following a conflict with a larger dog at a park. Approximately 2/3 of the dorsal skin was removed from the convex surface of the left pinna along with an irregular, full thickness injury on the lateral aspect of the pinna distal to the cutaneous marginal pouch. A caudal auricular axial pattern flap (CAAPF) was used to reconstruct the pinna. The flap healed with no noted necrosis over the long-term. Postoperative cellulitis was noted for approximately 3 mo. The dog was medically managed for bilateral otitis externa multiple times over the course of recovery. Long-term function and cosmesis at 1.5 y after surgery revealed adequate functional movement of the pinna and acceptable cosmesis. It is concluded that, rather than a pinnectomy, a CAAPF can be offered as a surgical option in dogs that have injuries localized to the pinna.Key clinical message:A CAAPF is an alternative to pinnectomy for reconstruction of the pinna after degloving injury and yields a functional and cosmetically acceptable outcome.     

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.     

Direct approach to the nasal cavity through a bone flap for the treatment of a large nasal cyst

A 21‐year‐old Warmblood mare was referred to the Equine Department, Vetsuisse Faculty, University of Zurich, because of recurrent unilateral nasal discharge 3 months after partial removal of a large cyst from the left maxillary and frontal sinuses. Endoscopic, radiographic and computed tomographic examinations showed that the remnant of the cyst, which originally had extended from the left maxillary and frontal sinuses into the left nasal cavity, had expanded and was obliterating the left middle nasal meatus. A direct surgical approach to the cyst through the left nasal and maxillary bones rostral to the facial crest was chosen, which allowed evaluation and removal of the entire cyst. Endoscopic examination 3 days post operatively showed no remnants of the cyst, and the mare was discharged in good health. Re‐examination one year later showed no recurrence of the cyst.     

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.     

Preservation of the fistula for reconstruction of the anal canal and the anus in atresia ani and rectovestibular fistula in 2 dogs

OBJECTIVE: To report a technique for correction of atresia ani and rectovestibular fistula with fistula preservation, and outcome in 2 dogs. STUDY DESIGN: Case report. ANIMALS: Two intact female puppies. METHODS: The fistula was approached by episiotomy. A vertical median perineal incision was made starting dorsal to the anal region and extended to surround the fistula. The rectum and vagina were separated, and the end of the fistula was sutured to the skin. RESULTS: Early postoperative complications included constipation, fecal incontinence, and perineal soiling, but long-term outcome was good in both dogs. CONCLUSION: With careful dissection, the fistula and internal anal sphincter can be preserved and used in the surgical reconstruction of the anal canal and anus. CLINICAL RELEVANCE: Preservation of the fistula may provide an internal sphincter that contributes to a better functional result during correction of atresia ani. A surgical approach that combines episiotomy and perineal incision for separation of the vagina and rectum, and preserves the fistula may decrease the risk of dehiscence.     

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.     

Reconstruction of the lower eyelid by third eyelid lateral advancement and local transposition cutaneous flap after "en bloc" resection of squamous cell carcinoma in 5 cats

OBJECTIVE: To describe a novel technique for blepharoplasty to cover a tissue defect involving >/=50% of the lower eyelid. STUDY DESIGN: Prospective clinical study. ANIMALS: Five cats with lower eyelid squamous cell carcinoma (SCC). METHODS: En bloc resection of SCC by removing >/=50% of the lower lid with either the medial or lateral canthus was performed without other adjunctive treatment for SCC. The lid defect was reconstructed with a transposition skin flap derived from the frontal (medial defect) or temporal (lateral defect) region. The third eyelid was advanced laterally without dissection from its insertion; its outer conjunctival layer was removed, and the skin flap was sutured with single interrupted sutures dorsally over the nictitating membrane, ventrally to the cutaneous edge of the surgical wound and medially or laterally (depending on the canthus removed) to the skin of the remaining lower lid. RESULTS: Satisfactory cosmetic and functional results were achieved and the Schirmer tear tests were normal. In 2 cats, the skin flap needed monthly hair trimming to avoid corneal lesions. CONCLUSIONS: After en bloc resection of SCC involving >/=50% of the lower eyelid, reconstruction can be achieved by relocation of the third eyelid and use of a cutaneous transposition flap sutured to the scarified external surface of the third eyelid. Eyelid apposition and lacrimal function were preserved. CLINICAL RELEVANCE: Blepharoplasty using a cutaneous transposition flap sutured to the scarified surface of a relocated third eyelid should be considered for reconstruction of lower eyelid defects with >/=50% tissue loss of the lid margin.     

Clinical evaluation of random skin flaps based on the subdermal plexus secured with sutures or sutures and cyanoacrylate adhesive for reconstructive surgery in dogs

OBJECTIVE: To evaluate the use of subdermal plexus skin flaps for closing defects after excision of cutaneous and subcutaneous tumors in dogs and to compare outcome of flaps secured with sutures and those secured with butyl-cyanoacrylate and intermittent sutures. STUDY DESIGN: Clinical study. ANIMALS: Fifteen dogs. METHODS: After excision of cutaneous or subcutaneous tumors the skin defect was reconstructed by random flaps based on the subdermal plexus. Flap skin edges were apposed with simple interrupted 4-0 monofilament nylon sutures (group 1; 5 dogs) or nylon sutures alternated with butyl-cyanoacrylate adhesive (group 2; 10 dogs). Flaps were evaluated every 48 hours when bandages were changed, until complete healing. RESULTS: Random flaps based on the subdermal plexus were effectively used to close wound defects; mean flap survival was 89%. Partial flap necrosis occurred in 4 dogs. Wound margins apposed with butyl-cyanoacrylate had thinner and more esthetic scars than sutured margins. CONCLUSION: Random flaps based on the subdermal plexus proved to be versatile for covering limb wounds after excision of cutaneous or subcutaneous tumors. Mean survival rate was comparable to that reported for axial pattern flaps. Butyl-cyanoacrylate adhesive was easy to apply, allowed accurate margin apposition with good cosmetic outcome and reduced sutures needed. CLINICAL RELEVANCE: Cyanoacrylate adhesive should be considered in lieu of suture closure to secure random skin flaps based on the subdermal plexus in dogs.