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

Random mucosal rotating flaps for rostral to mid maxillary defect reconstruction: 26 dogs (2000-2019)

OBJECTIVES

To evaluate the feasibility and the complications following single or double random mucosal rotating (transposition or interpolation) flaps for the closure of rostral to mid maxillary defects in dogs.

MATERIALS AND METHODS

Medical records of dogs treated with single or double random mucosal rotating flaps after maxillectomy for oral lesions or traumatic loss of tissue, were evaluated. Clinical findings, surgery performed, outcome and postoperative complications (major and minor) were extracted.

RESULTS

Twenty-six client-owned dogs were retrospectively included. Dogs underwent maxillectomy for canine acanthomatous ameloblastomas (9), oral squamous cell carcinomas (4), peripheral odontogenic fibromas (4), oral melanomas (3), oral fibrosarcomas (2), dentigerous cysts (2) and oral osteosarcoma (1) and trauma resulting in an oronasal fistula (1). Twenty-three dogs underwent a single transposition or interpolation flap and three dogs were treated with a double transposition flap. Postoperative complications, including dehiscence or flap necrosis, occurred in six dogs.

CLINICAL SIGNIFICANCE

Random mucosal rotating (transposition or interpolation) flaps are versatile when used to close rostral maxillary defects in dogs. Postoperative complications appear to be more likely when these flaps are used to close mid maxillary defects.

Buccal transposition flap for closure of maxillary lip defects in 5 dogs

OBJECTIVE

To describe the technique and outcomes of the closure of maxillary lip defects using a buccal transposition flap and to identify potential routes of vascular supply to the flap.

ANIMALS

Five dogs treated clinically and 1 cadaveric dog head.

STUDY DESIGN

Short case series and cadaveric study.

METHODS

A left maxillary labial defect and a buccal transposition flap were created on a cadaver head. Iodinated contrast was injected into the left common carotid artery and computed tomography was performed to assess the vascular supply. Medical records were reviewed for all dogs that underwent tumor excision with maxillary lip resection, reconstructed with a buccal transposition flap.

RESULTS

The buccal transposition flap was perfused by branches of the angularis oris artery and superior labial artery. Five dogs were included in this study. All flaps survived. Three dogs developed postoperative complications, including oronasal fistula (n = 2) and partial flap dehiscence (n = 1). The cosmetic and functional outcomes were considered satisfactory in all cases.

CONCLUSION

Buccal transposition flaps for the closure of large maxillary lip defects provided adequate functional and cosmetic outcomes. The buccal transposition flap had vascular contributions from the angularis oris artery and the superior labial artery.

Case report: Reconstruction of a complex maxillofacial gunshot defect using a titanium patient-specific implant in a dog

This report describes the surgical reconstruction of large maxillofacial defect caused by a short-range gunshot injury in a dog using titanium patient-specific implant (PSI). A 3-year-old male Wolf Shepherd was admitted for a large right facial defect with right nasal cavity exposure caused by a gunshot injury. Radiographic examination revealed severe loss of the right maxillary, nasal, and incisive bones, multiple fractures of both left and right palatine bones, and a comminuted fracture of the right mandible. Initial surgical procedure included computed tomography (CT) imaging for three-dimensional (3D) implant design. Open wound management was maintained for 18 days until the fresh granulation tissue fully covered the wound bed. The implant was designed in a “hand grasping shape” to cover the defect, align multiple fractured palatine bones, and make a snap fit function. Multiple holes, including cortical screw holes, were added to the final design. The implant was printed on a titanium alloy. Surgical application of titanium PSI was performed 19 days after the primary surgery. A free sublingual mucosal graft was used to reconstruct the mucosal layer of the right nasal cavity. The mucosa was then covered with collagen membrane to strengthen the structure of the nasal cavity. Blunt dissection of the hard palate mucoperiosteum above the palatine process and palatine bones, soft tissue above the maxilla was performed, and the 3D printed titanium implant was fastened in a preplanned position. The facial soft tissue defect was reconstructed, and the titanium PSI was covered using an angularis oris cutaneous flap. Partial flap necrosis occurred in the rostral aspect, and the wound was managed to heal by a second intension. Flap dehiscence at the junction of the flap and hard palate mucoperiosteum occurred with exposure of the implant 2 days postoperatively. Multiple attempts to close the defect failed, and the owner wanted to stop treatment. Healthy granulated tissue was observed proximal to the implant. The defect no longer increased in size and did not show any noticeable complications related to the defect at 60 days after titanium PSI application, and the dog was discharged. Six months post-operatively, the dog remained active with great appetite, gained weight, and showed acceptable facial symmetry without enlargement of the implant exposure or any implant-related problems.

Angularis oris axial pattern flap as a reliable and versatile option for rostral facial reconstruction in cats

OBJECTIVE

To evaluate outcomes associated with the use of an angularis oris axial pattern flap (AOAPF) for rostral facial reconstruction in cats.

ANIMALS

Nine adult client-owned cats.

STUDY DESIGN

Short case series.

METHODS

Ten AOAPF were performed in nine cats after resection of a tumor. Wounds were located at the nose, infraorbital, supraorbital, frontal, eye, and ear canal region. Orbital exenteration (n = 3), pinnectomy (n = 2), nasal planum resection, total ear canal ablation (n = 2), and partial eyelid reconstruction (n = 3) were performed.

RESULTS

Short-term postoperative complications included flap edema (n = 10), suture dehiscence (n = 3), and distal tip necrosis (n = 3). All wounds resulting from minor complications healed by second intention in 5-15 days. Long-term complications included epiphora (n = 2), frequent grooming around the eyes (n = 2), and enucleation due to corneal ulcer secondary to impaired postoperative eyelid function (n = 1). Tumor recurrence occurred in 3 cases.

CONCLUSION

The AOAPF was a versatile and reliable option for rostral facial reconstruction in cats with acceptable long-term outcomes.

Superficial temporal axial pattern flap for facial reconstruction of skin defects in dogs and cats

OBJECTIVES

Report the use, complications and outcome of the superficial temporal axial pattern flap (STA) when used for closure of skin defects localised to the maxillofacial region in dogs and cats.

MATERIALS AND METHODS

Multi-centre retrospective cohort study. Medical records of dogs and cats treated with a STA flap for closure of skin defects were reviewed. Information regarding signalment, reason for axial pattern flap use, flap size, flap healing, postoperative complications including need for surgical revision and overall outcome were collected.

RESULTS

Nineteen patients were included: nine dogs and 10 cats. Indications for the STA flap included closure of defects following excision of tumours (18/19, 94.7%) and fungal granuloma resection (1/19, 5.2%). 100% flap survival occurred in 17 of 19 flaps (89.4%). Postoperative complications occurred in eight of 19 flaps (42.1%). A major complication of full thickness partial necrosis of the flap occurred in one of 19 cases (5.2%), where the flap length exceeded recommended guidelines. Minor complications related to the flap were seen in four of 19 cases (21%). This included partial thickness flap necrosis, flap oedema and wound discharge. Complications related to the location of surgery (5/19, 26.3%) included mild ectropion, mild exposure of the eye, reduced ability to blink and subcutaneous emphysema.

CLINICAL SIGNIFICANCE

The STA flap is a good option for closure of a skin defect localised to the maxillofacial region. STA flaps were associated with a high percentage of survival and a low incidence of major complications.

Reconstruction of a large nasal-facial defect using an augmented temporal myocutaneous tube flap in a dog

The muzzle region of dogs contains various composite tissues, which are challenging to recreate during reconstruction. Small or moderate facial/nasal defects can be closed primarily or left for second‐intention healing. However, larger defects require the application of composite tissue or labial advancement flaps. Axial pattern flaps based on the caudal auricular artery, superficial temporal artery (STA), angularis oris artery, and other cutaneous arteries have been reported. In our case, we aim to report the reconstruction of a large composite defect of the rostral and dorsal nasal regions in a dog using an augmented, axial myocutaneous flap based on bilateral STAs. This is a clinical report on a spayed female mixed‐breed dog (age, 7 years; weight, 15 kg), in which a large‐scale nasal–facial composite tissue defect was surgically reconstructed using an axial myocutaneous flap based on bilateral STA branches. A delay technique was applied to prefabricate the flap to enrich the blood supply. New nostrils were created on a folded, rostral hard palate. As a result, the axial tube rotational flap was successfully transferred. The use of delay technique for prefabricating the tube flap optimized its size and survival. In addition to the folded rostral hard palate, the flap fully closed the defects on the face and nose. Functional and cosmetic outcomes were satisfactory, with minimal donor‐site morbidity. In, conclusion, a large‐scale nasal–facial defect in a dog was successfully reconstructed using an augmented tube pedicle flap based on the bilateral STAs, which may, thus, be used to repair very large facial‐nasal defects in dogs.

A large‐scale nasalfacial defect in a dog was successfully reconstructed using an augmented tube pedicle flap based on the bilateral STAs, which may, thus, be used to repair very large facial‐nasal defects in dogs.

Locoregional Flap Reconstruction Following Oromaxillofacial Oncologic Surgery in Dogs and Cats: A Review and Decisional Algorithm

Primary treatment of most oromaxillofacial tumors in dogs and cats is resective surgery. Management of malignant tumors may be very challenging as wide/radical free-margin surgical removal must be achieved while preserving vital functions. Removal of orofacial tumors may result in large defects exposing the oral cavity or creating a communication with the nasal, pharyngeal, or orbital cavities. Such defects require orofacial reconstruction in order to restore respiratory and manducatory functions. The veterinary surgeon must be familiar with reconstructive techniques in order to prevent the inability of closing the defect, which could lead to an insufficient resection. Small oral defects exposing the nasal cavity are best closed with local random mucosal flaps. Closure of large oral defects may be better achieved with a facial or major palatine-based axial-pattern flap. Small to moderate facial defects can be closed with local advancement or transposition skin flaps. Reconstruction of large facial defects often requires the use of locoregional axial pattern flaps such as the caudal auricular, the superficial temporal, or the facial (angularis oris) myocutaneous axial pattern flaps. Recent publications have shown that the facial (angularis oris) flap is a very versatile and reliable flap in orofacial reconstructive surgery. A surgical decision algorithm based on the size, nature, and location of the defect is proposed.

Staged mandibular lip flap for closure of a large palatal defect after maxillectomy in a dog

OBJECTIVE

To report closure of an oronasal defect secondary to maxillectomy with a staged mandibular lip flap.

STUDY DESIGN

Case report ANIMALS: One 9-year-old female spayed golden retriever.

METHODS

A combined dorsolateral and intraoral approach was used to perform a central maxillectomy to excise a 2.4- × 2- × 2.7-cm oral osteosarcoma with 1-cm margins. A buccal mucosal flap was used to close the palatal defect but the site subsequently dehisced. A staged mandibular lip flap was performed to close the defect. An incision was made on the mandible at the intersection of the buccal mucosa and gingiva from the mandibular canine to the level of the commissure. A second incision was made 3 cm ventral to the lip margin. The flap pedicle was based at the commissure. The flap was rotated to cover the palatal defect from rostral to the canine tooth to the fourth premolar. A second procedure was performed 4 weeks after flap placement to desquamate the haired skin and transect the flap pedicle.

RESULTS

Partial dehiscence at the caudal aspect of the flap occurred after the first revision. The defect was closed after pedicle transection on day 41, with acceptable cosmesis. The dog was eating canned food with no evidence of discomfort 159 days after the maxillectomy. Recurrence was noted on day 270 postoperatively.

CONCLUSION

Closure of a large palatal defect with a staged mandibular lip flap led to good cosmesis and function.

Case Report: Surgical Treatment of Severe Facial Wounds and Proptosis in a Dog Due to a Traffic Accident

Although facial wounds caused by traffic accidents in dogs are common, the surgical management of severe facial injuries involving the soft tissue, bone, dentition, nose and orbit are challenging. A 2 year-old Korean Jindo dog was diagnosed with severe skin defects of the face and proptosis caused by a vehicular accident. Along the left lateral maxilla, severe injury involving the overlying skin and platysma muscle occurred, to the extent that the middle part of the sphincter colli profundus pars intermedia muscle was exposed. Repair surgeries of the skin defects and globe displacement were performed using a local subdermal plexus rotation flap and a partial transposition of the dorsal rectus muscle combined with small intestinal submucosa (SIS) instead of enucleation as the first attempt. SIS was used to sustain the torn medial region. In this case, the surgery resulted in good cosmetic and functional outcome in the dog, despite the atypical complexities upon presentation.

Hard palate defect repair by using haired angularis oris axial pattern flaps in dogs

OBJECTIVE

To describe the repair of large hard palate defects with a haired angularis oris axial pattern flap (HAOF) and to report the postoperative outcome.

STUDY DESIGN

Anatomical cadaver study and short case series.

ANIMALS

One cadaver and three dogs with neoplasia of the caudal hard palate.

METHODS

Large caudal and central hard palate defects were reconstructed by using the HAOF. The flap, composed of full-thickness skin and buccal mucosa, was rotated at the base of the angularis oris artery. The haired surface of the skin flap was placed facing into the oral cavity.

RESULTS

Reconstruction of defects extending as far rostral as the maxillary canine tooth were feasible on the cadaver. The flap in dog 1 healed without complication and was intact at day 649 after surgery. Two minor areas of dehiscence were noted in dog 2, without further evidence of complications at 1331 days after surgery. Dog 3 had upper respiratory obstructive noise due to swelling immediately after surgery. These signs resolved, but local recurrence of the tumor prompted euthanasia at day 86.

CONCLUSION

Anatomical studies provide evidence that the HAOF can be used to reconstruct caudal and central hard palate defects extending to the maxillary canine teeth. Its clinical use led to successful closure of such defects in three dogs.

CLINICAL SIGNIFICANCE

HAOF provides an alternative for reconstruction of large defects of the caudal and central hard palate.

Use of the angularis oris cutaneous flap for repair of a rostral mandibular skin defect in a cat

The angularis oris axial pattern flap is based on the blood supply of the angularis oris artery and vein. While the use of this flap for repair of canine facial wounds is well documented, this technique has not been reported in the cat. This Case Report presents the reconstruction of a large ventral chin and rostral lip wound with the use of this flap. Complete survival of this flap was observed in this patient.

Axial Pattern Flaps

Axial pattern flaps are based on a direct cutaneous artery and vein supplying a segment of skin. They provide a large, robust option for large wound closure. Many different axial pattern flaps have been described to provide options for closure of wounds located from the nose to the tail. All axial pattern flaps require good surgical technique and careful attention to detail while developing of the flap.

Nose and Nasal Planum Neoplasia, Reconstruction

Most intranasal lesions are best treated with radiation therapy. Computed tomographic imaging with intravenous contrast is critical for treatment planning. Computed tomographic images of the nose will best assess the integrity of the cribriform plate for central nervous system invasion by a nasal tumor. Because of an owner's emotional response to an altered appearance of their dog's face, discussions need to include the entire family before proceeding with nasal planectomy or radical planectomy. With careful case selection, nasal planectomy and radical planectomy surgeries can be locally curative.

Complications of the angularis oris axial pattern buccal flap for reconstruction of palatine defects in two dogs

CASE REPORT

Complications associated with surgical reconstruction of hard palate defects with a buccal mucosal flap based on the angularis oris artery and vein in two dogs are described. Distal flap necrosis occurred in both cases, but the flaps were successfully salvaged by division of the original flap pedicle and rotation of the flap material into the remaining defect. Postoperative dysphagia was observed in both dogs until flap revision. Salvage of the intact distal portion of the flap following division of the direct artery and vein 14 days postoperatively is discussed.

CONCLUSION

The angularis oris axial pattern buccal flap is an option for reconstruction of large defects of the hard palate. Survival of the flap can be improved by removal of teeth likely to cause occlusal trauma to the flap's pedicle. In the event of distal flap necrosis, the repair may be salvaged by rotation of the remaining flap into the defect, following establishment of vascular supply from adjacent tissue.

Cosmetic reconstruction of a nasal plane and rostral nasal skin defect using a modified nasal rotation flap in a dog

OBJECTIVE

To report reconstruction of a defect of the nasal plane and the rostral dorsum of the nose in a dog using a nasal rotation flap with Burow's triangles.

STUDY DESIGN

Clinical report.

ANIMALS

Mixed-breed dog (1.5 years, 8.6 kg).

METHODS

A nasal defect caused by chronic granulomatous inflammation and involving the lateral nasal plane and adjacent rostral nasal dorsum in a dog was reconstructed and closed using a unilateral nasal rotation flap incorporating dorsal nasal plane tissue, with excision of Burow's triangles.

RESULTS

The modified unilateral nasal rotation flap was effective in closing a defect of the rostral nasal dorsum. Incorporation of dorsal nasal plane tissue in the flap allowed for a cosmetic reconstruction of the lateral nasal plane defect (wing of nostril).

CONCLUSIONS

Skin defects on the rostral dorsum of the nose and defects of the nasal plane in dogs can be closed and/or reconstructed using nasal rotation flaps incorporating nasal plane tissue.