Axial pattern flap based on the cutaneous branch of the superficial temporal artery in dogs: an experimental study and case report

Short-term outcome and complications following cutaneous reconstruction using cranial superficial epigastric axial pattern flaps in dogs: six cases (2008-2022)

OBJECTIVES

To investigate short-term outcome and complications following the use of the cranial superficial epigastric axial pattern flap to reconstruct cutaneous defects in dogs.

MATERIALS AND METHODS

Medical records from dogs undergoing reconstructive surgery between 2008 and 2022 by means of cranial superficial epigastric axial pattern flap were reviewed. Data on signalment, reason for reconstruction, defect size, flap healing, post-operative complications and need for revision surgery were collected.

RESULTS

Six dogs were included in the study. Indications for reconstruction included neoplasia (4/6), skin necrosis due to vehicular trauma (1/6) and dog bite (1/6). Postoperative complications occurred in 50% of the patients and included seroma (1/6), bruising (2/6) and necrosis of the distal portion of the flap (2/6), with two dogs developing concurrent complications. One dog required open wound management and additional surgery. Overall outcome was scored excellent in three, good in two, and fair in one dog.

CLINICAL SIGNIFICANCE

Despite the relatively high complication rate, most of the complications were deemed minor and could be managed conservatively. Eventually, all wounds healed completely and only one flap required revision surgery.

The pinna composite flap for wound reconstruction in a dog

OBJECTIVE

To report the surgical technique and outcome of the use of a pinna composite flap for reconstruction of a wound defect following wide surgical resection of a mast cell tumor.

ANIMALS

A 4-year-old female spayed golden doodle.

STUDY DESIGN

Clinical case report.

METHODS

A dog with a histologically confirmed cutaneous mast-cell tumor at the base of the ear was treated with a wide surgical resection, including total ear canal ablation and lateral bulla osteotomy. The defect could not be closed primarily and, as a result, the defect was reconstructed with a composite pinna flap.

RESULTS

Partial avascular necrosis of the distal aspect of the composite flap required debridement and closure 13 days after the initial surgery. The flap was fully healed at 27 days postoperatively. The dog had facial nerve paralysis, which had not resolved by 45 weeks postoperatively.

CONCLUSION

The surgical technique described in this report is novel. The use of the pinna as a composite flap is a novel reconstructive option for dorsal and dorsolateral head wounds.

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.

Composite Resection of Tumors of the Rostral Maxilla and Dorsolateral Muzzle Utilizing an Upper Lip-Sparing, Combined Approach in Dogs

Tumors of the rostral maxilla that involve both the oral mucosa and the dermis or subdermis of the dorsolateral muzzle provide unique challenges for the oromaxillofacial surgeon. Traditionally described approaches to such lesions may involve an intraoral incision that extends and involves the upper lip to envelope the involved dermis of the dorsolateral muzzle. However, such an approach unnecessarily resects upper lip tissue resulting in a large defect that likely requires advanced skin flaps or grafts for reconstruction. Such flaps are technically challenging and introduce potential for significance postoperative complications. In this article, we provide a detailed description a combined intra- and extraoral approach that allows for composite resection of tumors of the rostral maxilla that also involve the dorsolateral muzzle. The described technique allows for excellent intraoperative visualization and provides a superior cosmetic outcome that minimizes postoperative complications. In addition, we describe our experience utilizing the technique in three clinical cases.

Locally injected autologous platelet-rich plasma enhanced tissue perfusion and improved survival of long subdermal plexus skin flaps in dogs

OBJECTIVES

Distal flap necrosis remains a major complication in subdermal plexus (random) skin flaps. Platelet-rich plasma (PRP) has been shown to improve the survival of ischemic random skin flaps in rats. The objective of this study was to evaluate the effect of locally injected autologous PRP on the survival of long (5:1 length-to-width ratio) subdermal plexus skin flaps in dogs.

METHODS

A 2x10 cm subdermal plexus skin flap was created bilaterally on the abdominal wall of six Beagle dogs. One randomly selected side received 2.5 ml of fresh auto-logous PRP injected evenly between sutures underneath the flap, whereas the other side was left untreated (control). Skin flap survival was evaluated macroscopically, histologically and by laser-Doppler flowmetry measurements of tissue perfusion.

RESULTS

Flap percentage survival on day 10 (96.3% versus 74.5%; p = 0.046) and tissue perfusion (p <0.036) were significantly higher in PRP-treated flaps compared with controls. Histologically, there was less oedema in PRP-treated flaps compared to controls (p = 0.01), whereas collagen production and angiogenesis did not differ significantly between the two groups.

CLINICAL SIGNIFICANCE

The use of locally injected autologous PRP increases tissue perfusion and improves the survival of long subdermal plexus skin flaps in dogs.

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.

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.

Facial reconstructive surgery

Reconstruction of facial defects can be very challenging, even in the hands of an experienced surgeon. Most defects can be repaired using local available tissues. Lip defects can be reconstructed using geometric closure techniques and advancement of local tissues. Forehead defects can be reconstructed using skin grafts, caudal auricular flaps, or rotational or transposition flaps. Care must be taken to minimize tension on eyelids and maintain the integrity of the facial nerve. Cheek defects can be reconstructed using local advancement, superficial temporal, omocervical, and caudal auricular flaps. The bridge of the nose can be very difficult to reconstruct due to a paucity of local tissues; however, skin grafts, indirect pedicle flaps, and superficial temporal flaps can be considered. .

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 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.

Clinical Evaluation of Caudal Superficial Epigastric Axial Pattern Flap Reconstruction of Skin Defects in 10 Dogs (1989–2001)

Ten dogs with caudal superficial epigastric axial pattern flap reconstruction of extensive skin defects were reviewed. Nine dogs had complete survival of the flap. In one dog, a small area of necrosis occurred near the flap tip. Other complications included seroma formation (n=3), partial incisional dehiscence (n=3), flap edema (n=9), and bruising (n=7). Use of the caudal superficial epigastric axial pattern flap provided full-thickness skin coverage of extensive skin defects of the rear limb and inguinal region, with relatively minor complications that were amenable to conservative management.

Surgical approaches to recipient vessels of the head and neck for microvascular free tissue transfer in dogs

OBJECTIVE

To develop and evaluate surgical approaches to the arteries and veins of the head and neck for use as potential recipient vessels for free tissue transfer.

STUDY DESIGN

Experimental anatomic study.

SAMPLE POPULATION

Eleven canine cadavers; 2 preserved cadavers and 9 fresh cadavers.

METHODS

The head and neck of one preserved cadaver injected with pigmented silicone/barium, through the common carotid artery and external jugular vein, was cut in 1 cm sagittal sections and cross-sections. These tissue sections were used to identify the location of recipient vessels >1 mm that could be used as recipient vessels for free tissue transfer. The other preserved cadaver was used to develop surgical approaches to these vessels. Three board certified surgeons evaluated the written descriptions and illustrations of the approaches using fresh cadavers. Modifications to the surgical approaches were made based on recommendations from these surgeons.

RESULTS

Seven approaches were developed to isolate recipient vessels of the head and neck region. The infraorbital, temporal, and sublingual approaches were easily performed and provided excellent access to the vessels in the region. The approach to the caudal auricular vessels was found to be more difficult but modification of the approach resolved this problem. Access to the facial artery was difficult; it was consistently <1 mm in diameter and thus its use could not be recommended. The approach to the vessels in the cervical region was easily performed. Because of the large size of the external jugular vein and the common carotid artery, end-to-side anastomosis of the donor to recipient vessels is necessary. The large superficial cervical vessels were easily accessed by a lateral shoulder approach.

CONCLUSIONS

Surgical approaches to potential recipient vessels of the head and neck were consistently achieved and provided relatively easy access to the vessels. Clinical Relevance- The surgical approaches described in this report can be used to isolate arteries and veins of the head and neck that are >1 mm in diameter. These vessels are suitable for use as recipient vessels for free tissue transfer for reconstruction of complex wounds of the head and neck.

Central hemimaxillectomy and reconstruction using a superficial temporal artery axial pattern flap in a domestic short hair cat

A 2-year-old, neutered male domestic short hair cat presented with a large mass involving the right upper lip and underlying gingiva. A previous attempt at mass excision had failed, and the histopathological diagnosis was reported to be a fibrosarcoma. The cat was otherwise in good health.A central hemimaxillectomy was performed with extensive soft-tissue dissection and maxillofacial reconstruction achieved using an axial pattern flap based on the superficial temporal artery. This is the first reported clinical case of the use of the superficial temporal artery axial pattern flap in the cat. Histopathology identified a periodontal fibromatous epulis.

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.

O retalho hipogástrico cutâneo no cão: modelo para o aprendizado experimental de microcirurgia

O treinamento em microcirurgia constitui-se de diversas etapas, uma delas é a prática em animais. Retalhos microcirúrgicos cutâneos no cão são pouco descritos na literatura médica. Objetivo: O presente trabalho propõe um modelo de retalho hipogástrico cutâneo no cão centrado nos vasos circunflexos laterais. Métodos: Foram utilizados nove cães de raças e idades desconhecidas e peso variando entre 8 e 15kg. Descrevem-se com detalhes todos os passos seguidos no procedimento. O fluxo das anastomoses foi comprovado por observação direta, teste de enchimento (empty-and-refill test) imediatamente após as microanastomoses, por doppler após uma hora do procedimento e por avaliação clínica (coloração do retalho e sangramento após furo com agulha). Resultados: Todos os retalhos mostraram-se viáveis pelos critérios acima descritos. Conclusão: Este é um instrumento valioso para os que desejam aprender microcirurgia de forma autodidata, pois o modelo é dotado de todos os requisitos necessários para o aprendizado de microcirurgia experimental.