Squamous Cell Carcinoma in a Bitch: Facial Reconstruction using Axial-Pattern Skin Flap with Oral Angular Artery

Abstract

Background: Reconstructive surgeries are essential in veterinary oncology for closing large defects after tumor excision, especially in areas with limited skin elasticity. Axial pattern flaps, supplied by specific arteries, demonstrate higher viability and lower risk of necrosis compared to subdermal flaps. Squamous cell carcinoma is common in canines and often requires wide surgical excision followed by reconstruction. This report aims to describe the use of an axial flap based on the angular oral artery for facial reconstruction in a bitch with squamous cell carcinoma.
Case: A 15-year-old bitch poodle weighing 9 kg was presented with a rapidly enlarging, ulcerated mass located below the right lower eyelid, which had been evolving for approximately 10 days. The owner reported initial treatment with prednisolone. On physical examination, the dog exhibited pink mucous membranes, a capillary refill time of 2 s, a temperature of 38.2°C, and a good body condition score. Laboratory tests revealed mild elevations in alkaline phosphatase, creatinine, platelet count, and total plasma proteins. Surgical excision was planned following clinical stabilization. Pre-anesthetic medication included remifentanil and lidocaine without vasoconstrictor, followed by induction with propofol and maintenance with isoflurane. A regional maxillary nerve block was performed using bupivacaine. The lesion was excised with a 1.5 cm lateral margin and 0.5 cm depth. Reconstruction of the surgical defect was accomplished using an axial myocutaneous flap based on the angular oral artery. The flap was carefully dissected, preserving the vascular pedicle, rotated, and sutured using simple interrupted nylon 3-0 sutures. The donor site was closed in layers, employing poliglecaprone 3-0 in a walking suture pattern for the subcutaneous layer and nylon 3-0 in a Wolff pattern for the skin. Postoperative  management included analgesia (dipyrone, tramadol, ketamine, and robenacoxib), antibiotic therapy, and strict wound care instructions. The dog recovered uneventfully, with suture removal performed nine days postoperatively. Histopathological examination confirmed complete excision of squamous cell carcinoma with tumor-free margins. The owner ultimately elected not to pursue oncologic follow-up. Fifteen days postoperatively, telephone contact revealed that the patient remained active and showed no signs of swelling at the surgical site.
Discussion: The use of an axial pattern flap based on the angular oral artery in this case proved to be an effective reconstructive technique for closing a large facial defect with limited skin elasticity. Compared to subdermal advancement flaps, axial flaps offer enhanced perfusion and greater survival rates due to their arterial blood supply, reducing the risk of necrosis and dehiscence. The anatomical location presented challenges for postoperative bandaging, but meticulous surgical technique and postoperative care prevented complications. The choice of suture pattern and selective use of walking sutures helped distribute tension and protect vascular supply, contributing to successful healing. Mild laboratory abnormalities were addressed with appropriate supportive care. This report reinforce the viability of axial oral artery flaps as a reliable option in veterinary oncologic surgery for facial reconstruction and encourages further studies to optimize surgical planning and postoperative management for improved outcomes in similar cases.
Keywords: axial pattern flap, squamous cell carcinoma, canine, reconstructive surgery, veterinary oncology.

Título: Carcinoma de Células Escamosas em uma cadela: reconstrução facial usando retalho cutâneo de padrão axial com a artéria angular oral

Descritores: retalho de padrão axial, carcinoma de células escamosas, canino, cirurgia reconstrutiva, oncologia veterinária.