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

Treatment of metastatic apocrine sweat gland adenocarcinoma in a cat with association of surgical resection and angular oris reconstruction, extensive lymphadenectomy, electrochemotherapy and systemic chemotherapy

Apocrine sweat gland adenocarcinoma (ASGAC) is a rare skin carcinoma in cats. In some cases, this tumor occurs in anatomical sites of challenging wide surgical resection, which increases the need for adjuvant therapies for residual disease. These include radiotherapy or electrochemotherapy (ECT), local treatments for invasive tumors in companion animals often associated with surgery. However, the current literature for ASGAC treatment is limited and there are no reports of ECT as an adjuvant therapy. In this case report, we account for the case of an 11-year-old cat with a history of a non-ulcerated recurrent ASGAC, measuring 1.3 × 1.0 cm, located by the rostral mandibular region. Surgical resection included the angularis oris axial flap for facial reconstruction associated with electroporation of the surgical bed and, post-operatively, in the surgical scar. Histopathological results confirmed the presence of a recurrent ASGAC. Immunostaining revealed cyclooxygenase 2 (COX-2) expression with a score of 6, 50 % positivity in Ki-67, and positive for pan-cytokeratin (PCK AE-1/ AE-3). A selective COX-2 inhibitor was initiated along with systemic chemotherapy with chlorambucil. The local approach including surgery and ECT was chosen due to the unfavorable anatomical site for extensive resection and the unavailability of radiotherapy. Subsequently, carboplatin chemotherapy was required due to metastasis in the mandibular lymph node. This case report supports the effectiveness of a multimodal treatment including surgery, ECT, and chemotherapy in a cat with recurrent ASGAC.

Surgical reconstruction of a composite nasomaxillary and superior labial defect in a dog with a fascia lata graft, titanium mesh implant and angularis oris axial pattern flap

Objective

To document the successful surgical reconstruction of a composite nasomaxillary and superior labial defect using a fascia lata graft, titanium mesh and angularis oris axial pattern flap in a dog.

Case summary

An estimated 2-year-old female intact mixed-breed dog was presented with a composite (hard and soft tissue) nasomaxillary defect, suspected to be caused by a chemical burn. Physical examination revealed nasal discharge, exposed bilateral maxilla and nasal bone, nasomaxillary fistula with air movement, and intrinsic discoloration of the left maxillary canine tooth. The soft tissue lesion extended from the nasal planum rostrally to the medial canthus of the left eye distally and from the right maxillary bone to include a full thickness loss of the left maxillary labium laterally. Computed tomographic images of the head showed chronic osteomyelitis of the maxilla, zygomatic and nasal bones with nasomaxillary fistula and numerous exposed roots of the left maxillary premolars. Staged surgical procedures to address the dentition and nasomaxillary defect were planned. The first procedure consisted of the extraction of periodontally compromised left maxillary premolars, and standard root canal therapy of bilateral maxillary canine teeth. The second procedure consisted of debridement of the non-vital soft and hard tissues and surgical reconstruction of the nasomaxillary defect after virtual surgical planning. Head computed tomography performed 5 months post-operatively revealed a decrease in the size of the osseous defect as well as the resolution of rhinitis.

Clinical relevance

This case demonstrates the feasibility of using a combination of soft tissue graft, titanium mesh, and axial pattern flap in managing nasomaxillary defects. Such defects can lead to chronic rhinitis, infection, discomfort, and long-term morbidity. This case report provides a novel but practical approach for managing defects in the nasomaxillary region in dogs.

Use of a haired angularis oris axial pattern flap in a dog to correct a large oronasal fistula secondary to resection of a hard palate multilobular osteochondrosarcoma

A 6-year-old neutered male mixed-breed dog underwent curative-intent surgical resection of a hard palatal multilobular osteochondrosarcoma and closure of the defect using bilateral buccal mucosal flaps. However, failure of the flaps resulted in a massive hard palatal defect that was subsequently repaired using a haired skin angularis oris axial pattern flap. This report describes the clinical outcome using this surgical approach and novel complications encountered. Key clinical message: The haired skin angularis oris axial pattern flap appears to be a suitable and robust option for reconstruction of large palatal defects.

Free labial mucocutaneous graft for eyelid reconstruction in four dogs

PURPOSE

To describe a technique for eyelid margin reconstruction following large mass resection utilizing a free labial mucocutaneous graft.

METHODS

Four dogs (4 eyes) underwent en bloc eyelid mass excision under general anesthesia. Measurements were made of the mass followed by free labial mucocutaneous graft retrieval, resection of the mass, and then transplantation of retrieved region of labial mucocutaneous tissue into the resulting defect.

RESULTS

Three patients underwent eyelid margin reconstruction with a free labial mucocutaneous graft. One patient received a pedicle advancement graft combined with a free labial mucocutaneous graft. In all cases, a length of 120%-150% of the eyelid defect was retrieved from the oral labia. Postoperative follow-up ranged from 6 weeks to 4 months. All cases had superficial graft necrosis and depigmentation of the donor tissue with total healing time taking up to 8 weeks. All cases had an esthetic and functional reconstruction.

CONCLUSIONS

This technique allows reconstruction of the majority of the eyelid margin, greater than that which can be closed primarily. Due to tissue sloughing, the healing time can be extended but cosmetic outcomes are good. Eyelid reconstruction utilizing a free labial graft restored a mucocutaneous margin and recreated a functional eyelid, thus avoiding trichiasis or secondary keratitis.

Breed-Specific Skull Morphology Reveals Insights into Canine Optic Chiasm Positioning and Orbital Structure through 3D CT Scan Analysis

This study's CT scan-based morphometric analysis of 50 adult dogs explored the relationship between skull shape variations (determined by the skull index, SI), optic chiasm, optic canals, and orbital shape. Dogs were classified as brachycephalic (SI ≥ 59), mesocephalic (SI ≥ 51 but <59), and dolichocephalic (SI < 51). No significant age or weight differences were observed. Skull lengths (brachycephalic: 11.39 ± 1.76 cm, mesocephalic: 15.00 ± 2.96 cm, dolichocephalic: 17.96 ± 3.44 cm) and facial lengths (brachycephalic: 3.63 ± 1.00 cm, mesocephalic: 6.46 ± 1.55 cm, dolichocephalic: 8.23 ± 1.03 cm) varied significantly, with shorter orbital depths (brachycephalic: 2.58 ± 0.42 cm, mesocephalic: 3.19 ± 0.65 cm, dolichocephalic: 3.61 ± 0.77 cm) in brachycephalic dogs. The optic chiasm-to-inion horizontal length ratio to cranial horizontal length positively correlated with the SI (r = 0.883, p < 0.001), while the ratio to neurocranial length showed no SI correlation (range: 55.5-75.0). Brachycephalic breeds had a significantly wider optic canal angle (93.74 ± 16.00°), along with broader lacrimal-zygomatic and zygomatic frontal process angles. These findings highlight the zygomatic bone's role in influencing breed-specific orbital variations by connecting the face to the neurocranium, projecting the orbital rim outward and forward with facial shortening.

A modified full-thickness labial/buccal rotational flap reconstruction technique following bilateral rostral maxillectomy and nasal planectomy for resection of maxillary tumors: Technique and results in two dogs

OBJECTIVE

To describe a naso-facial reconstruction technique following bilateral rostral maxillectomy and its functional and cosmetic outcomes.

ANIMALS

Two dogs.

STUDY DESIGN

Clinical case series.

METHODS

Two dogs were presented with a right rostral maxillary mass. Preoperative biopsy and staging revealed a biologically high-grade and histologically low-grade fibrosarcoma (Hi-Lo FSA). A combined nasal planectomy and radical bilateral rostral maxillectomy was performed sparing the labial/buccal mucocutaneous flaps bilaterally. Surgery resulted in asymmetry of the width of the flaps; the narrower flap was rotated medially to reconstruct the lip and create an oral vestibule. The wider flap was rotated medially to cover the remaining dorsolateral opening of the nasal conchae. The flaps overlapped in a parallel manner, discretely concealing the nasal passages, and separating them from the oral cavity. Hemorrhage occurred in both dogs, with one dog requiring a blood transfusion postoperatively.

RESULTS

Oral Hi-Lo FSA with tumor-free margins was confirmed in both dogs. Both dogs recovered uneventfully within 4 weeks. Owners reported being very satisfied with the functional (return to normal exercise/activities and uncompromised respiration) and cosmetic outcomes. Based on the owners' telephone follow up, no tumor recurrence was noted at 15 (Dog 1) and 6 (Dog 2) months postoperatively.

CONCLUSION

The full-thickness bilateral labial/buccal rotational flaps were used successfully to reconstruct the rostral maxilla, external nose and facial defects involving the nasal cavity. The technique resulted in acceptable functional and cosmetic outcomes and can be considered for naso-facial reconstruction in selected cases.

Case report: Ghost cell odontogenic carcinoma in a dog: diagnostics and surgical outcome

A 6 year-old spayed female Poodle presented with a mandibular mass. Radiographic examination revealed osteolysis from the right mandibular canine to the fourth premolar, along with horizontal bone loss and dorsal displacement of the right mandibular first and second premolars. Skull cone beam computed tomography revealed osteolysis at the level of the right mandibular canine and fourth premolar. A destructive bone lesion was observed in the apical area of the right mandibular canine, with mass invasion of the interradicular bone of the right mandibular first molar near the mandibular canal. Consequently, unilateral total mandibulectomy and skin flap surgery were performed. Histopathological examination revealed poorly demarcated and infiltrative neoplastic epithelial cells that formed small islands and trabeculae. Neoplastic cells exhibited the malignant features of cytological atypia and high mitotic activity. Furthermore, the neoplastic epithelial cells frequently showed ghost cell changes and were diagnosed as ghost cell odontogenic carcinoma (GCOC). The dog was followed up for 1 year, during which no severe complications or local recurrence was observed, except for slight mandibular drift, tongue protrusion, and drooling. This case report describes the clinical features, diagnostic imaging, and histologic features of an unreported GCOC in a dog and the favorable outcome following surgical resection.

Segmental (Central) Maxillectomy Using a Piezoelectric Surgery Unit in a Dog

Piezoelectric surgical units operate with a vibration in the range of 25 to 35 KHz, offering several advantages including high precision, selective cutting of bone while limiting damage to the surrounding soft tissues, less trauma to neurovascular tissues, reduced hemorrhage, and improved healing. Manual bone-cutting instruments operate at a high speed and can lead to thermal injury to the bone, severe damage to blood vessels, nerves, and soft tissues, and increased pain following bone surgery. This step-by-step manuscript describes the use of a piezoelectric surgical unit to perform a segmental (central) maxillectomy.

Successful Surgical Outcome of Feline Inductive Odontogenic Tumor in Three Cats

BACKGROUND/AIM

A feline inductive odontogenic tumor (FIOT) is a rare type of tumor that is unique to young cats.

CASE REPORT

Herein, we report on three cats (aged 6 months to 2.5 years) that had a bulging mass on the maxilla. On diagnostic imaging, cases 1 and 3 had bone expansion in the affected area, and all three cats were diagnosed with FIOT by histological examination. Maxillectomy and/or incisivectomy techniques were performed according to the tumor site with an intended surgical margin of 5 mm. To increase both precision and safety, a piezoelectric surgical instrument was used. The local advancement flaps were used to repair the surgical sites. The surgical outcomes were excellent, and there were no major complications related to the surgery or tumor recurrences during long-term follow-up (3-5 years) for any of the cats.

CONCLUSION

The results from this study were excellent, which may have been due in part to the choice of the surgical instrument that allowed for the implementation of precise and accurate surgical excision and the tension-free flap method for preventing dehiscence of the surgical site.

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.

Evaluation of the superior and inferior labial musculomucosal flaps in cats: An angiographic study and case series

OBJECTIVE

To evaluate the angiosomes of the superior and inferior labial arteries in the cat and describe the use of a musculomucosal axial pattern flap incorporating each artery for reconstruction of palatal defects in cats.

STUDY DESIGN

Cadaveric study and a series of two clinical cases.

SAMPLE POPULATION

Five feline cadavers and two client-owned cats.

METHODS

The common carotid arteries of five feline cadavers were injected with barium sulfate. Radiographs of excised tissue specimens were examined to map the location of the superior and inferior labial arteries and to visualize each angiosome available for an axial pattern flap. Labial musculomucosal flaps were utilized to reconstruct palatal defects in two live cats.

RESULTS

The superior and inferior labia were predominantly perfused by the superior and inferior labial arteries, respectively, and the angiosome of each artery encompassed the majority of its respective labium. Comparative positive contrast angiograms revealed the vascular supply was located within the musculomucosal layer. Reconstruction of recurrent palatal defects utilizing musculomucosal flaps based on these angiosomes in two clinical cases was successful with complete survival of the flaps.

CONCLUSION

The upper and lower lips were found to have robust vascular supplies within the musculomucosal layer which can support musculomucosal axial pattern flaps.

CLINICAL SIGNIFICANCE

This information provides the veterinary surgeon with additional surgical options for reconstruction of central and caudal palatal defects in the cat.

Oral and Maxillofacial Tumor Management - From Biopsy to Surgical Removal

The main objective of oral and maxillofacial (OMF) tumor resection is to get local control of the disease. Many OMF tumors can be cured with wide or radical surgery, whereas others might only achieve temporary local control of the disease by removing infection and the source of pain, thereby improving the quality of life of the patient while keeping masticatory function. The standard of care on managing OMF tumors includes the diagnosis and identification of the local and distant extension of the disease to establish an appropriate treatment plan tailored for each patient. In this article, we provide a practical review of the current information related to staging, biopsy, and main surgical techniques for OMF tumor removal.