Free tissue transfer of the rectus abdominis myoperitoneal flap for oral reconstruction in a dog

Risk Factors for Failure of Hard Palate Mucoperiosteal Flap Repair of Acquired Oronasal Communication in Dogs: A Pilot Study

The objective of this retrospective pilot study was to describe potential risk factors for failure of hard palate mucoperiosteal flaps (HPF) transposed for closure of oronasal communication. Dogs (n = 28) with acquired oronasal communication defects were included in the study population. Functional success of an HPF was determined by visual inspection at the last examination and lack of clinical signs. Risk factors for HPF failure including age, sex, body weight, presence of neoplasia at the time of surgery, presence of neoplasia after surgery due to incomplete or narrow margins, use of CO₂ laser, previous surgeries in the same location, HPF blood supply, size of the HPF as a percentage of the total area of the hard palate mucoperiosteum, and distance traveled by the apex of the HPF were evaluated using descriptive statistics and unadjusted logistic regression modeling. Seven out of 28 (25%) hard palate flap procedures resulted in persistent oronasal communication and were considered failures. Body weight (Median: 17 vs. 25 kg, OR = 0.94, 80% CI = 0.90, 0.99), presence of neoplasia at the time of surgery (86 vs. 57%, OR = 4.50, 80% CI = 1.01, 20.06), HPF area (Median: 0.49 vs. 0.41, OR = 84.40, 80% CI = 1.66, 4,298) and apex travel distance (Median: 2.06 vs. 0.67, OR = 5.15, 80% CI = 2.14, 12.38) were associated with flap failure. Within this sample, the presence of neoplasia at the time of initial surgery, increasing the area of the HPF, and distance traveled by the HPF apex were associated with a greater odds of HPF failure. Further studies with larger sample sizes are needed to confirm repeatability of these results. HPFs remain a viable surgical option for closure of oronasal communication. Careful surgical planning, strict adherence to surgical principles, and awareness of anatomical limitations can increase the likelihood of success.

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.

Diaphragmatic hernia repair using a rectus abdominis muscle pedicle flap in three dogs

Objective: To report the clinical use of a pedicle flap from the rectus abdominis muscle to repair extensive diaphragmatic tears in dogs with diaphragmatic hernia.

Materials and methods: Three dogs with a combination of radial and circumferential diaphragmatic tears were studied. The circumferential tear was repaired by suturing the wound edge with the edge at the abdominal wall. A pedicle flap of the rectus abdominis muscle was used for repairing the radial tear. The dogs were examined radiographically for lung and diaphragm appearance and evidence of reherniation at 10 days, and at one, two, and four months after surgery, and fluoroscopically for paradoxical motion of the diaphragm at one and four months.

Results: The rectus abdominis muscle pedicle flap was successfully used in all three dogs. The animals recovered uneventfully without evidence of reherniation during the four follow-up months. Fluoroscopic examination revealed no paradoxical motion of the diaphragm.

Clinical significance: A rectus abdominis muscle pedicle flap can be used for repairing large diaphragmatic defects in dogs.

Radical maxillectomy as a successful treatment for gunshot-induced maxillary and nasal cavity trauma in a dog

OBJECTIVE

To report the successful treatment of gunshot-induced maxillary and nasal cavity damage with total maxillectomy in a two-year-old Labrador retriever dog.

METHODS

Radical maxillectomy was performed on highly comminuted maxillary and nasal cavity fractures resulting from gunshot trauma. The procedure was performed to remove the damaged region and reconstruct the remaining tissue.

RESULTS

Treatment of the fractures by total maxillectomy was successful in reconstruction of the remaining structures following debridement and in re-establishing return to normal activities and high owner satisfaction.

CLINICAL SIGNIFICANCE

The outcome in this case suggests that severe maxillary and nasal cavity trauma in other dogs may be treated with radical maxillectomy given appropriate patient and owner selection.

Free Auricular Cartilage Autograft for Repair of an Oronasal Fistula in a Dog

An eight-year-old female/spayed Pomeranian dog was presented for surgical treatment of an acquired right oronasal fistula. The maxillary right canine tooth had been extracted non-surgically 7-weeks prior to presentation. Clinical signs were consistent with an oronasal fistula during this time period. Oral examination showed an oronasal fistula in the area of the extracted tooth. The referring veterinarian performed simple debridement and suturing with subsequent recurrence of the oronasal fistula. This case report describes the successful surgical treatment of an acquired oronasal fistula with a free auricular cartilage autograft and reviews techniques described for oronasal fistula repair, including free auricular cartilage autografts.

Head and Facial Wounds in Dogs and Cats

Injuries to the head and facial area are common in small animal surgery. Although many of the injuries at first may seem formidable, most can be repaired using basic reconstructive surgery procedures. The excel-lent blood supply in this area and the availability of local tissues provide many options for repairing most wounds. This article describes the indications and techniques for reconstructing wounds in this area.

Surgical Approaches to Recipient Vessels of the Fore- and HindLimbs for Microvascular Free Tissue Transfer in Dogs

OBJECTIVE

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

STUDY DESIGN

Experimental anatomic study.

SAMPLE POPULATION

Canine cadavers (11): 2 preserved and 9 fresh cadavers.

METHODS

Fore- and hindlimbs from 1 preserved cadaver injected with a pigmented silicone/barium mixture, through the common carotid artery and external jugular vein, were cut in 1 cm cross-sections. Tissue sections were used to identify the location of 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 surgeons evaluated the written descriptions and illustrations for these approaches using fresh cadavers. Modifications to the surgical approaches were made based on recommendations from these surgeons.

RESULTS

Six approaches were developed to isolate forelimb recipient vessels: palmar access, distal medial antebrachial, mid-antebrachial, proximal antebrachial, distal humeral, and mid-humeral vascular access. Twelve approaches were developed to isolate recipient vessels of the hindlimb: plantar access, dorsal tarsal, cranial distal tibial, craniomedial distal tibial, lateral distal tibial, medial distal tibial, medial femorotibial, lateral distal femoral, medial femoral, proximal medial femoral, groin, and proximal lateral femoral vascular access.

CONCLUSIONS

Six forelimb and 12 hindlimb sites were identified for surgical access to recipient vessels (>1 mm diameter) suitable for use in free tissue transfer for wound reconstruction.

CLINICAL RELEVANCE

For reconstruction of complex wounds of the extremities of dogs, surgeons should consider use of readily accessible recipient vessels that would allow for free tissue transfer to the fore- and hindlimbs.