Oronasal fistula repair

Oronasal fistula is a relatively common complication associated with maxillary canine tooth extraction, problematic healing of maxillectomy, and repair of secondary cleft palate in small animals. Regardless of the clinical scenario associated with oronasal fistula, therapy requires surgical treatment. Principles for surgical repair of oronasal fistula include development of mucosal flaps with excellent vascular supply to transpose over the defect to restore continuity of the nasal and oral cavities. The specific surgical technique may vary but includes either single or double mucosal flaps. Oronasal fistula refractory to multiple attempts at surgical repair may be obturated by using a prosthodontic device.     

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

A five-month-old intact/male Boxer dog was presented 5-days following bite wound trauma to the maxillary region resulting in an oronasal fistula extending from the maxillary canine teeth to the soft palate. Multiple surgical procedures using local, buccal mucosal flaps failed to repair the oronasal fistula. Free tissue transfer of the rectus abdominis myoperitoneal flap using microvascular surgical techniques was successful in providing soft tissue reconstruction of the hard palate area. Complications of these surgical techniques included muscle contraction and subsequent muzzle distortion. Small, refractory oronasal fistulae at the perimeter of the myoperitoneal flap were repaired by primary wound closure.     

Pseudallescheria boydii infection of the nasal cavity of a horse

An 18-year-old 454-kg (1,000-lb) American Quarter Horse gelding was evaluated because of chronic intermittent malodorous right-sided nasal discharge. Endoscopy revealed a mycotic plaque in the nasal cavity adjacent to the nasomaxillary opening of the right caudal maxillary sinus. The nasomaxillary opening appeared to be larger than normal. Fungal culture of specimens of the mycotic plaque yielded Pseudallescheria boydii. The horse was treated with 2% miconazole intranasally, sodium iodide i.v., and potassium iodide p.o. Thirty and 60 days after treatment was initiated, the nasal cavity was found to be free of infection.     

Use of mucosal grafts and temporary tube implants for treatment of teat sinus mucosal injuries

A mucosal lesion was created in the center of each test sinus of 6 mature, healthy, nonlactating Holstein cows by resecting a circumferential band of mucosa. Each lesion was then treated by implantation of strip grafts of autogenous oral mucosa, temporary silastic tube implant, or a combination of strip grafts and temporary silastic tube implant. All teats were evaluated for patency 6 weeks after treatment, and tube implants were removed through a second thelotomy incision. All teats were reevaluated for gross and radiographic patency 12 weeks after treatment, and teats were collected for histologic evaluation of lesions. All 4 teats treated with grafts only were obstructed at 6 and 12 weeks after treatment. Incomplete coverage of the lesion with mucosa was observed in all 4 teats. The major source of obstruction was proliferation of epithelium and keratin into the lumen. All 8 teats treated with temporary silastic tube implants alone were patent at 6 weeks after treatment, but were obstructed at 12 weeks after treatment. Foci of mucosa at the lesion site were detected in only 2 of the 8 teats. Obstruction resulted from proliferation of granulation tissue into the lumen. All 12 teats treated with grafts and a temporary tube implant were patent at 6 weeks after treatment and 11 of 12 were patent at 12 weeks after treatment, although marked luminal narrowing was evident in 9 of 11 teats. Partial to complete coverage of the lesion with mucosa was seen in all teats. Proliferative granulation tissue, epithelium, and keratin contributed to luminal narrowing in 10 of 11 patent teats. Bacteriologic culture of quarters from 6 of the 11 teats patent at the final evaluation yielded pathogens.     

COMMUNICATIONS OF NORMAL NASAL AND PARANASAL CAVITIES IN COMPUTED TOMOGRAPHY OF HORSES

Heads from 15 male and female horses of various breeds and ages were examined with computed tomography under general anesthesia in dorsal recumbency. The main interest was the evaluation of the entire paranasal sinus system. Special attention was paid to the location, size, and shape of the conchomaxillary, nasomaxillary, frontomaxillary, and sphenopalatinal openings. The frontomaxillary opening was the largest aperture and was found to be age-dependent in size mostly. Orientation and shape of the openings were sagittal or horizontal; the narrowest of them was the slit-like nasomaxillary aperture. The thickness of the vascularized mucous membranes in the nasal cavity was obtained up to 6 mm; the surface was smooth and well defined. The paranasal lining was invisible in computed tomography (CT) images because of its thin layer. CT proved to be a very useful method for documentation of the paranasal openings and for evaluation of the state of the mucous membranes in the nasal and paranasal cavities.     

Complications of mandibular brachygnathism in a North African leopard

A 9-year-old, male North African leopard (Panhtera pardus) presented with mandibular brachygnathism and lingually displaced mandibular canine teeth causing a large left oronasal fistula, rhinitis and nasal discharge, and a right orocutaneous fistula. Surgical closure of the left oronasal defect, bilateral mandibular canine tooth crown reduction, and root canal therapy resulted in a positive clinical outcome. A small recurrent left oronasal fistula and the right orocutaneous fistula healed spontaneously after alleviating the occlusal contact with the mandibular canine teeth. At 12-months postoperatively, clinical signs of oral and dental disease had resolved.     

Repair of oronasal fistulae using auricular cartilage grafts in five cats

OBJECTIVE: To describe repair of chronic palatine defects in cats, with free cartilage graft harvested from either the pinna (scapha) or vertical ear canal (annular cartilage). STUDY DESIGN: Retrospective study. ANIMALS: Cats (n=5) with chronic oronasal fistula. METHODS: Cartilage was harvested from either the scapha or annular cartilage and epithelium removed. After preparation of the edges of the palatal defect by separation of the oral and palatal mucosa circumferentially, the graft was inserted between the epithelial layers and secured without tension. The graft acted as a scaffold for migration of granulation tissue and epithelialization. RESULTS: Oronasal fistulae were successfully repaired in 5 cats (3 pinna grafts; 2 annular cartilage grafts); 1 cat required a second graft after the first graft was dislodged. CONCLUSIONS: Auricular cartilage provides a reliable framework for repair of oronasal fistulae in cats. CLINICAL RELEVANCE: Chronic oronasal fistulae refractory to conventional repair can be treated by use of auricular free graft (pinna or annular cartilage) without disfigurement. Use of annular cartilage to support palatal repairs offers surgeons an additional option when other methods have failed. We recommend using conchal cartilage as the initial treatment approach for repair of small oronasal fistulae in cats.     

Surgical repair of traumatic oronasal fistula in a domestic short-haired cat

A 9-month-old, spayed female domestic shorthair was presented with a suspected traumatic oronasal fistula. Two surgical attempts using mucosal advancement flaps and single layer closure failed, likely due to inadequate blood supply that was potentially exacerbated by excess tension and trauma on the graft.     

Acquired Oronasal Fistula in a Domestic Ferret (Mustela Putorius Furo)

Acquired oronasal fistula is a rare cause of chronic nasal disease in ferrets (Mustela putorius furo) and other species. An adult male ferret presented with an acute unilateral swelling on the head and a 1-year history of sneezing. Physical examination and diagnostic procedures revealed an oronasal fistula of dental origin with concurrent abscess formation. Treatment included drainage of the abscess, treatment of the infection, extraction of the teeth involved in the oronasal fistula, debriding of the fistula edges, and placement of a medicated gauze. To the authors’ knowledge, this is the first report of an acquired oronasal fistula in a domestic ferret.     

Surgical repair of a chronic,oronasal fistula in a horse using an alveolar bone flap

An 8‐year‐old Andalusian stallion was presented to the Equine Hospital with a 1.5 year history of an oronasal fistula measuring approximately 2 cm long (caudal to rostral) by 1.5 cm wide following an oral extraction of the right second maxillary premolar (106). An alveolar bone flap was created adjacent to the oronasal fistula and rotated axially and ventrally to close the oral aspect of the fistula. At 3 days after surgery, clinical signs of the fistula, such as green‐tinged purulent nasal discharge and malodorous breath, were no longer evident. At 10 days after surgery, the oral opening of the fistula filled with granulation tissue and mucosa and decreased in size to less than 2 ml. The horse was fed a pelleted mash and grass diet and the small fistula was flushed orally twice daily until it completely healed. At 6 months following surgery, the fistula had completely healed. Few options are available for repairing an oroantral or an oronasal fistula in horses. This case report suggests that a large, chronic oronasal fistula involving the alveolus of a maxillary second premolar can be repaired successfully with an alveolar bone flap.     

Palatal erosion and oronasal fistulation following covered nasopharyngeal stent placement in two dogs

Treatment options for dogs with nasopharyngeal stenosis include fluoroscopic placement of metallic stents. Reported complications include entrapment of hair and food, obstruction and persistent nasal discharge. Two toy breed dogs were examined for persistent nasal discharge and halitosis at 4 and 20 months after placement of permanent metallic stents for acquired nasopharyngeal stenosis. Full thickness defects were found in the palate of both dogs, with extensive communication between the mouth and the nasal passages. Portions of the metal stent were observed within the lesion in both patients. Additional treatment was declined by the owner of one dog; the stent was removed through the fistula in the other dog. Palatal erosion with secondary oronasal fistulation is a potential complication of nasopharyngeal stent placement in dogs.     

Surgical considerations of nasal discharge

Surgery of the nasal cavity may be exposed primarily via a dorsal or ventral approach. Surgical treatment of lesions of the nasal cavity usually is limited to benign lesions or in combination with adjunctive therapy such as radiation therapy. Caution must be exercised with a dorsal approach to the nasal cavity to avoid complications of inadvertent penetration of the brain case. Gentle tissue handling and careful closure of the mucoperiosteum must be exercised following a ventral approach to minimize the risk of oronasal fistula formation.     

Experimental infection of pigs with the porcine respiratory coronavirus (PRCV): measure of viral excretion.

Twelve pigs were experimentally infected with a porcine respiratory coronavirus (PRCV) by the oronasal route. Viral excretion was measured daily by two means-deep nasal swabs and air samples obtained in a cyclone sampler. Clinical signs were very slight on infected pigs. Airborne virus could be recovered from day 1 to day 6 post-infection in the cyclone sampler as well as in petri dishes placed in the same loose-box. Viral titres obtained from nasal swabs were significantly correlated with those obtained from air samples. Different collection media were compared. The most efficient media for the collection of infectious viral particles contained a protective agent such as foetal calf serum.     

Unsuccessful surgical repair of a short soft palate in a dog

An 8-week-old male Miniature Schnauzer had nasal discharge of milk, food, and water since birth, especially during eating. Examination of the oral cavity revealed a short soft palate. Numerous unsuccessful surgical procedures were performed to construct a shelf of tissue to prevent oronasal reflux. The dog was euthanatized.     

Computed tomographic description of the highly variable imaging features of equine oromaxillary sinus and oronasal fistulae

Oronasal and oromaxillary sinus fistulae are well‐documented complications following removal or loss of a maxillary cheek tooth. Diagnosis is currently based on a combination of oral examination, videoendoscopy, radiography, and computed tomography (CT). The objective of this retrospective, case series study was to describe the CT characteristics of confirmed oronasal and oromaxillary sinus fistulae in a group of horses. Inclusion criteria were a head CT acquired at the authors’ hospital during the period of 2012–2017, a CT diagnosis of oronasal or oromaxillary sinus fistulae, and a confirmed diagnosis based on a method other than CT. Signalment, clinical findings, oral examination findings, presence of a confirmed fistula, and method for confirmation of the diagnosis were recorded. A veterinary radiologist reviewed CT studies for all included horses and recorded characteristics of the fistulae. Seventeen horses were sampled. Fourteen oromaxillary sinus fistulae and three oronasal fistulae were identified. All fistulae appeared as variably sized focal defects in the alveolar bone. Defects frequently contained a linear tract of heterogeneous material interspersed with gas bubbles, considered consistent with food. Computed tomographic attenuation of the material (Hounsfield units, HU) varied widely within and between cases. In 16 of 17 cases, there was evidence of concurrent dental disease in addition to the fistulae. Although the gold standard diagnostic test remains identification of feed material within the sinus or nasal passages, findings from the current study support the use of CT as an adjunctive diagnostic test for assessing the extent of involvement and presurgical planning.     

Nasal Mucosal Adenocarcinoma in a Pet Rabbit

A 6-year-old male rabbit (Oryctolagus cuniculus) presented with upper respiratory disease that was nonresponsive to antibiotic therapy. Computed tomography revealed a severe space-occupying lesion of the right nasal cavity, deviation of the nasal septum to the left, and narrowing of the left nasal cavity. An exploratory rhinostomy was performed for the purposes of diagnostic sample collection and to improve airflow as clinical signs of dyspnea were becoming more pronounced. The histopathologic disease diagnosis from the biopsy samples was nasal mucosal adenocarcinoma. Palliative rhinostomy provided only temporary improvement in airflow, and the patient was euthanized 3 days later. On necropsy, neoplasia was found to extend into the rhinopharynx. This is the first reported case of nasal mucosal adenocarcinoma in rabbits. This important differential diagnosis should be considered for any rabbit with clinical signs of upper respiratory disease that is nonresponsive to medical therapy.     

Nasal Septoplasty for Correction of Septal Deviation in a Foal

Objective — This article reports an alternative to septal resection in nasal septal deviations involving the rostral 7 to 10 cm of the nasal septum.
Study Design — Case report.
Sample Population — One client-owned foal.
Methods — A nasal approach with mucosal elevation was used to gain access to the cartilaginous portion of the nasal septum. Once exposed, a series of parasagittal incisions in the cartilage allowed the septum to be repositioned while providing some intrinsic stabilization.
Results — The nasal approach provided good access to the rostral 7 cm of the nasal septum. The technique resulted in minimal hemorrhage from the site. Bleeding was reduced with the use of ephedrine to vasoconstrict the mucosal vessels, and primary closure of the mucosa.
Conclusions — Use of an intrinsically stabilized septoplasty should be considered as a means of decreasing the airway obstruction caused by nasal septal deviation in foals while allowing for normal development of facial contour.     

Tunnel grafting for wound repair in horses: a novel technique in graft production and placement

There are several skin grafting methods described in the human and animal literature. Currently, there are five types of free grafts used in horses: pinch and punch grafts, split and full-thickness sheet or mesh grafts and tunnel grafts. Published methods of tunnel grafting describe the use of alligator forceps. The alligator forceps create a poor tunnel and are excessively traumatic to the granulation bed. This technique utilised a 13G Jamshidi needle that was placed across the granulation bed and created a uniform tunnel. The Jamshidi needle was atraumatic to the granulation bed increasing the opportunity for graft survival. A twin bladed scalpel allowed for the quick creation of uniform width grafts. Removal of the overlying tunnel ‘roof’ took place 5–14 days later to allow graft expansion. This case series included five horses with distal limb wounds and one with a wither injury. Four horses required general anaesthesia for graft placement and three required general anaesthesia for the removal of the tunnel roof. The acceptance of the grafts varied from 70% to 100%. Graft expansion to cover the granulation tissue took 2–5 months. This case series demonstrates that this technique of graft production and placement is an easy method for achieving successful skin grafting. Compared to other graft types, tunnel grafts are more readily accepted. Cosmetic and functional results achieved are better than those with pinch and punch grafts. Tunnel grafting does not require expensive equipment or advanced training, and in some cases can be performed under standing sedation.