Levator labii superioris muscle transposition to treat oromaxillary sinus fistula in three horses

OBJECTIVE: To describe surgical transposition of the levator labii superioris muscle to treat oromaxillary sinus fistula in horses. STUDY DESIGN: Clinical study. ANIMALS: Three horses with chronic oromaxillary sinus fistula. METHODS: After severing its tendinous insertion, the muscle belly of the levator labii superioris muscle was retracted and transposed through the oromaxillary sinus fistula. The tendon exited the oral cavity through a full-thickness buccal incision created adjacent to the oral end of the fistula and was then tunneled subcutaneously in a ventral direction before being anchored by sutures to the cheek tissues. RESULTS: Fistulae healed with few complications and with good cosmetic and functional results. CONCLUSIONS: Oromaxillary sinus fistula associated with molariform tooth loss in horses can be treated successfully by transposition of the levator labii superioris muscle. CLINICAL RELEVANCE: Transposition of the levator labii superioris muscle should be considered for resolution of chronic oromaxillary sinus fistula in horses.     

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.     

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.     

Surgical repair and reconstruction of a nasal fistula following intra-lesional formalin injection

A 6-year-old Cleveland Bay mare was referred to the University of Liverpool Equine Hospital for repair of an iatrogenic nasocutaneous fistula. The fistula had developed following attempted ablation of an epidermal inclusion cyst located in the right nasal diverticulum with intra-lesional formalin 6 weeks previously. Subsequent tissue necrosis resulted in the formation of a full-thickness defect in the overlying tissues and the creation of a 5 × 5 cm nasocutaneous fistula. Surgical management consisted of initial debridement of the fistula and use of a commercial dermal regeneration mesh to bridge the defect, acting as a tissue scaffold. The levator labii superioris muscle was utilised to cover the scaffold by transecting it close to its proximal origin and reflecting it rostrally. Finally, a transposition skin flap was created adjacent to the site and was rotated to cover the defect. The mare made an excellent recovery, and follow-up confirmed complete healing of the surgical site with an excellent cosmetic outcome.     

Head and neck abscessation and thrombophlebitis following cheek tooth extraction in a pony

Due to their long hypsodont reserve crowns, extraction of equid cheek teeth can be difficult and result in more complications than the extraction of their shorter brachydont counterparts although the more recent resumption of oral extraction has greatly reduced such complications. The more common post-extraction sequelae in equids include non-healing alveoli due to retained dental or alveolar sequestrae which may lead to oromaxillary or oronasal fistula formation, chronic external sinus tract formation or osteomyelitis of the supporting bones. Collateral damage to adjacent teeth has also occasionally been reported during dental repulsion. Systemic complications following equine cheek tooth extraction have been infrequently described, including a small number of cases of exodontia-related bacterial meningioencephalitis. This is surprising, as dental manipulation can lead to bacteraemia in many species, including horses. Infections at distant sites related to the spread of dental pathogens have been well described in humans and in small animals. This report describes deep abscessation of the masseter muscles followed by extensive thrombophlebitis of the jugular, facial and rostral cervical veins following oral cheek tooth extraction in a pony affected by pituitary pars intermedia dysfunction (PPID) that was successfully treated by abscess drainage and thrombectomy of the affected veins.     

Treatment of oromaxillary fistulae in nine standing horses (2002–2006)

Reasons for performing study: There is minimal published information on equine oromaxillary fistulae that are unrelated to cheek teeth (CT) repulsion or on the conservative treatment of these atypical fistulae. Objectives: To report equine oromaxillary fistulae unrelated to CT extraction and describe their management in standing horses. Methods: Case details of oromaxillary fistulae of atypical aetiology occurring at 2 referral centres between 2002–2006, including their treatment and response to treatment were examined. Results: Nine cases of oromaxillary fistula were recorded, mainly in aged horses (median 22 years). Fistulae were associated with CT diastemata in 7 cases, fractured CT in one and a central defect in a worn CT in another. After removing food and exudate from the sinuses, 6 cases were treated successfully by filling the diastema or dental defect with polymethylmethacrylate (PMMA). Following dental extraction, the other 3 cases were treated successfully by use of PMMA alveolar packing. Conclusion: Older horses can spontaneously develop oromaxillary fistulae, usually secondary to CT diastemata. In the absence of apical infection, this disorder can usually be treated successfully in standing horses by treating the sinusitis and sealing the oral aspect of the diastema with PMMA. Potential relevance: Older horses with sinusitis should be assessed for the presence of CT diastemata and oromaxillary fistulae. If detected, these disorders can be treated successfully in the standing horse.     

Use of reversed periosteal flaps in the repair of large nasocutaneous fistulas in two horses

Head injuries occur frequently in horses and a successful outcome after repair depends upon the severity of the initial trauma, the anatomical structures involved and the extent of tissue loss. Often these injuries involve facial bones and enter into the nasal passages or paranasal sinus system. When these injuries occur in conjunction with substantial tissue loss, the resulting defect may be difficult to close and naso/sinocutaneous fistulae can develop. These defects can be challenging and time consuming to repair and an appropriate reconstructive technique must be selected. We describe the use of reverse periosteal flaps as a technique in repairing large nasocutaneous fistulae in 2 horses after previous attempts to close the defects by other means had failed.     

Dental bridging as a treatment for large oral fistulae in two horses

Chronic orocutaneous, oronasal, or orosinus fistulae can be challenging to repair. This report describes placement of a dental bridge as a treatment for oral fistulae and outcome in two horses. A 12-year-old, Westphalian gelding was presented for nasal discharge because of an oromaxillary fistula after dental repulsion of the Triadan 209 4 years earlier. The second case, a 5-year-old Oldenburg mare was presented for an orocutaneous fistula 7 weeks after dental repulsion of the Triadan 208. Both were treated by placing an 8-shaped cerclage wire, inserted through the rostral and caudal interdental spaces and crossing at the level of the missing tooth. Polymethylmethacrylate (PMMA) was then used to seal the fistula. No significant complications occurred during or after the surgery. In both cases clinical signs did not recur. In the first case the dental bridge is currently (5 years after the intervention) in place. In Case 2 the construction was removed after 1.5 years and the fistula had healed completely. This case report suggests that placing a dental bridge composed of cerclage wire and PMMA should be considered as an easy, noninvasive and efficient way to manage large oromaxillary or orocutaneous fistulae.     

Treatment of equine oro-nasal and oro-maxillary fistulae

Equine oro-nasal or oro-sinus fistulae are usually problematic disorders to treat. As these lesions are mainly a sequel to standard dental repulsions, it is obvious that safer exodontia techniques such as oral extraction should now be used. The initial treatment of such fistulae is to ensure that there is a healthy granulating alveolus, without any dental or alveolar sequestrae and that all epithelium lining the fistula is removed. Provided there is a tooth on either side of the fistula, the initial and usually successful treatment is the use of an acrylic alveolar plug attached to adequately prepared adjacent teeth. Reinforcing such prostheses with wire tied between adjacent teeth will stabilise such prostheses. For fistulae that extend far onto the hard palate or those at the Triadan 06 or 11 alveolar sites that cannot be treated by acrylic prostheses, a variety of surgical treatments including; mucoperiosteal sliding flap, transposition of facial muscles, maxillary bone flap or an ear cartilage graft are all potential therapies, but there  are no large, objective long-term reports on their success available.     

Transmaxillary anchored silicon embedded gauze plug in the post-operative treatment of a large oromaxillary fistula caused by a supernumerary cheek tooth

A 9-year-old Hungarian sport horse gelding was presented to the clinic in poor condition displaying malodorous bilateral purulent nasal discharge. Oral examination revealed the presence of supernumerary 111 and 211. Bilateral diastema formation between the third maxillary molars and the supernumerary teeth with deep periodontal pockets and massive food impactions were diagnosed endoscopically. Radiography revealed inhomogenous sinus opacities in the left and right paranasal sinuses. Following bilateral oral extractions of the supernumerary cheek teeth and third maxillary molars, bilateral oromaxillary fistula formations were diagnosed (about 17 mm diameter on the right side). Bilateral frontal and right-sided maxillary trephinations and resection of the right bulla of the maxillary septum were performed. Massive food impactions of the left and right paranasal sinuses were removed under endoscopic control. Repeated trans-endoscopic sinus lavage was performed post-operatively. After 2.5 months, the large right-sided oromaxillary communication was temporarily closed with a transmaxillary anchored, gauze-cored silicon plug on an outpatient basis. Follow-up examination after 187 days revealed complete closure of the oromaxillary fistula and absence of sinusitis. In a 1.5-year follow-up control, no pathological conditions were found.     

Angularis oris axial pattern buccal flap for reconstruction of recurrent fistulae of the palate

OBJECTIVE: To describe the use of an axial pattern flap based on the angularis oris artery and vein for reconstruction of palate defects. STUDY DESIGN: Clinical case report ANIMALS: Two dogs with recurrent oronasal fistulae. METHODS: Oronasal fistulae previously treated by buccal mucosal random pattern flaps that subsequently dehisced were repaired using an angularis oris-based buccal tissue axial pattern flap. This flap was developed by full thickness incision of the cheek tissue, excluding the skin, about the angularis oris vascular pedicle resulting in a vascularized flap covered by oral mucosa on one side. RESULTS: In one dog, the repair was intact and healed 6 months after surgery. In the second dog with a fistula that resulted because of radiation necrosis, approximately 95% of the defect healed with a small (<1.0 cm(2)) area of dehiscence. Repair of this persistent fistula with a random pattern buccal flap failed and this small fistula remained with minimal clinical signs. CONCLUSION: An axial pattern flap based on the angularis oris artery and vein can be used to repair difficult or recurrent palate defects. CLINICAL RELEVANCE: Angularis oris axial pattern flaps provide an additional effective option for repair of defects in the hard and soft palate to the distal gingival margin of the canine tooth or beyond, depending on skull conformation. Advantages of this flap include its highly vascular and robust character, high degree of mobility and a surface of tough buccal mucosa.     

Muscle Flap Closure of a Frontocutaneous Fistula in a Horse

A frontal sinus fistula was corrected surgically using a temporalis muscle flap and split thickness skin graft in a horse. The operative approach for temporalis muscle transposition is described. Application of the temporalis muscle flap allowed restoration of a functional covering and excellent final appearance.     

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.     

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.     

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.     

Greater palatine island axial pattern flap for repair of oronasal fistula related to eosinophilic granuloma

A Greyhound presented with eosinophilic granuloma lesions of the soft palate and oronasal fistula. Since other siblings had been known to also have oral eosinophilic granuloma, it was suspected that the dog reported here had a familial predisposition to develop the disease. Preoperative medical management consisting of anti-inflammatory and immunosuppressive therapy was required before surgical repair of the oronasal fistula. Multiple surgical techniques, including a greater palatine island axial pattern flap, were used to repair the oronasal fistula.     

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.     

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.     

Transposition of first digital pad for reconstruction of a palmar antebrachial soft tissue defect in a cat

An 8-year-old female neutered Siamese cat was presented with a recent history of incomplete excision of an apocrine gland adenocarcinoma from the palmar aspect of the right antebrachium, just proximal to the carpal joint. There was no evidence of metastasis. Wide surgical excision of the previous surgery site was performed resulting in a soft tissue defect. Partial reconstruction was achieved using digital pad transposition of the first digit (dewclaw), forming a local axial pattern flap that was transposed into the adjacent defect. The remaining defect was closed by primary apposition. The skin flap healed successfully. Some breakdown of the skin closed by primary apposition necessitated open wound management. The cosmetic and functional result of the first digital pad transposition was considered excellent, rendering it a useful means to reconstruct soft tissue defects in the carpal region.     

Equine paranasal sinus disease: a long-term study of 200 cases (1997-2009): treatments and long-term results of treatments

Reasons for performing study: There is limited objective information available on the treatment and the long‐term response to treatment of the different types of equine sinus disease. Objectives: To document the treatments and long‐term response to these treatments in 200 cases of equine sinus disease (1997–2009). Methods: The treatments of horses affected with subacute primary sinusitis (n = 52); chronic primary sinusitis (n = 37); dental sinusitis (n = 40); sinus cyst (n = 26); traumatic (n = 13); dental‐related oromaxillary fistula (n = 8); sinus neoplasia (n = 10); mycotic sinus disease (n = 7); and intrasinus progressive ethmoid haematoma (n = 7) and the long‐term response to these treatments were retrospectively reviewed. Results: Treatments evolved throughout the study and latterly were as conservative as possible, including sinoscopic lavage and standing sinusotomy, with a maxillary sinusotomy approach preferred for the mainly mature horses treated in this study. Removal of intrasinus inspissated pus, including transendoscopically (by sinusotomy and via existing sinonasal fistulae), was the main treatment for chronic primary sinusitis and sinonasal fistulation was seldom performed latterly. Attempted oral extraction of infected cheek teeth, even if unsuccessful, facilitated subsequent dental repulsion, resulting in few post operative problems. Sinus cyst removal carried an excellent prognosis. Except for cases of sinus neoplasia (only 22% cured), an excellent long‐term response to treatment (91% fully cured, 7% partially cured) was obtained for all other types of sinus disease following a median of one treatment. Conclusions: More conservative treatments, including removal of intrasinus inspissated pus by sinoscopy, pre‐existing sinonasal fistula or sinusotomy, are effective for chronic primary sinus disease. Standing sinusotomy, mainly using a small maxillary site, was suitable for most cases of sinus disease in mature horses.