Sinoscopic Treatment of Rostral Maxillary and Ventral Conchal Sinusitis in 60 Horses

Objective— To evaluate the use of sinoscopy for detection and treatment of ventral conchal sinus (VCS) and/or rostral maxillary sinus (RMS) disease in horses.
Study Design— Case series
Animals— Horses (n=60) with suspected paranasal sinus disease.
Methods— Horses were evaluated by sinoscopy through a conchofrontal sinus (CFS) portal with ventral conchal bulla (VCB) fenestration. Other endoscopic sinus approaches and adjunctive diagnostic tests; oral examination, computed tomography, radiography, scintigraphy and endoscopic examination of the upper portion of the respiratory tract were used in some horses.
Results— The CFS approach permitted adequate observation of the RMS and VCS in 53 horses (88%). Hemorrhage caused by VCB fenestration prevented examination of the RMS and/or VCS in 12 horses (21%). Observation of lesions was possible in all horses diagnosed with neoplasia, sinus cysts, and progressive ethmoidal hematomas. Endoscopy of the paranasal sinuses was useful diagnostically in 82% of horses with primary sinusitis. Other diagnostic modalities were usually required to confirm a diagnosis of dental sinusitis.
Conclusions— Trephination into the CFS with VCB fenestration is a minimally invasive technique that provides consistent access to the RMS and VCS. It facilitates diagnosis of many sinus disorders and endoscopically guided treatment of many horses with sinus cysts and primary sinusitis, in combination with sinus lavage.
Clinical Relevance— Many diseases affecting the RMS and VCS can be diagnosed and resolved endoscopically using a CFS approach with VCB fenestration, thus avoiding the need for osteoplastic sinus surgery and its associated risks and complications.     

Endoscopic Examination and Treatment of Paranasal Sinus Disease in 16 Horses

Sixteen horses with suspected paranasal sinus disease had endoscopic examination of the paranasal sinuses with a 4.0 mm arthroscope either while standing and sedated (14 horses) or under general anesthesia (two horses). Endoscopic diagnosis included sinusitis (four horses), sinus cyst (three horses), hemorrhage (three horses), neoplasia (three horses), and tooth root abnormalities (two horses). No abnormalities were detected in one horse. Endoscopic findings concurred with the radiographic findings in 13 horses (81%). Samples of sinus contents for bacteriologic (eight horses) and histologic examinations (five horses) were obtained using sinus endoscopy. Diagnostic sinus endoscopy was combined with debridement, lavage, and suction as a therapeutic technique in 10 horses. In three horses, sinus exploration was performed after diagnostic endoscopy confirmed sinus disease, whereas in three horses, further therapy was not recommended after sinus endoscopy. Clinical signs of sinus disease resolved in 11 horses (69%) overall and in eight of 10 horses (80%) with sinusitis, cyst formation, or hemorrhage using endoscopic techniques alone. Mild, local subcutaneous emphysema occurred at the portal sites in all horses, but healing occurred without additional complications, latrogenic damage to sinus structures occurred in one horse. Sinus endoscopy was useful in the diagnosis and management of paranasal sinus disease and avoided the need for exploratory sinusotomy in some horses.     

Paranasal Sinusitis Complicated by Inspissated Exudate in the Ventral Conchal Sinus

Primary paranasal sinusitis complicated by inspissated exudate within the ventral conchal sinus was diagnosed in five horses. Clinical signs included a unilateral, foul-smelling, mucopurulent nasal exudate of 2 to 7 months' duration. Two of the horses had partial nasal obstruction from distortion of the ventral concha. Radiographs of the skull showed a mass of soft tissue density dorsal to the roots of the superior third and fourth or fourth and fifth cheek teeth. Treatment included bone flap maxillary sinusotomy with exposure of the ventral nasal concha and removal of inspissated exudate. Resolution of the sinusitis occurred in all five horses.     

Surgical management of a sinonasal angiomatous polyp and associated cyst involving the paranasal sinuses and nasal cavity via standing axial rhinotomy

This case report describes the successful surgical management of a sinonasal angiomatous polyp involving the dorsal conchal bullae, dorsal conchal sinus, ventral conchal sinus, ventral conchal bullae and ventral conchal recess of the left nasal cavity resulting in a secondary sinusitis and compression of the nasal passage.     

Use of serial standing computed tomography for diagnosis,treatment and monitoring of a horse with acute myonecrosis of the head

An 11-year-old American Quarter Horse gelding was referred to the JT Vaughan Large Animal Teaching Hospital at Auburn University, College of Veterinary Medicine, for investigation of acute and severe right-sided facial swelling and nasal discharge. Standing computed tomographic (CT) examination of the head identified severe soft tissue swelling surrounding the right mandible, emphysema within the soft tissues tracking along fascial planes and right-sided caudal and rostral maxillary sinusitis. Using CT identification and ultrasound guidance, several targeted fasciotomies were created into the right masseter, cranial cervical musculature, supraorbital space and caudo-medial aspect of the mandible. The right-sided sinusitis was treated by right conchofrontal sinus trephination and lavage. Aerobic and anaerobic cultures obtained from the fasciotomy sites and conchofrontal sinus both yielded Prevotella intermedia and Peptostreptococcus asaccharolyticus. During hospitalisation, serial, standing CT examinations were performed for monitoring case progression and guiding further fasciotomies in the face of continued myonecrosis. Follow-up CT performed at 1 month showed resolution of the emphysema and presence of chronic right ventral conchal sinusitis. The sinusitis was treated by fenestration of the right ventral concha with a diode laser via the nasal passage.     

A Large Frontonasal Bone Flap for Sinus Surgery in the Horse

A large frontonasal bone flap was created to treat diseases of the paranasal sinuses in 14 horses. The bone flap was made as wide as possible within the confines of the nasolacrimal duct so the floor of the frontal sinus and the dorsal and ventral conchae could be opened. These openings exposed the nasal passages, maxillary sinuses, and ventral conchal sinus thereby facilitating removal of diffuse and localized lesions from these sites. Diseases treated were ethmoid hematomas (4 horses), sinus cysts (5 horses), cryptococcal granuloma, osteoma, hemangiosarcoma, pus in the ventral conchal sinus, and periapical infection of a second molar. Four horses were euthanatized during or after surgery, one because of postsurgical pleuritis and pneumonia (horse with osteoma) and three because of their primary problems (cryptococcal granuloma, hemangiosarcoma, pus in the ventral conchal sinus). Skin suture abscesses that responded to treatment developed in four horses. Ten horses returned to their intended uses, the sinus flaps healed without blemish, and the original problems did not recur. The frontonasal flap technique provided greater access to all paranasal sinuses than methods described previously.     

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.     

Equine paranasal sinus disease: a long-term study of 200 cases (1997-2009): ancillary diagnostic findings and involvement of the various sinus compartments

Reasons for performing study: There is a lack of objective information on the value of ancillary diagnostic techniques used to investigate equine sinus disease, and also on which sinus compartments are commonly affected in this disorder. Objectives: To record the ancillary diagnostic findings used to investigate equine sinus disease and to document which compartments are affected. Materials and methods: The clinical case records of 200 consecutive cases of sinus disease, including subacute (<2 months' duration) primary (n = 52); chronic (>2 months' duration) primary (n = 37); dental (n = 40); traumatic (n = 13); sinus cyst (n = 26); sinus neoplasia (n = 10); dental related oromaxillary fistula (n = 8); mycotic sinusitis (n = 7) and intra‐sinus progressive ethmoid haematoma (n = 7) were retrospectively examined. Results: Nasal endoscopy showed exudate draining from the sino‐nasal ostia in 88% of cases and a sino‐nasal fistula was present in 15% of cases. Sinoscopy was performed in 79% of cases and was of great diagnostic value. More recently, 22% of cases had fenestration of the ventral conchal bulla performed to allow sinoscopy of the rostral sinus compartments. Radiography was performed in 97% of cases and showed intra‐sinus fluid lines to be common (69% prevalence) in subacute primary sinusitis. Radiographic dental apical changes were not specific to dental sinusitis, e.g. 29% of chronic primary sinusitis cases had radiographic dental changes. Scintigraphy was performed in 20% of cases and was helpful in identifying dental apical changes when radiography was inconclusive. Overall, the caudal maxillary (78% involvement) and rostral maxillary (61%) sinuses were most commonly affected, with the ventral conchal sinus (VCS) (54% involvement) and conchofrontal sinuses (48%) less so. The VCS showed the greatest tendency to contain inspissated pus (present in 46% of all affected VCS). Conclusions: Nasal endoscopy, sinoscopy and skull radiography are of great value in diagnosing the presence and causes of equine sinus disease.     

USING SEMI‐AUTOMATED SEGMENTATION OF COMPUTED TOMOGRAPHY DATASETS FOR THREE‐DIMENSIONAL VISUALIZATION AND VOLUME MEASUREMENTS OF EQUINE PARANASAL SINUSES

The system of the paranasal sinuses morphologically represents one of the most complex parts of the equine body. A clear understanding of spatial relationships is needed for correct diagnosis and treatment. The purpose of this study was to describe the anatomy and volume of equine paranasal sinuses using three‐dimensional (3D) reformatted renderings of computed tomography (CT) slices. Heads of 18 cadaver horses, aged 2–25 years, were analyzed by the use of separate semi‐automated segmentation of the following bilateral paranasal sinus compartments: rostral maxillary sinus (Sinus maxillaris rostralis), ventral conchal sinus (Sinus conchae ventralis), caudal maxillary sinus (Sinus maxillaris caudalis), dorsal conchal sinus (Sinus conchae dorsalis), frontal sinus (Sinus frontalis), sphenopalatine sinus (Sinus sphenopalatinus), and middle conchal sinus (Sinus conchae mediae). Reconstructed structures were displayed separately, grouped, or altogether as transparent or solid elements to visualize individual paranasal sinus morphology. The paranasal sinuses appeared to be divided into two systems by the maxillary septum (Septum sinuum maxillarium). The first or rostral system included the rostral maxillary and ventral conchal sinus. The second or caudal system included the caudal maxillary, dorsal conchal, frontal, sphenopalatine, and middle conchal sinuses. These two systems overlapped and were interlocked due to the oblique orientation of the maxillary septum. Total volumes of the paranasal sinuses ranged from 911.50 to 1502.00 ml (mean ± SD, 1151.00 ± 186.30 ml). 3D renderings of equine paranasal sinuses by use of semi‐automated segmentation of CT‐datasets improved understanding of this anatomically challenging region.     

CT and cross-sectional anatomy of the paranasal sinuses in the Holstein cow

The structure of paranasal sinuses in cattle is difficult to understand due to its complexity, age-related changes, and insufficient published data. In this prospective, anatomic study, we described the anatomy of the paranasal sinuses in the Holstein cow using computed tomography (CT) and cross-sectional anatomic slices. Twelve healthy adult Holstein cow heads were used for this study. The heads were scanned using CT, and frozen anatomical sections were taken. The locations, borders, and relationships of the paranasal sinuses were defined on the anatomical sections and CT images. The paranasal sinuses on each side of the head consisted of conchal (dorsal, middle, and ventral), maxillary, lacrimal, palatine, frontal, sphenoid sinuses, and ethmoidal cells. The frontal sinus pneumatized all bones surrounding the cranial cavity, except for the ethmoidal and body of basisphenoid bones. The sphenoid and ventral conchal sinuses were the most asymmetrical, and the middle conchal sinus was the simplest. The ventral conchal sinus was detected in eleven animals, one of which was unilateral. This sinus communicated with the middle nasal meatus (13/21) and ventral nasal meatus (8/21). Findings can be used as background for interpreting CT studies of cattle with clinical signs of sinonasal region diseases. Future cross-sectional radiological and reconstructive anatomical studies and investigation of the postnatal development of related structures in cattle are needed.     

Evaluation of a novel post operative treatment for sinonasal disease in the horse (1996-2007)

Reasons for performing study: Results of surgical treatment of sinonasal disease in horses have been reported previously; however, this paper describes the outcome of horses in which a specific post operative treatment protocol was used. Objectives: The objectives of the study were to determine: 1) short‐ and long‐term outcome; 2) complications; and 3) recurrence rates of different disease processes, when horses were treated with a specific treatment protocol. Methods: Medical records of horses presented for surgical treatment of sinonasal disease from 1996–2007 were reviewed. Results and duration of surgical exploration were recorded. Post operatively, the sinus flaps were re‐opened with the horses standing and sedated. Number of horses requiring further treatment (debridement and/or lavage), median number of post operative days when the flap was re‐opened, median number of times the flap was opened and median duration of hospitalisation were recorded. Short‐ and long‐term survival and complication rates were determined. Results: Ninety‐one horses were included in the study. The sinus flaps were re‐opened with the horses standing a median of 3 days post operatively. Thirty‐nine horses (43%) required further treatment at this time and 89 horses (97%) survived to discharge. Incision infection was the most common complication encountered (29%). No horse required a blood transfusion. Recurrence rates were 5% for paranasal sinus cysts, 12% for progressive ethmoid haematoma and 50% for neoplasia. Conclusions: Rapid removal of the primary lesion followed by packing the sinuses and re‐evaluating in the standing horse in a more controlled environment offers a safe and effective means to thoroughly assess and treat sinonasal disease. Potential relevance: Surgical time, intraoperative haemorrhage, long‐term complications and recurrence rates of paranasal sinus diseases treated via frontonasal or maxillary sinus flap may be reduced using this technique.     

Histopathological findings in equine sinonasal disorders.

Biopsies collected from 79 referred cases of equine sinonasal disease, including 27 horses with primary sinusitis, 10 with secondary dental sinusitis, 19 with sinus cysts, 11 with progressive ethmoid haematomata (PEH), 4 with false nostril epidermal inclusion cysts, 4 with sinonasal polyps, 3 with sinonasal mycosis and from 2 control animals were examined histologically. Observations were made on epithelial type and integrity, cellular inflammatory response, fibroplasia and presence of potential pathogens. Chronic inflammatory changes including mucosal thickening, ulceration and significant fibroplasia, were found in the sinus mucosa with most sinus disorders, similar to those found in human chronic sinusitis. Bacteria were variably present on sinusitis mucosae but their aetiological significance was unclear. The presence of apparently irreversible changes including fibroplasia in some of these sinusitis cases may explain their poor or delayed response to treatment. Sinus cysts had histological similarities to human mucocoeles. Progressive ethmoid haematomata showed recent and older haemorrhage, as did sinus cysts (and occasionally some chronic sinusitis sections), but support for a common aetiology between sinus cysts and PEH was absent.     

Historical and clinical features of 200 cases of equine sinus disease

The historical and clinical findings in 200 referred cases of equine sinus disease were reviewed retrospectively. Univariable and multivariable analyses were performed to detect significant differences in historical or clinical features between various categories of sinus disease. The causes of sinus disease were classified as subacute primary (less than two months duration) (n=52), chronic primary (more than two months duration) (n=37), dental (n=40), sinus cyst (n=26), traumatic (n=13) or mycotic sinusitis (n=7), sinus neoplasia (n=10), dental-related oromaxillary fistula (n=8) and intrasinus progressive ethmoid haematoma (n=7). The majority of sinus disorders were of chronic duration at the time of referral and most (including 97 per cent of chronic primary sinusitis cases) had not responded to previous antibiotic therapy and/or sinus lavage in some cases. Clinical signs included unilateral nasal discharge in most cases, including purulent or mucopurulent discharge in all horses with primary, dental and mycotic sinusitis. Haemorrhagic nasal discharge was a feature of traumatic sinusitis and intrasinus progressive ethmoid haematomas. Firm facial swellings and nasal airflow obstruction were features of sinus cysts and neoplasms. Ipsilateral lymphadenitis was a more prominent feature of sinus disease with active infections such as primary, dental or mycotic sinusitis.     

Radiographic identification of the equine ventral conchal bulla

Involvement of the ventral conchal sinus (VCS) is an important diagnostic and prognostic feature in cases of the equine sinus disease. The authors aimed to ascertain if the caudo-dorsal extension of the VCS, the ventral conchal bulla (VCB) is identifiable on plain radiographs of cadaver skulls without sinus disease. Bilateral frontonasal sinus flaps were made in 10 equine cadaver skulls. Plain lateral, lateral oblique and dorso-ventral radiographs were then obtained followed by the same views taken with stainless steel wire outlining the caudal border of the VCB. Plain radiographs were randomised and blindly evaluated by two observers who marked where they believed the VCB to be positioned. This was then correlated with the true position of the VCB using radiographs with wires in place. The ease of identification of the VCB was classified as 'easy' or 'difficult'. The VCB was correctly identified in 70 per cent of lateral radiographs, but only 45 per cent of lateral oblique radiographs and 17 per cent of dorso-ventral radiographs. If a clinician was confident that he or she could identify the VCB, they were usually correct. Conversely if the clinician judged VCB identification as 'difficult', they usually identified it incorrectly. In the authors' clinical experience, the VCB of horses with sinusitis involving this compartment is more radiologically evident than in clinically normal horses. Knowledge of the normal radiographic anatomy of this structure should aid clinicians in identifying horses with sinusitis affecting the VCS.     

A long-term study of 277 cases of equine sinonasal disease. Part 2: treatments and results of treatments

The treatments of 277 horses with equine sinonasal disease (1984-1996), described by Tremaine and Dixon (2001), are reported here. Long-term (median duration 24 months) outcomes of treatment of the more common disorders were good, with 92% of horses with sinonasal mycosis, 84% with primary sinusitis, 82% with sinus cysts, 78% with dental sinusitis and 75% with sinonasal trauma reported to have complete remission of clinical signs. However, only 33% of horses with progressive ethmoidal haematoma (PEH) and 12% with sinonasal neoplasia reported long term remission of clinical signs.     

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.     

An anatomical study of the dorsal and ventral nasal conchal bullae and middle nasal conchae in normal Shetland ponies: Computed tomographic anatomical and morphometric findings

Equine paranasal sinuses are susceptible to inflammation. Insufficient drainage through the nasal passages and meatus may lead to the accumulation of inspissated purulent discharge. Particularly in ponies, these anatomical structures are suspected to be relatively small. To date, there are no reports considering the morphology of nasal conchal bullae in small horse breeds such as Shetland ponies. The aim of the present study was to evaluate the size of the conchal bullae and the medial nasal conchae of Shetland ponies and their relation to the skull dimension using computed tomography. Reconstructed images of healthy adult heads of Shetland ponies were used. Linear skull measurements as well as two cranial indices of the head dimensions were taken. Length, width and height of the dorsal and ventral conchal bullae and the medial nasal conchae were measured in relation to the skull and compared with the data of skulls of large breed horses. The anatomical proportions of pony heads were characterized by a smaller cranial index and a greater nasal index than those of large breed horses. Shetland ponies showed a longer cranial length compared with the nasal length. Heads are consistently smaller, and the relationship of the bullae to the head length was also smaller than those measured in large breed horses. A negative correlation between the head and bullae size was found. In conclusion, this study suggests that Shetland ponies have distinguishing proportions of the head. These findings are relevant for clinical examination and surgical treatment of equine sinus disease in those breeds.     

A long-term study of 277 cases of equine sinonasal disease. Part 1: details of horses, historical, clinical and ancillary diagnostic findings

The clinical and ancillary diagnostic findings in equine sinnasal disease were studied. The diagnoses in 277 referred (1984-1996) cases of equine sinonasal disease included the following (% all cases): 67 cases (24.2%) primary sinusitis, 61 (22.0%) dental sinusitis, 37 (13.4%) sinus cysts, 22 (7.9%) sinonasal neoplasia, 21 (7.6%) progressive ethmoid haematoma, 17 (6.1%) sinonasal trauma, 13 (4.7%) sinonasal mycosis, 11 (4.0%) rostral maxillary cheek tooth infection, 7 (2.5%) sinonasal polyps, 7 (2.5%) cases of nasal epidermal inclusion cysts and 14 (5.1%) miscellaneous sinonasal disorders. Many disorders showed similar clinical signs including nasal discharge (present in 88% of all cases) and facial swelling (46%). Most disorders were chronic, with a median duration of signs of 12 weeks (range 3 days- 6 years) prior to referral. Sinus cysts and sinonasal neoplasia were significantly (P<0.05) more frequently associated with gross distortion of the nasal passages and facial bones than the other sinonasal disorders. Endoscopic changes were detected per nasum in 91% of cases, but contributed to the exact diagnosis in only 20%. Radiography revealed abnormalities in 81% of cases but was diagnostically useful in only 36%. Sinoscopy was diagnostically useful in 70% of the 61 cases where used.     

CONTRAST PARANASAL SINUSOGRAPHY FOR EVALUATION OF DISEASE OF THE PARANASAL SINUSES OF FIVE HORSES

Positive-contrast paranasal sinusography was employed to evaluate 5 horses with disease of the paranasal sinuses. Diseases of the paranasal sinuses of these horses were progressive ethmoidal hematoma, bacterial sinusitis secondary to dental disease, and neoplasia. Positive-contrast sinusography allowed more complete evaluation of disease of the paranasal sinus of the horse than did survey radiographs.