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.     

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.     

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.     

A review of equine paranasal sinusitis: Medical and surgical treatments

Treatment of the different types of equine sinusitis, in particular those of chronic (>2 months' duration) sinusitis can be difficult, with many such cases not responding to more conservative measures such as rest, antibiotic therapy or sinus lavage. Such refractory cases require further clinical examinations and imaging as outlined in a companion article to achieve confirmation of the cause of the sinusitis. Many sinusitis cases will then require some form of surgical treatment that may include sinusotomy, dental extraction or intrasinus growth removal, that are increasingly being performed by less invasive techniques under standing sedation.     

Equine dental disease part 4: a long-term study of 400 cases: apical infections of cheek teeth

Of 400 horses referred because of equine dental disease, 162 suffered from primary apical infections of their cheek teeth (CT), including 92 with maxillary CT infections and 70 with mandibular CT infections. Maxillary swellings and sinus tracts were more common (82 and 26% incidence, respectively) with infections of the rostral 3 maxillary CT, than with infections of the caudal 3 maxillary CT (39 and 5% incidence, respectively). Nasal discharge was more commonly present with caudal (95%) than rostral (23%) maxillary CT infections. Mandibular CT apical infections commonly had mandibular swellings (91%) and mandibular sinus tracts (59%) and these infections were closely related to eruption of the affected CT. A variety of treatments, including medical treatment, apical curettage, repulsion and oral extraction of affected teeth were utilised in these cases, with oral extraction appearing to be most satisfactory. Infections of caudal maxillary CT with a secondary paranasal sinusitis were most refractory to treatment, with a complete response to the initial treatment achieved in just 33% of these cases. Most other cases responded fully to their initial treatment. The long-term response to treatment was good in most cases.     

Use of scintigraphy for diagnosis of equine paranasal sinus disorders

OBJECTIVES: To describe and analyze subjective and objective scintigraphic findings in horses with paranasal sinus disorders. ANIMALS: Horses with suspected disorders of the paranasal sinuses or cheek teeth (n = 48) and control horses (n = 30). METHODS: 99Technetium-methylenediphosphate (99Tc-MDP; 7500 MBq) was administered for scintigraphic examination of the skull. Abnormal patterns of increased radionuclide uptake (IRU) were identified and subjectively described. Scintigrams and radiographs were blindly assessed by 2 clinicians and the accuracy of the imaging modalities was compared. Objective analysis was performed by comparing regions of interest (ROI) drawn over areas of abnormal IRU to the equivalent area on the unaffected side using the Mann-Whitney test. An ROI ratio (affected:non-affected sides) was also calculated for each lesion. RESULTS: Twenty-eight horses were diagnosed with primary (15) or secondary (13) sinusitis. Nine primary sinusitis cases had focal area(s) of moderate or marked IRU in addition to a more diffuse uptake in the affected sinus(es). kappa was marginally higher for scintigraphic assessment of paranasal sinus disorders than for radiographic assessment. There were significant differences in mean counts/pixel in ROI drawn on the affected side compared with the non-affected side. There was considerable overlap between the magnitudes of ROI ratios found with many different disorders. CONCLUSIONS: Scintigraphy can be useful for differentiation of sinusitis of dental origin from other causes of sinusitis. Quantitative analysis of scintigrams is not reliable for identification of particular disorders. CLINICAL RELEVANCE: Focal areas of moderate or marked IRU may be observed with primary sinusitis. Careful 3-dimensional localization of the lesion, along with consideration of other clinical and diagnostic findings should be performed to prevent false-positive diagnoses of periapical infection in such instances.     

Peripheral nerve sheath tumour of the equine maxillary sinus

This case report describes an 8‐year‐old Belgian Warmblood mare that was initially diagnosed and treated for a dental sinusitis. Despite removal of the diseased teeth and appropriate treatment, the sinusitis did not resolve. Over time, growth of a peripheral nerve sheath tumour of the left maxillary sinus became apparent, with recurrence after surgical removal. The clinical, radiographic, computed tomography, magnetic resonance imaging and pathological (gross and histological) findings of the first reported peripheral nerve sheath tumour of the equine paranasal region are described and illustrated.     

A review of swellings of the frontal region of the equine head

Gross swellings of the equine frontal area are most commonly caused by the poorly understood disorder of nasofrontal suture line periostitis that is usually self‐resolving, sinus cysts that are highly amenable to treatment, sinus tumours that in contrast usually respond poorly to treatment and facial trauma that may later lead to nasofrontal suture line periostitis. Other causes of conchofrontal sinus disease such as intrasinus progressive ethmoid haematoma, primary sinusitis and dental sinusitis seldom cause gross swellings of the overlying bones.     

A review of equine paranasal sinusitis. Aetiopathogenesis,clinical signs and ancillary diagnostic techniques

The equine paranasal sinuses are air filled cavities of uncertain function that are susceptible to inflammation, usually associated with bacterial infection. A common feature of most types of sinusitis is the accumulation of exudate within the affected sinus and subsequent ipsilateral nasal discharge. Equine sinusitis can have a variety of causes, including primary sinusitis following upper respiratory tract infections, and secondary sinusitis caused by dental infections, intrasinus benign and malignant growths and head trauma.     

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.     

Equine nasal cavity and paranasal sinus disease: A review of 85 cases

Eighty-five cases of equine nasal cavity and/or paranasal sinus disease (NC-PNSD) at Washington State University were reviewed with respect to incidence, clinical signs, treatment regimen and outcome. Incidence was 1.06 percent of all equine admissions over an 8-year period (July 1, 1977–June 30, 1985). For purposes of review, cases were divided into 6 groups depending upon etiology: 1. traumatic disorders, 2. developmental disorders, 3. neoplasia, 4. primary bacterial sinusitis, 5. sinusitis secondary to dental disorders, and 6. miscellaneous conditions.No correlation between sex or breed with NC-PNSD was identified. Traumatic and developmental disorders were most common in horses under 6-years-of-age and neoplastic conditions were most prevalent in horses over 10-years-of-age.The most common clinical signs of NC-PNSD, regardless of etiology were bony swelling or abnormalities noted externally, nasal discharge, and rhinodyspnea, followed by signs referrable to the oral cavity, external draining tracts, and epistaxis. All clinical signs were usually of a chronic duration (more than 2 weeks). Procedures which were most helpful in establishing a diagnosis were radiography (92% of cases), endoscopy (38%) sinocentesis (21 %), and examination of the oral cavity (20%).Of 74 horses available for follow-up, 49 were treated. Treatment was either not recommended or was declined by the owner in 12 cases, and euthanasia was performed without treatment in 13. Forty-six cases were treated surgically. The outcome of 23 of the cases was judged successful. Five had reduced clinical signs following surgery, and 18 were unsuccessfully treated. Those disorders judged to be traumatic in origin responded best to treatment while those involving neoplasia were the least successfully treated.     

Transnasal endoscopic treatment of equine sinus disease in 14 clinical cases

Transnasal endoscopic sinus treatment was used in four horses diagnosed with primary sinusitis and 10 horses with dental sinusitis. Pre-existing (n = 5) or surgically created (n = 9) sinonasal fistulae were used as portals for transnasal endoscopic exploration, debridement and lavage of the inflamed sinus cavities. Endoscopic sinonasal fistulation was performed using either trans-endoscopic diode laser fibre (four cases) or an electrocautery instrument under endoscopic control (five cases). All procedures were performed on standing sedated horses with the use of local anaesthesia. In six cases, the ventral concha was fenestrated in order to gain a portal into the ventral conchal and rostral maxillary sinus. In two cases the dorsal concha was fenestrated to access the caudal group of the paranasal sinuses. One case required fenestration of the ventral conchal bulla due to its empyema. Post-operative bleeding was controlled with a nasal cavity tamponade for 24 h. Endoscopic lavage and debridement of the inflamed sinuses were performed every 2–3 days. Medical treatment consisted of antibiotic and anti-inflammatory drugs. In the cases of dental sinusitis, the underlying dental pathology was addressed. Median hospitalisation time was 10 days (range 5–25 days) and the median number of endoscopic procedures (including the initial procedure) was 4 (range 3–7). Cases were followed-up by telephone consultations with their owners. Intervals between discharge and last follow-up ranged from 4 to 22 months (median 9.5 months). Complete recovery was reported in 10 cases, clinical improvement (occasional nonpurulent discharge) in two cases. Two cases were readmitted due to recurrence of the purulent nasal discharge; both subsequently underwent trephination of the affected sinuses and made a full recovery after removal of the remaining pathological sinus content.     

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.     

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.     

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.     

Distribution and persistence of topical clotrimazole after sinus infusion in normal canine cadavers

Objectives : To determine the in vitro persistence of clotrimazole 1% cream in the canine frontal sinus and to evaluate the distribution of clotrimazole solution over the sino‐nasal mucosa using a previously described surgical treatment protocol for canine nasal aspergillosis. Methods : Two canine skulls were used to monitor the persistence of clotrimazole cream in the lateral frontal sinus at 37°C. The distribution of irrigation solution around the frontal sinus compartments and nasal cavity was determined using six canine cadaver heads by trephining either the lateral or both the lateral and rostral compartments of the frontal sinus. Stain was added to the sinus irrigation solution before visually inspecting the sagittally sectioned heads. Results : Clotrimazole cream persisted in the frontal sinus for at least 96 hours. The nasal cavity mucosa was completely stained in 8 of 12 sides and almost completely stained in the remaining 4 of 12 sides. Flushing irrigation solution through the lateral compartment of the frontal sinus resulted in inadequate staining of the rostral compartment but medicating both the lateral and rostral compartments resulted in complete coating of all frontal sinus mucosa in eight of eight sides. Clinical Significance : Clotrimazole cream has the potential to be retained in the frontal sinus for several days and is distributed effectively in normal canine cadavers. Medicating both the rostral and lateral compartments of the frontal sinus may be indicated in some clinical cases.     

Radiographic examination of the facial, nasal and paranasal sinus regions of the horse. II. Radiological findings

The radiographic findings in 167 horses subjected to radiography of the facial area, nasal cavity and paranasal sinuses are recorded. Cases were grouped according to clinical diagnosis and the common and disparate radiographic features between and within groups are discussed. Dental disease occurred most frequently and accounted for about 30 per cent of cases, most of which had periapical infection. This disorder presented as two distinct clinical entities in almost equal numbers affected teeth with roots rostral to the maxillary sinus usually produced facial swelling, whereas those with roots within the sinus were generally associated with nasal discharge as a result of secondary sinusitis. In the former group periapical changes could readily be identified on radiographs, but in the latter group affected teeth could be recognised with confidence in only about half the cases. Primary sinusitis was the commonest specific condition recorded and accounted for 32 cases, three of which were mycotic. Using lateral erect projections, comparison of the radiographic features of primary sinusitis and sinusitis secondary to dental disease showed some useful differentiating signs. In four ponies, rhinitis associated with sinusitis led to disruption of the intra-nasal structures but mycotic rhinitis, nasal ulceration and an intra-nasal foreign body produced no radiographic abnormalities. Sixteen cases of suture periostitis were recorded, with varying degrees of new bone formation, and of 13 animals presented for evaluation of trauma, pre-diagnosed fractures were demonstrated in 10 and complications due to sinusitis in three.(ABSTRACT TRUNCATED AT 250 WORDS)     

Laser Vaporization of the Dorsal Turbinate as an Alternative Method of Accessing and Evaluating the Paranasal Sinuses

Objective: To report a technique for stoma creation into the conchofrontal sinus (CFS) through the dorsal turbinate and to evaluate stoma as a site for sinoscopy. Study Design: Prospective experimental study. Animals: Cadaveric equine heads (n=2) and normal adult horses (5). Methods: Technique feasibility was established on 2 cadaver heads. A diode laser fiber with a contact probe was passed into the nasal passage through a custom built, laser introducer rod (LIR). A videoendoscope was passed ventral to the LIR. A site on the caudal, medial aspect of the turbinate overlying the dorsal conchal sinus (DCS) was identified. A stoma to facilitate endoscope passage was created through the turbinate and sinoscopy performed to identify structures within the CFS and caudal maxillary sinus (CMS) and to evaluate the quality of the approach. The procedure was then performed in standing, sedated horses. Time required, laser energy used and complications were recorded. Endoscopy was performed ≥5 weeks postoperatively to assess stoma size and long‐term effects of the procedure. Results: A stoma was successfully created through the turbinate in both cadaveric skulls and in 4 horses; the stoma persisted for ≥5 weeks. The location of the stoma in 1 horse precluded sinoscopy. Conclusions: Laser vaporization of the dorsal turbinate through the nasal passage creates a stoma that lasts for at least 5 weeks providing a portal to the paranasal sinuses. Based on experience in 1 horse stoma location is critical to ensure adequate endoscope manipulation and sinoscopy. Clinical Relevance: Standing endoscopic sinusotomy within the nasal cavity through the DCS is an alternative to more invasive sinusotomy techniques with fewer potential complications and a cosmetic result.     

Cullen frontal sinus valved glaucoma shunt: preliminary findings in dogs with primary glaucoma

PURPOSE: To evaluate the efficacy of a novel, professionally manufactured, frontal sinus valved glaucoma shunt in maintaining normal intraocular pressure (IOP) and vision in dogs with primary glaucoma. METHODS: Three eyes of three dogs diagnosed with primary glaucoma were included in this prospective clinical study. A Cullen frontal sinus valved glaucoma shunt was implanted into each glaucomatous globe. Dogs were treated postoperatively with topical neomycin/polymyxin B/0.1% dexamethasone and 0.03% flurbiprofen every 6 h tapered over 8-12 weeks, and meloxicam at 0.1 mg/kg orally every 24 h for 7-10 days. IOP, intracameral shunt position and apparent patency, and vision were assessed twice daily for up to 4 (n= 3 eyes) and 10 (n= 2 eyes) days postoperatively, and then at re-examination periods of up to 36 weeks (n= 1 eye). Postoperative complications were recorded and documented photographically. RESULTS: Normal IOP was maintained in all shunted globes (range 10-29 mmHg; mean = 16.7 mmHg at 24 h; IOP = 23 mmHg at 36 weeks) postoperatively for 2 days (3/3 eyes), 8 weeks (2/2 eyes), and 36 weeks (1/1 eye) without additional antiglaucoma therapies. Photopic vision and shunt position and patency were maintained in all shunted globes for all follow-up periods. Postoperative complications included mild aqueous flare and fibrin (n= 3 eyes for 3-10 days postoperatively); intracameral shunt occlusion with fibrin (n= 1 eye at days 2 and 4); partial anterior chamber tube extrusion (n= 1 eye at day 4), and focal corneal edema (n= 1 eye at 18 weeks). Tissue plasminogen activator injected intracamerally through the silicone tube near the frontal sinus effectively resolved the fibrinous shunt occlusion. CONCLUSIONS: The Cullen frontal sinus valved glaucoma shunt shows promise for the management of canine primary glaucoma.