Fluoroscopically guided neocanalization for treatment of nasolacrimal atresia in two horses

Abstract

Case description A yearling Thoroughbred stallion and an 8‐year‐old Saddlebred mare were evaluated for persistent mucoid ocular discharge. Clinical findings Examination of both horses revealed copious yellow‐tan mucoid ocular discharge with a negative Jones I test, absent nasal punctum, and unsuccessful anterograde nasolacrimal duct (NLD) irrigation. Clinical abnormalities were present on the right side only in one horse and bilaterally in the other. Computed tomography (CT) with contrast confirmed nasolacrimal duct atresia in both horses. Treatment and outcome Under general anesthesia, the affected NLD was catheterized anterograde and contrast injected. Using fluoroscopic guidance, retrograde access to the distal NLD was obtained for through‐and‐through wire access. Over the wire, the stoma was dilated and a temporary stent placed for 4‐8 weeks. After the procedure, both horses were comfortable and free of ocular discharge at the minimum time of last follow‐up, 9 months postoperatively. Clinical relevance Fluoroscopically guided neocanalization is a viable alternative to traditional surgical approaches for NLD atresia, especially when access to the site of obstruction is limited.

Endoscopic‐guided diagnosis of and interventional stent placement for nasolacrimal duct obstruction in a horse

“…The stent remains in place for 4–6 weeks 1 . However, as previous studies have demonstrated, horses often rub due to irritation from the stenting material, leading to early dislodgement and potential failure of the procedure 7,9 . Canaliculosinostomy has successfully redirected tear flow into the frontal and maxillofacial sinuses 2,7 .…”

“…Materials that have been reported to stent the equine NLD include red rubber catheters, 1,5 rigid open‐end ureteral stents, 9 and silastic or plastic canine urinary catheters 1,2 . These materials are often irritating, leading to early extrusion by the patient or owner intolerance 7,9 …”

“…5 Reported methods for correction of NLDO include application of topical corticosteroids and systemic anti-inflammatory medications to diminish swelling and widen the NLD lumen; placement of a stent after canaliculosinostomy 2,6 or canaliculorhinostomy 7 and laser ablation of NLD atresia with placement of a silicone feeding tube as stenting material. 8 Materials that have been reported to stent the equine NLD include red rubber catheters, 1,5 rigid open-end ureteral stents, 9 and silastic or plastic canine urinary catheters. 1,2 These materials are often irritating, leading to early extrusion by the patient or owner intolerance.…”

“…1,2 These materials are often irritating, leading to early extrusion by the patient or owner intolerance. 7,9 To better characterize the equine nasolacrimal system, Spadari et al performed endoscopic examination of the equine NLD using a 3 mm diameter endoscope. 10 They identified three distinct zones of the duct according to the mucosal surface and diameter of the lumen.…”

Stenting of a partially obstructed nasolacrimal duct using a steerable angle‐tipped hydrophilic guidewire in a cat

“…The nasolacrimal drainage system consists of the superior and inferior puncta, superior and inferior canaliculi, lacrimal sac, NL duct, and nasal puncta 1 . Various congenital and acquired diseases of the nasolacrimal duct system have been described in dogs, 2,3 rabbits, 4 cats, 5 horses, 6,7 and cattle 8 . The most common consequence of disorders of the NL duct is obstruction which results in epiphora and secondary facial dermatitis and tear staining.…”