Iatrogenic Nasolacrimal Duct Obstruction following Tooth Extraction in a Cat

Abstract

A 10-year-old DSH cat was referred for a dental evaluation and extraction procedure. Subsequently, the animal developed an acute onset of ocular discharge. Ophthalmologic examination revealed presence of unilateral ocular mucoid discharge leading to a diagnosis of epiphora secondary to nasolacrimal duct obstruction. Dacryocystorhinography was performed and confirmed the presence of a nasolacrimal duct obstruction, presumably acquired after an invasive dental procedure. Additionally, a vinyl cast in situ study of the nasolacrymal apparatus was performed to demonstrate the route of the nasolacrimal duct in the cat and its relationship to oral dental structures. This report documents an unusual case in which excessive inflammation/edema following tooth extraction caused acute epiphora secondary to extraluminal compression of the distal nasolacrimal duct.

Anatomy of the nasolacrimal duct in Persian cats determined by computed tomographic dacryocystography

“…31,32 Iatrogenic complications inherent to tooth extraction in this region may also cause an extramural NLD obstruction. 1,7,12,13,31 Normal NLD duct trajectory and width is thought to determine lacrimal drainage efficiency. 1,11,33 Larger NLD width in this sample was similar to other brachycephalic cats, so it is possible that stenosis observed could play a role in epiphora development in this breed.…”

“…Anatomical proximity between these structures and potential extramural lacrimal sac compression support cause-effect relationships between lacrimal sac inflammation and pathological conditions affecting the nasal or oral cavity, such as ectopic teeth and nasal tumors and cysts, 3,27,38 the influences of nasal mucosal inflammations, 3 and tooth extraction. 13 Abnormal tear drainage into the caudal aspect of the nasal cavity/nasopharynx or the oral cavity has been reported in brachycephalic dogs, 33 and in underexplored in brachycephalic cats. 21 However, in a study with 36 nonbrachycephalic cats, the nasolacrimal duct drained into the ventrolateral aspect of the nasal vestibulum floor, below the alar fold, and no anomalous openings were found.…”

“…complete or incomplete duct and caniculi obstruction, stenosis, lacrimal fistulae and diverticula and extramural compression by neoplastic masses. 3 This imaging modality has been used to examine normal nasolacrimal duct anatomy and width in bone specimens 1,3 and in studies investigating nasolacrimal duct abnormalities in humans, [4][5][6] dogs, 7,8 buffaloes, 9 llamas, 10 cats, [11][12][13] dromedaries, 14 rabbits, 15 horses, 16 and cattle. 17,18 The head conformation 19 and its influence on the course of the NLD 1 were stated in cats, and sex and agerelated differences in NLD width measured using direct computed tomography have been reported in humans.…”

Applied Feline Oral Anatomy and Tooth Extraction Techniques

“…3 instrument slippage could cause local or distant soft tissue trauma or injury to the operator or assistant. [24][25][26] < Sublingual edema iatrogenic trauma or excessive pharyngeal packing can result in sublingual edema. intravenous dexamethasone may be administered if respiratory compromise is present.…”

“…developing permanent teeth could be injured when extracting adjacent deciduous teeth.3 instrument slippage could cause local or distant soft tissue trauma or injury to the operator or assistant. 24–26…”