A multidisciplinary, minimally invasive approach combining lacrimoscopy and fluoroscopically guided stenting for management of nasolacrimal apparatus obstruction in dogs

A transconjunctival surgical technique for dacryocystotomy in dogs with foreign body-induced dacryocystitis

PURPOSE

The purpose of this study is to describe a simplified, less invasive dacryocystotomy technique that allows for complete inspection of the canine lacrimal sac and to retrospectively evaluate this surgical technique in a larger series of dogs. The anatomical background of the canine nasolacrimal system is described as a basis for the surgical technique.

METHODS

Records of dogs from 2003 to 2023 which were diagnosed with dacryocystitis due to presumed foreign body and underwent surgical exploration and removal of foreign bodies within the lacrimal sac using this technique were reviewed. Postoperative treatment and outcome were evaluated.

RESULTS

Records of 48 dogs were included. A foreign body was discovered during the surgery or upon retrieval of the catheter in 85% of cases (41/48). An indwelling catheter was placed in 83% of cases (40/48) for a median of 21 days. At the last recheck, the nasolacrimal duct was patent in 87% of the cases (41/47). The median follow-up time was 34 days (3-1255 days). The most commonly affected breeds were Golden retrievers (11) and dachshunds (8). The following complications occurred: two dogs removed or partly removed the catheter themselves (day 7, day 14), and one dog showed marked irritation at the catheter site which had to be removed by day 10.

CONCLUSIONS

The transconjunctival dacryocystotomy technique is simple and less invasive than other described techniques with a successful long-term outcome in the majority of cases.

Nasolacrimal sac foreign body extraction using vitreoretinal forceps in 28 dogs

PURPOSE

To describe a novel technique of nasolacrimal foreign body extraction in dogs by using a 20G vitreoretinal forceps introduced through the superior lacrimal punctum.

METHODS

A retrospective review of the medical records of dogs with dacryocystitis due to nasolacrimal foreign bodies between the years 2001 and 2022 was performed. We recorded the breed, age, affected eye, type and number of foreign bodies, concomitant diseases, and the use of imaging techniques. All animals underwent the same procedure of a 20G vitreoretinal forceps insertion through the upper canaliculus reaching the lacrimal sac and retrograde extraction of the foreign bodies.

RESULTS

A total of 28 dogs were included, 16 males and 12 females, with a mean (±SD) age of 4.7 (±3.2) years. The most common breeds were Wire-Haired Dachshund (4/28; 14.29%) and Labrador Retriever (3/28; 10.71%). Additional imaging techniques were used, such as orbital ultrasound in 13 cases (13/28; 46.43%) and computed tomography in one case (1/28; 3.57%). The most common type of foreign body retrieved was grass awns, although seeds and plant debris were also found. Dacryocystitis resolved after removal of the foreign body and appropriate medical therapy was ensured in all cases in the 1-month postprocedure follow-up.

CONCLUSION

Extraction of nasolacrimal foreign bodies with vitreoretinal forceps is a novel, noninvasive, and easily applicable technique that, although not successful in all cases, can be attempted before performing more aggressive surgery.

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

OBJECTIVE

This case report describes the successful correction of partial obstruction of the NL duct in a cat by means of a modified retrograde NL duct cannulation using a steerable angle-tipped hydrophilic guidewire (AH guidewire) following a paranasal incision.

ANIMAL STUDIED

A 2-year-old neutered male American domestic shorthair cat was referred to the Purdue University Veterinary Hospital (PUVH) for chronic epiphora suspected secondary to nasolacrimal (NL) system obstruction.

PROCEDURES

At the first visit, the cat had epiphora OD and facial dermatitis but no other abnormalities on physical and ophthalmic examinations. Computed tomography (CT)-dacryocystorhinography revealed partial obstruction of the NL duct secondary to stenosis near the distal root of the right maxillary third premolar (107). A digital three-dimensional (3D) model of the right maxilla and NL duct was created for inspection and virtual cannulation of the NL. The model was 3D printed and cannulation of the NL duct was rehearsed with various stent materials. Retrograde NL stenting with the guidance of a steerable angle-tipped hydrophilic guidewire was conducted following a paranasal incision. A urethral catheter was cannulated over the guidewire and maintained for 44 days.

RESULTS

The epiphora resolved immediately after stenting. At 21 days post-stenting, the cat developed acute bullous keratopathy secondary to self-trauma which was treated with a third eyelid flap. On the final follow-up communication with the owner at 210 days post-stenting, no epiphora or any other concerns were reported.

CONCLUSION

To the authors' knowledge, this is the first report of successful NL stenting and resolution of epiphora in a cat with a partial NL system obstruction.

Endoscopic diagnostic and surgical orbital approach in canines

The aim of this study is to describe new diagnostic and surgical orbital approaches using video endoscopy in canines. Four different endoscopic approaches were investigated in this study of video endoscopy in cadavers: dorsal transorbital ligament approach via incision of the orbital ligament (DTOLA), dorsal subpalpebral transconjunctival approach (DSTA), ventral subpalpebral transconjunctival approach (VSTA), and transoral orbital approach (TOA). Two additional approaches, the ventral transpalpebral approach (VTA) and dorsal caudal transmuscular approach (DCTA) along with the DTOLA and DSTA were used in clinical patients. The most technically demanding approach was DTOLA; however, it provided the best visualisation of different anterior and posterior orbital structures. Visualisation of primarily the dorsal orbital wall, dorsal portion of the eye globe, and dorsal extraconal space also was achieved by DSTA. The VSTA enabled good visualisation of the ventral orbital floor and the ventral extraconal and intraconal space. In contrast, the TOA provided relatively poor visualisation of orbital structures, limited to the ventral orbital quadrant. Meanwhile, the VTA provided visualisation similar to the VSTA, while DCTA visualisation was limited to the dorsal and caudal orbital space. Orbital endoscopy is an effective and minimally invasive procedure that can be used for diagnostic and surgical orbital procedures.

Dacryocystitis in dogs caused by foreign bodies-Diagnosis and therapy in 14 Cases

OBJECTIVE

To describe foreign bodies (FBs) in the nasolacrimal sac of dogs, the history, and simple diagnostic and therapeutic approaches. Animals studied Fourteen dogs of different breeds, ages, and sexes were presented with unilateral dacryocystitis and had been treated without success for over 1-8 months.

PROCEDURES

Patient history, including prior treatment, was obtained from medical records. Slit-lamp examination was performed in all cases (SL 17, Kowa Company Ltd.). Jones tests 1 and/or 2 were performed in 13/14 cases. Dacryocystotomy was initiated with an incision into one canaliculus until the lacrimal sac was exposed and could be explored. After extracting the FB from the nasolacrimal sac, the surgical wound and canaliculus were left open. Aftercare included the administration of antibiotic eye drops with or without dexamethasone and systemic analgesia.

RESULTS

All 14 dogs were mesocephalic. Four of them were Dachshunds. Dacryocystotomy revealed plant-related FBs in all cases. The purulent discharge disappeared immediately after removal and did not recur during follow-up.

CONCLUSIONS

A simple dacryocystotomy is recommended for dogs with a strong suspicion of a foreign body in the lacrimal drainage system. Dacryocystorhinography appears to be an optional tool in these cases.

Evaluation of the upper and lower proximal lacrimal canaliculi using spectral-domain optical coherence tomography in normal Beagle dogs

OBJECTIVE

To confirm the feasibility of visualizing upper and lower proximal lacrimal canaliculi (LC) using spectral-domain optical coherence tomography (SD-OCT).

ANIMALS STUDIED

Eight eyes of four normal Beagle dogs.

PROCEDURES

To obtain an upper proximal LC image, the head was turned in the opposite direction to the eye being imaged, and the medial part of the upper eyelid was everted to expose the LC. To obtain a lower LC image, the lower eyelid was everted just below the punctum. Using "angle mode", the scan line was placed parallel on the long axis of the LC. The inlet LC width (LCW) was measured. Artificial tears (AT) were instilled, and LCW was compared before and after AT instillation. Additionally, the return time to the initial LCW inlet width was recorded.

RESULTS

Before AT instillation, there was a significant difference between the mean upper and lower LCW (91.8 ± 3.2 µm and 110.1 ± 8.4 µm, respectively). After AT instillation, the mean upper and lower LCW were 236.9 ± 27.7 µm and 238.4 ± 30.4 µm, respectively. Significant differences in the LCW before and after AT instillation in both the upper and lower LCWs were observed. The mean return time of the upper and lower LCW to their initial widths after AT instillation was within 4 min.

CONCLUSIONS

Spectral-domain optical coherence tomography was an effective method for providing high-resolution images of the upper and lower proximal LC. This method enables observation of LC changes after instillation of eyedrops in veterinary clinical practice.

Dacryoendoscopy for dacryocystitis management in a dog: A case report

A castrated, mixed‐breed, 10‐year‐old male dog developed a skin fistula from a ruptured periorbital swelling on the right eye; the patient was successfully treated with dacryoendoscope‐guided cannulation using a nasolacrimal tube. On presentation, computed tomography with concurrent dacryocystography (CT‐DCG) revealed obstruction of the right nasolacrimal duct and abnormal flow of contrast agents towards the root of tooth 109 at the right maxillary bone; however, the origin of the fistula remained unclear on CT‐DCG. Dacryoendoscopy was used to confirm the physical association between the fistula and the nasolacrimal duct; the fistula end was found to be near the right upper gum mucosa around tooth 107. CT‐DCG and dacryoendoscopy revealed that the periorbital swelling occurred owing to an infection or inflammation of the accessory nasolacrimal duct. The fistula end was connected to the oral cavity through a nasolacrimal tube installed in the oral mucosa. The tube was removed a week later, and the clinical symptoms completely resolved.

Canaliculorhinostomy as a treatment for nasolacrimal duct obstruction in dogs and cats

OBJECTIVES

To create a replacement nasolacrimal system, using the puncta and canaliculi, with prolonged implant retention and minimal use of Elizabethan collars or other restraint devices.

MATERIALS AND METHODS

The method was used in 11 dogs and two cats. Silicone tubing was placed through both canaliculi and, via a drill hole, into the nasal cavity. Distally, the tubing ends were tied in a subcutaneous pocket lateral to the premaxilla. Tubing retention time was 4 to 7 months. Elizabethan collars were used only until skin suture removal at 2 weeks.

RESULTS

In all animals, a functional nasolacrimal system was re-created and remained patent over prolonged follow-up periods. Adverse effects and complications were mild.

CLINICAL SIGNIFICANCE

The described method is relatively straightforward, thereby making relief of tear outflow problems widely accessible.