Modified lateral enucleation technique-Surgery without ligation or clamping of the optic nerve: Technique description, complication rate and risk factors, and intraoperative blood loss estimation in companion animals.

Purpose: The purpose of this study is to describe modification of the lateral enucleation technique without ligation or clamping of the optic nerve, document the incidence of complications, estimate intraoperative blood loss and identify possible risk factors for the developments of complications.

Methods: Medical records of dogs, cats, and rabbits undergoing lateral enucleation without clamping of the optic nerve were identified and retrospectively reviewed for post-operative complications (2000-2022). The significance of possible risk factors for the development of complications, including species, sex, age, eye, surgeon, presumed ocular surface infection, cultures, follow-up, antibiotics, NSAIDs, complications and diabetes mellitus was examined in a subset of these patients (2019-2022). As a prospective study, intraoperative blood loss was estimated by gravimetric analysis in an additional subset.

Results: Records of 1296 enucleations were retrospectively reviewed and detailed evaluation regarding potential risk factors was performed in 446 enucleations. The overall complication rate and surgical site infection rate was 2.31% and 2.08% respectively. Only Pseudomonas spp. bacterial culture was associated with development of complications. Estimated relative intraoperative blood loss was 2.2% and 4.1% in 43 dogs and 29 cats respectively.

Conclusions: The modified lateral enucleation technique is a safe and fast procedure with minimal risk of postoperative complications in dogs, cats, and rabbits. Based on the anatomy of the orbital vasculature ligation or clamping of the optic nerve and surrounding tissue is contraindicated.