Comparison of percutaneous endoscopic and standard open mini-hemilaminectomy in cats – a prospective, controlled, paired cadaver study

The purpose of this study was to evaluate the feasibility and operative outcomes of percutaneous endoscopic mini-hemilaminectomy (PE-MHL) compared to standard open mini-hemilaminectomy (SO-MHL) in feline cadavers. A prospective, controlled, paired cadaver study was conducted using fifteen skeletally mature domestic short-haired cat cadavers (median body weight 3.9 kg). At the L4–L5 intervertebral space, PE-MHL was performed on the left and SO-MHL on the right side. Times for fluoroscopic localization, approach, spinal cord exposure and closure were recorded. Incision length, suture length, and bone window area were measured. Bone windows were assessed by postoperative CT. Mixed-effects models compared techniques and evaluated procedure times across cases as a potential indicator of surgical improvement. All 30 procedures provided full visualization of spinal cord, nerve root and ventral aspect of the vertebral canal. Mean ± standard error of the mean (SEM) of total surgical time was longer for PE-MHL than SO-MHL (65.4 ± 3.5 min vs. 30.3 ± 0.2 min), owing chiefly to longer exposure time; modelling predicted time parity after 20 PE-MHL cases. PE-MHL produced smaller skin incisions (8.5 ± 0.2 mm vs. 22.1 ± 0.5 mm), closure lengths (11.4 ± 0.5 mm vs. 23.1 ± 0.7 mm) and bone-window areas (51.3 ± 1.7 mm² vs. 64.7 ± 2.2 mm²). PE-MHL resulted in a single nerve-root injury. No other complications were observed. Percutaneous endoscopic mini-hemilaminectomy is technically feasible in the feline lumbar spine. Procedure times decreased with increasing number of cases and experience. The results support further prospective evaluation of PE-MHL in clinical feline patients.