The interlaminar contralateral approach to far-lateral lumbar disc herniations: a singlecenter comparison with traditional techniques and literature review.

Background The interlaminar contralateral approach (ICA) is a promising surgical alternative for the treatment of far-lateral lumbar disc herniations (FLLDH). To date no study has compared ICA and FLLDH conventional surgical treatments, namely the intertransverse, the transmuscular and the intermuscular approaches, in terms of safety and outcome. Methods Patients who underwent FLLDH surgery at our Institution between January 2015 and September 2018 were reviewed. ICA complications and clinical outcomes were compared with those of conventional approaches at 1-month post-operatively and at the last follow-up available. Improvement was defined as reduction of at least two point in the visual analogue scale (VAS) or increase of at least 1 point in the Medical Research Council (MRC) scale of muscle strength. Patient-reported outcome was assessed with the Oswestry Disability Index (ODI). Results Among 38 patients, 18 underwent ICA and 20 a conventional approach (intertransverse in 16, transmuscular in 2, intermuscular in 2). Median follow-up was 21 months (range, 2-47). At 1 month, no differences between the two groups were noticed in terms of clinical outcome and symptoms relief (p> 0.05). The median post-operative ODI score was significantly lower in the Conventional approach group at 1 month (p 0.05). No differences were found between the two groups in surgical complication and recurrence rates. Conclusions Our data suggest that the ICA is a safe and effective alternative to conventional approaches in FLLDH surgery. Larger prospective studies are needed to confirm our results.