Microscopic extra-laminar sequestrectomy (MELS) for the treatment of hidden zone lumbar disc herniation: report of the surgical technique, patient selection, and clinical outcomes [post]

Chunxiao Wang, Yao Zhang, Xiaojie Tang, Haifei Cao, Qinyong Song, Jiangwei Tan, Chengzhen Jin, Hongkai Song
2020 unpublished
Background Surgical management of lumbar disc herniation in the hidden zone is technically challenging due to its difficult surgical exposure. The conventional interlaminar approach harbors the potential risk of post-surgical instability, while other approaches consist of complicated procedures with a steep learning curve and prolonged operation time. Objective To introduce a safe and effective technique named microscopic extra-laminar sequestrectomy (MELS) for treatment of hidden zone lumbar
more » ... sc herniation and present clinical outcomes within a two year follow-up period. Methods Between Jan 2016 to Jan 2018, twenty one patients (13 males) with hidden zone lumbar disc herniation were enrolled in this study. All patients underwent MELS (19 patients underwent sequestrectomy only, 2 patients underwent an additional inferior discectomy). The nerve root and herniated fragment were visually exposed using this extra-laminar approach. The operation duration, blood loss, intra- and postoperative complications, and recurrences were recorded. The Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and the modified MacNab criteria were used to evaluate clinical outcomes. Postoperative stability was evaluated both radiologically and clinically. Results The mean follow-up period was 20.95 ± 2.09 months, ranging from 18 to 24 months. The mean operation time was 32.43 ± 7.19 min and the mean blood loss was 25.52 ± 5.37 ml. All patients showed complete neurological symptom relief after surgery. The VAS and ODI score were significantly improved at the final follow-up compared to those before operation (7.88 ± 0.70 vs 0.10 ± 0.30, 59.24 ± 10.83 vs 11.29 ± 3.59, respectively, p < 0.05). Seventeen patients (81%) obtained an "excellent" outcome and the remaining four (19%) patients obtained a "good" outcome based the MacNab criteria. One patient suffered reherniation at the same level one year after the initial surgery and underwent a transforaminal endoscopic discectomy. No major complications and postoperative instability were observed. Conclusions Our observation suggest that MELS is a safe and effective method in the management of hidden zone lumbar disc herniation. Due to its relative simplicity, it comprises a flat surgical learning curve and shorter operation duration, and overall results in reduced disturbance to lumbar stability.
doi:10.21203/rs.3.rs-37318/v1 fatcat:22pzioe6qfesxhnedlry6bmosu