An algorithm for selection of full endoscopic approach for symptomatic nerve root decompression

Prasad Patgaonkar; Vaibhav Goyal; Pratik Patel; Kiran Dhole; Achyut Ravi; Vivek Patel; Pushkar Borole

doi:10.1016/j.xnsj.2023.100244

An algorithm for selection of full endoscopic approach for symptomatic nerve root decompression

N Am Spine Soc J. 2023 Jul 16:15:100244. doi: 10.1016/j.xnsj.2023.100244. eCollection 2023 Sep.

Authors

Prasad Patgaonkar¹, Vaibhav Goyal¹, Pratik Patel¹, Kiran Dhole¹, Achyut Ravi¹, Vivek Patel¹, Pushkar Borole¹

Affiliation

¹ Indore Spine Centre, 5-6 RS Bhandari Marg, Indore, Madhya Pradesh 452009, India.

Abstract

Background context: Both Transforaminal (TF) and Interlaminar (IL) endoscopic approaches are established techniques of decompression for lumbar compressive radiculopathy. In the absence of adequate literature, there is always some dilemma in selecting the approach for endoscopic decompression leading to long learning curves and high chances of inadequate decompression, iatrogenic instability, dural tear, or dysesthesia. Hence authors propose a new surgical nomenclature and algorithm for selection of endoscopic approach.

Methods: This retrospective study included 396 of 626 consecutive patients who met the inclusion criteria, who underwent either TF (n=302) or IL (n=202) full endoscopic spine surgery. MRI findings of every patient were classified as per FAPDIS (Facet angle, Anterior pathology, Posterior pathology, Dorsal, Inferior, and Superior migration) algorithm. Inter-observer variations were calculated. The targeted nomenclature was used to define the selection of endoscopic TF or IL approach for symptomatic nerve root decompression. All patients were followed up for preop and postop 6 months VAS and Oswestry Disability Index score for validation of FAPDIS algorithm.

Results: Median age: 46.8 years; Sides and levels operated 330 single-level ipsilateral, 54 multiple-level ipsilateral, 6 single-level bilateral, and 6 multiple-level bilateral. Interobserver agreement in the selection of TF approach was 0.873 and IL approach was 0.882. Interobserver variability was also calculated for each FAPDIS factor, selection of P3 and P4 pathology was the main reason for disagreement. All other FAPDIS factors show good to excellent correlation. The overall VAS score decreased from a preoperative value of 9 to 1 at 6 months follow-up (p-value < 0.001), and the overall Oswestry Disability Index score improved from 89 to 12 (p-value <.001).

Conclusions: The author's new FAPDIS surgical nomenclature and algorithm is a reliable tool for describing the symptomatic nerve root compression for the selection of endoscopic surgical approach to achieve adequate decompression of offending neural structure with minimum challenges to minimize perioperative complication rate.

Keywords: Algorithm; Approach selection; FAPDIS; Full endoscopic spine surgery; Interlaminar; Transforaminal.