Clinical and radiological outcomes following insertion of a novel removable percutaneous interspinous process spacer: an initial experience

Abstract

Purpose: To evaluate clinical and radiological outcomes of a series of patients treated with a removable percutaneous interspinous process spacer (IPS) (LobsterProject® Techlamed®) for symptomatic degenerative lumbar spinal stenosis (DLSS).

Methods: All patients treated in two centres with this IPS during 2019 were retrospectively reviewed. Procedures were performed under deep sedation or general anaesthesia by two interventional radiologists. Patients were clinically evaluated before intervention and at 3-month follow-up with Visual Analog Scales for pain (VAS), Oswestry Disability Index (ODI) and radiologically with MRI or CT scans. Neural foramina were independently measured for each patient on pre- and post-procedural CT scans by two radiologists.

Results: Fifty-nine patients were treated in the selected period of which fifty-eight had complete documentation (mean age 71.2 ± 9.2 years [55-92], 32 males, 26 females). Forty-eight interventions were performed under deep sedation and ten under general anaesthesia, without procedural complications. Clinical follow-up at 3 months showed a significant reduction of pain (VAS from 83 ± 9 to 29 ± 19, - 65%; p < 0.001) and an improvement in functional outcomes (ODI from 31 ± 12 to 13 ± 10%, - 58%; p < 0.001). There was one case of unsatisfactory positioning post procedure, two cases of posterior migration at 3-month follow-up and one case of spinous process fracture. Mean neural foramina area increased from 77 ± 23 to 95 ± 27 mm² (+ 26%; p < 0.001) with very good inter-observer reliability (Cronbach's alpha = 0.899).

Conclusion: Percutaneous minimally invasive insertion of a removable IPS device demonstrates a favourable safety profile, good clinical outcomes at 3 months, and apparent anatomical increase in foraminal dimensions.

Trial registration: ClinicalTrials.gov Identifier: NCT05203666-Release Date: 21^st January 2022, retrospectively registered.

Keywords: Computed tomography; Intermittent claudication; Interspinous spacer; Interventional radiology; Spinal stenosis.