A Mobile Outside-in Technique of Transforaminal Lumbar Endoscopy for Lumbar Disc Herniations

Summary

Here we present a protocol of a novel outside-in technique of transforaminal endoscopic discectomy for lumbar disc herniations. The technical aspects of the technique, the wide indications of use, and the results of the treatment in 184 patients are described in detail.

Abstract

Percutaneous endoscopic transforaminal lumbar discectomy (PETLD) has now become a standard of care for the management of lumbar disc disease. There are two techniques for the introduction of a working cannula with respect to disc—outside-in and inside-out. The aim of this prospective study is to describe the technical aspects of a novel mobile outside-in method in dealing with different types of disc prolapse. A total of 184 consecutive patients with unilateral lower limb radiculopathy due to lumbar disc prolapse were operated on with the mobile outside-in technique of PETLD. Their clinical outcomes were evaluated based on the type of disc prolapse they had, a visual analog scale (VAS) leg pain score, the Oswestry Disability Index (ODI), and the Macnab criteria. The completeness of the decompression was documented with a postoperative magnetic resonance imaging. The mean age of the patients was 50 ± 16 years and the male/female ratio was 2:1. The mean follow-up was 19 ± 6 months. A total of 190 lumbar levels were operated on (L1–L2: n = 4, L2–L3: n = 17, L3–L4: n = 27, L4–5: n = 123, and L5–S1: n = 19). Divided into types, the patient distribution was central: n = 14, paracentral: n = 74, foraminal: n = 28, far lateral: n = 13, superior-migrated: n = 8, inferior migrated: n = 38, and high canal compromise: n = 9. The mean operative time was 35 ± 12 (25 - 56) min and the mean hospital stay was 1.2 ± 0.5 (1–3) days. The VAS score for leg pain improved from 7.5 ± 1 to 1.7 ± 0.9. The ODI improved from 70 ± 8.3 to 23 ± 5. According to the Macnab criteria, 75 patients (40.8%) had excellent results, 104 patients (56.5%) had good results, and 5 patients (2.7%) had fair results. Recurrence (including early and late) was seen in 15 out of the 190 levels that were operated on (7.89%). This article presents a novel outside-in approach that relies on a precise landing within the foramen in a mobile manner and does not solely depend upon the enlargement of the foramen. It is more versatile in application and useful in the management of all types of disc prolapse, even in severe canal compromise and high migration.

Introduction

Chronic low back pain and leg pain are common ailments in any society. The treatment modalities to combat degenerative lumbar disc diseases have been continuously evolving. The armamentarium has been wide, from open surgery and fixation to microlumbar discectomy, and now the endoscopic route^1,2,3,4. The transforaminal pathway, initially suggested by Parvez Kambin, is now gradually becoming a standard of care^5,6,7. The advantages of full-endoscopic s....

Protocol

The protocol follows the guidelines of Nanoori Hospital's human research ethics committee. A written informed consent was obtained from all the patients with unilateral lower limb radiculopathy due to lumbar disc prolapse. The exclusion criteria were the presence of segmental instability, spondylolisthesis (more than grade 1), and the presence of significant spinal stenosis.

1. Patient Position and Skin Marking

1. Place the patient in the prone position on the radiolucent operating table with the spine in slight flexion.
   NOTE: Indications for surgery in patients are as follows: intractable, frequently unilateral radiculo....

Results

Outcome Evaluation:

The outcome of the surgery was measured by the VAS leg pain score¹¹, the ODI¹², and the Macnab criteria¹³. These were measured in the preoperative period and during follow-up visits (1 week after the surgery, 3 months after the surgery, and at the last follow-up).

Discussion

The study is based on the prospective analysis of 184 patients with lumbar disc disease that were managed at our institute. X-ray imaging, computed tomography (CT), and magnetic resonance imaging (MRI) were done in all cases to confirm the diagnosis and to rule out other pathologies. The findings demonstrated on the CT and MRI scans were correlated with a neurologic examination. After the proper diagnosis, patients were operated on with the mobile outside-in technique of PETLD. The exclusion criteria were the presence of.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Contrast dye injection	Iobrix injection, Taejoon pharm,Seoul, Korea	S.No. 1
0.8% indigo carmine	Carmine, Korea United Pharmaceutical, Yoenki, Korea	S.No. 2
30° endoscope	Joimax GmbH, Germany	S.No. 3
Radiofrequency coagulator	Elliquence, New York, USA	S.No. 4
Drill	Primado 2 NSK, Tochigi, Japan	S.No. 5