Clinical outcome of biportal endoscopic revisional lumbar discectomy for recurrent lumbar disc herniation

Abstract

Background: Although literature provides evidence regarding the superiority of surgery over conservative treatment in patients with lumbar disc herniation, recurrent lumbar disc herniation (RLDH) was the indication for reoperation in 62% of the cases. The major problem with revisional lumbar discectomy (RLD) is that the epidural scar tissue is not clearly isolated from the boundaries of the dura matter and nerve roots; therefore, unintended durotomy and nerve root injury may occur. The biportal endoscopic (BE) technique is a newly emerging minimally invasive spine surgical modality. However, clinical evidence regarding BE-RLD remains limited. We aimed to compare the clinical outcomes after performing open microscopic (OM)-RLD and BE-RLD to evaluate the feasibility of BE-RLD.

Methods: This retrospective study included 36 patients who were diagnosed with RLDH and underwent OM-RLD and BE-RLD. RLDH is defined as the presence of herniated disc material at the level previously operated upon in patients who have experienced a pain-free phase for more than 6 months. BE-RLD was performed as follows: two independent surgical ports were made inside the medial pedicular line of the target segment and on the intact upper and lower laminas. Peeling off the soft tissue from the vertebral lamina helps to easily identify the traversing nerve root and the recurrent disc material without dealing with the fibrotic scar tissue. Clinical outcomes were obtained using a visual analog scale (VAS) and the modified Macnab criteria before and at 2 days, 2 and 6 weeks, and 3, 6, and 12 months after surgery.

Results: The data of 20 and 16 patients who underwent OM-RLD and BE-RLD, respectively, were evaluated. The demographic and perioperative data were comparable between the groups. During the year following the surgery, in the BE-RLD group, the VAS scores at each point were significantly improved over the baseline and remained improved up to 2 weeks after surgery (p < 0.05); however, no statistical difference between the two groups was observed after 6 weeks of surgery (p > 0.05). According to the modified Macnab criteria on the follow-up, the excellent or good satisfaction rates reported at 2 weeks, 6 weeks, 6 months, and 12 months after surgery were 81.25%, 81.25%, 75%, and 81.25%, respectively, in the BE-RLD group, and 50%, 75%, 75%, and 80%, respectively, in the OM-RLD group.

Conclusion: BE-RLD yielded similar outcomes to OM-RLD, including pain improvement, functional improvement, and patient satisfaction, at 1 year after surgery. However, faster pain relief, earlier functional recovery, and better patient satisfaction were observed when applying BE-LRD.

Trial registration: Retrospectively registered.

Keywords: Biportal endoscopic; Lumbosacral radiculopathy; Open microscopic; Recurrent lumbar disc herniation; Revisional lumbar discectomy.

Fig. 1

Location of the surgical portal. a The viewing and working surgical ports (bold line) were made right inside the medial pedicular line of the target segment and above the intact upper and lower laminas. These were located more lateral than the ports made during conventional biportal endoscopic discectomy (dotted line). b Direct access to the lamina and the facet joint was made to complete the red vision discectomy with minimal laminotomy (triangle). c Clinical photographs show independent surgical ports on the outside of the previous midline incision site

Fig. 2

a Mimetic diagram of lumbar revision discectomy. b The placement of surgical ports laterally with respect to those of the conventional method helps to easily access the epidural space (white bar) without dealing with the fibrotic tissue (red star). c Decompressive laminectomy was performed

Fig. 3

Case presentation: A 39-year-old man with right subarticular recurrent lumbar disc herniation at L4–L5 and L5–S1. a Magnetic resonance imaging (MRI) of the right subarticular protruded lumbar disc herniation in the first event. b Postoperative MRI after primary open lumbar microdiscectomy. c MRI of the recurrent lumbar disc herniation at the same level and direction at 2.5 years after the virgin surgery. d Postoperative MRI after biportal endoscopic lumbar redo discectomy: adequate decompression of the sequestrated nucleus and preservation of the facet joint. MRI magnetic resonance imaging

Fig. 4

Changes in clinical outcomes between the two surgeries during the 12-month follow-up period

Fig. 5

Changes in the ratio of “good” and “excellent,” according to the modified Macnab criteria