Percutaneous transforaminal endoscopic decompression with removal of the posterosuperior region underneath the slipping vertebral body for lumbar spinal stenosis with degenerative lumbar spondylolisthesis: a retrospective study

Abstract

Background: Percutaneous transforaminal endoscopic decompression (PTED) is an ideal minimally invasive decompression technique for the treatment of lumbar spinal stenosis (LSS) with degenerative lumbar spondylolisthesis (DLS). The posterosuperior region underneath the slipping vertebral body (PRSVB) formed by DLS is an important factor exacerbating LSS in patients. Therefore, the necessity of removing the PRSVB during ventral decompression remains to be discussed. This study aimed to describe the procedure of PTED combined with the removal of the PRSVB and to evaluate the clinical outcomes.

Methods: LSS with DLS was diagnosed in 44 consecutive patients at our institution from January 2019 to July 2021, and they underwent PTED combined with the removal of the PRSVB. All patients were followed up for at least 12 months. The clinical outcomes were evaluated using the visual analog scale (VAS), Oswestry Disability Index (ODI), and modified MacNab criteria.

Results: The mean age of the patients was 69.5 ± 7.1 years. The mean preoperative ODI score, VAS score of the low back, and VAS score of the leg were 68.3 ± 10.8, 5.8 ± 1.0, and 7.7 ± 1.1, respectively, which improved to 18.8 ± 5.0, 1.4 ± 0.8, and 1.6 ± 0.7, respectively, at 12 months postoperatively. The proportion of patients presenting "good" and "excellent" ratings according to the modified MacNab criteria was 93.2%. The percent slippage in spondylolisthesis preoperatively (16.0% ± 3.3%) and at the end of follow-up (15.8% ± 3.3%) did not differ significantly (p>0.05). One patient had a dural tear, and one patient had postoperative dysesthesia.

Conclusions: Increasing the removal of PRSVB during the PTED process may be a beneficial surgical procedure for alleviating clinical symptoms in patients with LSS and DLS. However, long-term follow-up is needed to study clinical effects.

Keywords: Bone drill; Degenerative lumbar spondylolisthesis; Local anesthesia; Lumbar spinal stenosis; Percutaneous transforaminal endoscopic decompression; Posterosuperior region underneath the slipping vertebral body.

Fig. 1

Intraoperative perspective images for establishing work channels. Sagittal (A) and anteroposterior (B) fluoroscopic images of the Tom Shidi. 6 mm bone drill (C and D) and 8 mm bone drill (E and F) were used to remove the soft and osseous tissues. Sagittal (G) and anteroposterior (H) fluoroscopic images of the working cannula

Fig. 2

Intraoperative endoscopic views. (A and B) The PRSVB was removed with an endoscopic bone knife. (C and D) Dorsal and ventral L5 nerve roots were fully decompressed. The black arrow represents the PRSVB. The white arrow represents the superior articular process of L5

Fig. 3

Pre- and postoperative MRI. (A) Preoperative MRI showed that DLS caused a posterosuperior protruded compression underneath the slipping vertebral body in the lumbar spinal canal, forming a stepped shape (white arrow). (D) The central spinal canal stenosis, foraminal stenosis and lateral recess stenosis (white circle). (B, E) On the third day after operation, the MRI revealed the PRSVB were fully removed (white arrow), and lateral recess, foramen and the central spinal canal were enlarged (white circle). (C, F) The MRI examination showed no evidence of significant further compression at the twelve months after surgery

Fig. 4

Pre- and postoperative CT. (A, B) Preoperative CT showed that the PRSVB (white arrow), the central spinal canal stenosis, foraminal stenosis and lateral recess stenosis (white circle). (C, D) On the third day after operation, the CT showed complete decompression of the nerves and removal of PRSVB (white arrow). The ventral and dorsal edges of the spinal canal became smooth and continuous. The lateral recess, foramen, and central spinal canal were enlarged (white circle)

Fig. 5

Clinical outcomes before and after PTED at different follow-up time points. (A) VAS scores for low back pain. (B) VAS scores for leg pain. (C) ODI scores before and after PTED. (D) Outcome of the modified MacNab criteria. # #P < 0.01 vs. pre‑operation group

Fig. 6

Percent slip of spondylolisthesis before surgery and at final follow-up was compared. No statistically significant differences were observed between them (P > 0.05)

Fig. 7

Illustrations of the endoscopic decompression procedure. (A, C) The special pathological compression of DLS with LSS was shown on the sagittal (A) and cross-sectional planes (C), (B, D) The PRSVB and hypertrophic LF were removed under endoscopy. The final view of the state of nerve decompression and the enlargement of spinal canal, foramen and lateral recess