Short-term effectiveness of percutaneous endoscopic transforaminal bilateral decompression for severe central lumbar spinal stenosis

Abstract

To observe the effectiveness and safety of percutaneous endoscopic transforaminal bilateral decompression for severe central lumbar spinal stenosis. A retrospective analysis of 44 patients with single-segment severe central lumbar spinal stenosis with bilateral lower extremity symptoms between October 2015 and December 2017 was performed. Among them, 36 cases underwent bilateral decompression through bilateral transforaminal approach, and 8 cases underwent bilateral decompression through unilateral transforaminal approach. There were 25 males and 19 females, the age ranged from 56 to 89 years with an average of 68.6 years. The disease duration was 5-39 months with an average of 14.5 months. Involved segments: L 3, 4 in 6 cases, L 4, 5 in 33 cases, and L 5, S 1 in 5 cases. The dural sac cross-sectional area (DSCA) of the MRI was (66.36±8.48) mm 2. Morphological grading (MG) classification: 29 cases of grade C, 15 cases of grade D. The visual analogue scale (VAS) score of preoperative low back pain was 2.3±1.0 and the VAS score of lower extremity pain was 7.8±1.2; the Oswestry disability index (ODI) was 77.8±7.3. Postoperative VAS scores, ODI scores, MG classification, and DSCA were recorded and compared with preoperative ones, and clinical outcomes were assessed by using the modified MacNab criteria. All patients successfully underwent surgery and the wounds healed by first intention. All 44 patients were followed up 13-46 months with an average of 24.8 months. One patient developed postoperative lower extremity paralysis and 1 patient developed a dural tear. There was no infection, recurrence, or revision surgery during the follow-up. Postoperative imaging showed that the central spinal canal was enlarged and the area of the dural sac was significantly increased compared with preoperative one. The VAS score of low back pain was 2.4±0.6 and 2.5±0.8 at 1 month after operation and at last follow-up, showing no significant difference when compared with preoperative scores ( P>0.05). The VAS of lower limb pain was 2.1±0.6 and 2.0±1.1 at 1 month after operation and at last follow-up, which was significantly improved when compared with preoperative scores ( P<0.05); but no significant difference was found between at 1 month after operation and at last follow-up ( P>0.05). At last follow-up, the ODI score was 19.7±6.4, and the DSCA was (104.93±12.56) mm 2, which was significantly improved when compared with preoperative values ( P<0.05). The MG classification was also significantly higher than preoperative one ( Z=-5.789, P=0.000). According to the modified MacNab criteria, the results were excellent in 32 cases, good in 9 cases, and fair in 3 cases, with an excellent and good rate of 93.2%. Percutaneous endoscopic transforaminal bilateral decompression for treating severe central lumbar spinal stenosis has the advantages of less trauma, adequate decompression, and rapid recovery. The short-term effectiveness is good.