[Effect and effectiveness analysis of different approaches of transforaminal endoscope on extirpation amount of nuclues pulposus]

Objective: To investigate the effect and effectiveness analysis of different approaches of transforaminal endoscope on extirpation amount of nuclues pulposus.

Methods: Between August 2011 and December 2014, a total of 165 patients with lumbar disc herniation were retrospectively enrolled and were treated with nucleus pulposus discectomy through transforaminal endoscope. The patients were randomly divided into 4 groups according to different approach of transforaminal endoscope. The posterolateral approach (Yeung's technology) was used in group A (42 cases), transforaminal endoscopic spine system (TESSYS) technology was used in group B (40 cases), improved transforaminal endoscopic access (ITEA) technology was used in group C (43 cases), and interlaminar approach (40 cases) was used in group D (40 cases). There was no significant difference in gender, age, disease duration, symptomatic side, and segments among 4 groups ( P>0.05). The extirpation amount of nuclues pulposus was calculated and compared among 4 groups; the effectiveness was evaluated by pre- and post-operative visual analogue scale (VAS) score, Oswestry disability index (ODI), lumbar curvature index (LCI), and intervertebral height.

Results: The discectomy amount of nucleus pulposus was (3.7±0.8), (3.6±0.7), (4.5±1.1), and (3.0±0.8) cm ³ in groups A, B, C, and D, respectively. The amount of group C was significantly larger than that of the other 3 groups ( P<0.05), and the amount of group D was significantly smaller than that of the other 3 groups ( P<0.05); no significant difference was found between groups A and B ( P>0.05). Cerebrospinal fluid leakage was found in 1 case; no other postoperative complications including intervertebral space infection and epidural hematoma was found. All the incisions healed by first intension. All the patients were followed up 12-24 months (mean, 18 months), and no typical symptoms of recurrence was found during the follow-up period. There was no significant difference in preoperative lower back pain VAS score, lower extremities VAS score, and ODI scores among 4 groups ( P>0.05). The above scores at last follow-up were significantly improved when compared with preoperative ones in each group ( P<0.05), but no significant difference of above scores and recovery values was found among 4 groups ( P>0.05). The difference in LCI and intervertebral height at preoperation and at last follow-up were not significant between 4 groups ( P>0.05). The difference in LCI and intervertebral height of each group between at preoperation and last follow-up were not significant ( P>0.05). And the recovery value of LCI and the lost of height at last follow-up also showed no significant differences between 4 groups ( P>0.05).

Conclusion: The ITEA technology can give a wider field of view than other technologies. It is more convenient to find and remove the nucleus pulposus. However, the appropriate operative approaches should be chosen according to the symptoms and characteristics of lumbar disc herniation.