Percutaneous Endoscopic Lumbar Discectomy for Highly Migrated Lumbar Disc Herniation.

BACKGROUND Percutaneous endoscopic lumbar discectomy (PELD) has been growing in popularity for the treatment of lumbar disc herniation (LDH) due to its irreplaceable advantages over conventional open surgery. Compared with common lumbar disc herniations, discectomy of highly migrated LDH by PELD is known to be very difficult. Highly migrated lumbar disc herniation has long been a challenge for its specific characteristics. Three approaches for PELD have been applied to access a highly migrated LDH, including an interlaminar approach (IL), transforaminal approach (TF), and contralateral transforaminal approach (CTF). However, none of the existing research has systematically described the selection of the most appropriate procedure from the 3 approaches or the individualization of an operative procedure in different cases. OBJECTIVES The purpose of this study was to present a detailed surgical approach selection and individualization of procedure in the treatment of highly migrated LDH with PELD. We also mean to compare the outcomes of patients with highly migrated LDH treated with PELD by the 3 approaches. STUDY DESIGN Single-center retrospective observational study. SETTING An interventional pain management practice, a medical center, major metropolitan city, China. METHODS In our retrospective analysis between March 2011 and March 2013, 73 patients with single level highly migrated LDH received PELD. Clinical outcomes were assessed with the visual analogue scale (VAS) score, the modified MacNab criteria, and the Oswestry disability index (ODI). Relevant data such as operation duration and fluoroscopy frequency of the 3 operative approaches were recorded. RESULTS The mean operating time of IL was 56 minutes, compared with 64 minutes for TF and 112 minutes for CTF. The mean intraoperative fluoroscopy times were 5.5 for IL, 9.7 for TF, and 14.6 for CTF. In each group, the mean VAS and ODI after surgery and 3 months after surgery improved dramatically compared with preoperative counterparts. However, the difference between postoperative results and the results 3 months after surgery was not significant (P > 0.05). The overall excellent rate was 90.4% according to the modified MacNab criteria; there was no significant statistical difference between the 3 operative routes. Operative complications occurred in 3 patients (2 after IL and one after CTF, 3 of 73, 4.1%). LIMITATIONS This study is limited by its sample size. CONCLUSION In our research, PELD with all 3 approaches was similarly effective to highly migrated disc herniation. The CTF approach required the longest operation duration and the most intraoperative times. On the contrary, the least operation time and radiographfrequency was required with the IL approach. In addition, we came to a conclusion of surgery approach selection when it comes to varied HM-LDH. Key words: Highly migrated, lumbar disc herniation, percutaneous endoscopic lumbar discectomy, minimally invasive treatment.