Comparison of 3 Anesthetic Methods for Percutaneous Transforaminal Endoscopic Discectomy: A Prospective Study

Background: Percutaneous transforaminal endoscopic discectomy (PTED) under local anesthesia (LA) is growing popular in recent years because of its safety, effectiveness and increased patient demands for minimally invasive procedures. To avoid neural injuries, local anesthesia that can keep the patient conscious is recommended. However, many patients complain about the severe pain during surgery. Epidural anesthesia (EA) is an alternative choice. We put forward an anesthetic method that combined preemptive analgesia (PA) and local anesthesia. Objectives: The study aimed to assess the effectiveness of 3 methods of anesthesia for PIED, LA, EA and PA. Study Design: A prospective study. Methods: Three groups of patients were treated with standard PIED under LA, PA or EA, respectively. The data collected for analysis were operative time, x-ray exposure time, postoperative bed time, visual analog scale (VAS), Oswestry Back Pain Disability Index (ODI), the global outcome based on the Macnab outcome criteria, satisfaction rate of anesthesia, and complications. Results: A total of 240 consecutive patients were enrolled in this study from January 2014 to December 2016. Among 3 groups, 1-week postoperatively VAS (back and leg) and ODI were improved compared with preoperative data, and the excellent/good rates were all above 90%. However, satisfaction rate of anesthesia showed significant differences among the 3 groups. PA and EA showed significantly better performance in pain management intraoperatively and 1 hour postoperatively. The operation time of group PA was the shortest and group EA was the longest. No severe neural injuries occurred in any of the 3 groups. Transient paresis of lower limbs occurred in all 3 groups and showed no significant differences. Decreased muscle strength of lower limbs postoperatively occurred in 2 patients in group EA. The incidence of nausea and vomiting postoperatively was significantly higher in group PA (6 cases, 7.50%). There were 3 cases of dysuria postoperatively in group EA (3.75%). Limitation: First, this is a single center study. Second, this study investigated the effects of anesthesia on perioperative period and the follow-up time was relatively short. Third, we choose morphine in group PA and there are other types of anesthetics which may be used in preemptive analgesia in further study. Conclusion: All 3 of these anesthetic methods are safe to avoid neural injuries. EA and PA showed better performance in pain management but had more anesthesia-related complications.