Conclusions and Outlook

As a minimally invasive surgery, PELD is superior to  conventional open surgery due to its shorter operation  time, lower bleeding volume, minimal soft tissue damage, and faster return to work. However, it also has several disadvantages. First, surgeons are required to be  very skilled in spine surgery. Incidence of complications  or revisions for beginners could be high owing to the  shortage of experience and proficiency, which results in  a sheer learning curve. Second, although local  anesthesia applied in PELD helps protect nerve roots  from damage, side effects could be greater with PELD  compared to other procedures conducted by general  anesthesia when patients cannot tolerate intraoperative pain. Severe painful feelings may even cause a deadly cardiovascular accident. Finally, frequent fluoroscopy is needed to obtain a correct puncture route,  so radiation exposure to medical staff and patients is  inevitable.

In terms of different surgery techniques, PETD  and PEID each have their unique indications and complications. As we mentioned previously, PETD is more  suitable in cases of L4/5 or the upper index. The PETD  technique is also an appropriate treatment for lateral  stenosis and foraminal stenosis. However, PETD has difficulty in dealing with highly migrated disc herniation,  and in this situation incomplete removal of herniated  disc fragments occurs. Improper location and puncturing in PETD can lead to injury of lumbar arteries and  exiting nerve roots. Therefore, postoperative dysesthesia and hematoma are more common in PETD. On  the other hand, PEID has advantages in L5/S1 lumbar  disc herniation, central lumbar stenosis, and highly migrated disc herniation due to the great intervertebral  space of the L5/S1 segment. However, excessive stretch  in PEID can injure the thecal sac, so the risk of dural tear  is higher than in PETD . In addition, local anesthesia  is not applicable to PEID because of its relatively poor analgesic effect, which heightens the risks of anesthesia  for elderly patients.