Why does such a cyst appear after unilateral biportal endoscopy surgery: A case report and literature review.

Background: Unilateral biportal endoscopy (UBE) has been widely and skillfully used in the treatment of lumbar disc herniation and spinal canal stenosis. UBE surgery also brings some complications, such as dural tear, epidural hematoma, residual nucleus pulposus, etc. And we found a rare case of arachnoid cyst after UBE.

Case Presentation: A 48 years old female who had a history of cholecystectomy, nephrolithiasis, hyperthyroidism, chronic atrophic gastritis, and colonic polyps with several years of low back pain and numbness in both lower limbs was found have arachnoid cyst 3 years after UBE operation. We hope that we can give a new aspect of complication after the UBE treatment in the future.

Conclusion: We believe that the postoperative hypertension and the lack of postoperative back muscle strength training and some personal factors are the possible reasons for the arachnoid cyst in this case.