Transforaminal Endoscopic Decompression for a Giant Epidural Gas-Containing Pseudocyst: A Case Report and Literature Review.

The isolated epidural gas-containing pseudocyst is an uncommon pathogenic factor for severe pain of the lower limb as a result of nerve root compression. After reviewing these rare cases reported in the literature, we found that the name, pathogenesis, and treatment strategy of this pathology remained controversial. The most common treatment is conservative treatment or percutaneous aspiration which might result inpoor pain relief and high recurrence rates. Moreover, the patient who received open surgery had good clinical outcome; however, he or she might experience a significant soft tissue injury.In this study, we report the first case of a patient who had a giant epidural gas-containing pseudocyst and received percutaneous endoscopic surgery. This 57-year-old man had been complaining of severe radicular pain in his right ankle for one year. According to computed tomography (CT) and magnetic resonance imaging (MRI) prior to the surgery, the results showed an isolated epidural gas-containing pseudocyst was located in the right lateral recess of S1. At the last follow-up period, postoperative CT scan showed the gas-contained pseudocyst was completely resected and this patient was free from the pain.Due to the great advances in endoscopic techniques and equipment, it is easier to perform lumbar surgery through the endoscope. With this first case of percutaneous endoscopic treatment for the symptomatic epidural gas-containing pseudocyst reported in this study, we believe that this surgical method provides an option to treat this rare condition because it provides sufficient decompression, has a low recurrence rate, and is minimally invasive. Key words: Endoscopic surgery, pseudocyst, epidural gas, intraspinal gas, radiulopathy.