The Remote Intradural Migration of Polyethylene Glycol-Based Hydrogel Sealant Following Lumbar Laminectomy: A Case Report

<b>Background/Objectives</b>: Synthetic polyethylene glycol (PEG)-based hydrogel sealants, such as Adherus, are commonly used in spinal surgeries to achieve watertight dural closure and prevent cerebrospinal fluid (CSF) leaks. This case report describes an unusual instance of suspected hydrogel sealant migration resulting in an intradural collection at a spinal level remote from the original surgery. <b>Methods</b>: A 57-year-old female with a history of osteoarthritis and prediabetes underwent a minimally invasive L5-S1 laminectomy for the removal of an epidural abscess causing cauda equina and S1 nerve root compression. During the procedure, a dural puncture occurred, which was repaired using Duragen (collagen matrix) and Adherus (synthetic PEG hydrogel sealant). Postoperatively, the patient developed urinary retention and new bilateral posterior leg pain. An MRI on postoperative day four revealed a new peripherally enhancing dorsal intradural collection at the L2 level, causing significant thecal sac narrowing and compression of the cauda equina nerve roots, suggestive of migration of the hydrogel sealant used during surgery. Conservative management was adopted. <b>Results</b>: The patients symptoms gradually resolved. Follow-up imaging at five months showed resolution of the intradural collection, with residual intradural inflammatory changes and arachnoiditis. <b>Conclusions</b>: While PEG-based hydrogel sealants like Adherus are effective in preventing CSF leaks, they can, in rare instances, migrate and cause remote intradural collections with neurological symptoms. Surgeons should exercise meticulous application techniques, thoroughly document the use of sealants, and maintain vigilant postoperative monitoring to mitigate these risks.