Serial magnetic resonance imaging for spontaneously resolving spinal subdural hematoma and hygroma after endoscopic lumbar decompression: a case report

Abstract Background Endoscopic spine surgery (ESS) is a minimally invasive, standard-of-care intervention with a favorable safety profile. Spinal subdural hematoma (SDH) and spinal subdural hygroma (SSH) are rare complications after microscopic lumbar decompression and fusion, and their concurrent occurrence is a unique circumstance. Therefore, we report on a patient presenting with simultaneous SDH and SSH after successful lumbar endoscopic decompression. We provide a complete demonstration of the spontaneous resolution of symptoms and serial imaging findings from development to complete resorption of both subdural collections. Case Description A 76-year-old male patient who underwent uneventful endoscopic lumbar decompression for spinal canal stenosis and foraminal lumbar disc herniation, without recognized intraoperative durotomy, developed dorsal subdural collections at L1-2 and L5-S1 (hygromas) and an S2-level subdural hematoma (SDH). The hygromas demonstrated cerebrospinal fluid-equivalent signal characteristics on serial MRI and displaced the cauda equina roots within the dural sac. There were no signs of cauda equina syndrome, and the patient was managed conservatively with close neurological surveillance. Serial MRI was obtained at 5, 9, 18, 37, 72, and 213 days. The sacral SDH was present from POD5 and subsequently resolved; the SSHs showed dynamic partial resorption and regrowth before complete resolution. Conclusions SDH and SSH can occur concurrently, generally sharing a broad clinical spectrum ranging from asymptomatic cases to severe neurological deficits. Neurologically stable and mildly symptomatic patients can be managed conservatively, as it can be a safe and effective strategy.