Symptomatic extradural spinal arachnoid cyst: More than a simple herniated sac

Area of Science:

• Neurosurgery
• Spinal Surgery
• Radiology

Background:

• Spinal arachnoid cysts are uncommon, typically intradural.
• Extradural arachnoid cysts (EDACs) are rare, with debated pathogenesis.
• EDACs present with neurological deficits like radiculopathy or paraparesis.

Purpose of the Study:

• To retrospectively analyze the clinical profile of rare extradural arachnoid cysts (EDACs).
• To evaluate the surgical approach and outcomes for EDACs.

Main Methods:

• Retrospective analysis of 19 patients with EDACs operated between January 2006 and June 2016.
• Surgical management via open laminectomy and cyst excision for patients with Oswestry disability index score >20.
• Clinical outcome assessment using a 5-point satisfaction scale and McCormick grading.

Main Results:

• All 13 operated patients had EDACs with intradural communication.
• Complete cyst wall excision was achieved in 84.6% of patients; dural communication was closed in all.
• No patients experienced clinical deterioration or radiological recurrence; all patients reported satisfaction post-surgery.

Conclusions:

• Symptomatic EDACs constitute less than 2% of spinal tumors.
• EDACs demonstrate communication with the intradural compartment.
• Complete surgical excision, including disconnection from intradural connections, is crucial for preventing recurrence.