Diagnosis and Treatment of Symptomatic Multiple Sacral Perineural Cysts-Technical Note

Sacral perineural cysts are rarely symptomatic; however, they may occasionally cause various symptoms. As the patient exhibits multiple cysts, it often becomes difficult to determine if these cysts are symptomatic.

Six patients with multiple sacral cysts, identified using magnetic resonance imaging (MRI), were further examined using myelography and computed tomography (CT) immediately and 6-18 h after myelography. Symptomatic cysts were exclusively diagnosed as not enhanced immediately (filling defect sign) but displayed enhancement later (delayed filling sign/retention sign) compared to the subarachnoid space. A minimal laminectomy was performed on the target cyst. The dura and epineurium with the arachnoid of the cyst were then longitudinally incised along the nerve root, and the adhesion at the junction between the cyst and the dura mater was released. The incised epineurium and dura mater were sutured using 6-0 nylon and covered with multiple layers of polyglycolic acid seat and fibrin glue. A suction drain was placed for 1 or 2 days, and the patients were mobilized on postoperative day 1. Symptoms improved in all patients; however, the improvement ratio varied. At an average follow-up of 39 months, no recurrence was observed on the MRI.

This case series reports the diagnostic and surgical methods for multiple sacral perineural cysts and their outcomes. Delayed CT myelography is helpful in diagnosing symptomatic cysts. Moreover, all cysts with filling defect signs or delayed filling/retention signs demonstrated neural adhesions in the neck. Microsurgical fenestration and the release of adhesions are effective for the improvement of symptoms without recurrence.