Management of Symptomatic Sacral Perineural Cysts: A New Surgical Method

Abstract

Microsurgical techniques are increasingly being recommended for the treatment of symptomatic Tarlov cysts (TCs) due to improved long-term outcomes compared to those of other strategies. However, these techniques are associated with a high risk of cyst recurrence and cerebrospinal fluid (CSF) leakage, resulting in the surgical strategy of TCs remaining controversial. We hypothesize that incomplete closure of the ostium between the cyst and the subarachnoid space is the probable cause of surgical failure. Accordingly, we present a novel method of cyst separation and ostium closure that aims to block the ostium more firmly and reliably. Thirty-five consecutive patients (21 females) underwent the modified ostium obstruction surgery due to symptomatic TCs. We collected and compared their outcomes at the final follow-up to evaluate the surgical effect. Thirty-five patients had 74TCs (S2 level, 48.7%; mean diameter, 2.0±1.0cm); ostia nerve root fibers were found in all TCs. The mean follow-up duration was 37.8 (range, 13.5-76.8) months. At the final follow-up, 33 patients experienced complete or substantial resolution of the preoperative symptoms. The symptom with the highest improvement rate was radicular pain. Both the modified evaluation criteria for the efficacy of lumbar function criterion and Japanese Orthopedic Association score 29 showed an overall improvement rate of 94.3%. Two patients experienced surgery-related neurological dysfunction. No cyst recurrence or CSF leakage was observed. Magnetic resonance imaging showed that all cysts disappeared or significantly reduced postoperatively. The microscopic fenestration of cysts and modified ostium obstruction described herein is a safe and effective strategy for management of patients with symptomatic TCs and is associated with a low incidence of cyst recurrence and CSF leakage since it achieves complete closure of cyst ostium.