Long-term effectiveness and feasibility of CT-guided cryoablation as a novel treatment option for symptomatic lumbar synovial cysts.

Objective: To present a case series with a long-term follow-up of CT-guided cryoablation procedure for the minimally invasive treatment of symptomatic lumbar facet synovial cyst with a mean follow-up of 38 months (range, 15-55).

Materials and methods: We present a retrospective, uncontrolled clinical case series in a single institution on patients treated with CT-guided cryoablation for symptomatic lumbar facet joint synovial cyst refractory to or not suitable for imaging-guided rupture procedure. In two cases, patients underwent cryoablation and cyst rupture within a 2-week period. Outcome measures were post-procedural radiologic studies and clinical examinations up to the end of the follow-up. Selected patients underwent post-procedural clinical and CT and MRI imaging which were reviewed up to the conclusion of the follow-up. All patients were clinically assessed and evaluated by spine surgery team. Technical success was complete resolution of patient's symptoms.

Results: We treated 3 females and 3 males (mean age 64 years). Four patients had cysts located at L4-L5, and the remaining two at L5-S1. We used two cryoprobes in five patients, and three in one. Clinical and/or technical success was documented in all cases (mean follow-up, 38 months [range, 15-55]). We found no major complications related to the cryoablation itself.

Conclusion: Our initial experience with CT-guided cryoablation for symptomatic lumbar facet synovial cysts describes a less invasive alternative treatment option to surgery for the management of such lesions. Our long-term outcome experience showed low recurrence and complication rates. CT-guided cryoablation may be a reasonable alternative approach to treat lumbar synovial cysts that are refractory or contraindicated to the rupture procedure and where surgical management is unfeasible.