Symptomatic Tarlov cysts cause chronic pelvic and lower extremity pain. These cysts may be large and can expand the spinal canal or cause erosion of overlying bone. Patel et al. describe a single-needle approach to Tarlov cysts in which they inject fibrin adhesive to treat the cyst.1 This is a three-stage procedure: (1) cyst entry and aspiration, (2) injection of myelographic contrast material to ensure that a wide neck is not present, and (3) injection of tissue adhesive. Many of our initial patients were treated by this standard technique and experienced considerable pain that required significant sedation with fentanyl and midazolam. We believe this pain was caused by a flux in pressure in the cystic cavity during aspiration of the injected substances. Patients with Tarlov cysts are complex to manage and have innumerable complaints. In our experience, narrow-necked Tarlov cysts may be symptomatic, whereas wide-necked Tarlov cysts are not. They can be differentiated by their T2 signal on magnetic resonance imaging (MRI). Wide-necked cysts have the same signal as the general CSF space around the cord, but narrow-necked cysts have higher signal than the adjacent CSF space. In 1993, Davis et al. published evidence of signal change within symptomatic cysts.2 Their paper demonstrated that in 19 patients with 24 cysts, narrow-necked cysts were consistently more symptomatic than wide-necked cysts. The only patients we have treated with our CT-guided technique (now > 90 patients in the last 2 years) have been symptomatic with narrow-necked cysts. We have also treated patients with symptomatic wide-necked lesions who had previously undergone surgical repair and subsequently developed persistent CSF leaks. 1. Good candidates with narrow-necked cysts go straight to fibrin injection under CT fluoroscopy. 2. Surgical candidates with wide-necked cysts proceed to surgical repair. 3. Candidates for whom a consensus cannot be reached undergo CT myelography with early and delayed imaging to examine the cyst neck. They are then treated appropriately according to the first two paradigms.
Image-Guided Intervention for Symptomatic Tarlov Cysts
Indications