Endoscopic-guided proximal catheter placement in treatment of posterior fossa cysts

Purpose:Treatment of posterior fossa cysts by cystoperitoneal shunting may be complicated by a malpositioned proximal catheter located within the brai nstem or cerebellum causing acute shunt malfunction or neurological deficit s. We propose that proximal catheter placement from a posterior fossa appro ach aided by a malleable endoscope may prevent malposition and its complica tions. Methods: We present 4 procedures we performed on 3 patients with pos terior fossa cysts using a posterior fossa approach. In each case, the prox imal catheter was molded along with a malleable endoscope to place the cath eter parallel to the long axis of the fourth ventricle. Direct visualizatio n during catheter placement insured an intracavitary position. Results:Ulti mately, the procedure was successful in all 3 patients as judged by intraca vitary catheter position and decrease in cyst size on postoperative imaging . In 1 patient, revision using the same technique was required based upon s uboptimal catheter position within one of numerous cystic compartments with in the posterior fossa. There were no complications related to direct or in direct brainstem injury. Conclusions: Many posterior fossa cysts can be tre ated effectively and safely via a posterior fossa approach with the aid of a malleable endoscope. Direct visualization facilitates intracavitary cathe ter placement and orientation of the catheter in the long axis of the cyst, thereby decreasing the risk of injury to surrounding structures.