[Percutaneous revision of shunt with obstructed ventricular catheter (author's transl)].

Shunt dysfunction due to an obstructed ventricular catheter can be avoided, at least in part, by placing the of the catheter anteriorly to the Foramen of Monro. However, once the catheter is obstructed, surgical removal under general anesthesia is almost inevitable. Irrigation method for an obstructed ventricular catheter enables us to gain scarcely anything and accumulation of instilled fluid in the ventricle often causes the dangerously increased intracranial pressure. 1) Technique for placement of the ventricular catheter. The skin incision is a semicircular. After the skin flap is reflected, "8-shaped" burr hole is placed (Fig. 1 in the text). At first, two openings, large and small, are made in the skull. At 1/4 inch drill is used for making a small hole and a regular perforator for an adjacent large one, then, with a small Schlessinger roungeur, a thin wall dividing these two holes is removed. Two to 3 cm lateral from the midline and also posterior to the frontal hair line is usually chosen for placement of burr holes. A straight ventricular catheter with multiple small perforations at its tip is connected to the Rickham reservoir and inserted in the ventricle anteriorly to the Foramen Monro, through the small hole of the "8-shaped" burr hole. Rest of surgical procedure is performed according to a routine manner. 2) Technique for release of ventricular catheter obstruction by percutaneous management through the "8-shaped" burr hole. A 20-gaze modified spinal needle is inserted through the Rickham reservoir under fluoroscopic control and gradually progressed to the tip of the obstructed catheter. Simple aspiration through the needle may occasionally open the catheter by removing small obstruents, but in many instances, insertion of an another ventricular needle through the large hole and combined irrigation are indispensable. 3) Results. Ten of 72 patients who had placement of the ventricular catheter by this technique developed obstructions of the catheter. Percutaneous technique was successful in releasing the obstructions in 12 times of these 8 patients and remaining 2 patients were subsequently operated upon for the following reasons. One patient, because of dislodging of the reservoir cap after successful release of obstruction and the other, due to extraventricular location of the tip of the catheter prior to the percutaneous management. No serious complications has been encountered and the technique was proved to be safe and simple ensuring good functional return of the shunt in long-term follow-up.