Abstract: A device and method for removing ingrown biological tissue from the fluid passageway of a drainage shunt which has been implanted in a patient to relieve a hydrocephalic condition, includes a tubular catheter which is slidably insertable through the passageway of the drainage shunt. A blade extends from the distal end of the catheter and, as the tubular catheter is rotated, the blade cuts away any biological tissue which has ingrown in the passageway. A viewing element is insertable through the tubular catheter to view the blade's progress through the tubular catheter and determine its relationship with any tissue that has ingrown in the passageway.