Objective: Long-term anticoagulation is often considered a contraindication to shunt surgery for elderly patients with normal pressure hydrocephalus (NPH). However, no studies have investigated this question.
Methods: We evaluated 25 patients who were taking warfarin for NPH between 2001 and 2004 with a protocol of cerebrospinal fluid (CSF) pressure monitoring and controlled CSF drainage via spinal catheter. Warfarin was stopped 5 to 7 days before lumbar puncture or shunt surgery and restarted 3 to 5 days after operation or at the time of discharge from the hospital. Programmable shunts with antisiphon devices set at the high-pressure range were preferentially used and adjusted in small increments.
Results: After CSF drainage, 16 patients showed improvement and 15 underwent shunt surgery. Thirteen (87%) out of these 15 patients showed significant improvement in at least one symptom during a mean follow-up period of 8.2 months (range, 1-70 mo) after shunt surgery. There were two bleeding complications. One patient (6.7%) with cirrhosis who developed a subdural hematoma 13 days after operation had the shunt removed; another patient who developed an abdominal subcutaneous hematoma 5 days after operation required surgical evacuation and shunt revision surgery. Otherwise, 14 (93.3%) out of the 15 patients had no subdural hematoma during the follow-up period and there were no thromboembolic complications while the patients were not taking warfarin.
Conclusion: Elderly patients on long-term warfarin anticoagulation can be safely evaluated and treated for NPH using a protocol of continuous CSF drainage via spinal catheter for diagnosis, cautious periprocedural management of anticoagulation, and use of programmable shunts with antisiphon devices. The risk of subdural hematoma is not higher than reported series. Long-term anticoagulation with warfarin is not a contraindication per se for shunt surgery in NPH.