Morbidity of Ventricular Cerebrospinal Fluid Shunt Surgery in Adults: An 8-Year Study

BACKGROUND: Cerebrospinal fluid (CSF) shunt procedures have dramatically reduced the morbidity and mortality rates associated with hydrocephalus. However, despite improvements in materials, devices, and surgical techniques, shunt failure and complications remain common and may require multiple surgical procedures. OBJECTIVE: To evaluate CSF shunt complication incidence and factors that may be associated with increased shunt dysfunction and infection rates in adults. METHODS: From January 1999 to December 2006, we conducted a prospective surveillance program for all neurosurgical procedures including reoperations and infections. Patients undergoing CSF shunt placement were retrospectively identified among patients labeled in the database as having a shunt as a primary or secondary intervention. Revisions of shunts implanted in another hospital or before the study period were excluded, as well as lumbo- or cyst-peritoneal shunts. Shunt complications were classified as mechanical dysfunction or infection. Follow-up was at least 2 years. Potential risk factors were evaluated using log-rank tests and stepwise Cox regression models. RESULTS: During the 8-year surveillance period, a total of 14 275 patients underwent neurosurgical procedures, including 839 who underwent shunt placement. One hundred nineteen patients were excluded, leaving 720 study patients. Mechanical dysfunction occurred in 124 patients (17.2%) and shunt infection in 44 patients (6.1%). These 168 patients required 375 reoperations. Risk factors for mechanical dysfunction were atrial shunt, greater number of previous external ventriculostomies, and male sex; risk factors for shunt infection were previous CSF leak, previous revisions for dysfunction, surgical incision after 10 AM, and longer operating time. CONCLUSION: Shunt surgery still carries a high morbidity rate, with a mean of 2.2 reoperations per patient in 23.3% of patients. Our risk-factor data suggest methods for decreasing shunt-related morbidity, including peritoneal routing whenever possible and special attention to preventing CSF leaks after craniotomy or external ventriculostomy.