Shunt-dependent hydrocephalus and shunt failure rate in patients with aneurysmal subarachnoid hemorrhage in Korea

OBJECTIVE Shunt-dependent hydrocephalus is a major complication of aneurysmal subarachnoid hemorrhage (SAH). Despite this, the factors influencing shunt dependency and shunt failure remain unclear. Therefore, the aim of this study was to estimate shunt dependency and failure rates and determine the contributing factors in patients with aneurysmal SAH using the Korean National Health Insurance database over a 13-year period. METHODS Patients with aneurysmal SAH aged > 18 years who underwent surgical procedures were included. Using the shunt surgery prescription data, the shunt-dependent hydrocephalus rate was evaluated according to sex, age, aneurysm location, and year of admission. Among patients who underwent shunt surgery, the shunt failure rate was estimated using surgical prescription data. RESULTS A total of 57,030 patients with SAH who underwent aneurysm surgery were included. The overall raw rate of shunt-dependent hydrocephalus was 15.0% (8530/57,030). Age (HR 1.04, 95% CI 1.04-1.04; p < 0.001) and endovascular coiling (vs surgical clipping, HR 0.71, 95% CI 0.67-0.74; p < 0.001) were related to shunt-dependent hydrocephalus in the multivariate logistic regression analysis. Posterior circulation and anterior communicating aneurysms showed a high risk of shunt dependency. Among 8530 patients who underwent shunt surgery, the shunt failure rate was 11.3% (961/8530). Female sex (HR 1.18, 95% CI 1.01-1.39; p = 0.0324), age (HR 0.99, 95% CI 0.98-0.99; p < 0.001), early shunt placement (HR 1.25, 95% CI 1.08-1.47; p = 0.004) and lumboperitoneal shunt placement (HR 2.19, 95% CI 1.65- 2.91; p < 0.001) were the risk factors for shunt failure in the multivariate logistic regression analysis. CONCLUSIONS The rate of shunt-dependent hydrocephalus after aneurysmal SAH was 15.0% in this study using a medical claims database in Korea. The shunt surgery rate was highest in patients in their 60s and 70s. Shunt failure occurred in 11.3% of the patients, and a lumboperitoneal shunt was most related to the need for revision surgery.