Abstract
OBJECTIVE Conditional survival incorporates the effect of time passed since an event to current data in an easy-to-understand, relevant format. Data from the Hydrocephalus Clinical Research Network (HCRN) registry were analyzed with conditional survival to improve patient and family counseling after hydrocephalus treatment. METHODS Children with hydrocephalus who underwent first-time treatment by a single proximal catheter ventriculoperitoneal shunt (VPS) or endoscopic third ventriculostomy (ETV) with or without choroid plexus cauterization with at least 3 years of follow-up in the prospective HCRN registry (14 sites, April 24, 2008–December 31, 2020) were included. Those with nonperitoneal or multiple proximal catheters were excluded. The probability of failure-free survival at 3, 5, and 10 years was calculated as a function of time since surgery. RESULTS Overall, 5782 patients were included (1609 with ETV, 4173 with VPS placement). The median time to censoring was 5.3 years. The overall respective 3-, 5-, and 10-year failure-free survival rates were 59%, 58%, and 57%, respectively, for ETV and 62%, 58%, and 54%, respectively, for VPS. If VPS failure had not occurred by 1 year postoperatively, the 3-, 5-, and 10-year failure-free survival rates were 85%, 79%, and 66%, respectively. If ETV failure had not occurred by 1 year, the 3-, 5-, and 10-year failure-free survival rates were 93%, 91%, and 86%, respectively. Conditional survival also varied by age and etiology. CONCLUSIONS Patients who do not require revision surgery in the 1st year have an excellent chance of being revision free for an extended period. Conditional survival plots provided are intuitive and can be used in the counseling of North American patients with surgically treated hydrocephalus. ©AANS 2025.