Intrathecal pump therapy: a retrospective cohort with over 1500 pump-years of follow-up

Intrathecal therapy (ITT) is an established treatment for severe spasticity and chronic pain syndromes. However, long-term device-related complications, such as infections and surgical revisions, remain a significant clinical concern.

This study aims to quantify the incidence of these complications in a large retrospective cohort and evaluate the impact of compounded intrathecal medications on device longevity.

We conducted a retrospective cohort study of patients undergoing intrathecal pump implantation or replacement (2003-2025). Complication burdens were calculated and expressed as incidence per 100 pump-years. To evaluate temporal risk, Kaplan-Meier time-to-event analyses were performed for both infections and revisions. The impact of compounded therapy versus monotherapy on revision-free survival was compared using the Log-Rank test, and pump exchange intervals were analysed via the Mann-Whitney U test.

The cohort included 132 patients (328 pumps), yielding a cumulative follow-up of 1551.6 pump-years. Nine infections occurred, corresponding to a low incidence of 0.58 per 100 pump-years. Forty-eight surgical revisions were performed, resulting in an incidence of 3.1 per 100 pump-years. The use of compounded medications was not associated with a statistically significant reduction in time to first or subsequent pump exchanges, and Log-Rank testing confirmed no significant difference in overall revision-free survival distributions between the monotherapy and compounding cohorts.

With over 1500 cumulative pump-years of follow-up, ITT was associated with a low infection incidence and a moderate, time-dependent revision burden. The utilization of compounded intrathecal medications did not inherently compromise device survivability, providing empirical reassurance for individualized off-label therapy management.