Intraoperative cone-beam CT for real-time quality control in CSF shunt surgery: a prospective workflow study.

INTRODUCTION: Postoperative CT is routinely performed after cerebrospinal fluid (CSF) shunt implantation to verify catheter position. Intraoperative cone-beam CT (iCBCT) enables real-time verification and may obviate routine postoperative CT. RESEARCH QUESTION: Does an iCBCT-based workflow reduce radiation exposure and permit omission of routine postoperative CT? METHODS: This interim analysis of an ongoing, prospective, observational study enrolled 10 patients undergoing ventriculoperitoneal (VP), lumboperitoneal (LP), ventriculoatrial (VA), or cyst shunt implantation with iCBCT-based quality control and compared them with a matched retrospective cohort of 10 patients managed by conventional postoperative CT. The primary endpoint was radiation exposure. Secondary endpoints were operative duration and the number of immediate revisions for catheter malposition. RESULTS: The volumetric dose index was lower in the iCBCT group than in the control group (CBDIw median 9.27 mGy [IQR, 6.5-11.5] vs CTDIvol 31.15 mGy [IQR, 23.5-34.2]; p = 0.002). Intraoperative imaging detected catheter malposition in one VP shunt and enabled immediate revision within the same surgical session. Routine postoperative CT was omitted in all iCBCT patients, without catheter-related complications through the routine 2-3-week postoperative follow-up. OR time was longer in the iCBCT group due to image acquisition without statistical significance (median 142 min [IQR, 114-157] vs 127 min [IQR, 104-140]; p = 0.2948). Surgical time was comparable between groups (median 65.5 min [IQR, 54-80] vs 60 min [IQR, 50-76]; p = 0.590). DISCUSSION AND CONCLUSION: In this interim cohort, iCBCT lowered the radiation dose index and replaced postoperative CT, enabling real-time catheter verification across CSF shunts.