Intraoperative application of different imaging techniques in sacral neuromodulation: a systematic review and meta-analysis.

BACKGROUND: Sacral neuromodulation (SNM) treats bladder dysfunction by implanting electrodes in the sacral foramen to regulate bladder reflexes. Accurate electrode placement is critical but challenging due to anatomical variations, intestinal gas interference, and radiation exposure from X-ray fluoroscopy. Alternative imaging methods are needed to improve precision and safety. METHODS: We searched PubMed, EMBASE, and Ovid Medline for studies (inception–June 2025) comparing imaging techniques for SNM. Outcomes included operative time, puncture attempts, and radiation dose. Study quality was assessed using ROB2, Newcastle‒Ottawa, and JBI tools. RESULTS: Sixteen studies were included. Beyond X-ray fluoroscopy, ultrasound, CT, 3D printing, O-arm, reduced C-arm fluoroscopy, and electromagnetic navigation were successfully applied. Ultrasound shortened procedure time, reduced punctures, and lowered radiation (3 studies). CT (5 studies), O-arm (2 studies), and computer-assisted lead placement (1 study) also proved effective. 3D printing decreased test time, puncture attempts, and radiation (5 studies). Reduced fluoroscopy minimized radiation while maintaining success. CONCLUSION: Ultrasound, CT, and 3D printing enhance SNM success by reducing fluoroscopy time, puncture attempts, and radiation exposure compared to conventional X-ray methods. Further large-scale randomized trials are needed to validate these techniques and explore multi-modal imaging fusion for improved outcomes.