Peripheral Nerve Block for Carbon Dioxide Angiography in Below-the-Knee Interventions: Impact on Pain Control, Image Quality, and Procedural Efficiency.

PURPOSE: To evaluate the efficacy and safety of combined popliteal sciatic and femoral nerve blocks and their impact on image quality during carbon dioxide (CO2) angiography. MATERIALS AND METHODS: This retrospective study evaluated patients undergoing CO2 angiography who received either moderate sedoanalgesia or combined popliteal sciatic and femoral nerve block. Intra-procedural pain was assessed using the visual analog scale (VAS), and image quality, procedural parameters, and patient and operator satisfaction were compared between groups. A 1:1 propensity score matching (PSM) analysis was performed to reduce baseline confounding. RESULTS: Among 103 patients (nerve block, n=45; sedoanalgesia, n=58), VAS scores were lower in the nerve block group (0 [0-2] vs. 5 [3-8], p <0.001). Procedure duration (89.7±47.3 vs. 124.2±44.5 min), fluoroscopy time (28.6±19.9 vs. 42.0±16.8 min), fluoroscopy exposures (12.8±5.1 vs. 19.4±8.1), radiation dose (342.9 [100-1733] vs. 448.4 [130-3199] mGy), and iodinated contrast volume (4 [3-8] vs. 19 [8-40] mL) were lower in the nerve block group (all p <0.001). Patient and operator satisfaction and image quality were also improved (all p <0.001). After PSM, 29 matched pairs were analyzed; differences in VAS scores, image quality, contrast use, procedure duration, fluoroscopy time, and exposures remained significant, whereas radiation dose was comparable between groups. CONCLUSION: Combined popliteal sciatic and femoral nerve blocks appear to be a safe and effective analgesic strategy for CO2 angiography and may improve both image quality and procedural efficiency compared with moderate sedoanalgesia. LEVEL OF EVIDENCE: Level 3.