Background: A novel ultrasound-guided paravertebral block, the edge laminar block (ELB) was reported recently. However, it was unclear how effective ELB was in comparison with traditional blocking methods. We conducted a trial to compare the analgesic efficacy of ELB with the thoracic paravertebral block (TPVB) and the retrolaminar block (RLB) in patients undergoing video-assisted thoracic surgery (VATS).
Methods: We identified 90 patients who were scheduled for VATS and randomly assigned them to three groups: ELB group (Group E), TPVB group (Group T), and RLB group (Group R). Each group underwent ELB, TPVB, and RLB, respectively, under ultrasound guidance before general anesthesia induction. All patients received post-operative routine analgesia protocol. Our primary outcome was the extent of dermatomal sensory loss on the midclavicular, midaxillary, and scapular lines, measured using a pinprick 15 minutes after the nerve block. Secondary outcomes included the intraoperative dose of sufentanil, the numerical rating scale (NRS) scores assessed in the post-anesthesia care unit (PACU) and at 6, 12, and 24 hours post-operatively, and pethidine administrated as analgesic rescue dose.
Results: The percentages of nerve block range reaching the midclavicular line, midaxillary line, and scapular line in Group E were 96.7%, 93.3%, 93.3%, and 60% in Group T and 30%, 56.7%, and 96.7% in Group R, respectively. Group E had wider dermatomal sensory loss on the midclavicular line and midaxillary line compared to Group R (P < 0.001) and had a wider range compared to Group T on the scapular line (P < 0.001). There was no significant difference in the intraoperative use of sufentanil in the three groups. Post-operative NRS scores at each time point were significantly lower in Group E than those in the other two groups (P < 0.01).
Conclusion: ELB had a wider nerve block range and applied better post-operative analgesia in comparison with TPVB and RLB.
Keywords: analgesia, retrolaminar block, thoracic paravertebral block, ultrasound guidance, video-assisted thoracic surgery