Abdominal muscles infiltration analgesia for donor-site pain in autologous ear reconstruction: A randomized controlled clinical trial

Background: Costal cartilage donor-site pain is an adverse effect of autologous ear reconstruction. This study aimed to introduce rectus abdominis and external oblique muscle infiltration analgesia (RAM+EOM-IA) for costal cartilage donor-site pain and evaluate its efficacy and safety. Methods: The study was a randomized controlled clinical trial. Patients were randomized between intermittent RAM+EOM-IA combined with intravenous patient-controlled anesthesia (IPCA) and IPCA alone. Thirty patients were followed in the RAM+EOM-IA combined with the IPCA group and 30 patients in the IPCA alone group. The primary outcome was the numerical rating score (NRS) of pain recorded during 48 h postoperatively. Secondary outcomes included the Barthel index (BI) and rescue analgesic consumption. Sensory block areas were tested using a cold stimulus. Results: NRS was significantly lower with RAM+EOM-IA combined with IPCA than with IPCA alone at 28 h (P < 0.01), 32 h (P < 0.01), 36 h (P < 0.01), 44 h (P < 0.001), and 48 h (P < 0.01) postoperatively. The number of patients who received rescue analgesics (P < 0.01) and consumption (P < 0.01) was significantly higher for IPCA alone. RAM+EOM-IA improved the BI at 24 h postoperatively (P < 0.001), especially for mobility (P < 0.001), using the stairs (P < 0.001) and toilet use domains (P < 0.001). At 10 and 60 min after RAM+EOM-IA, the total sensory block area in the abdomen had not extended proximally beyond the xiphoid, distally beyond the navel, and beyond midaxillary and midsternal lines on either side. Conclusion: RAM+EOM-IA effectively and safely prevented costal cartilage donor-site pain by blocking anterior and lateral cutaneous branches of intercostal nerves from T6 to T10 in microtia patients. (c) 2024 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.