Ilioinguinal-Transversus Abdominis Plane (I-TAP) Block with Liposomal Bupivacaine for Analgesia After Cesarean Delivery: A Randomized Controlled Trial

Purpose: Cesarean delivery is frequently associated with suboptimal postoperative analgesia. While PROSPECT guidelines recommend transversus abdominis plane (TAP) block for post-cesarean analgesia, conventional TAP block may provide incomplete coverage of the L1 dermatome, potentially limiting analgesia for lower abdominal incisions. This study evaluated the efficacy and safety of ultrasound-guided ilioinguinal-transversus abdominis plane (I-TAP) block with liposomal bupivacaine after cesarean delivery. Patients and Methods: In this single-center, randomized controlled trial, 150 healthy parturients undergoing elective cesarean delivery under combined spinal-epidural anesthesia were allocated in a 1:1:1 ratio to I-TAP block, transversus abdominis plane (TAP) block, or sham block. The I-TAP and TAP blocks were performed using a mixture of 266 mg liposomal bupivacaine and 50 mg bupivacaine hydrochloride, diluted with 0.9% sodium chloride to a total volume of 60 mL. The primary outcome was the cumulative intravenous sufentanil consumption from the patient controlled intravenous analgesia (PCIA) device during the first 24 h after surgery. Secondary outcomes included 48 h PCIA sufentanil requirements, Quality of Recovery-15 (QoR-15) scores, pain scores, time to first rescue analgesia, time to ambulation, successful breastfeeding initiation, maternal satisfaction, and adverse events. Results: At 24 h postoperatively, the I-TAP group had significantly lower sufentanil consumption than the TAP group (mean difference −11.4 μg, 95% CI: −17.6 to −5.3; 37.1% reduction) and the control group (mean difference −23.2 μg, 95% CI: −29.4 to −17.1; 54.5% reduction) (both P < 0.001). This difference persisted at 48 h. The I-TAP group also had lower postoperative pain scores, higher QoR-15 scores, longer time to first opioid rescue request, higher maternal satisfaction and higher rate of successful breastfeeding initiation. Adverse events were similar among groups. Conclusion: Compared with TAP block plus epidural hydromorphone and epidural hydromorphone alone, liposomal bupivacaine I-TAP block combined with epidural hydromorphone significantly reduced post-cesarean PCIA sufentanil requirements, improved postoperative analgesia and recovery quality, and increased maternal satisfaction without evidence of increased adverse events. This technique may provide a safe and effective option for implementation within multimodal analgesic strategy after cesarean delivery. Clinical Trial Number and Registry: ChiCTR2500112390.