Effects of Ultrasound-Guided Oblique Subcostal Transversus Abdominis Block Combined with Patient-Controlled Intravenous Analgesia on Analgesia and Early Recovery after Open Hepatectomy

Objectives: Open hepatectomy is associated with acute severe postoperative pain. The oblique subcostal transversus abdominis plane (OSTAP) block combined with patient-controlled intravenous analgesia (PCIA) has gained attention as a multimodal analgesic strategy, but evidence for their synergistic efficacy remains limited. Therefore, we conducted a randomized-controlled trial to access the effect of ultrasound-guided bilateral OSTAP blockade combined with PCIA in open hepatectomy. Methods: This study is a single-center, prospective, randomized-controlled trial. All subjects were randomized to receive either the OSTAP+PCIA (OSTAP group) or PCIA alone (PCIA group) (1:1). Primary endpoints were mean postoperative visual analog scale (VAS) scores at rest and on movement. Secondary endpoints included pain scores at different time point postoperatively, cumulative opioid consumption, hemodynamic parameters, adverse events, time to functional recovery, postoperative hospitalization duration and total costs. Results: A total of 74 patients underwent randomization. The mean VAS scores of the OSTAP group were significantly lower than the PCIA group in both rest and movement ( P <0.001), with a significant difference in the postoperative period of 6 hours ( P <0.001 and =0.001) and 24 hours ( P =0.001 and 0.046). The OSTAP group can significantly reduce perioperative opioid consumption ( P <0.001 and =0.032). The hemodynamic parameters in the OSTAP group showed more stable. The time to first ambulation and oral intake was earlier in the OSTAP group ( P =0.040 and 0.028). No significant difference in other measurements. Discussion: The combination of OSTAP and PCIA provides effective pain relief and reduces perioperative opioid consumption for patients undergoing open hepatectomy without increasing adverse events and costs.