Effects of Ultrasound-Guided Oblique Subcostal Transversus Abdominis Block Combined With Patient-Controlled Intravenous Analgesia on Analgesia and Early Recovery After Open Hepatectomy: A Randomized Controlled Clinical Trial.

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 its synergistic efficacy remains limited. Therefore, we conducted a randomized controlled trial to assess 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 participants 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 points 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 statistically 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 significantly reduced perioperative opioid consumption ( P <0.001 and 0.032). The hemodynamic parameters in the OSTAP group showed more stability. The time to first ambulation and oral intake was earlier in the OSTAP group ( P =0.040 and 0.028). No statistically significant differences in other measurements were observed. DISCUSSION: The combination of OSTAP and PCIA provided effective pain relief and reduces perioperative opioid consumption for patients undergoing open hepatectomy without increasing adverse events and costs.