Ultrasound-Guided Subcostal Transversus Abdominis Plane Block versus Port-Site Infiltration for Postoperative Analgesia following Elective Laparoscopic Cholecystectomy: A Prospective Randomised Controlled Study

Abstract

Background and Objectives: Laparoscopic cholecystectomy is associated with significant early postoperative pain despite its minimally invasive nature. Port-site infiltration provides limited somatic coverage, whereas the ultrasound-guided subcostal transversus abdominis plane (STA) block targets the thoracolumbar nerves T6–L1 within the fascial plane, offering wider supraumbilical analgesia. This study aimed to compare the analgesic efficacy of ultrasound-guided STA block with port-site infiltration in patients undergoing elective laparoscopic cholecystectomy.

Methods: Fifty ASA I–II patients aged 18–65 years undergoing elective laparoscopic cholecystectomy under general anaesthesia were prospectively randomised into two equal groups. Group P (n = 25) received port-site infiltration and Group S (n = 25) received ultrasound-guided STA block, both using 20 mL of 0.25% bupivacaine administered before extubation. Postoperative pain was assessed by Visual Analogue Scale (VAS, 0–10 cm) at 1, 4, 8, 12, and 24 hours. Secondary outcomes included time to first rescue analgesia, drug-specific rescue analgesic consumption, cumulative 8-hour equivalent morphine dose, recovery unit discharge time, and complications.

Results: Group S demonstrated significantly lower VAS scores than Group P at all postoperative time points (P < 0.01, repeated-measures ANOVA). Median fentanyl requirement in recovery was reduced by 40.0% in Group S (0.9 vs. 1.5 µg/kg). Cumulative 8-hour equivalent morphine dose was 45.2% lower in Group S (9.2 vs. 16.8 mg). Codeine rescue requirement was significantly less frequent in Group S (24% vs. 68%; P < 0.05). Recovery unit discharge time was shorter in Group S (65 vs. 110 min). No major block-related complications were recorded.

Conclusion: Ultrasound-guided STA block provides superior and sustained postoperative analgesia compared with port-site infiltration following laparoscopic cholecystectomy, with clinically meaningful reductions in opioid consumption and recovery unit stay, and a favourable safety profile.