Advantages of Transmuscular Quadratus Lumborum Block via Subfascial Approach Versus Extrafascial Approach for Postoperative Analgesia After Laparoscopic Cholecystectomy: A Randomized Controlled Study

We aimed to compare the analgesic effect and incidence of lower limb weakness of transmuscular quadratus lumborum (TQL) block via subfascial approach with that via extrafascial after laparoscopic cholecystectomy (LC). METHODS: Eighty patients undergoing LC were randomized to receive ultrasound-guided bilateral TQL block via subfascial (subfascial group) or extrafascial (extrafascial group) using 30 mL of 0.33% ropivacaine unilaterally. Pain scores of port sites while rest and coughing at 1, 6, 12, 24, 36, and 48 hours postoperatively as primary outcome were compared. Modified Lovett Rating Scale, ambulatory dependency, and rescue analgesia requirement was also compared. RESULTS: The pain score of the subxiphoid and of the right subcostal port site for up to the postoperative 36 hours (2 [1 to 2]) and 24 hours (2 [2 to 3]) in the subfascial group was significantly lower than that in extrafascial group (2 [2 to 2] and 3 [2.25 to 4]). Up to postoperative 24 hours, the rescue analgesia requirement in subfascial group was significantly lower than that in extrafascial group, namely less fentanyl consumption and parecoxib (1.3 [±5.5] μg vs. 5.6 [±10.6] μg; 17.5% vs. 37.5%). The ratio of patients with LRS score of 6 at postoperative 1 hour (65.0%), and with dependent ambulation at postoperative 1 and 6 hours in subfascial group (15.0% and 0.0%) was significantly lower than that in extrafascial group (10.0%, 80.0%, and 17.5%). CONCLUSION: TQL block via subfascial had the advantages of better analgesic effect and less lower limbs weakness after LC over that via extrafascial.