Ultrasound Guided Modified Thoracoabdominal Nerve Block Through Perichondrial Approach (M-TAPA) Versus Quadratus Lumborum Block for Postoperative Analgesia in Laparoscopic Cholecystectomy

transversus abdominis, internal oblique, and external oblique muscles will be identified with a high-frequency (10 MHz) linear probe on the costochondral angle in the sagittal plane under ultrasound guidance at the 10th costal margin. A deep angle was given to the costochondral angle at the edge of the 10th costal margin with the probe in the sagittal direction to view the lower surface of the costal cartilage in the midline. A 22-G, 100-mm block needle will be inserted in the cranial direction using the in-plane technique and the needle tip will be moved to the posterior aspect of the 10th costal cartilage. It is noted that the needle tip never crossed the cranial edge of the 10th costal cartilage

using ultrasound guidance (Sonosite turbo M, Bothell, Washington, USA) and a curved ultrasound probe (2.5-7.5 MHz). The probe will be placed in the mid-axillary line between the lower costal margin and the iliac crest in a transverse plane to view all abdominal layers. The probe will be moved towards the posterior axillary line, to reach a point where all three abdominal muscle layers merge to form aponeurosis.

The aponeurosis will then be followed dorsally until the quadratus lumborum muscle is seen deep to transversalis fascia with its attachment to the transverse process of the L4 vertebral body. A 22 G, 100 mm, blunt, insulated nerve block needle will be inserted 1 cm medial to the probe and advanced using the in-plane technique with ultrasound real-time assessment. The injection site will be the junction of transversalis fascia and the anterolateral border of quadratus lumborum muscle