Efficacy of Erector Spinae Plane Block Versus Subcostal Transversus Abdominis Plane Block in Laparoscopic Nephrectomy

Group A, The patient was in the supine position then; the Subcostal TAP block was given by a high frequency linear ultrasound transducer (Siemens acuson x300 3-5MHz ultrasound). After skin preparation and isolation, the transducer was placed 2 cm sub-xiphoid, then moved along the subcostal edge to identify the rectus abdominis muscle and the transversus abdominis then, a blunted tip, 20-gauge, short bevel needle (Pajunk Sonoplex, Geisingen, Germany) was introduced in-plane 2-3 cm lateral to the transducer, under direct ultrasound visualization. After confirming the correct placement of the needle and the negative aspiration probe, the rest of the anaesthetic substance was injected along the subcostal line in the transversus abdominis plane 20 ml 0.25% bupivacaine on each side after aspiration to avoid intravascular placement, and the dissection of the plane was observed. The block was performed bilaterally.

Group B, the patient was placed in the prone position. Then, the Erector Spinae block was given by same ultrasound transducer . It was sagittaly placed against the target vertebral level (T7 transverse process) in the prone position and moved in approximately 3-cm lateral to the spinous process.. The Erector Spinae muscle and transverse process was identified, and a same blunted tip , 20-gauge, short bevel needle was advanced, using the in-plane approach, in cephalad-to-caudal direction, through the interfascial plane between the Erector Spinae and the underlying transverse process under strict aseptic precautions until the tip is deep to erector spinae muscle, as evidenced by visible hydro-dissection below the muscle plane. The block was performed bilaterally by injecting 40 mL of 0.25% bupivacaine (20 mL into each side) into the fascial plane between the deep surface of the Erector Spinae muscle and the transverse processes of the thoracic vertebrae laterally (specifically at T7).