Other: M-TAPA block with bupivacaine 25%

Following sterile conditions for bilateral M-TAPA block application, the transducer will
be inserted on the chondrium in the sagittal plane at the 9-10th rib level. Subsequently,
a deep angle will be created with the probe for visualization of the underside of the
costochondrium. The sonovisible needle tip will be placed just below the chondrium and
saline (5 ml) will be injected for site confirmation. After the confirmation, 20 ml of
0.25% bupivacaine will be administered for each group for a total of 40 ml of local
anesthetic. Blocks will be applied using an 80 mm sonovisible needle with a 6-10 MHz
linear probe under the guidance of a portable ultrasound. M-TAPA block with the same
standard technique and drug dose will be applied to the contralateral side for each group
of M-TAPA patients.
Other Name: Modified thoracoabdominal nerve block through perichondrial approach

Other: TAP block with bupivacaine 25%

After the necessary sterilization conditions established, the linear ultrasound probe
will be placed in the middle of the iliac crest with the end limit of the ribs. Starting
with skin, the layers in descending order, subcutaneous adipose tissue, external oblique
muscle, internal oblique muscle, transversus abdominis muscle, and peritoneum will be
identified. As the tip of the 80 mm sonovisible needle passes through the muscular layers
and fascia, the needle will be advanced in a controlled manner. After receiving the click
sensation (passage of the fascia of the internal oblique muscle), the location of the
needle will be fixed and 20 ml of 0.25% bupivacaine will be injected between internal
oblique and transversus abdominis muscles. Same procedure will be performed to the other
site. (40 ml local anesthetics in total)
Other Name: Transversus abdominis plane block