This study will be conducted to evaluate efficacy of ultrasound guided modified thoracoabdominal nerves block via a new perichondrial approach (M-TAPA) for postoperative analgesia in major abdominal surgeries in comparison to subcostal transverse abdominis plane (SCTAP) block.

It is hypothesized that M-TAPA block will be advantageous to SCTAP block as a promising effective alternative for analgesia for major abdominal surgeries with fewer side effects.

Postoperative pain management for major abdominal surgeries can reduce postoperative respiratory dysfunction and promote early mobilization. Traditionally, opioids have been used to manage postoperative pain. However, an increasing awareness of opioid-related adverse events including respiratory depression, paralytic ileus, and sedation, has led to a shift towards utilizing opioid-sparing techniques for postoperative analgesia. As such, outcomes associated with the transverse abdominis plane block are of increasing interest. A modified thoracoabdominal nerves block via a new perichondrial approach (M-TAPA) is a novel analgesic technique that involves local anesthetic injection into the lower aspect of the chondrium. It can block thoracoabdominal nerves at T5 in cephalic direction and down to T11-T12 in caudal direction and may be an effective analgesic for major abdominal surgeries.

The aim of this study is to assess the quality of pain relief in patients who will undergo major abdominal surgery receiving either (M-TAPA) block or (SCTAP) block by comparing and evaluating the differences between the two techniques.

This prospective, randomized, comparative clinical study will include 80 patients who will be scheduled for major abdominal surgery under general anesthesia in Mansoura university hospitals. Informed written consent will be obtained from all subjects in the study after ensuring confidentiality. Eligible patients will be randomly assigned to 2 equal groups (M-TAPA group and SCTAP group) according to computer-generated table of random numbers using the permuted block randomization method. The collected data will be coded, processed, and analyzed using SPSS program. All data will be considered statistically significant if P value is ≤ 0.05.

Inclusion Criteria:

• American Society of Anesthesiology (ASA) I and II patients.
• Scheduled for elective major abdominal surgeries.

Exclusion Criteria:

• Patient's refusal.
• Altered mental status or un-cooperative patients.
• History of known sensitivity to the used anesthetics.
• Bleeding or coagulation diathesis.
• Infection at the injection site.