Interest in surgical weight loss interventions continues to rise in the face of what has been dubbed the obesity epidemic. The most popular of these weight loss interventions is laparoscopic sleeve gastrectomy, which has proven to reduce morbidity and mortality of morbidly obese patients. The aim of effective perioperative pain management extends beyond increased patient comfort and includes reduced recumbency period, enhanced recovery, reduced hospital stay, and lowers postoperative complication rates.

Effective postoperative pain management has traditionally relied on multimodal strategies that combine systemic opioids, non-opioid medications, and regional anesthesia. Despite their efficacy, opioids are associated with a range of undesirable effects, such as nausea, vomiting, sedation, pruritus, and respiratory depression, which may impede early mobilization and recovery. These concerns have accelerated the adoption of ultrasound-guided regional anesthesia techniques as part of Enhanced Recovery After Surgery (ERAS) protocols, delivering superior pain control with fewer systemic adverse effects.

Among the newer regional techniques described for thoracoabdominal analgesia are the Modified thoracoabdominal plane block through perichondrial approach (M-TAPA) block and the erector spinae plane (ESP) block. The visceral analgesic effect of ESPB appears inconsistent and may be limited by technical and anatomical factors. ESPB requires relatively deep needle placement at thoracic levels, and achieving reliable anterior spread of local anesthetic is highly operator dependent. These challenges may be exacerbated in obese patients undergoing bariatric surgery, in whom ultrasound visualization and needle control can be technically demanding. Furthermore, uncertainty regarding the mechanism and extent of visceral afferent blockade, along with concerns about potential complications related to deep paraspinal injection, may limit the reproducibility and routine clinical applicability of ESPB in this population.

In contrast, the modified thoracoabdominal nerve block through the perichondrial approach (M-TAPA) is a more superficial and anatomically predictable technique designed to block thoracoabdominal nerves supplying the upper abdominal wall. Emerging evidence suggests that M-TAPA provides effective postoperative analgesia and opioid-sparing benefits in upper abdominal laparoscopic surgery, with a simpler and potentially safer technical profile compared with deeper regional techniques. Given its reduced operator dependency and technical simplicity, M-TAPA may represent an appealing alternative for patients undergoing laparoscopic sleeve gastrectomy. However, direct comparative evidence between ESPB and M-TAPA in this specific surgical context, particularly with respect to visceral pain control, remains lacking. Therefore, a randomized comparison of these two techniques is warranted.

Inclusion Criteria:

• Patients from both sexes.
• 18 to 60 years old.
• ASA physical status II-III scheduled for laparoscopic sleeve gastrectomy.
• Patients with BMI (40-50) kg/ m2

Exclusion Criteria:

• Patient Refusal
• Lack of patient cooperation.
• Patients with any contraindication to regional nerve blocks as coagulopathy or infection at site of injection
• Patients with anatomical abnormalities at site of injection
• Patients with known hypersensitivity to bupivacaine, or any of the used drugs.
• Patients with pre-existing neurological disorder
• Patients with chronic pain syndromes including fibromyalgia, complex regional pain syndrome (CRPS), or chronic pain requiring long-term opioid or neuropathic pain medications.
• Patients with history of long-acting opioids, steroids, anticonvulsants perioperatively.