This study aims to compare the costotransverse foramen block with erector spinae plane block in modified radical mastectomy.

Postoperative pain following modified radical mastectomy (MRM) is a considerable consequence, impacting the ipsilateral upper limbs, axillae, and thorax, resulting in diminished functional ability and substantial economic and societal repercussions.

Erector spinae plane block (ESPB), an interfascial block, minimizes nerve and vessel injury by allowing local anesthetics to diffuse across relevant spaces; it is technically simpler and has shown benefits in reducing postoperative analgesic use and pain scores.

A novel technique, the costotransverse foramen block (CTFB), is one type of Inter-transverse process (ITP) blocks. This technique entails the anterior dispersion of the local anesthetic injectate into the paravertebral region, affecting the thoracic nerve at the injection site and neighboring levels, while exhibiting negligible posterior diffusion of dye to the deep back muscles

Inclusion Criteria:

• Adult females > 18 years and ≤ 65 years old.
• American Society of Anesthesiologists (ASA) physical status П-III.
• Body mass index (BMI) 18-35 kg/m2.
• Scheduled for modified radical mastectomy.

Exclusion Criteria:

• Known allergy or hypersensitivity to local anesthetic agents.
• Active infection at the injection site (e.g., cellulitis, abscess).
• Coagulopathy or ongoing anticoagulant/antiplatelet therapy [International Normalized Ratio (INR) > 1.5 or platelet count < 100,000/µL].
• Severe respiratory, cardiac, hepatic, or renal disease.
• Morbid obesity.
• Severe cognitive impairment or uncooperative behavior that could interfere with block placement.

Females scheduled for modified radical mastectomy

The data will be available upon a reasonable request from the corresponding author after the end of study for one year.

After the end of study for one year.

The data will be available upon a reasonable request from the corresponding author.