Postoperative analgesia after breast cancer surgery is a challenge for anesthesiologists due to the complex innervation of the breast. Interfascial plane blocks of the chest are gaining widespread popularity with the introduction of ultrasonography into the regional anesthesia practice. We aimed to investigate the efficacy of Rhomboid intercostal and subserratus plane block (RISS) for postoperative analgesia in patients undergoing breast cancer surgery.

This prospective randomized controlled trial will be carried out on female patients who scheduled for breast cancer surgery. Our hypotesis is that this new interfascial plane block technique will able to provide postoperative analgesia in breast cancer surgery.

Inclusion Criteria:

• Female patients aged 18-85 years and ASA physiological score I-III who undergone breast cancer surgery

Exclusion Criteria:

• Patients refused to participate.
• Patients with known or suspected allergy to the used medication.
• Patients with psychiatric-neurological disorders that may affect pain perception,
• Patients regularly taking antipsychotics and antidepressants.
• Patients with potential risk of coagulopathy.
• Uncooperative patients.