Thermal-Imaging Comparison of Nerve Blocks for Bilateral Mastectomy

This is a one-armed trial of two regional anesthesia (peripheral nerve block) techniques to provide postoperative analgesia after bilateral mastectomy. The two techniques are paravertebral block and erector spinae plane (ESP) block. Patients will serve as their own controls, with one block technique applied on one side of the body and the other technique contralaterally. Anatomical distribution of block effectiveness will be assessed with thermal imaging, and this distribution will be visually compared between the two techniques.