Erector Spinae Block Versus Paravertebral Block on Chronic Pain After Mastectomy

The goal of this clinical trial is to learn if the erector spinae block can reduce the incidence of chronic pain compared to the paravertebral block in adult patients undergoing total mastectomy. The study includes patients aged 18 to 80 years scheduled for mastectomy, with or without axillary dissection. The main questions it aims to answer are:

* Does erector spinae block reduce the incidence of chronic pain at 3 months after mastectomy compared to paravertebral block? * Does erector spinae block affect postoperative outcomes such as opioid consumption at 48 hours, pain scores (in PACU, 24 and 48 hours), block performance time, and the incidence of complications, anxiety or depression, and pain intensity at 3 months?

Researchers will compare patients receiving erector spinae block to those receiving paravertebral block to determine if erector spinae block provides equivalent or improved outcomes in terms of chronic pain and perioperative measures.

Participants will:

* Be randomly assigned to receive either erector spinae block or paravertebral block prior to surgery * Undergo total mastectomy (with or without axillary dissection) * Have their pain assessed in the PACU and at 24 and 48 hours postoperatively * Have opioid consumption measured during the first 48 hours after surgery * Be followed up at 3 months to assess chronic pain, pain intensity, and psychological outcomes (anxiety or depression)