Pectoral Nerve Block Versus Paravertebral Block In The Incidence of Chronic Pain After Mastectomy:

Bupivacaine 0.25% 20 ml was injected between the costotransverse ligament and the parietal pleura.

entering the plane between the pectoralis minor muscle and serratus anterior muscle, and bupivacaine 0.25% 10 ml was deposited in this space