Erector Spinae Block Versus Paravertebral Block on Chronic Pain After Mastectomy

Thoracic paravertebral block is performed at the level of T4 or T5 if no axillary procedure is to be performed, and additionally at the level of T2 if axillary procedure is planned. A high-frequency transducer probe connected to an ultrasound (US) machine is positioned in a para-median sagittal plane, approximately 2-2.5 cm lateral to the spinous process at the ipsilateral side of surgery location to localize the transverse process and the paravertebral space. The skin is sterilized and the US probe covered with a sterile cap. A 22-gauge, 100 mm stimuplex nerve block needle is introduced in an in-plane direction. After perforating the costotransverse ligament and confirming negative aspiration of blood, 20ml of a mixture of ropivacaine 0.5% is injected. Anterior displacement of the pleura indicates appropriate spread of local anaesthesia (LA) in the paravertebral space.

The ESB is performed at the level of T4-T5 if no axillary procedure is to be performed, and additionally at the level of T2 (5ml) if axillary procedure is planned. A transducer probe is positioned in a para-median sagittal plane approximately 3 cm lateral to the spinous process at the ipsilateral side of surgery. Following the same sterilization procedure, the 10 cm stimuplex needle is introduced in an in-plane direction. The transverse process of the vertebrae, trapezius muscle, rhomboid major and erector spinae muscle are visualized, and 25 ml of ropivacaine 0.5% mixture is injected after confirming negative aspiration of blood (lower the concentration not to exceed 2 mg/kg ideal body weight). The LA spread lifts the erector spinae muscle off the bony shadow of the transverse process.