Thoracic Interfascial Plane Block Versus Thoracic Paravertebral Block in Gynecomastia Surgery

Surgical disinfection of the area will be performed, skin infiltration with 2 mL of 1% lidocaine will be done, and wetting fluid will be used (1000 ml normal saline, 20 ml lidocaine 2%, and 1 mg epinephrine).

Infiltration will be initiated with a 25-gauge needle. The 25-gauge needles cause little discomfort and provide enough local anesthesia to allow painless, more complete infiltration using a 20-gauge spinal needle. After the glandular nipple tissue is made somewhat tumescent, a larger (20-gauge) spinal needle can be more easily passed through the otherwise dense and resistant tissue.

The paravertebral block (PVB) will be performed in the sitting position. Surgical disinfection of the thoracic paravertebral area will be done. A linear high-frequency transducer will be used. The scanning process (longitudinal out-of-plane technique) will be started at 5 to 10 cm lateral to the spinous process to identify the rounded ribs and parietal pleura underneath. The transducer is then moved progressively more medially until transverse processes are identified as more squared structure and deeper to the ribs. Once the transverse processes will be identified, skin infiltration with 2 mL of 1% lidocaine will be done. A 100-mm, 22 G needle will be inserted out of the plane to contact the transverse process and then walk off the transverse process 1 to 1.5 cm deeper searching for loss of resistance to inject 20 mL (5mL lidocaine 2% and 15 mL bupivacaine 0.25%) at each level of T4.

Total LA injected was 80 mL (10 mL lidocaine 2% and 70 mL bupivacaine 0.25%) The linear probe will be placed below the outer third of the clavicle to detect anatomical landmarks, such as the serratus anterior muscle (SAM), external intercostal muscle (EIM), pectoralis muscles, thoracoacromial artery, and second rib. A test bolus of 1-2 ml of LA will be injected; upon confirmation of diffusion of the test dose between the external intercostal muscles and the SAM, a total of 20 ml of LA will be injected. The needle will be then carefully moved in the direction of the third and fourth ribs while confirming the expansion of the fascial plane.

In the performance of the pecto-intercostal fascial plane block (PIFB), a probe will be placed parallel to the long axis of the sternum at a distance greater than 2 cm from the attachment of the second rib and sternum to identify the pectoralis muscles, EIM, and second rib. A