Combined PECS II and Transversus Plane Blocks Versus Erector Spinae Block in Modified Radical Mastectomy

Modified pectoralis nerve block (Pecs II) aims to block at least the pectoral nerves, the intercostobrachial, intercostals III-IV-V-VI. This will cover dermatomes T2, T3 and T4. The probe is positioned under the lateral third of the clavicle .After locating the subclavian muscle, the axillary artery and the axillary vein we move the probe distally towards the axilla, until the pectoralis minor is identified. We start counting the ribs , from r1 under the axillary artery, we move distally and laterally until the lateral border of pectoralis minor is reached. The serratus anterior muscle which covers r2, r3, r4 is the point of entrance into the axilla. Blocking of multiple anterior branches of intercostal nerves (Th2-6) using a transversus thoracic muscle plane (TTP) block is used as an additive to pecs II to cover the internal mammary region

The patient is placed in a sitting position and The T5 spinous process is located by palpating and counting down from the C7 spinous process. Under complete aseptic conditions a linear ultrasound probe is then placed in a transverse orientation at the level of the T5 transverse process. The tip of the transverse process is centred on the ultrasound screen and the probe is then rotated into a longitudinal orientation to produce a parasagittal view. From T1 to T5 the erector spinae, rhomboid major and trapezius muscles are visible posterior and superficial to the transverse processes.