Parasagittal versus transverse approaches of erector spinae plane block for post operative analgesia in patients undergoing modified radical mastectomy-A randomized controlled trial

Modified radical mastectomy (MRM) is most common type of surgery performed in patients of breast cancer. Regional blocks for breast surgery have reduced post-operative pain score, reduced opioid requirement, decrease post-operative nausea and vomiting and decrease duration of stay in post anesthesia care unit. 

Various regional anesthesia techniques have been described for management of post-operative pain following breast surgery like epidural administration, thoracic paravertebral block, intercostal block, brachial plexus block, pectoral nerve block, serratus anterior block and recently described erector spinae plane block (ESPB).

ESPB is a recently described ultrasound guided technique for management of acute and chronic thoracic pain. In this block, local anesthetic is injected deep to erector spinae muscle which results in blocking of ventral and dorsal rami of spinal nerve. ESPB is safe and efficacious for pain management of most of the thoracic wall structures including MRM.

Parasagittal approach of ESPB is commonly used , however identification of tip of transverse process is difficult in this approach and may lead to block failure. Recently transverse approach of ESPB has been described in which needle can be accurately positioned at the tip of transverse process. This approach also has less risk of the puncture of the lung or other visceral organs.