Modified Paramedic Sagittal vs. Transverse TMQLB

The classical transmuscular qudratus lumborum block(TMQLB) described by Borglum aims to provide lower thoracic paravertebral space(PVS) and sympathetic blockade by injecting local anesthetics between QL and PM muscle at the L3-L4 vertebral level using a transverse scan, posterior-anterior, in-plane approach. Recently, a paramedian sagittal oblique(TMQLB) approach has been introduced to facilitate cranial spread by injecting the local in a caudal to cranial direction. Currently, there are no data comparing the two techniques mentioned above with regards to extent of spread for PVS. Our objective is to investigate the extent of cranial dermatomal spread of TMQLB when equal dosage(ml/kg) of local anesthetic are injected with the transverse versus an modified paramedian sagittal approach for patients undergoing laparoscopic adrenalectomy. In addition, the investigators wish to compare the performance time, caudal dermatomal spread of TMQLB and postoperative analgesia effect.