Erector Spinae Plane Block Versus Quadratus Lumborum Block for Postoperative Analgesia After Laparoscopic Resection of Colorectal Cancer.

Colorectal cancers are one of the leading causes of cancer-related mortality, and the incidence is increasing day by day. For this reason, colorectal cancer surgery and postoperative analgesia have gained more importance in recent years.Although laparoscopic surgery is less invasive, it can still generate moderate to severe acute postoperative pain.For a long time, opioids have played a major role in postoperative analgesia, but heavy use of these drugs will cause adverse reactions such as nausea, vomiting and enteroparalysis, which is not conducive to rapid recovery after surgery Therefore, it is critical to developing a more effective regional analgesic technique for patients undergoing abdominal surgery . Erector spinae plane block (ESPB) is a novel interfascial plane block technique that was firstly described in 2016. It involves injecting local anesthetic into the plane between the deep fascia of the erector spinae muscle and the vertebral transverse process under ultrasound guidance to relieve pain in the thoracoabdominal region .The quadratus lumborum block (QLB) is a new posterior abdominal trunk block which produces analgesic effects through local anesthetic that covers thoracolumbar fascia and thoracic paravertebral space. Based on the injection position and approach, there are 3 QLB techniques: lateral approach, posterior approach and anterior approach. The anterior transmuscular quadratus lumborum block (TQLB) is a truncal block (ventral rami of T7- L2) that produces its analgesic effect by blocking the thoracic sympathetic trunk, the ventral rami of lower spinal nerves, the sympathetic fibers and mechanoreceptors within the thoracolumbar fascia, and the celiac ganglion by spread via the splanchnic nerves .