Comparison of Postoperative Analgesic Efficacy of Ultrasound-Guided Ilioinguinal-Iliohypogastric Block, Transversus Abdominis Plane Block, and Quadratus Lumborum Block in Inguinal Hernia Surgery

Inguinal hernia is a common condition, particularly among male patients, and represents one of the most frequent indications for lower abdominal surgeries. Postoperative acute pain and, more importantly, the progression of acute pain into chronic pain, remain significant challenges in the postoperative period. Effective postoperative pain management is therefore crucial in inguinal hernia repair. In addition to systemic analgesia, various regional anesthesia techniques are employed in this setting. In recent years, peripheral nerve blocks such as the ilioinguinal-iliohypogastric (IL/IH) block, transversus abdominis plane (TAP) block, and quadratus lumborum block (QLB) have gained popularity for postoperative analgesia. These techniques offer several advantages, including reduced opioid consumption and decreased need for additional analgesics, while also minimizing hemodynamic instability and facilitating early mobilization. The IL/IH block is performed by injecting a local anesthetic into the fascial plane between the transversus abdominis and internal oblique muscles, targeting the ilioinguinal and iliohypogastric nerves, which are branches of the L1 spinal nerve. The TAP block, first described by Rafi in 2001, involves injecting local anesthetic into the fascial plane between the internal oblique and transversus abdominis muscles within the Petit triangle, where the T6-T11 spinal nerve branches responsible for abdominal wall innervation are located. The quadratus lumborum block (QLB) was initially described by Blanco. The first version, known as QLB1, involves posterior injection of local anesthetic lateral to the quadratus lumborum muscle. In 2013, Jens Børglum introduced the transmuscular variant (QLB3), where the local anesthetic is administered between the quadratus lumborum and psoas muscles. In this study, we aimed to compare postoperative outcomes in patients undergoing inguinal hernia repair under spinal anesthesia, with and without additional periphera