mTLIP vs QIPB for Postoperative Analgesia in Lumbar Microdiscectomy Surgery

Comparison of Ultrasound-Guided Modified Thoracolumbar Interfascial Plane Block Versus Quadro-Iliac Plane Block for Postoperative Analgesia in Patients Undergoing Lumbar Microdiscectomy

The aim of this prospective randomized clinical study is to compare the analgesic efficacy and side effects of modified thoracolumbar interfascial plane block and quadroiliac plane block applied preoperatively in patients undergoing lumbar microdiscectomy surgery.The study will include a total of 80 patients aged 18-65 years with ASA I-III, with 40 patients in each group( Group mTLIP and Group QIPB) undergoing lumbar microdiscectomy surgery.

The primary objective of the study is to compare groups in terms of PCA opioid consumption during the 48-hour postoperative period. Secondary objectives are to compare groups in terms of QoR-15 recovery score, dynamic and static numerical rating scale scores, total rescue analgesic use, time to first request for rescue analgesia, length of hospital stay, block and opioid-related side effects and complications, and perioperative remifentanil infusion dose.

Lumbar spine surgery is commonly associated with moderate to severe postoperative pain . Inadequate pain control may lead to delayed mobilisation, increased cardiopulmonary complications, and prolonged hospital stay.

Ultrasound-guided regional analgesia techniques, particularly fascial plane blocks, are increasingly used as part of multimodal analgesia in lumbar spine surgery. The thoracolumbar interfascial plane (TLIP) block is an established technique that provides effective analgesia and has been modified to improve its clinical application, resulting in the modified thoracolumbar interfascial plane (mTLIP) block. Previous studies have demonstrated the effectiveness of mTLIP for postoperative analgesia after lumbar spine surgeries.

The quadro-iliac plane block (QIPB) is a recently described ultrasound-guided fascial plane block. Early reports suggest that QIPB may provide effective analgesia in lumbar spine procedures; however, comparative evidence with established techniques remains limited.

This prospective randomized clinical trial aims to compare bilateral ultrasound-guided mTLIP and QIPB performed before the surgery in patients undergoing elective lumbar microdiscectomy surgery under general anesthesia, to evaluate whether QIPB can be considered a safe and effective alternative to mTLIP for postoperative analgesia.

Inclusion Criteria:

• Age between 18 and 65 years
• Classified as American Society of Anesthesiologists physical status I-III
• Scheduled for elective lumbar microdiscectomy surgery under general anesthesia
• Provision of written informed consent

Exclusion Criteria:

• Use of anticoagulant medications or presence of bleeding diathesis
• Known allergy or hypersensitivity to local anesthetics or opioid drugs
• Infection at the planned block site
• Alcohol or drug dependence
• Cognitive impairment preventing reliable pain assessment
• Pregnancy or lactation
• History of previous lumbar spine surgery
• Diabetes mellitus
• Renal or hepatic insufficiency