Efficacy of TLIP Block for Postoperative Analgesia of Lumbar Spinal Fusion

This is a multicenter, randomized, double-blind (participant and care provider assessing outcomes), parallel-group controlled, trial assessing the interest of the association of TLIP block to general anesthesia for postoperative analgesia management in patients undergoing posterior lumbar spinal fusion.

This study compares two groups:

"Control" group: standard general anesthesia. "TLIP" group: standard general anesthesia + TLIP block with an injection of 40 ml of ropivacaine 0.25% (2 injections of 20 ml on each side) between multifidus and longissimus muscles.

• General anesthesia

General anesthesia will be standardized in the two groups:

• Induction with propofol 2-3 mg/kg, sufentanyl 0.2-0.3 µg/kg and ketamine 0.3 mg/kg
• Intubation facilitated according centre's protocol and ventilation performed with 50% oxygen and 50% air in order to maintain normocapnia and normoxia.
• Anesthesia maintained according to the centre's usual care.
• Prevention of postoperative nausea and vomiting (NVPO) according centre's protocol.

• TLIP block technique ("TLIP" group only) The regional anesthesia procedure will be performed under general anesthesia and will be guided by ultrasound with high-frequency linear probe, patient in prone position or genupectoral (knee-chest) position. The probe will be positioned in order to have an axial view of lumbar vertebrae. The 3rd lumbar vertebra (L3), the 4th lumbar vertebra (L4) and the 5th lumbar vertebra (L5) will be identified after initial identification of the sacrum. A needle will be inserted in plane (IP) and advanced to reach the interspace between the multifidus and the longissimus muscles on the tip of the articular process. For each patient, the block will be performed bilaterally by injecting of 20 ml of Ropivacaine 0.25% on each side. Before each procedure, a skin disinfection will be carried out using an alcoholic iodine solution.

Patients will not receive any LA by intravenous injection or infiltration.

Inclusion criteria

• ≥ 18 years old,
• Undergoing posterior lumbar spinal one-level or two-level fusion surgery (L3-L4, L4-L5 and/or L5-S1),
• Having signed a written informed consent form,
• Affiliation to the social security system.

Exclusion criteria

• Contraindication for regional anesthesia (allergy to local anesthetics, neuropathic disease, infection at the puncture site, coagulation disorder, refusal of the technique,…)
• Contraindication to nonsteroidal anti-inflammatory drugs,
• Patient who have already had a spinal surgery,
• Patient with chronic pain syndrome (use > 3 months of morphine, opioid analgesics of class 3, pregabalin or gabapentin) or fibromyalgia,
• A mental or linguistic inability to understand the study,
• Patient under protection of the adults (guardianship, curators or safeguard of justice),
• Pregnant or or breastfeeding women.