Ultrasound Guided Retrolaminar Block Versus Transverse Abdominis Plane Block in Laparoscopic Upper Abdominal Surgeries

Laparoscopic surgery is now a widely accepted practice, offering several advantages, including better cosmetic outcomes, increased patient satisfaction, and shorter hospital stays . The complexity and range of procedures performed laparoscopically have grown significantly, now including complex operations like cholecystectomy, nephrectomy, hernia repair, and an increasing number of emergency surgeries .

Despite these benefits, postoperative pain following laparoscopic procedures, such as cholecystectomy, can be substantial and hinder recovery . This pain may negatively affect respiratory function, delay ambulation, and ultimately prolong their hospital stay. Historically, pain management has often relied on high doses of narcotics, which may lead to complications like dizziness, respiratory depression, and postoperative nausea and vomiting (PONV) . These drawbacks have spurred the search for alternative and improved pain relief strategies .

Ultrasound-guided nerve blocks have become an essential component of multimodal postoperative analgesia due to their effectiveness, precision, and safety profile . One of such techniques is the Transversus Abdominis Plane (TAP) block, which is used as part of a comprehensive strategy to optimize postoperative pain control. Local anesthetic is injected into the neurovascular plane of the abdominal wall . The TAP block works by providing sensory blockade to the spinal nerves that run between the internal oblique and transverse abdominis muscles. The anesthetic infiltration affects the thoracic intercostal nerves, the ilioinguinal and iliohypogastric nerves, and the lateral cutaneous branches of the lumbar nerves.

Another important technique is the Retrolaminar Block (RLB), introduced in 2006 as a simpler alternative to the thoracic paravertebral block (TPVB) . The RLB is less invasive because it targets the bony vertebral lamina, unlike the TPVB, which requires puncturing the superior costotransverse ligament . The procedure involves injecting a local anesthetic (LA) into the fascial plane located between the posterior thoracic lamina and the overlying transversus spinae muscles allowing spread of the local anesthetic to the thoracic paravertebral and epidural spaces, thus the blockade of the dorsal branch of the spinal nerves that cross the retrolaminar plane .Studies, including cadaveric models, have confirmed that the anesthetic injected during an RLB spreads through the intertransverse ligaments into the paravertebral and epidural spaces, effectively numbing 2-4 spinal segments . For instance, a 2022 clinical trial showed that ultrasound-guided RLBs significantly reduced opioid consumption in patients recovering from laparoscopic cholecystectomy compared to conventional pain management , highlighting its potential as a safe and effective option.

• Numeric Rating Scale (NRS) at rest and during coughing [Time frame: Immediately after arrival in the post-anesthesia care unit (0 hours), and at 2, 4, 6, 12, and 24 hours after surgery.]
• Total dose of rescue analgesics administered (mg) within the first 24 hours after surgery [Time frame: From the end of surgery to 24 hours after surgery.]
• Time to first postoperative opioid analgesic request (hours) [Time frame: From the end of surgery until the first request for opioid analgesia, up to 24 hours postoperatively]
• Duration of hospital stay [Time frame: From the date of surgery until hospital discharge, assessed for up to 30 days after surgery]
• Mean intraoperative mean arterial pressure (mmHg) [Time frame: At baseline (before block), immediately after block (0 minutes), at 5, 10, 20, 30, 60, 90, and 120 minutes after block , or until the end of surgery, whichever occurs first.]
• Mean intraoperative heart rate (beats/min) [Time frame: At baseline (before block), immediately after block (0 minutes), at 5, 10, 20, 30, 60, 90, and 120 minutes after block , or until the end of surgery, whichever occurs first.]
• Mean intraoperative peripheral oxygen saturation (%) [Time frame: At baseline (before block), immediately after block (0 minutes), at 5, 10, 20, 30, 60, 90, and 120 minutes after block , or until the end of surgery, whichever occurs first.]
• Number of participants with postoperative nausea [Time frame: From the end of surgery to 24 hours after surgery]
• Number of participants with postoperative vomiting [Time frame: From the end of surgery to 24 hours after surgery]
• Number of participants with postoperative shivering [Time frame: From the end of surgery to 24 hours after surgery]
• Number of participants with postoperative hypotension [Time frame: From the end of surgery to 24 hours after surgery]
• Number of participants with postoperative bradycardia [Time frame: From the end of surgery to 24 hours after surgery]