Targeted Management of Somatic Pain in Laparoscopic Cholecystectomy: A Prospective Comparison of Lateral and Subcostal TAP Block Approaches for Drain-Site Analgesia

Introduction Laparoscopic cholecystectomy is one of the most frequently performed surgical procedures for the treatment of gallbladder diseases. Although it is considered a minimally invasive technique, patients may still experience significant postoperative pain. This pain has both visceral and somatic components, with somatic pain being particularly prominent at trocar incision sites and surgical drain entry sites.

Effective management of postoperative pain is crucial for enhancing patient comfort, promoting early mobilization, and shortening hospital stay. Therefore, multimodal analgesia protocols and opioid-sparing regional anesthesia techniques are increasingly being incorporated into perioperative care. The transversus abdominis plane (TAP) block is a widely used regional analgesia technique that targets the somatic innervation of the anterior abdominal wall and has demonstrated efficacy in reducing postoperative pain and opioid requirements following abdominal surgery [1][2] .

The transversus abdominis plane (TAP) block can be performed using different ultrasound-guided approaches, including the lateral, posterior, and subcostal techniques. These approaches differ in their dermatomal coverage and duration of analgesia. The lateral TAP block is performed by injecting a local anesthetic into the fascial plane between the internal oblique and transversus abdominis muscles under ultrasound guidance. This technique aims to provide temporary blockade of the T6-L1 spinal nerve branches that supply somatic innervation to the anterior abdominal wall. It is widely used for postoperative pain management following lower and lateral abdominal procedures, including cesarean section, gynecological surgery, appendectomy, laparoscopic abdominal surgery, and inguinal hernia repair [1]. Previous studies have demonstrated that TAP block can provide prolonged postoperative analgesia and significantly reduce both opioid consumption and pain scores, particularly during the first 12-48 hours after surgery [3,4].

Similarly, randomized controlled trials have demonstrated that TAP block techniques can reduce postoperative pain scores and decrease opioid requirements [5]. Consequently, TAP blocks have become an important component of multimodal analgesia protocols in laparoscopic surgery [1]. However, most studies in the current literature have focused on overall postoperative pain and opioid consumption, while specific sources of postoperative pain have rarely been evaluated separately.

In patients undergoing surgical drain placement, the drain insertion site has been clinically recognized as a distinct source of somatic pain, particularly involving the lateral abdominal wall. Despite its clinical relevance, studies specifically investigating analgesic strategies targeting drain-related pain remain scarce. Most available studies have evaluated global pain scores and opioid consumption, whereas localized outcomes such as drain-site pain have seldom been assessed.