Laparoscopic-Assisted Transversus Abdominus Plane Block Versus Intraperitoneal Irrigation of Local Anesthetic for Patients Undergoing Laparoscopic Cholecystectomy - A Prospective, Randomised Clinical Trial

Laparoscopic cholecystectomy remains the cornerstone in treating benign diseases of the gallbladder and biliary tree, with approximately 5,000 of these procedures being performed annually in the Republic of Ireland. While significant complications, including bile leak, common bile duct injury (CBDI), and converting to an open incision, are typically discussed in detail when counselling patients in the preoperative setting, post-operative pain in the first 24-hours after surgery remains the main barrier of early discharge following the procedure. To counteract this issue, multimodal analgesic strategies have practically been adopted to minimise post-operative pain following laparoscopic cholecystectomy, as outlined by the Procedure Specific Post-Operative Pain Management (PROSPECT) in their review and recommendations. More specifically, the PROSPECT guidelines provide GRADE A recommendations in support of both standard paracetamol and non-steroidal anti-inflammatory (or cyclooxygenase-2 specific inhibitors), combined with surgical site local anaesthetic infiltration in patients in the peri-operative setting 'as the first line for routine use'.

Despite these recommendations, there remains ambiguity in the surgical literature surrounding to the optimal strategy for the infiltration of local anaesthetic; previous data has coherently demonstrated the superiority of surgical site wound infiltration, intraperitoneal infiltration and intra-abdominal wall blocks with local anaesthetic agents in reducing post-operative pain relative to placebo. In particular, data from a previous randomised clinical trial (RCT) has indicated that infiltrating the gallbladder fossa with local anaesthetic is more effective in reducing post-operative pain than local wound infiltration, however these results were subsequently refuted in a sequential RCT, leaving ambiguity as to the effect of this technique in reducing post-operative pain. Furthermore, recent RCTs have demonstrated that infiltration of local anaesthetic into either transversus abdominus plane (TAP) or the rectus sheath intraoperatively reduced post-operative pain compared to infiltration into the wound alone, directly reducing the post-operative morphine requirement. While ultrasound-guided transversus abdominus plane (US-TAP) are now commonly utilised in the perioperative setting following laparoscopic cholecystectomy, the suitability of a laparoscopic-guided approach (L-TAP) has been less well established within the surgical literature.

Given the contrasting results of these previous studies, there remains no consensus as to the validity of using L-TAP or intraperitoneal infiltration of local anaesthetic to the liver bed as contemporary modes of delivering local anaesthetic following laparoscopic cholecystectomy. Accordingly, the aim of this study was to perform a prospective, randomised study evaluating the benefit of L-TAP or intraperitoneal infiltration in patients indicated to undergo laparoscopic cholecystectomy. This study is a parallel two-arm study which will evaluate outcomes following local anesthetic infiltration (1) directly into the laparoscopic port sites combined with intraperitoneal infiltration, and (2) directly into the laparoscopic port sites combined with laparoscopic infiltration via TAP block.