Laparoscopic cholecystectomy (LC) can cause moderate-to-severe postoperative pain from visceral, referred shoulder, and incisional sources. Multimodal analgesia is recommended, but opioids carry significant side effects. Ultrasound-guided interfascial plane blocks offer a safe alternative. The Modified Thoracoabdominal Nerve Block through Perichondrial Approach (M-TAPA) blocks T5-T12 dermatomes, while the Recto-Intercostal Fascial Plane Block (RIFPB) provides sensory blockade across the upper anterolateral abdomen. This study compares the postoperative analgesic efficacy of bilateral M-TAPA versus bilateral RIFPB in patients undergoing LC.

The gallbladder is a small organ located in the right upper quadrant of the abdomen that stores bile, which aids in food digestion. Gallstones form as a result of changes in bile composition caused by hormones, medications, diet, and weight fluctuations. When a gallstone obstructs the cystic duct, acute cholecystitis develops, leading to gallbladder distension and inflammation. Cholecystectomy is the standard surgical treatment performed worldwide for this condition.

Management of acute cholecystitis is either medical - consisting of bed rest, analgesics, antibiotherapy, and intravenous fluid replacement - or surgical, involving removal of the gallbladder. While the procedure can be performed via open or laparoscopic technique, laparoscopic cholecystectomy (LC) is superior in terms of less incisional pain, shorter hospital stay, improved quality of life, and faster recovery.

Despite being minimally invasive, LC can cause moderate-to-severe postoperative pain. The majority originates from incision sites (50-70%), with additional contributions from pneumoperitoneum (20-30%) and the cholecystectomy itself (10-20%). Severe pain leads to delayed mobilization, reduced patient satisfaction, chronic pain development, and increased pulmonary and cardiac complications. A multimodal analgesic approach is therefore recommended. Although NSAIDs, paracetamol, opioids, and local anesthetics are commonly used, opioids carry significant risks including postoperative nausea and vomiting (PONV), constipation, and respiratory depression. Neuraxial analgesia is rarely preferred due to potential complications and technical difficulties.

Ultrasound-guided interfascial plane blocks have gained increasing use in LC due to their safety and efficacy. The anterolateral abdominal wall is composed of the rectus abdominis, external oblique, internal oblique, and transversus abdominis muscles. The transversus abdominis plane contains the T6-L1 thoracolumbar nerves between the internal oblique and transversus abdominis muscles, and local anesthetic injection into this plane provides T7-L1 sensory blockade.

The Modified Thoracoabdominal Nerve Block through Perichondrial Approach (M-TAPA), introduced by Tulgar et al., applies local anesthetic solely to the inferior surface of the costochondral perichondrium at the 9th-10th rib level under ultrasound guidance, targeting T4/T5-T12/L1 thoracoabdominal nerves. It blocks anterior and lateral cutaneous branches to provide abdominal analgesia, with reported efficacy in both minor and major abdominal surgeries.

The Recto-Intercostal Fascial Plane Block (RIFPB), also described by Tulgar et al. in 2023, deposits local anesthetic into the interfascial plane between the rectus abdominis muscle and the 6th-7th costal cartilages, just below the xiphoid process. Methylene blue studies have demonstrated significant spread to the anterior cutaneous branches of T6-T9 and laterally, covering nearly the entire upper anterolateral abdomen. Based on these findings, 20 ml of local anesthetic will be used for RIFPB in this study, targeting T6-T9 dermatomal coverage.

This prospective, randomized, double-blind study aims to compare the postoperative analgesic efficacy of bilateral M-TAPA versus bilateral RIFPB in 70 patients (35 per group) undergoing LC. Both blocks will be applied under ultrasound guidance using 20 ml of 0.25% bupivacaine bilaterally after surgery while patients remain under anesthesia.

Postoperative pain will be assessed using the Numeric Rating Scale (NRS) at 0, 1, 3, 6, 12, 18, and 24 hours. Dermatomal spread will be evaluated at postoperative 2nd and 24th hours via pinprick testing across T3-L1 levels. Opioid consumption will be recorded via tramadol PCA at 0-1, 1-12, 12-24 hours, and total 24 hours. PONV will be monitored using a 4-point scale, and ondansetron rescue doses will be recorded. Quality of recovery will be assessed using the QoR-15 scale (scored 0-150) preoperatively and at 24 hours postoperatively, evaluating physical comfort, pain, physical independence, psychological support, and emotional state.

Inclusion Criteria:

• Age 18-65 years
• ASA physical classification I-II
• BMI < 35 kg/m²
• Scheduled for elective laparoscopic cholecystectomy due to cholelithiasis
• Able to use and understand the NRS pain scoring system
• Able to use and understand the QoR-15 scale
• Able to communicate in Turkish
• Provided written informed consent

Exclusion Criteria:

• Refusal to participate in the study
• BMI > 35 kg/m²
• ASA physical classification III-V
• Age < 18 or > 65 years
• Allergy to local anesthetics or study analgesics
• Pregnancy or breastfeeding
• Inability to use or understand the NRS pain scoring system or QoR-15 scale
• Inability to communicate in Turkish
• Uncontrolled anxiety disorder
• Alcohol or drug dependency
• Neuromuscular or peripheral nerve disease
• High-dose opioid use within 3 days prior to surgery
• Widespread chronic pain
• Diabetes mellitus
• Hepatic or renal insufficiency
• Coagulation disorders or anticoagulant use
• Infection at the block needle insertion site
• Concurrent second surgical procedure alongside laparoscopic cholecystectomy
• Previous abdominal surgery or trauma history
• Conversion from laparoscopic to open surgery
• Technical problems with the PCA device
• NRS score > 7 for four consecutive hours despite multimodal analgesia
• Planned postoperative non-extubation
• Termination of surgery before completion for any reason