This prospective, randomized clinical study aims to evaluate the effectiveness of the Transversus Abdominis Plane (TAP) block performed under direct laparoscopic vision in reducing postoperative pain and improving recovery after laparoscopic inguinal hernia repair using the TAPP (Transabdominal Preperitoneal) technique.

The study will enroll 100 adult patients undergoing elective laparoscopic TAPP hernia repair at the University Clinical Hospital in Olsztyn, Poland. Participants will be randomly assigned to two equal groups. In the study group, a bilateral TAP block will be performed under direct vision using 20 ml of 0.25% bupivacaine on each side after establishing pneumoperitoneum. The control group will undergo the same surgical procedure without the TAP block.

All patients will receive standardized anesthesia and postoperative pain management according to hospital protocol. Postoperative pain intensity will be assessed using the Visual Analogue Scale (VAS) at 0, 6, and 12 hours after surgery. Additional data, such as time to mobilization, use of rescue analgesics, and occurrence of postoperative complications (hematoma, swelling, subcutaneous emphysema, transient muscle weakness), will also be recorded.

The primary goal of this study is to determine whether a laparoscopically guided TAP block can effectively reduce postoperative pain and improve recovery parameters following TAPP hernia repair. The results may help establish a simple, safe, and reproducible method of multimodal analgesia in minimally invasive inguinal hernia surgery.

Inguinal hernia is one of the most common surgical conditions, affecting approximately 3% of the adult population. The only effective and lasting method of treatment is surgical repair. The laparoscopic transabdominal preperitoneal (TAPP) technique has become one of the most widely used minimally invasive approaches, offering reduced postoperative pain, shorter hospital stay, and faster return to daily activities compared with open repair. However, postoperative pain remains a relevant clinical problem and an important factor limiting early mobilization and recovery.

Multimodal analgesia is currently considered the standard approach for postoperative pain management. It combines systemic analgesics with regional anesthesia techniques. One of the increasingly used regional methods is the Transversus Abdominis Plane (TAP) block, which provides analgesia of the anterior abdominal wall by anesthetizing the intercostal, subcostal, iliohypogastric, and ilioinguinal nerves. The block can be performed under ultrasound guidance or, more recently, under direct laparoscopic vision, which improves safety and accuracy.

This single-center, prospective, randomized clinical study aims to assess the effect of a visually guided TAP block on postoperative pain and recovery after laparoscopic inguinal hernia repair (TAPP). The study will be conducted at the University Clinical Hospital in Olsztyn, Poland, between 2025 and 2027.

A total of 100 adult patients scheduled for elective laparoscopic TAPP hernia repair will be enrolled and randomly assigned (1:1) to one of two groups:

1. TAP Block Group (n = 50): After pneumoperitoneum is established and the laparoscope is introduced, a bilateral TAP block will be performed under direct vision. Using a needle and syringe, 20 ml of 0.25% bupivacaine (50 mg) will be injected approximately 2 cm below the costal margin in the anterior axillary line on both sides. Proper distribution of the local anesthetic will be confirmed visually by observing the characteristic elevation of the transversus abdominis muscle layer (known as the "Doyle's bulge sign").
2. Control Group (n = 50): The standard TAPP repair will be performed without additional regional anesthesia.

All patients will receive standardized general anesthesia and postoperative pain management. Analgesics will be administered according to a fixed schedule: metamizole 1.0 g orally at 6 and 12 hours after surgery. If needed, additional rescue medication will be provided: paracetamol 1.0 g orally for moderate pain (VAS < 6) or oxycodone 10 mg subcutaneously for severe pain (VAS > 6).

Pain intensity will be assessed using the Visual Analogue Scale (VAS) at 0, 6, and 12 hours after surgery, with separate evaluation for each surgical site (umbilical port, working trocar on the operated side, working trocar on the opposite side, operated groin, and operated testicle). Additional parameters include time to first mobilization, total analgesic consumption, and early postoperative recovery assessed with the Post Anesthesia Discharge Scoring System (PADSS). The occurrence of adverse events such as subcutaneous emphysema, hematoma, swelling, or transient lower limb weakness will also be recorded.

Patients with chronic pain syndromes, psychiatric disorders, alcohol or opioid dependence, recurrent hernias, or emergency indications will be excluded from the study. All participants will provide written informed consent before enrollment.

The collected data will be statistically analyzed to compare pain intensity, analgesic requirements, and recovery parameters between groups. The primary endpoint is postoperative pain intensity at 6 hours (VAS). Secondary endpoints include pain at 0 and 12 hours, time to mobilization, use of rescue analgesics, and adverse event rates.

The hypothesis of the study is that a laparoscopically guided TAP block significantly reduces postoperative pain intensity and improves recovery after laparoscopic TAPP hernia repair. The results of this study may contribute to the optimization of multimodal analgesia protocols in minimally invasive inguinal hernia surgery by introducing a simple, reproducible, and safe intraoperative analgesic technique.

Inclusion Criteria:

• Age 18-80 years
• Elective laparoscopic inguinal hernia repair using the TAPP (Transabdominal Preperitoneal) technique
• ASA physical status I-III
• Ability to provide written informed consent
• No contraindications to regional anesthesia or local anesthetic administration

Exclusion Criteria:

• Recurrent or strangulated inguinal hernia
• Emergency surgery
• Chronic pain syndromes or preoperative opioid use
• Known allergy or hypersensitivity to local anesthetics (bupivacaine or similar)
• Severe hepatic or renal impairment
• Psychiatric disorders or inability to provide informed consent
• Conversion to open surgery during the procedure
• Technical difficulties preventing TAP block administration

Individual participant data (IPD) will not be shared because this is a single-center, investigator-initiated academic study involving a limited number of participants. The collected data include sensitive personal and clinical information that cannot be fully anonymized without compromising data integrity. Only aggregated, de-identified results will be published in peer-reviewed journals and conference presentations.

This study uses a single-blind design. Randomization is performed immediately before surgery using a concealed allocation sequence. The operating surgeons are aware of group assignment in order to perform the appropriate intervention (TAP block or none). Participants remain blinded to their allocation throughout the study period. Postoperative data, including pain intensity (VAS) and recovery parameters, are collected according to a standardized protocol by staff not involved in the randomization or intervention process to reduce potential bias.