WOFAPS 2025 8th World Congress of Pediatric Surgery

Hannah Rachel Neeser ¹, Tim P. Gerwinn ¹, Victoria C. Forschbach ¹, Joerg Thomas ¹, Christian P. Both ¹, Stefanie von Felten ², Ueli Moehrlen ¹

¹ Children's University Hospital of Zurich, Switzerland
² Department of Biostatistics at Epidemiology, Biostatistics and Prevention Institute (EBPI), University of Zurich, Switzerland

Purpose: Laparoscopic surgery is commonly performed in children, partly due to its association with reduced postoperative pain compared to open surgery. However, it remains unclear whether lower pressure of pneumoperitoneum reduces postoperative abdominal and/or shoulder pain in pediatric patients. The main objective was to determine whether low-pressure pneumoperitoneum (8 mmHg) reduces postoperative pain compared to standard-pressure pneumoperitoneum (12 mmHg) in children undergoing laparoscopic appendectomy for acute appendicitis.

Methods: We conducted a single-center, parallel-group, superiority randomized controlled trial. Children aged 5–17 years scheduled for laparoscopic appendectomy were randomly assigned (1:1) to low-pressure (8 mmHg) or standard-pressure (12 mmHg) pneumoperitoneum. Stratified block-randomization with patient age (5-10 years vs. ≥11 years) was performed. The patients and their parents were blinded regarding group allocation. The primary outcome was postoperative abdominal pain intensity, measured using the revised Faces Pain Score on the first postoperative day (over 8h postoperatively). Secondary outcomes included shoulder pain intensity, side of shoulder pain, and intra- and postoperative complications. Analyses were mainly performed on the per-protocol population. Pain scores were analyzed using mixed-effects proportional odds models, due to their ordinal nature.

Results: Of 250 randomized patients, 191 completed the study per protocol (low pressure n=81, standard pressure n=110) with a median age of 11.55 years and median weight of 40 kg. Contrary to our hypothesis, low-pressure pneumoperitoneum was associated with higher postoperative abdominal pain scores (proportional odds ratio 1.74, 95% CI 1.01 - 3.00, p=0.046) compared to standard pressure. Shoulder pain, when present, was more intense on the right side in both groups (OR 7.81, 95% CI 3.92 – 15.55). There were no significant differences regarding secondary outcomes between groups.

Conclusions: In children undergoing laparoscopic appendectomy, low-pressure pneumoperitoneum does not reduce postoperative pain compared to standard pressure. Both approaches demonstrated similar safety profiles.