Low vs. conventional intra-abdominal pressure in laparoscopic colorectal surgery: a prospective cohort study

Purpose: Low intraabdominal pressure (IAP) during laparoscopy is associated with improved post-operative outcomes across a variety of surgical specialties. A prospective cohort study was undertaken to assess post-operative outcomes in patients undergoing laparoscopic colorectal surgery (LCRS) with low (8mmHg) versus conventional (15mmHg) IAP.

Methods: A prospective real-world observational study of patients undergoing LCRS in a single-centre, between June 2020 and June 2023 was performed. Operative procedures for diverse colonic pathology such as diverticular disease, inflammatory bowel disease (IBD), and colorectal cancers (CRC) were included. The evaluated primary outcomes were post-operative pain, return of gastrointestinal motility, and length of hospital stay. Secondary outcomes were the overall safety profile including intra- and post-operative complications and morbidity. Outcomes of interest were investigated using multivariate analysis.

Results: A total of 120 patients were included of which 69 (57.5%) were male. Median age and BMI of the cohort was 67 years (51-75 years) and 27 kg/m² (24-32 kg/m²), respectively. 61 (50.8%) patients were categorised as an ASA grade 3. Two (1.7%) patients had diverticular disease; 31 (25.9%) had IBD, and 87 (72.4%) were operated on for colonic malignancy. Low IAP (8mmHg) was used in 53 (44.2%) cases, whilst the remainder (55.8%) had IAP set at 15mmHg (conventional). Low-pressure surgery was associated with improved intraoperative lung compliance (p < 0.001) and peak inspiratory pressures up to 6 h (p < 0.001); reduced analgesic requirement (p ≤ 0.028), and decreased postoperative pain both at rest (p = 0.001) and on exertion (p < 0.001). Moreover, low IAP was associated with an earlier time to pass flatus postoperatively (p = 0.047) with no significant difference in length of hospital stay (p = 0.574). Additionally, no significant difference was observed between the groups for outcomes including median operating time (p = 0.089), conversion to open surgery (p = 0.056), overall complication rate (p = 0.102), and 90-day mortality (p = 0.381).

Conclusion: Low IAP use during LCRS is feasible with a comparable safety profile to conventional laparoscopy. Intra-operative respiratory physiology is improved with reduced postoperative pain and analgesic requirement, and earlier time to pass flatus. Future rationally designed; well-powered, randomised trials are needed to understand the benefits of low intra-peritoneal pressure during laparoscopic colorectal resections.