Low-pressure versus standard-pressure pneumoperitoneum in minimally invasive colorectal surgery: a systematic review, meta-analysis, and meta-regression analysis.

ABSTRACT

Background: We aimed to assess the efficacy and safety of low-pressure pneumoperitoneum (LPP) in minimally invasive colorectal surgery. Methods: A PRISMA-compliant systematic review/meta-analysis was conducted, searching PubMed, Scopus, Google Scholar, and clinicaltrials.gov for randomized-controlled trials assessing outcomes of LPP vs standard-pressure pneumoperitoneum (SPP) in colorectal surgery. Efficacy outcomes [pain score in post-anesthesia care unit (PACU), pain score postoperative day 1 (POD1), operative time, and hospital stay] and safety outcomes (blood loss and postoperative complications) were analyzed. Risk of bias2 tool assessed bias risk. The certainty of evidence was graded using GRADE. Results: Four studies included 537 patients (male 59.8%). LPP was undertaken in 280 (52.1%) patients and associated with lower pain scores in PACU [weighted mean difference -1.06, 95% confidence interval (CI) -1.65 to -0.47, P = 0.004, I 2 = 0%] and POD1 (weighted mean difference -0.49, 95% CI -0.91 to -0.07, P = 0.024, I 2 = 0%). Meta-regression showed that age [standard error (SE) 0.036, P < 0.001], male sex (SE 0.006, P < 0.001), and operative time (SE 0.002, P = 0.027) were significantly associated with increased complications with LPP. In addition, 5.9%-14.5% of surgeons using LLP requested pressure increases to equal the SPP group. The grade of evidence was high for pain score in PACU and on POD1 postoperative complications and major complications, and blood loss, moderate for operative time, low for intraoperative complications, and very low for length of stay. Conclusions: LPP was associated with lower pain scores in PACU and on POD1 with similar operative times, length of stay, and safety profile compared with SPP in colorectal surgery. Although LPP was not associated with increased complications, older patients, males, patients undergoing laparoscopic surgery, and those with longer operative times may be at risk of increased complications.