Insufflation pressure above 25 mm Hg confers no additional benefit over lower pressure insufflation during posterior retroperitoneoscopic adrenalectomy: a retrospective multi-centre propensity score-matched analysis

BACKGROUND: Insufflation pressures of or in excess of 25 mm Hg CO(2) are routinely used during posterior retroperitoneoscopic adrenalectomy (PRA) in most centres. A critical analysis of the surgical literature provides limited evidence to support this strategy. OBJECTIVE: To determine whether high pressure (≥ 25 mm Hg) compared with lower pressure (< 25 mm Hg) retroperitoneoscopy reduces operating time and complications. METHODS: A multi-centre retrospective cohort study was performed using data collected over a period of almost one decade (1st November 2008 until 1st February 2018) from surgical centres in Germany. A total of 1032 patients with benign adrenal tumours were identified. We compared patients undergoing PRA with insufflation pressures of < 25 mm Hg (G20 group) versus ≥ 25 mm Hg (G25 group). A propensity score matching analysis was performed using BMI, tumour size and surgeon's experience as independent variables. The main outcomes were (1) the incidence of perioperative complications and (2) the length of operating time. RESULTS: The baseline patient characteristics were similar in both groups, with the exception of tumour size, BMI and surgeon's experience in PRA. After propensity score matching, perioperative outcomes, especially perioperative complications (3.7% vs. 5.5% in G20 and G25, respectively; p = 0.335) and operation duration (47 min vs. 45 min in G20 and G25, respectively; p = 0.673), did not significantly differ between the groups. CONCLUSION: Neither patient safety nor operative success was compromised when PRA was performed with insufflation pressures below 25 mm Hg. Prospective studies are required to determine whether an optimal insufflation pressure exists that maximizes patient safety and minimizes the risks of post-surgical complications. Nevertheless, our results call for a careful re-evaluation of the routine use of high insufflation pressures during PRA. In the absence of prospective data, commencing PRA with lower insufflation pressures, with the option of increasing insufflation pressures to counter intraoperative bleeding or exposition difficulties, may represent a reasonable strategy.