Specific resistance of Veress needles, disposable and reusable trocars is limiting CO2 gas flow performance in pelviscopy and laparoscopy

Abstract

SummaryAn efficient insufflation technique is essential for laparoscopy. Up to now physicians have had to rely on their experience and intuition when putting together an insufflation system. Comparable, objective data about the insufflation properties of all insufflation components used has not been available. In this study, details of the insufflation properties of disposable and reusable Veress needles and trocars and Luer lock connectors and the particular meaning of flow resistance for function and efficiency of the entire insufflation system have been measured and compared. In an independent laboratory study, a computer-based data acquisition measurement model was developed. Specific pressure dependent flow and resistance curves of insufflation components from manufacturers such as Auto Suture, Dexide, Ethicon, HiTec, Olympus, Origin, Richard-Allan, Volzer, Wiest, Wolf and Storz were evaluated by measurement of physical parameters pressure, CO2 gas flow and resistance. Through the introduction of reference values, different insufflation properties for all studied components were characterised for the first time and can be compared. Despite similar type of construction, remarkable differences of CO2 gas flow were found in Veress needles (0.85–2.38 L mim−1, disposable (3.91–9.61 L mim−1) and reusable trocars (5.27–21.07 L min−1) at reference pressure of 12 mmHg, if used for insufflation only. It further decreased after insertion of a 10 mm optic for disposable (1.53–7.08 L min−1) and reusable trocars (1.22–14.03 L min−1). All insufflation components have different flow properties, due to the space left for insufflation. The largest resistance is usually the diameter size at the insufflation supply (1.5–4.3 mm). In general, disposable trocars are not useful for high flow insufflation (> 10 L mim−1) at PRef = 12 mmHg). Only two reusable trocars studied deliver high flow with a 10 mm optic inserted (HiTec 1013, Olympus A 5359). Resistance, especially of disposable trocars, needs to be improved by enlarging the insufflation diameter. Resistance-optimised insufflation components are more efficient, faster and could save time and money. Users need to demand resistance-improved products from manufacturers, who should publish reference values about specific flow and resistance properties of their products.