Differences in the Effectiveness of Smoke Evacuator Types for Reducing Surgical Smoke: a Randomized Controlled Trial

BACKGROUND: Surgical smoke contains respirable particles and volatile organic compounds (VOCs) associated with carcinogenic and infectious risks to operating room personnel. Whether electrocautery‐incorporated smoke evacuation improves particulate and VOC clearance compared with hose‐type evacuation remains undefined. STUDY DESIGN: In this randomized, double‐blind clinical trial (UMIN000047033) conducted from February 2022 to May 2023 at The University of Tokyo Hospital, 64 patients undergoing laparotomy were assigned 1:1:1 to electrocautery‐incorporated evacuation with an 8 mm tip distance (n = 22), 18 mm tip distance (n = 23), or hose‐type evacuation (n = 21). The primary endpoint was the change in particle counts at 0.3, 0.5, 1.0, and 5.0 μm during a standardized 10‐minute sampling period. Secondary endpoints were acetaldehyde and formaldehyde levels. Comparisons used the Wilcoxon rank‐sum testing with Bonferroni correction. RESULTS: The 8 mm electrocautery‐incorporated system reduced particle counts by 96% to 97% across 0.3 to 5.0 μm compared with hose‐type evacuation (all p < 0.05). The 18 mm system reduced 0.3 μm particles by 78% vs hose (p = 0.005), with 81% to 88% reductions for 0.5 to 5.0 μm particles (p > 0.05). Median (interquartile range) acetaldehyde levels were 1.90 (1.10 to 2.50), 2.70 (0.50 to 4.00), and 7.90 (3.10 to 15.20) μg/m3 in the 8 mm, 18 mm, and hose groups, respectively; both electrocautery groups were lower than hose (all p < 0.05). Formaldehyde levels were similarly reduced (all p < 0.05). CONCLUSIONS: Electrocautery‐incorporated smoke evacuation significantly reduced respirable particle and VOC exposure compared with hose‐type evacuation, with maximal particulate reduction at an 8 mm tip distance. Device selection and proximity to the cautery source materially influence operating room exposure to surgical smoke.