Automated intracorporeal tool exchange with the Symphera multi-tool prototype: a crossover evaluation of efficiency and surgeon workload in a porcine laparoscopic model

Abstract

Conventional laparoscopic instrument exchange requires repeated trocar withdrawal, redirecting surgeon gaze and disrupting operative flow. The Symphera system enables intracorporeal tool-tip switching, but its impact on procedural efficiency, visual attention, and workload has not been evaluated in a controlled setting. Two surgical fellows performed three standardised laparoscopic tasks (cholecystectomy, controlled hepatic bleeding, dissection–coagulation relay) under Symphera and conventional conditions in a live porcine crossover model. Primary outcomes were total task time and tool change time; secondary outcomes included gaze behaviour (eyes-on proportion, disruption events), subjective workload (SURG-TLX), device usability, and heart rate. Mean total task time was 27.3 ± 10.9 vs. 33.9 ± 13.2 min (−19.6%; HL estimate −6.7 min, 95% CI −12.4 to −1.5; p = 0.10). Tool change time was reduced by 61.5% (3.6 ± 2.3 vs. 9.4 ± 6.6 min; HL estimate −5.2 min, 95% CI −9.7 to −3.4; p = 0.10). Intracorporeal exchanges were completed in a mean of 4.3 ± 4.4 s (75% within 5 s) versus 25.3 ± 23.4 s for extracorporeal exchanges. Eyes-on proportion was higher with Symphera (86.0 ± 10.9% vs. 78.1 ± 9.8%; HL estimate + 7.7 pp, 95% CI + 0.9 to + 14.8; p = 0.031), with instrument exchange as a gaze disruption cause markedly reduced. SURG-TLX scores were 44.8% lower with Symphera (40.2 ± 15.8 vs. 72.9 ± 19.8), with reductions across all six dimensions. Symphera demonstrated favourable trends in procedural efficiency, gaze behaviour, and subjective workload versus conventional instrument exchange. The convergence of behavioural, subjective, and efficiency data supports the hypothesis that intracorporeal exchange preserves visual attention and may reduce perceived workload. Larger, adequately powered studies are warranted.