Novel Simulation Device for Targeting Tumors in Laparoscopic Ablation: A Learning Curve Study

Introduction. A novel 3-dimensional (3D) guidance system was developed to aid accurate needle placement during ablation. Methods. Five novices and 5 experienced hepatobiliary surgeons were recruited. Using an agar block with analog tumor, participants targeted under 4 conditions: in-line with the ultrasound plane using ultrasound, in-line using 3D guidance, 45° off-axis using ultrasound, and off-axis using 3D guidance. Time to target the tumor, number of withdrawals, and the National Aeronautics and Space Administration Task Load Index were collected. Initial and final parameters for each of the conditions were compared using a within-subjects paired t test. Results. A significant reduction was seen in the number of required withdrawals in all situations when using the 3D guidance (0.75 vs 3.65 in-line and 0.25 vs 3.6 for off-axis). Mental workload was significantly lower when using 3D guidance compared with ultrasound both for novices (29.85 vs 41.03) and experts (31.98 vs 44.57), P <.001 for both. The only difference in targeting time between first and last attempt was in the novice group during off-axis targeting using 3D guidance (115 vs 32.6 seconds, P =.03). Conclusion. Though 3D guidance appeared to decrease time to target, this was not statistically significant likely as a result of lack of power in our trial. Three-dimensional guidance did reduce the number of required withdrawals, potentially decreasing complications, as well as mental workload after proficiency was achieved. Furthermore, novices without experience in ultrasound were able to learn targeting with the 3D guidance system at a faster pace than targeting with ultrasound alone.