<b><i>Background:</i></b> The use of stereoscopic laparoscopic systems in minimally invasive surgery (MIS) allows a three-dimensional (3D) view of the surgical field, which improves hand-eye coordination. Depending on the stereo base used in the construction of the endoscopes, 3D systems may differ regarding the 3D effect. Our aim was to investigate the influence of different stereo bases on the 3D effect. <b><i>Methods:</i></b> This was a prospective randomized study involving 42 MIS-inexperienced study participants. We evaluated two laparoscopic 3D systems with stereo bases of 2.5 mm (system A) and 3.8 mm (system B) for differences in learning MIS skills using the Lübeck Toolbox (LTB) video box trainer. We evaluated participants’ performance regarding the times and repetitions required to reach each exercise’s goal. After completing the final exercise (“suturing”), participants performed the exercise again using a two-dimensional (2D) representation. Additionally, we retrospectively compared our study results with a preliminary study from participants completing the LTB curriculum with a 2D system. <b><i>Results:</i></b> The median number of repetitions until reaching the goals for LTB exercises 1, 2, 3, and 6 for system A were: 18 (range 7–53), 24 (range 8–46), 24 (range 13–51), and 21 (range 10–46), respectively, and for system B were: 12 (range 2–30), 16 (range 6–43), 17 (range 4–47), and 15 (range 6–29), respectively (<i>p</i> = not significant). Changing from a 3D to a 2D representation after completing the learning curve led to a longer average time required, from 95.22 to 119.3 s (<i>p</i> &#x3c; 0.0001), for the last exercise (exercise 6; “suturing”). When comparing the results retrospectively with the learning curves acquired with the 2D system, there was a significant reduction in the number of repetitions required to reach the LTB exercise goals for exercises 1, 3, and 6 using the 3D system. <b><i>Conclusion:</i></b> Stereo bases of 2.5 and 3.8 mm provide acceptable bases for designing 3D systems. Additionally, our results indicated that MIS basic skills can be learned quicker using a 3D system versus a 2D system, and that when the 3D effect is eliminated, the corresponding compensatory mechanisms must be relearned.

Urolithiasis is a common disease with increasing prevalence across all ages. A common treatment option for smaller kidney stones is flexible ureterorenoscopy (fURS), where a flexible ureteroscope (FU) is used for stone removal and to inspect the renal collecting system. The handling of the flexible ureteroscope and end effectors (EEs), however, is challenging and requires two surgeons. In this paper, we introduce a modular robotic system for endoscope manipulation, which enables solo surgery (SSU) and is adaptable to various hand-held FUs. Both the developed hardware components and the proposed workflow and its representation in software are described. We then present and discuss the results of an initial user study. Finally, we describe subsequent developmental steps towards more extensive testing by clinical staff.

Background. In minimally invasive surgery (MIS), the loss of stereoscopic depth perception in a two-dimensional (2D) representation is most challenging. Recently introduced 4K ultrahigh definition (UHD) 2D optical systems could potentially facilitate the learning and use of compensation mechanisms for the loss of depth perception. However, the role of the new 4K technology against three dimensional (3D) in learning and implementation of MIS remains unknown. The aim of this trial was to determine the influence of 4K UHD 2D vs 3D HD representation on the acquisition of MIS skills. Methods. This was a prospective randomized study involving 62 MIS-inexperienced study participants. We compared a laparoscopic 4K UHD 2D (system A) vs a laparoscopic 3D HD system (system B) for differences in learning MIS skills using the Lübeck Toolbox (LTB) video box trainer. We evaluated participants’ performance regarding the repetitions required to reach the goal of each LTB task. Results. Comparing systems A and B, participants using the laparoscopic 3D system required fewer repetitions to achieve goals of LTB tasks No. 1 ( P = .0048) and No. 3 ( P = .0014). In contrast, for LTB tasks No. 2 and No. 4, no significant difference could be determined between both groups. Conclusion. Our results indicated that MIS basic skills can be learned quicker using a 3D HD system vs a 4K UHD 2D system. However, for MIS tasks in confined spaces, the learning speed with 4K UHD 2D imaging seems to be comparable to a 3D HD system.