Robotic versus non-robotic instruments in spatially constrained operating workspaces: a pre-clinical randomized crossover study Thomas P. Cundy*†, Hani J. Marcus*†, Archie Hughes-Hallett*†, Thomas MacKinnon†, Azad S. Najmaldin‡, Guang-Zhong Yang* and Ara Darzi*† *Hamlyn Centre, Institute of Global Health Innovation, †Department of Surgery and Cancer, Imperial College London, London, and ‡Department of Paediatric Surgery, Leeds General Infirmary, Leeds, UK
Objective To compare the effectiveness of robotic and non-robotic laparoscopic instruments in spatially constrained workspaces.
Materials and Methods Surgeons performed intracorporeal sutures with various instruments within three different cylindrical workspace sizes. Three pairs of instruments were compared: 3-mm non-robotic mini-laparoscopy instruments; 5-mm robotic instruments; and 8-mm robotic instruments. Workspace diameters were 4, 6 and 8 cm, with volumes of 50, 113 and 201 cm3 respectively. Primary outcomes were validated objective task performance scores and instrument workspace breach counts.
Results A total of 23 participants performed 276 suture task repetitions. The overall median task performance scores for the 3-, 5- and 8-mm instruments were 421, 398 and 402, respectively (P = 0.12). Task scores were highest (best) for the 3-mm non-robotic instruments in all workspace
Introduction Robotic surgery is felt to have a niche role in operating environments that are spatially confined and have limited access [1,2]. The technical features offered by robot assistance are perceived to be of value in performing delicate and precise surgery in these settings [1]. As endoscopic instruments act as extensions of the surgeon’s hands, instrument characteristics have a critical impact on the capability and quality of surgical task performance. Instinctively, smaller instruments are better suited for small and challenging operating workspaces; however, there is a balance to achieve when it comes to the minimization potential of instruments, with smaller-calibre instruments risking compromise in structural rigidity, durability and concentration of force over tip surface area. As © 2014 The Authors BJU International © 2014 BJU International | doi:10.1111/bju.12987 Published by John Wiley & Sons Ltd. www.bjui.org
sizes. Scores were significantly lower when spatial constraints were imposed, with median task scores for the 4-, 6- and 8-cm diameter workspaces being 388, 415 and 420, respectively (P = 0.026). Significant indirect relationships were seen between boundary breaches and workspace size (P < 0.001). Higher breach counts occurred with the robotic instruments.
Conclusions Smaller workspaces limit the performance of both robotic and non-robotic instruments. In operating workspaces 200 Estimated simulation-based training time involving intra-corporeal suturing 0–20 h 20–50 h >50 h IQR, interquartile range.
32 (4) 7 (2.5) 19:4 12 7 4
14 4 5
Secondary Outcomes Vertical orientation sutures were performed with higher task scores using robotic instruments than with non-robotic instruments, but this difference did not reach statistical significance (Table 4). Higher perceived task workload ratings were observed for smaller workspace sizes (Fig. 3C). NASA-TLX ratings were significantly different for the 8-mm robotic instruments only, with median values of 57, 61 and 73 for 8-, 6- and 4-cm
Table 2 Pediatric Laparoscopic Surgery simulator task scores. Workspace size
8-cm diameter 6-cm diameter 4-cm diameter P
3-mm non-robotic instrument, median (IQR) score*
5-mm robotic instrument, median (IQR) score*
8-mm robotic instrument, median (IQR) score*
P
431 (90) 421 (69.5) 414 (126) 0.631
407 (77) 414 (84) 386 (100.5) 0.434
424 (54.5) 412 (81.5) 354 (107.5) 0.014
0.619 0.409 0.186
IQR, interquartile range. *Higher scores represent superior performance for non-robotic and robotic instruments.
Table 3 Workspace boundary breaches for non-robotic and robotic instruments in various workspace sizes.
8-cm diameter 6-cm diameter 4-cm diameter P
3-mm non-robotic instrument, median (IQR) score
5-mm robotic instrument, median (IQR) score
8-mm robotic instrument, median (IQR) score
P
1 (2) 4 (5) 17 (8)
Objective To compare the effectiveness of robotic and non-robotic laparoscopic instruments in spatially constrained workspaces.
Materials and Methods Surgeons performed intracorporeal sutures with various instruments within three different cylindrical workspace sizes. Three pairs of instruments were compared: 3-mm non-robotic mini-laparoscopy instruments; 5-mm robotic instruments; and 8-mm robotic instruments. Workspace diameters were 4, 6 and 8 cm, with volumes of 50, 113 and 201 cm3 respectively. Primary outcomes were validated objective task performance scores and instrument workspace breach counts.
Results A total of 23 participants performed 276 suture task repetitions. The overall median task performance scores for the 3-, 5- and 8-mm instruments were 421, 398 and 402, respectively (P = 0.12). Task scores were highest (best) for the 3-mm non-robotic instruments in all workspace
Introduction Robotic surgery is felt to have a niche role in operating environments that are spatially confined and have limited access [1,2]. The technical features offered by robot assistance are perceived to be of value in performing delicate and precise surgery in these settings [1]. As endoscopic instruments act as extensions of the surgeon’s hands, instrument characteristics have a critical impact on the capability and quality of surgical task performance. Instinctively, smaller instruments are better suited for small and challenging operating workspaces; however, there is a balance to achieve when it comes to the minimization potential of instruments, with smaller-calibre instruments risking compromise in structural rigidity, durability and concentration of force over tip surface area. As © 2014 The Authors BJU International © 2014 BJU International | doi:10.1111/bju.12987 Published by John Wiley & Sons Ltd. www.bjui.org
sizes. Scores were significantly lower when spatial constraints were imposed, with median task scores for the 4-, 6- and 8-cm diameter workspaces being 388, 415 and 420, respectively (P = 0.026). Significant indirect relationships were seen between boundary breaches and workspace size (P < 0.001). Higher breach counts occurred with the robotic instruments.
Conclusions Smaller workspaces limit the performance of both robotic and non-robotic instruments. In operating workspaces 200 Estimated simulation-based training time involving intra-corporeal suturing 0–20 h 20–50 h >50 h IQR, interquartile range.
32 (4) 7 (2.5) 19:4 12 7 4
14 4 5
Secondary Outcomes Vertical orientation sutures were performed with higher task scores using robotic instruments than with non-robotic instruments, but this difference did not reach statistical significance (Table 4). Higher perceived task workload ratings were observed for smaller workspace sizes (Fig. 3C). NASA-TLX ratings were significantly different for the 8-mm robotic instruments only, with median values of 57, 61 and 73 for 8-, 6- and 4-cm
Table 2 Pediatric Laparoscopic Surgery simulator task scores. Workspace size
8-cm diameter 6-cm diameter 4-cm diameter P
3-mm non-robotic instrument, median (IQR) score*
5-mm robotic instrument, median (IQR) score*
8-mm robotic instrument, median (IQR) score*
P
431 (90) 421 (69.5) 414 (126) 0.631
407 (77) 414 (84) 386 (100.5) 0.434
424 (54.5) 412 (81.5) 354 (107.5) 0.014
0.619 0.409 0.186
IQR, interquartile range. *Higher scores represent superior performance for non-robotic and robotic instruments.
Table 3 Workspace boundary breaches for non-robotic and robotic instruments in various workspace sizes.
8-cm diameter 6-cm diameter 4-cm diameter P
3-mm non-robotic instrument, median (IQR) score
5-mm robotic instrument, median (IQR) score
8-mm robotic instrument, median (IQR) score
P
1 (2) 4 (5) 17 (8)
