A Randomized Comparison of Laparoscopic, Magnetically Anchored, and Flexible Endoscopic Cameras On Ex-Vivo and In-Vivo Performance and Workload for Laparoscopic and Single Incision Surgery

Nabeel A Arain, MD MBA, Erin M Webb, BS, Jeffrey Cadeddu, MD, Sara Best, MD, Richard Bergs, MS, Deborah Hogg, BS, Raul Fernandez, PhD, Thomas Roshek, MD, Victoria Chang, BBA, Daniel J Scott, MD. University of Texas Southwestern Medical Center, Southwestern Center for Minimally Invasive Surgery, Dallas, Texas

Introduction: The purpose of this study was to evaluate surgeon performance and workload using a new generation magnetically anchored (MAGS) camera in comparison to both laparoscopic and flexible endoscopic imaging systems for laparoscopic and Single Site Laparoscopy (SSL) settings.

Methods: Cameras included a 5mm 30° laparoscope (LAP, Storz), a MAGS camera (Storz imaging element), and a flexible endoscope (ENDO, Olympus GIF 160). The 3 systems were evaluated using standardized optical characteristic tests. In a randomized fashion, each system was used for ex-vivo and in-vivo visualization during the performance of a standardized suturing with intracorporeal knot-tying exercise by experts (n=2) and fellows (n=2); each participant performed 3-5 consecutive repetitions as surgeon during each evaluation and also served as camera driver during other participant’s repetitions. Ex-vivo testing used the FLS suturing model and metrics (time and errors); both multiport and SSL configurations were tested. In-vivo testing used FLS methods and scoring in a previously validated live porcine Nissen model; only a multiport configuration was used after SSL was attempted but abandoned due to being overly difficult. Surgeons and camera drivers completed a validated NASA-TLX Workload Scale to rate the mental, physical, temporal, performance, effort and frustration levels of each evaluation. Comparisons used ANOVA on ranks; p<0.05 was considered significant.

Results: Optical testing showed superior resolution for MAGS at 5cm and 10cm compared to LAP or ENDO. Field of view ranged from 39° to 99°; depth of focus was best for MAGS (6-270mm) compared to LAP (2-88mm) or ENDO (1-93mm). Both ex-vivo and in-vivo multiport surgical performance (Table) was significantly better for LAP compared to ENDO, but no significant differences were detected for MAGS. For multiport testing, workload ratings (scale 1-10, 10=high workload) were significantly less ex-vivo for LAP (3.23) and MAGS (3.26) compared to ENDO (6.38) and in-vivo for LAP (1.98) compared to ENDO (6.71) but not significant compared to MAGS (4.44). For ex-vivo SSL, no significant performance differences (Table) were detected but surgeons and camera drivers universally perceived benefit in terms of ergonomics and markedly fewer instrument conflicts. Workload ratings were significantly less for MAGS (4.04) compared to LAP (5.42) and ENDO (6.59) for ex-vivo SSL.

Conclusion: These data suggest that the optimized imaging element of the new generation MAGS camera has optical characteristics which meet or exceed those of LAP or ENDO systems. For multiport testing, performance was better for LAP compared to ENDO but no significant differences were detected for MAGS. For SSL, advantages were detected for MAGS including significantly decreased surgeon and camera driver workload compared to LAP and ENDO, as well as improved ergonomics. Additional investigations are encouraged to further evaluate the utility of the MAGS camera.