Performance of Kymerax© precision-drive articulating surgical system compared to conventional laparoscopic instruments in a pelvitrainer model.

Background: The Kymerax© Precision-Drive Articulating Surgical System by Terumo© is a handheld laparoscopic robot which permits motion in two additional degrees of freedom (deflection and rotation in the instrument tip). In a pelvitrainer model, we compared the performance of participants with different laparoscopic experiences and compared Kymerax© to conventional laparoscopic instruments.

Methods: 20 expert surgeons, performing more than 50 laparoscopic procedures per year, and 25 medical students without any experience in surgery at all were selected. Each participant was randomized into two groups: Group TK performed the tasks using the traditional laparoscopic Instruments (TLI) first and Kymerax© thereafter, group KT vice versa. Six standardized tasks were used: Two instructional exercises and four tasks where time, number of mistakes, and overall precision were measured. Finally, a questionnaire had to be answered.

Results: All four tasks were performed significantly more slowly with the Kymerax© device. Improved needle control in stitches towards the surgeon, significantly less deviation while cutting along different lines as well as a significantly reduced fraying of the cutting edge were found when participants were using Kymerax©. By questionnaire more than 90% of the participants indicated clear advantages using Kymerax©. However, participants needed more training time and had an earlier loss of concentration with Kymerax©. Further complaints about Kymerax© were its limitations in rotation and deflection, the impaired view as well as the non-ergonomic instrument handle. Rotation force, instrument weight, digital instrument-tip control, and needle fixation were rated as accurate.

Conclusions: This study shows that more time is needed to solve tasks with Kymerax© compared to conventional laparoscopic instruments. Kymerax© is superior to conventional laparoscopy for suturing at difficult angles and cutting along complex structures. Kymerax© can potentially bring benefits for certain laparoscopic tasks, but as seen in this study, further developments are necessary. Terumo© meanwhile closed down its Kymerax