Validation and motion analyses of laparoscopic radical nephrectomy with Thiel-embalmed cadavers

Our aim was to develop practical training for laparoscopic surgery using Thielembalmed cadavers. Furthermore, in order to verbalize experts' motion characteristics and provide objective feedback to trainees, we initiated motion capture analyses of multiple surgical instruments simultaneously during the cadaveric trainings. In the present study, we report our preliminary results.

Participants voluntarily joined the present cadaveric simulation trainings, and performed laparoscopic radical nephrectomy. After the trainings, scores for tissue similarity (face validity) and impression of educational merit (content validity) were collected from participants based on a 5-point Likert scale (tissue similarity: 5: very similar, 3: average, 1: very different; educational merit: 5: very high, 3: average, 1: very low). In addition, after the additional IRB approval, we started motion capture (Mocap) analyses of 6 surgical instruments (scissors, vessel sealing system, grasping forceps, clip applier, right-angled forceps, and suction), using an infrared trinocular camera (120-Hz location record). Mocap-metrics were compared according to the previous surgical experiences (experts: ≧50 laparoscopic surgeries, intermediates: 10-49, novices: 0-9), using the Kruskal-Wallis test.

A total of 9 experts, 19 intermediates, and 15 novices participated in the present study. In terms of face validity, the mean scores were higher than 3, other than for the Vena cava(mean score of 2.89). Participants agreed with the training value (usefulness for future skill improvement: mean score of 4.57). In terms of Mocap analysis, faster speed-related metrics (e.g., velocity, the distribution of tip velocity, acceleration, and jerk) in the scissors and vessel sealing system, a shorter path length of grasping forceps, and fewer dimensionless squared jerks, which indicated more purposeful motion of 4 surgical instruments (vessel sealing system, grasping forceps, clip applier and suction), were observed in the more experienced group.

The Thiel-embalmed cadaver provides an excellent training opportunity for complex laparoscopic procedures with participants' high level of satisfaction, and may become a promising tool for a better objective understanding of surgical dexterity. In order to enrich formative feedback to trainees, we are now proceeding with Mocap analysis.