Construct Validity of a Novel Assessment System for Laparoscopic Suture Accuracy Based on Stereoscopy.

BACKGROUND: An accurate and objective measuring tool is lacking for laparoscopic suture accuracy assessment in simulation training. We designed and developed the suture accuracy testing system (SATS) and aimed to determine its construct validity in this study.

METHODS: Twenty laparoscopic experts and 20 novices were recruited to perform a suturing task in three sessions using traditional laparoscopic instruments (Tra. session), a handheld multi-degree-of-freedom (MDoF) laparoscopic instrument (MDoF session) and a surgical robot (Rob. session), respectively. The needle entry and exit errors were calculated using the SATS and compared between the two groups.

RESULTS: No significant difference of the needle entry error was found in all comparisons. As for the needle exit error, the value of the novice group was significantly higher than that of the expert group in Tra. session (3.48 ± 0.61 mm vs. 0.85 ± 0.14 mm; p = 1.451e-11) and MDoF session (2.65 ± 0.41 mm vs. 1.06 ± 0.17 mm; p = 1.451e-11) but not in Rob. session (0.51 ± 0.12 mm vs. 0.45 ± 0.08 mm; p = 0.091).

CONCLUSIONS: The SATS demonstrates construct validity. Surgeons' experience in conventional laparoscopic instruments could be transferred to the MDoF instrument. Surgical robot helps to improve suture accuracy and may bridge the experience gap between laparoscopic experts and novices in basic exercises.