An ex vivo liver training model continuously perfused to simulate bleeding for suture skills involved in laparoscopic liver resection: development and validity.

Abstract

Suture skills are essential to laparoscopic liver resection. The current suture training models are not ideal enough. The aim of this study is to develop and verify a highly simulated-bleeding continuously perfused training model (CPTM) and to evaluate its training efficacy. CPTM was constructed using fresh lamb liver whose portal veins were perfused with red-dyed liquid gelatin. Construct validity of CPTMs was tested in 33 participants with three levels of laparoscopic experience (experts, intermediates, and novices) who were demanded to finish one superficial stitch and one deep stitch for suture hemostasis on CPTMs. The CPTMs were also evaluated by the experts. CPTMs were compared with dry box training models (DBTMs) regarding training efficacy among the novices who were assigned to DBTM and CPTM groups to, respectively, complete a 10-day training on CPTMs or DBTMs. Before and after their assignments, their superficial stitches were assessed by completion time, suture accuracy, and suture knot performance while their deep stitches by completion time and bleeding control. CPTM proved to be construct valid by both superficial and deep stitches. Significant differences were found regarding completion time (763, 271, 174s), suture accuracy (4.4, 1.8, 0.2mm), and suturing knot performance (12.1, 21.5, 22.0) for superficial stitches (p<0.001), as well as regarding completion time (807, 423, 277s) for deep stitches (p<0.001). Positive comments were given by all experts. CPTMs helped novices to acquire laparoscopic suture skills. Their training efficacy was significantly better than that of DBTMs (p<0.05). Learning curves of CPTM group plateaued at the sixth round for superficial stitches and at the seventh round for deep stitches. CPTM offers trainees a highly simulated-bleeding means to acquire advanced laparoscopic suture skills. The suture skills learned on CPTMs may improve significantly at the seventh round.