Task performance in standard laparoscopy in comparison with single-incision laparoscopy in a modified skills trainer

Single-incision laparoscopy (SIL) is similar to conventional laparoscopic surgery (LAP), but carries specific technical challenges due to lack of triangulation, reduced dexterity, conflicts due to inline instrumentation, and impaired visualization. This study was designed to evaluate technical skill performance of SIL versus LAP surgery in a simulated environment.

We developed a modified laparoscopic skills trainer for SIL based upon the fundamentals of laparoscopic surgery (FLS) model. This includes a standard laparoscopic tower for visualization, allowing replication of the conflicts between scope and instruments. It also has a modified trainer box allowing use of different access devices and instruments for SIL. Sixteen subjects at different levels of training (novice through expert) completed four FLS tasks with standard LAP techniques. They then practiced the same tasks using SIL technique until they reached a steady state of performance. The first and last SIL trials were recorded.

Baseline SIL peg transfer was worse than FLS (254 ± 157 s vs 99 ± 27, p < 0.0002). Final SIL time was still significantly worse than FLS (173 ± 130, p < 0.02). FLS, baseline SIL, and final SIL circle cutting were not significantly different (p = 0.058). Final SIL loop ligation was significantly faster than FLS (48 ± 19 vs 70 ± 42, p < 0.05). FLS suturing was faster than SIL suturing (281 ± 188 vs. 526 ± 105, p < 0.01). There was substantial dropout due to frustration with SIL, and only two surgeons were able to successfully complete SIL suturing.

There are technical challenges with SIL that vary depending on task. Peg transfer and suturing were significantly impaired in SIL, while circle cutting was not significantly affected, and ligating loop was faster with SIL than LAP. These challenges may impact clinical outcomes of SIL and should influence training in SIL as well as future product development.