Validation study of a computer-based open surgical trainer: SimPraxis^® simulation platform

Figures & data

Table 1 Description of individual steps of simulated pelvic lymph node dissection procedure

Step	Substep	Description
1	1	The table rotates away from the primary surgeon.
2	1	The surgeon lifts the lymph tissue on the superior medial aspect of the iliac vein with DeBakey forceps.
	2	The surgical assistant lifts the lymph tissue on the superior medial aspect of the iliac vein with the DeBakey forceps.
	3	The surgeon inserts the medium-sized right angle forceps between the lymph tissue and the vein and spreads the tines, pulling the lymph tissue taut.
	4	The surgical assistant cuts or cauterizes the lymph tissue, dividing it.
3	1	The surgeon lifts the lymph tissue on the inferior-radial aspect of the iliac vein with DeBakey forceps.
	2	Using DeBakey forceps, the assistant lifts the lymph tissue on the superior medial aspect of the iliac artery.
	3	The surgeon places medium-sized right angle forceps in the plane between the artery and the lymph tissue and spreads the tines of the right angle forceps.
	4	The assistant cauterizes (or cuts) to divide the lymph tissue lying between the tines of the right angle forceps.
4	1	The assistant uses the Kittner dissector to lift the external iliac vessels.
	2	The surgeon uses right angle forceps to spread and pull lymph tissue from the vein, moving toward the pelvic side wall.
5	1	Surgeon identifies obturator nerve and uses DeBakey forceps to pull the lymph tissue up and away from the obturator nerve.
	2	The assistant uses the Kittner dissector to retract caudally. The surgeon then places the right angle forceps in plane under the lymph tissue and spreads the tines, while the assistant divides the lymph tissue using the Bovie tool.
6	1	The assistant uses the Kittner dissector to retract iliac vessels.
	2	Using Russian forceps, the surgeon grasps the packet above the obturator nerve, narrowing the packet.
	3	The surgeon places the right angle forceps across the distal aspect of the packet and clamps.
	4	The assistant uses Metz scissors (or the Bovie tool) to divide the packet in front of the clamp.
	5	The assistant ties off the stump of the pedicle with 3.0 silk on a tonsil passer.
7	1	The assistant moves the Kittner dissector.
	2	The surgeon exposes and narrows the packet using Russian forceps.
	3	The surgeon bluntly dissects the packet with right angle forceps.
8	1	The surgeon grasps the lymph packet with right angle forceps.
	2	The assistant divides the packet at the pedicle using Metz scissors, and the surgeon removes the packet using Russian forceps.
	3	The assistant passes 3-0 silk on a tonsil clamp and ties behind the right angle forceps.

Figure 1 View of SimPraxis^® pelvic lymph node dissection screen.

Note: Copyright © 2003–2004. Reproduced with permission from Red Llama, Inc, Seattle, WA, USA.

Figure 2 Expert acceptance and evaluation of content of the SimPraxis^® simulator (Red Llama Inc, Seattle, WA, USA).

Figure 3 Comparison of experts and novices for total time needed and total deviations made while performing the simulated pelvic lymph node dissection procedure.

Table 2 Comparison of number of deviations between experts and novices for key metrics

	Experts		Novices		P-value
	Median deviations (n)	Interquartile range (25%–75%)	Median deviations (n)	Interquartile range (25%–75%)
Instrument choice	6	3.75–10.25	37	28.00–52.00	0.0006
Instrument placement	11	4.00–27.75	32	30.00–36.00	0.015
Choice of actor	7	2.75–17.75	10	8.00–12.00	0.3669

Table 3 Median values of deviation from steps 2 to 8 of the simulated procedure

	Instrument choice			Placement location of instrument			Choosing actor
	Experts	Novices	P-values	Experts	Novices	P-values	Experts	Novices	P-values
Step 2	0	8	0.0005*	0	3	0.0091*	0	1	0.017*
Step 3	1	0	0.0559	3	2	0.4247	0	2	0.0301*
Step 4	0	8	0.0003*	0	0	0.1335	0	1	0.0749
Step 5	2	1	0.4443	0	0	0.1922	1	0	0.0192*
Step 6	2	4	0.015*	7	19	0.0618	2	2	0.2514
Step 7	1	5	0.004*	0	1	0.2207	2	1	0.2981
Step 8	0	1	0.0301*	0	0	0.3520	0	0	0.5000

Note:

* Statistically significant P-values using Mann–Whitney test.

Table 4 Percentage of nonsignificant P-values on multiple comparison Chi-squares for the different steps

Measures	Experts	Novices
Time spent on step	92%	40%
Incorrect choice of instrument	48%	80%
Incorrect choice of actor	88%	96%
Incorrect instrument placement	100%	96%