Virtual Reality Simulator for Training on Photoselective Vaporization of the Prostate with 980 nm Diode Laser and Learning Curve of the Technique

Author	J.C. Angulo, I. Arance, A. García-Tello, M.M. Las Heras, G. Andrés, H. Gimbernat, F. Lista, F. Ramón de Fata

Objective

The utility of a virtual reality simulator for training of the photoselective vaporization of the prostate with diode laser was studied.

Material and Method

Two experiments were performed with a simulator (VirtaMed AG, Zürich, Switzerland) with software for specific training in prostate vaporization in contact mode with Twister fiber (Biolitec AG, Jena, German). Eighteen surgeons performed ablation of the prostate (55 cc) twice and compared the score obtained (190 points efficacy and 80 safety) in the second one of them by experience groups (medical students, residents, specialists). They also performed a spatial orientation test with scores of 0 to 6. After, six of these surgeons repeated 15 ablations of the prostate (55 and 70 ml). Improvement of the parameters obtained was evaluated to define the learning curve and how experience, spatial orientation skills and type of sequences performed affects them.

Results

Global efficacy and safety score was different according to the grade of experience (P=.005). When compared by pairs, specialist-student differences were detected (p=0.004), but not specialist-resident (P=.12) or resident-student (P=.2). Regarding efficacy of the procedure, specialist-student (p=0.0026) and resident-student (P=.08) differences were detected. The different partial indicators in terms of efficacy were rate of ablation (P=.01), procedure time (P=.03) and amount of unexposed capsule (p=0.03). Differences were not observed between groups in safety (P=.5). Regarding the learning curve, percentage median on the total score exceeded 90% after performing 4 procedures for prostates of 55 ml and 10 procedures for prostate glands of 70 ml. This course was not modified by previous experience (resident-specialist; P=.6). However, it was modified according to the repetition sequence (progressive-random; P=.007). Surgeons whose spatial orientation was less than the median of the group (value 2.5) did not surpass 90% of the score in spite of repetition of the procedure.

Conclusion

Simulation for ablation of the prostate with contact diode laser is a good learning model with discriminative validity, as it correlates the metric results with levels of experience and sills. The sequential repetition of the procedure on growing levels of difficulty favors learning.