Saliva stress biomarkers in ERCP trainees before and after familiarisation with ERCP on a virtual simulator.

Background: Stress during the early ERCP learning curve may interfere with acquisition of skills during training. The purpose of this study was to compare stress biomarkers in the saliva of trainees before and after familiarisation with ERCP exercises on a virtual simulator. Methods: Altogether 26 endoscopists under training, 14 women and 12 men, completed the three phases of this study: Phase 1. Three different ERCP procedures were performed on the simulator. Saliva for α-amylase (sAA), Chromogranin A (sCgA), and Cortisol (sC) were collected before (baseline), halfway through the exercise (ex.), and 10 min after completion of the exercise (comp.); Phase 2. A three-week familiarisation period where at least 30 different cases were performed on the virtual ERCP simulator; and Phase 3. Identical to Phase 1 where saliva samples were once again collected at baseline, during, and after the exercise. Percentage differences in biomarker levels between baseline and exercise (Diffex) and between baseline and completion (Diffcomp) during Phase 1 and Phase 3 were calculated for each stress marker. Results: Mean % changes, Diffex and Diffcomp, were significantly positive (p < 0.05) for all markers in both Phase 1 and Phase 3. Diffex in Phase 1 was significantly greater than Diffex in Phase 3 (p < 0.05) for sAA and sCgA. Diffcomp for sAA in Phase 1 was significantly greater than Diffcomp in Phase 3 (p < 0.05). No significant differences were found in sC concentration between Phases 1 and 3. Conclusion: This study shows that familiarisation with the ERCP simulator greatly reduced stress as measured by the three saliva stress biomarkers used with sAA being the best. It also suggests that familiarisation with an ERCP simulator might reduce stress in the clinical setting.

Validity of a virtual reality endoscopic retrograde cholangiopancreatography simulator: can it distinguish experts from novices?

Background: There is a lack of evidence regarding the effectiveness of virtual simulators as a means to acquire hands-on exposure to endoscopic retrograde cholangiopancreatography (ERCP). The present study aimed to assess the outcome and construct validity of virtual ERCP when training on the GI II Mentor simulator. Methods: A group of seven experienced endoscopists were compared with 31 novices. After a short introduction, they were requested to carry out three virtual ERCP procedures: diagnosing and removing a common bile duct (CBD) stone; diagnosing and taking brush cytology from a hilar stenosis; and, finally, diagnosing and treating a cystic leakage with a BD stent. For each task, the total time required to complete the task, time required to correctly view the papilla, total time of irradiation, time to deep cannulation, time to define diagnosis, time to complete sphincterotomy, and time to complete the respective intervention were measured. Cannulation of the BD, correct diagnosis, sphincterotomy, and time to complete intervention were assessed by an assessor blinded to the status of the endoscopist who performed the virtual ERCP. Results: The time required to visualize the papilla and to cannulate deeply when removing the BD stone was significantly shorter for the experts (both p < 0.05). The time to visualize the papilla, cannulate deeply, reach a diagnosis, complete sphincterotomy, and complete the intervention was significantly shorter for the experts when managing cystic leakage (all p < 0.05). In diagnosing and taking brush cytology from a hilar stenosis, there was only a trend toward the experts needing less time for the deep cannulation of the BD (p = 0.077). Conclusion: The performance differed between experts and novices, especially in the management of cystic leakage. This corroborates the construct validity of the GI II Mentor simulator.

Monte Carlo-Based Radiobiological Investigation of the Most Optimal Ion Beam Forming SOBP for Particle Therapy.

Proton (p) and carbon (C) ion beams are in clinical use for cancer treatment, although other particles such as He, Be, and B ions have more recently gained attention. Identification of the most optimal ion beam for radiotherapy is a challenging task involving, among others, radiobiological characterization of a beam, which is depth-, energy-, and cell type- dependent. This study uses the FLUKA and MCDS Monte Carlo codes in order to estimate the relative biological effectiveness (RBE) for several ions of potential clinical interest such as p, 4He, 7Li, 10Be, 10B, and 12C forming a spread-out Bragg peak (SOBP). More specifically, an energy spectrum of the projectiles corresponding to a 5-cm SOBP at a depth of 8 cm was used. All secondary particles produced by the projectiles were considered and RBE was determined based on radiation-induced Double Strand Breaks (DSBs), as calculated by MCDS. In an attempt to identify the most optimal ion beam, using the latter data, biological optimization was performed and the obtained depth-dose distributions were inter-compared. The results showed that 12C ions are more effective inside the SOBP region, which comes at the expense of higher dose values at the tail (i.e., after the SOBP). In contrast, p beams exhibit a higher DSOPB/DEntrance ratio, if physical doses are considered. By performing a biological optimization in order to obtain a homogeneous biological dose (i.e., dose × RBE) in the SOBP, the corresponding advantages of p and 12C ions are moderated. 7Li ions conveniently combine a considerably lower dose tail and a DSOPB/DEntrance ratio similar to 12C. This work contributes towards identification of the most optimal ion beam for cancer therapy. The overall results of this work suggest that 7Li ions are of potential interest, although more studies are needed to demonstrate the relevant advantages. Future work will focus on studying more complex beam configurations.

Use of saliva stress biomarkers to estimate novice male endoscopist's stress during training in a high-end simulator.

OBJECTIVE: Simulated endoscopic training can be challenging and stressful for the novice trainee. The absence of a reliable stress detection method during simulated endoscopic training makes estimating trainees' mental stress difficult to quantify. This study concomitantly measures the responses of four saliva stress biomarkers and compares them to the video score (VS) achieved by novice endoscopists in a reproducibly stressful simulation environment. METHODS: Thirty-six male endoscopy naïve surgery residents were enrolled. After an orientation phase, a saliva specimen was collected for cortisol (sC), alpha-amylase (sAA), Chromogranin A (sCgA), and immunoglobulin A (sIgA) measurements (baseline phase, BL). Thereafter, the simulation exercise phase (E) started, practicing in the Fundamentals of Endoscopic Surgery Skills module (GI-Bronch Mentor). Immediately after, a second saliva sample for measuring the above-cited biomarkers was collected. The whole experiment was videotaped, and the VS was calculated. The percentage (E-BL)diff of each of the four saliva biomarkers was calculated and examined for correlation to VS. RESULTS: sCgAdiff showed the best correlation with VS, followed by sAAdiff. CONCLUSIONS: sCgA and sAA, are saliva stress biomarkers that are easy to collect non-invasively and showed the best correlation with novice endoscopist's performance in our simulation setting, and therefore, they could be used for monitoring stress.

Validation of a Novel Needle Holder to Train Advanced Laparoscopy Skills to Novices in a Simulator Environment.

Background. Our aim was to determine if a newly designed Najar needle holder (NNH) shortens the time for novices to improve advanced laparoscopy (AL) techniques (suturing/knot tying), compared with a conventional macro needle holder (MNH) in a simulator. Furthermore, we aimed to validate a new video scoring system determining AL skills. Methods. Forty-six medical students performed identical surgical tasks in a prospective, crossover study evaluating AL skills (NNH vs MNH). All subjects performed a double-throw knot, 2 single-throw knots following 3 running sutures in the Simball Box (SB) simulator. After resting, subjects switched needle holders. All tasks were videotaped and analyzed using SB software and by 2 independent reviewers using the Objective Video Evaluation Scoring Table (OVEST). Trial performance expressed as SB Overall Score (SBOS) and OVEST. Results. In the group starting with NNH (followed by MNH) OVEST was consistently high during both trials (median = 12.5, range = 6.5-18.0, and median = 13.5, range = 6.5-21.0; P = .2360). However, in the group starting with MNH, OVEST improved significantly when the participants changed to NNH (median = 10.0, range = 2.5-19.5, vs median = 14.5, range = 4.5-18.0; P = .0003); an improvement was also found with SBOS (median = 37%, range = 27% to 92%, vs median = 48%, range = 34% to 70%; P = .0289). In both trials, both independent reviewers' OVEST measures correlated well: Trial 1: ß = 0.97, P < .0001; and Trial 2: ß = 0.95, P < .0001. A correlation also existed between SBOS and OVEST in both trials (ß = 2.1, P < .0001; and ß = 1.9, P = .0002). Conclusions. This study indicates a significantly higher improvement in laparoscopic suturing skills in novices training AL skills using NNH compared with MNH. Starting early, AL training in novices using NNH is a feasible option. Furthermore, OVEST used in experimental settings as an evaluation tool is comparable with the validated SBOS.