Endovascular procedures have become commonplace in vascular surgery. This development calls for new training strategies for future specialists (1). Most simulation-based educational (SBE) programs have a monodisciplinary focus on physicians (2), although successful surgery is a multidisciplinary team effort (3). In this setting, SBE has been shown to increase technical skills of the trainee, although proof of skills transferability into i.e., fewer complications and errors, and shorter procedure times, are scarce. To conduct such studies during real-time surgical procedures without supervisor take-over would, of course, be unethical, underlining the need for alternative measures to evaluate SBE-effects during surgery (4). Mental stress impairs the learning process (5) and surgical performance, and heart rate variability (HRV) can be measured as a proxy for both mental and physical stress (6, 7). This study aims to assess how SBE of endovascular nurse assistants (EVA) affects team performance and HRV during endovascular aneurysm repair (EVAR).

Prospective interventional study where EVAR-inexperienced EVAs followed a focused SBE program. A two-step SBE program for EVAs in EVAR-procedures was developed. It consisted of a two-hour introductory hands-on lesson led by an EVAR surgeon explaining the EVAR procedure step-by-step and allowing hands-on demonstration of the needed equipment. The introduction was done in small groups of 4 EVAs. Subsequently, and in pairs of two EVAs, standard EVAR procedures were performed in the simulator on two different days. The duration of the EVAR simulation sessions was fixed to 90 minutes, and the EVAs took turns working as operators and assistants, respectively. During real-life EVAR-procedures, HRV of the EVA was continuously recorded with a wireless ECG patch, and multidisciplinary team performance was assessed with the Imperial College Error CAPture (ICECAP) tool, before and after the SBE program, allowing each EVA to serve as their own control (8). Eight EVAs with experience in lower limb endovascular procedures, but not EVAR, were invited to participate. HRV was assessed with root mean square differences of successive RR-intervals (RMSSD). Higher RMSSD values indicates lower stress level.

Seven participants completed the study. In five out of seven EVAs, HRV-derived stress levels during real-time EVAR procedures were lower after SBE compared to before SBE, Figure 1a. Mean HRV increased from 24 msec (SD ±14.2) to 35 msec (SD ±30.2) (p < .001), indicating stress level reduction, Table 1 and Figure 1b. Before SBE, the mean number of errors/hour was 7.3 (SD ±1.8) compared to 3.6 (SD ±2.7) after SBE. Most errors were categorized as technical (58 %) and communicative (23 %).

The present study suggests that systematic SBE of EVAs improves both team performance and lowers mental stress during EVAR procedures. The SBE program was well-accepted by the EVAs, as well as the perioperative observation of errors and the use of ECG monitors. This study supports HRV and mental stress, and ICECAP and errors, as proxies of SBE transferability to real-life operations.

1. Freischlag JA, Kibbe MR. The evolution of surgery: the story of "TWO POEMS". Jama. 2014; 312: 1737-8. 2. Moss A, Stoll VM. Simulation training for the cardiology trainee. Heart. 2021; 107: 83-4. 3. Kawaguchi AL, Kao LS. Teamwork and Surgical Team-Based Training. Surg Clin North Am. 2021; 101: 15-27. 4. Maertens H, Aggarwal R, Moreels N, Vermassen F, Van Herzeele I. A Proficiency Based Stepwise Endovascular Curricular Training (PROSPECT) Program Enhances Operative Performance in Real Life: A Randomised Controlled Trial. Eur J Vasc Endovasc Surg. 2017; 54: 387-96. 5. Flinn JT, Miller A, Pyatka N, Brewer J, Schneider T, Cao CG. The effect of stress on learning in surgical skill acquisition. Med Teach. 2016; 38: 897-903. 6. Grantcharov PD, Boillat T, Elkabany S, Wac K, Rivas H. Acute mental stress and surgical performance. BJS Open. 2019; 3: 119-25. 7. Kim HG, Cheon EJ, Bai DS, Lee YH, Koo BH. Stress and Heart Rate Variability: A Meta-Analysis and Review of the Literature. Psychiatry Investig. 2018; 15: 235-45. 8. Mason SL, Kuruvilla S, Riga CV, Gohel MS, Hamady M, Cheshire NJ, et al. Design and validation of an error capture tool for quality evaluation in the vascular and endovascular surgical theatre. Eur J Vasc Endovasc Surg. 2013; 45: 248-54.