The role of EVAR simulation in boosting learning curve of trainee

Introduction: Endovascular aortic repair (EVAR) is a valid option in the treatment of abdominal aortic aneurysms and should be part of every vascular surgeon armamentarium. Since vascular residency program should include adequate EVAR training, simulation may help to gain confidence with these procedures. The purpose of this study was to evaluate and quantify procedural skills improvements in vascular residents through participation in a series of simulated EVAR procedures. Methods: Ten vascular surgery residents of different level of experience were recruited and divided in two groups of 5 (“Trainee Group” and “Control Group”). Each group included 3 junior residents (postgraduate year [PGY] 1-2) and 2 senior residents ([PGY] 3-4). All participants attended a preliminary standardized orientation session to practice on an endovascular simulator (Angio Mentor Dual Slim, 3D Systems/Simbionix, Littleton, CO USA). Subsequently, at a first session (t0), each participant of both groups performed two simulated EVAR cases (one “simple” and one “complex” anatomy). After two weeks, other two EVAR simple/complex cases were simulated by each participant in a final session (t1). In the period between t0 and t1, each resident in the Trainee Group performed a total of six simulated EVAR procedures divided in three separate sessions, while the Control Group did not train on simulator any more. At t0 and t1, both quantitative and qualitative analysis were provided. Quantitative analysis was by metrics provided by the simulator which included total procedural time (TP), total fluoroscopy time (TF), time for contralateral gate cannulation (TG) and volume of contrast medium (CM) used. Qualitative analysis was adapted for EVAR procedures using a Likert scale which evaluated participant’s skills involving major EVAR procedural steps by assigning a score from 1 to 5 for each of seven performance criteria and calculating a Total Performance Score (TPS). Analysis of data across the two groups included paired t-tests and Wilcoxon signed-rank tests. Results: All residents in the Trainee Group significantly reduced Tp (mean = 47.7±12.4 vs 31.5±7.7 min, t0 vs t1, P <0.05), TF (mean = 24.7±8.5 vs 18.4±4.4 min,, P <0.05) and CM used overtime (mean =121±37 vs 85±26 ml, P <0.05), but not TG (mean =5.4±4.6 vs 3.1±3.5 min, P=0.284). In the Control Group metrics did not change significantly in any field (mean TP = 55.2±10.5 vs 5.5±10.3 min; mean TF = 17.9±6.9 vs 13.5±6.3 min; mean CM = 132±51 vs 102±42 ml; mean TG = 5.7±3.9 vs 7.9±5.0 min, all P >0.05). The average Trainee Group qualitative TPS improved significantly (P<0.05) after rehearsal sessions when compared with the Control Group (Figure). Conclusion: Simulation is an effective method to improve competence and confidence of vascular residents with EVAR procedures. EVAR rehearsal on simulator can reduce overall procedure and fluoroscopy time, independently from trainee experience, and improve subjective qualitative measures of performance. Further studies are needed to assess the role of simulation-based training in the performance in real clinical settings.