Sixteen residents and 12 specialists from Dankook University Hospital with no prior experience in performing the REBOA procedure participated in this educational course. All specialists were board-certified and included: six emergency physicians, four general surgeons, one cardiothoracic surgeon, and one neurosurgeon who took calls in the Trauma Resuscitation Unit at the level I trauma center in Dankook University Hospital (Fig. 1). The course was conducted by four full-time trauma faculty members (one cardiothoracic surgeon and three general surgeons) from Dankook University Hospital who had experience with the REBOA procedure as well as the educational model. Each trainee was matched to two instructors at a time.
All participants were provided with pre-course learning materials one week prior to the course. These lecture notes provided an introduction to the aortic zone, role, indication and sequences of REBOA. The demonstration videos (Fig. 2) included instructions on how to perform the preparations (sheath, wire, and balloon catheter) and procedures (ultrasound-guided vascular access, balloon insertion, and balloon inflation in accordance to the target level). On the day of training, 60 minutes of lecture plus discussion was provided.
The course consisted of two sections: 1) ultrasound-guided sheath insertion and 2) balloon manipulation. Ultrasound-guided sheath insertion was performed on the lower torso model Blue PhantomTM (Femoral Vascular Access Lower Torso Ultrasound Model, CAE Healthcare, Texas, USA) using 7 Fr Radiofocus® Introducer II (Terumo, Tokyo, Japan). This model is a manikin with femoral vascular access replacement tissue, which allows for realistic ultrasound imaging to guide needle and catheter insertions into the pulsated femoral artery distinguished from vein. The balloon was inserted and inflated on the vascular circuit model EVETM (EndoVascular Evaluator, BR Biomedicals Pvt. Ltd., New Delhi, India) using 7 Fr RESCUE BalloonTM (Tokai Medical Products, Aichi, Japan). This model is made of special silicone that recreates the elasticity and friction of human vasculature, simulating the sensation and behavior of catheter manipulation during an endovascular procedure. Artery pulsation can be simulated using a pulsed flow pump, the pressure of which can be changed by aortic occlusion. It also provides compatibility with a wide range of X-ray imaging techniques.
Each section was repeated twice, and the time taken to complete each procedure was recorded to evaluate improvements in the skill of the participants. Participants performed both zone I and III REBOA alternately using two case scenarios: 1) a moribund patient with a massive hemoperitoneum confirmed by Focused Assessment with Sonography for Trauma (zone I) and 2) an unstable pelvic bone fracture by pelvic X-ray (zone III). Portable X-ray (Fig. 3) was taken to check the position of the guidewire and balloon during the course.
The procedure checklist contained a total of 13 items (Table 1). Participants received a “fail” if they: 1) did not successfully access a femoral artery using the ultrasound-guided technique, 2) inflated the REBOA balloon during preparation, 3) did not change from the soft guidewire to the stiff wire before balloon inflation, or 4) inflated the balloon before checking the balloon position. Residents who failed their first attempt were given additional opportunities to acquire the correct skills without a time limit. Instructors gave tips and feedback to the participants immediately after the first attempt according to the checklist.
Participants rated their confidence in performing REBOA immediately before and after the course on a scale from 1 (strongly disagree) to 10 (strongly agree). The post-assessment contained the same questions as the pre- assessment. After completing the course, participants also completed an 11-item course satisfaction questionnaire, which also employed a 10-point scale.
For the course analysis, continuous variables were compared using paired t tests, and P-values < 0.05 were considered statistically significant. All statistical analyses were performed using PASW Statistics 19 (IBM Corp., Somers, NY, USA). This study was approved by the Institutional Review
Board of the Dankook University Hospital (201910001).