IntroductionEndovascular aortic repair (EVAR) is a minimal-invasive technique that prevents life-threatening rupture in patients with aortic pathologies by implantation of an endoluminal stent graft. During the endovascular procedure, device navigation is currently performed by fluoroscopy in combination with digital subtraction angiography. This study presents the current iterative process of biomedical engineering within the disruptive interdisciplinary project Nav EVAR, which includes advanced navigation, image techniques and augmented reality with the aim of reducing side effects (namely radiation exposure and contrast agent administration) and optimising visualisation during EVAR procedures. This article describes the current prototype developed in this project and the experiments conducted to evaluate it.MethodsThe current approach of the Nav EVAR project is guiding EVAR interventions in real-time with an electromagnetic tracking system after attaching a sensor on the catheter tip and displaying this information on Microsoft HoloLens glasses. This augmented reality technology enables the visualisation of virtual objects superimposed on the real environment. These virtual objects include three-dimensional (3D) objects (namely 3D models of the skin and vascular structures) and two-dimensional (2D) objects [namely orthogonal views of computed tomography (CT) angiograms, 2D images of 3D vascular models, and 2D images of a new virtual angioscopy whose appearance of the vessel wall follows that shown in ex vivo and in vivo angioscopies]. Specific external markers were designed to be used as landmarks in the registration process to map the tracking data and radiological data into a common space. In addition, the use of real-time 3D ultrasound (US) is also under evaluation in the Nav EVAR project for guiding endovascular tools and updating navigation with intraoperative imaging. US volumes are streamed from the US system to HoloLens and visualised at a certain distance from the probe by tracking augmented reality markers. A human model torso that includes a 3D printed patient-specific aortic model was built to provide a realistic test environment for evaluation of technical components in the Nav EVAR project. The solutions presented in this study were tested by using an US training model and the aortic-aneurysm phantom.ResultsDuring the navigation of the catheter tip in the US training model, the 3D models of the phantom surface and vessels were visualised on HoloLens. In addition, a virtual angioscopy was also built from a CT scan of the aortic-aneurysm phantom. The external markers designed for this study were visible in the CT scan and the electromagnetically tracked pointer fitted in each marker hole. US volumes of the US training model were sent from the US system to HoloLens in order to display them, showing a latency of 259±86 ms (mean±standard deviation).ConclusionThe Nav EVAR project tackles the problem of radiation exposure and contrast agent administration during EVAR interventions by using a multidisciplinary approach to guide the endovascular tools. Its current state presents several limitations such as the rigid alignment between preoperative data and the simulated patient. Nevertheless, the techniques shown in this study in combination with fibre Bragg gratings and optical coherence tomography are a promising approach to overcome the problems of EVAR interventions.

The LTB curriculum constitutes a new highly standardized and proficiency level-based training program for basic skills in MIS. Transferability of the task content to a (sub)-realistic environment could be demonstrated. Still, future trials will have to further validate the effectiveness of the LTB curriculum.

Abstract

Standardised comprehensive video tutorials watched frequently throughout practice can significantly improve precision in MIC training. This aspect should be incorporated in MIS training.

Introduction: Accurate planning for endovascular aortic repair is essential. 3D printed models may be a valuable tool that allows surgeons to test their surgical plans and understand possible pitfalls. Objective: To evaluate the impact of patient-specific simulation using 3D printed aneurysms on EVAR planning. Methods: This was a prospective, controlled trial developed at São Paulo University Medical School. A simulator for training in EVAR was produced using 3D printing technology. During a 2-year period, ten vascular surgery residents were consecutively enrolled in Control Group (5 residents, 30 patients) or Training Group (5 residents, 25 patients). The residents from the Control Group planned and performed the surgery under the supervision of a senior vascular surgeon (routine practice). The residents from the Training Group, in addition to the routine practice, trained in a patient-specific simulator prior to the surgery. Technical success, unplanned adjunct manoeuvres and change in procedure planning after training were analysed. Statistics: Fisher exact test compared the groups. The software R was used. Results: Technical success was similar comparing the groups (control group 83%, training group 92%; odds ratio: 2.3; CI: 0.4e13; p¼0.37), unplanned adjunct manoeuvres were necessary in 30% of the procedures on the control group vs 8% on the training group (p¼0.05). On the control Group, three patients required the use of a proximal extension to treat type Ia endoleaks. The training sessions helped to establish the best diameter and position of the stent graft, therefore no proximal extension was necessary on the training group. The length measurements on the 3D printed aneurysms helped to avoid unplanned cover of the internal iliac artery, which occurred in one patient of the control group. Conclusion: 3D printed aneurysms may be a valuable tool for EVAR planning; it can identify potential difficulties and tend to reduce unplanned manoeuvres.Introduction: 3D printing technology allows the production of patient-specific simulators for training in Endovascular Aneurysm Repair (EVAR). Training in simulators allows that part of the learning curve is achieved without exposing patients to unnecessary risks. Objectives: To evaluate the impact of patient-specific training prior to EVAR on the surgical performance of vascular surgery residents in a university hospital in Brazil.Material and Methods: Prospective, controlled, single centre trial. A simulator for training in EVAR was developed using 3D printing technology. During a 2-year period, ten vascular surgery residents were consecutively enrolled in Control Group (5 residents, 30 patients) or Training Group (5 residents, 25 patients). The residents from the Control Group planned and performed the surgery under the supervision of a senior vascular surgeon (routine practice). The residents from the Training Group, in addition to the routine practice, trained in a patient-specific simulator prior to the surgery. Objective parameters were analyzed. The residents an...