To develop, construct and test an ultrasound capable flow model to simulate percutaneous arteriovenous fistula (pAVF) creation with Ellipsys®.

A life-like flow model anatomically representing the proximal elbow area with a polyvinyl chloride tube simulating the venous structures (cephalic vein and deep perforator vein (DPV) and a crossing tube in approximately 3 cm depth equivalent to the proximal radial artery (PRA) has been developed in collaboration with Vascular International School. A total of three “vessel” pairs are embedded in hydrogel in one inlay. The outer vessel diameters representing the PRA and DPV are approximately 3 to 4 and 4 to 5 millimeters. The distance of both tubes at the crossing point is between 1 and 2 mm. This inlay is placed in a box with a custom made styrodur frame and connected to a unidirectional pump system, delivering pulsatile flow with water through the artery simulating tube and continuous flow through the venous structure. The created hydrogel inlay enables visualization of all structures by ultrasound. Prototype testing was conducted to create a simulation training video.

A five-step procedure was developed to simulate creation of a pAVF: (1) vascular ultrasound (US) mapping, (2) US-guided puncture and needle crossing from DPV into PRA, (3) US-guided application of endovascular devices, (4) application of Ellipsys® catheter and (5) balloon dilatation of the anastomosis. All steps could be accomplished in an appropriate time-period and the applied material matched the specifications of the model. An instructional simulation training video using picture in picture editing to demonstrate sonographic views and probe handling was created.

Inlay hydrogel properties and perfusion of vessel structures permitted to perform and record all steps to simulate the creation of a percutaneous arteriovenous fistula. Simulation training may be a valuable adjunct to traditional forms of training when teaching ultrasound-guided percutaneous procedures. Based on these findings, we plan a randomized simulation training for vascular trainees. Further adjustments of the model will be performed according to participants' feedback.