The “Outside-In” Approach – a minimally invasive central access for future thoracic organ support

Hintergrund Many interventions require access to large central vessels, for which a peripheral cannulation is mainly used. This technique often shows various disadvantages. Our aim was to develop a device for central anastomosis (e.g. for artificial lung or ECLS) to the heart and great vessels using a minimally invasive VATS „outside-in“ approach.

Material und Methode We developed a prototype of a self-expanding „Anchor-Stent", which is lasercut and made of nitinol (Admedes, Germany). The mechanical characteristics of the stent (e.g. radial force and diameter after crimping) were measured. Experimental surgical evaluations were performed on porcine hearts in order to evaluate the stent regarding its overall fit in the vascular wall and leakage with different coatings of the stent. Therefore, the stents were inserted in different positions (aorta, pulmonary artery, atria) of the porcine hearts with the aid of various commercially available implantation tools by using the Seldinger-technique. In order to evaluate the leak-tightness, the vessels together with the attached devices were connected to a circulation in which water- and blood flow was provided by a pump. Different possibilities to connect the device to vascular prostheses were investigated.

Ergebnis A 10 mm device was proven to be crimpable down to a minimum diameter of 5 mm. The radial force of the stents cylinder which affects the vascular wall was measured as 3.94 N (in average) and 16.78 N (maximum). It was possible to insert the stent using the implantation tools and a stable fit inside the vascular/heart wall was achieved. Furthermore, the device was able to self-expand, which mostly provided a sufficient and leakproof lumen (water loss in various experiments with a pressure of 20 mmHg/27 cmH2O in average 17,3 ml/min), although there were some differences between various coatings.

Schlussfolgerung The developed “Outside-in” approach showed that a tight anastomosis is achievable with our prototype stent. Further refinement and investigations regarding cadaveric and in vivo animal trials are necessary and in preparation.

This project is funded by the German Research Foundation (Deutsche Forschungsgesellschaft, DFG): project-number: 347325614.

Publication History

Article published online:
13 September 2022