Lay summary

Background:Current surgicaldevelopments are evolving towards minimally invasive approaches, such asendoscopic and endovascular techniques. Patients with abdominal, cardiac andorthopaedic problems benefit already of these techniques. In the field of microsurgery,there are to date no available similar techniques for patients withneurovascular diseases or in need of microsurgical revascularization (bypass)procedures. They have to bear the risks of lengthy procedures with end-organischemia while classical microvascular anastomoses are being sutured. Thedevelopment of fast, effective and minimally invasive tissue fusion techniquesin the area of microvascular anastomosis are necessary.?The previous researchof our neurovascular and reconstructive teams, (SNF-grants # 32003B-107611 and# 310030-108447) succeeded in developing first microvascular tissue solderingtechniques capable of withstanding mechanical stress (i.e. extension with jointmovement etc) and pressures (i.e. blood pressure) encountered in the humanbody.

Goals: The proposed combined researchrepresents our combined interdisciplinary research interests aiming at two maingoals: The first part of the research investigates basic scientific concepts atcellular level in order to improve the understanding of the underlyinginteractions of variables and multiple factors present and necessary forsuccessful sutureless tissue fusion. The second part investigates clinicallynovel concepts of side-to-side and endovascular balloon assisted end-to-end lasersoldered microvascular tissue fusion and is planned to bring this research to apreclinical application level in large animal models to prove the necessaryblood flow can be established.

Methods: The basic principle of tissuefusion investigated in this project relies on Laser beams applied with the helpof a balloon catheter from inside the microvessel. They then pass through thevessel wall and are absorbed on the outside by a specially developed soldermaterial which hardens and fuses with the vessel wall leading to the necessarystrength of the minimally invasive repair. In the bypass technique, after twovessels will be fused parallel side-to-side an additional laser will beutilized to create the necessary holes across the walls of the two parallelsoldered microvessels in order to establish blood flow in the bypass.

Expectedimpact: The advantagecompared to the current „state-of-the-art“ sutured microsurgical vascularanastomosis lies in the increased velocity of the minimally invasive tissuefusion procedure. Furthermore this technique will enable bypass surgery withoutthe need of interrupting the blood flow to the organs and thus avoidingischemia by the side-to-side soldering technique