SV-Pro: a device for the intraoperative protection of saphenous vein grafts
Introduction
Coronary artery bypass grafting (CABG) causes occlusions, as early as 5 years after implantation, in 50% of patients which undergo the procedure. This is caused by cell proliferation within the blood vessels. One of the main causes is the damage sustained by the venous bypass during exposure and its maintenance in suboptimal conditions of oxygenation and hydration before implantation. The proposed technological solution will solve this problem, through a device to preserve the vitality of the vessel during the surgical procedure by optimizing the exchange of nutrients and oxygen. The immediate advantages of such a procedure are i) the maintenance of SV tissue humidity, and ii) the active control of SV adventitial tissue gas levels.

Technical features
Current practice involves protecting only the patient’s saphenous vein within a humidified gauze, pre-soaked in a solution. However, while maintaining relative hydration conditions, this solution does not allow to maintain an adequate exchange of oxygen and a supply of nutrients to the vessel due to the interruption of the vascular connections (vasa vasorum) present in the adventitial portion. The proposed solution consists of a disposable sleeve manufactured externally with waterproof and pliable material, containing a fluidic circuit (coil type) capable of facilitating the exchange of oxygen and nutrients with a layer of highly hydrophilic material placed in contact with the vessel. The mat is composed in principle by two main layers: a) an internal, vessel-contacting layer, made with a hydrogel material that keeps humidity and allows the transfer of respiratory gases; b) an external polymeric layer, which has a fluidic path embedded, for the recirculation of a gas-controlled saline solution. The fluidic circuit will be connected to an external tank containing the hydrating / oxygenating / nourishing solution and which will be operated via a small peristaltic pump.
Possible Applications
- Cardiovascular Surgery;
- Aorto-coronary bypass.
Advantages
- Protective environment of the vein outside the human body during pre-implant phase;
- Simple and intuitive procedure;
- Process easy to standardize;
- Controlled delivery of anti-fibrotic drugs.