A retrievable rescue stent graft and radiofrequency positioning for rapid control of noncompressible hemorrhage.

BACKGROUND

Noncompressible hemorrhage of the torso remains a challenging surgical dilemma. Stent graft repair requires endovascular expertise, imaging, and inventory that are not available within the critical window of massive hemorrhage. We developed a retrievable stent graft for rapid hemorrhage. We further investigated a radiofrequency (RF) positioning approach as a possible alternative to the logistics of fluoroscopy.

METHODS

A retrievable stent graft was constructed with a novel "petal and stem" design from nitinol and covered with a sleeve of electrospun polyurethane. The stent graft was tested using an in vitro model of simulated hemorrhage. Next, the stent graft was examined in vivo using a porcine model of noncompressible hemorrhage. The stent was examined for hemorrhage control in a porcine model of either aortic or caval injury. An RF reader was assembled from an Arduino processor while RF tags were affixed to the ends of the stent graft. Detection accuracy of a handheld RF wand for an RF tag was quantified both in vitro and through tissue.

RESULTS

The retrievable RESCUEstent graft was deployed within minutes and rapidly controlled traumatic hemorrhage angiographically in both aortic injury (n = 3) and caval injury (n = 2). Stent grafts were easily recaptured in both models in under 15 seconds. The LED light of a handheld RF detector illuminated when positioned directly over an RF tag. The RF detection approach revealed positioning accuracy to within 1 cm of the intended target, despite tissue interference.

CONCLUSION

This study demonstrates the rapid deployment and retrieval of a RESCUE stent graft as well as the ability to tamponade injuries of the aorta and cava. In addition, this study demonstrates the feasibility of RF tags to guide stent placement through tissue. More rigorous models are needed to define the effectiveness of this approach in the setting of vascular injury and shock.