Various methods have been developed to revascularize diseased or occluded branches of the aorta. Direct reconstruction via bypass originating from the aorta proximally and anastomosed distally to the artery of interest currently necessitates clamping and partial or total occlusion of the aorta. This interruption of aortic blood flow increases stress on the heart, potentially causing cardiac morbidity. Such occlusion of blood flow inevitably leads to ischemia of downstream organs and extremities, which potentially leads to other complications. Because the aorta itself is often diseased, with varying degrees of calcification within its wall, the act of placing occlusive clamps across the aorta risks injuring the aorta. In addition, plaque within the wall is potentially liberated to embolize distally, which is undesirable.
Numerous devices have been developed to avoid the use of clamps. These devices include various configurations of balloons, cannulae, and perfusion lumens that facilitate anastomosis of a bypass artery to an aorta without aortic clamping. Such devices are disclosed in U.S. Pat. No. 6,695,810 to Peacock et al.; U.S. Pat. No. 6,135,981 to Dyke; U.S. Pat. No. 6,143,015 to Nobles; and U.S. Pat. No. 6,045,531 to Davis. Some of these devices also facilitate “beating heart” bypass procedures in which some blood flow is maintained through the aorta to reduce the risks of complete blood flow occlusion. However, these devices are designed to facilitate coronary artery bypass, and are not suited to other non-coronary applications.
Maintenance of blood flow through the aorta during bypass procedures is important for several reasons. For instance, the avoidance of aortic clamping might allow more laparoscopic aortic procedures. Conventional operations to revascularize branch aortic vessels involve opening the chest or abdomen to allow direct exposure of the vasculature. These large incisions potentially lead to numerous complications, morbidity, or significant loss of body heat. Laparoscopic surgery via very small incisions avoids many of the disadvantages of conventional surgical exposures. It is used commonly in gastrointestinal, gynecologic, thoracic and urologic procedures, yet is not currently applied often to vascular operations. One reason for its sparse use is the current necessity for lengthy aortic occlusion times caused by conventional devices.
Therefore, there is a need in the art for a device and associated methods that facilitate the selective occlusion of blood flow in a working space, while maintaining blood flow through the aorta to allow less morbid arterial revascularizations.