Endovascular surgery system for atrial septal defect repair

DESCRIPTION (provided by applicant): Atrial septal defect (ASD) is one of the most common congenital heart defects found in pediatrics and adults. Surgical repair of ASD has been considered the gold standard for correction of ASD, however, to avoid complications associated with open-chest operation and cardiopulmonary bypass, transcatheter occlusion implant devices have been developed and are gaining clinical acceptance. While implant occlusion is less invasive than traditional surgery with shorter hospital stay and less scarring, a significant complication rate is associated with occlusion implants, including the erosion or puncture of implant structures through adjacent cardiac tissues. The investigators propose a system for endovascular-based surgical correction of atrial septal defect. The Phase I catheter-based system would achieve tissue stabilization, surgical ASD patch deployment and suture fixation capabilities and replicate traditional surgical correction of ASD via percutaneous access. As a result, our proposed system would eliminate the need for open-chest procedures and cardiopulmonary bypass (CPB). Furthermore, the this system will utilize a surgical patch comprised only of a polyester patch and suture material leaving no rigid metal structures in the body, therefore mitigating the risk of device related puncture or erosion. In this Phase I effort, a catheter-based system will be fabricated, including a custom surgical patch, a removable nitinol patch deployment frame, a transseptal suture tool, and a custom surgical knot pusher. Electromagnetic (EM) tracking of the Phase I tools and a transesophageal echo (TEE) probe will be used for navigation. We will develop a custom user interface to render TEE images and surgical tool positions in a virtual environment in real time. An in vitro test fixture will be fabricated to hold an excised abattoir porcine septum and impart a physiologic LA to RA pressure gradient. The fixture will include a simulated esophagus to facilitate TEE probe introduction and in vitro testing of the Phase I surgical tools using the EM-based navigation system. Following in vitro tests and refinement of tool designs, the investigators will perform six ASD corrections in adult pigs. Park Blade Catheters will be used to create ASD and subsequent ASD repair will be performed using Phase I prototype systems. Three acute procedures will be performed (2 hour post-op observation prior to sacrifice) to assess basic functionality of the system. Three recovery procedures will be performed (21 day post-op observation) to assess the long term custom surgical patch performance and safety. Successful development of the proposed tools could serve as a platform system for the expansion of endovascular procedures such as surgical manipulations of the left atrial appendage or failing mitral valve. An atrial septal defect (ASD) is a malformation in the heart which historically has been corrected with open- heart surgery. To avoid invasive surgery, ASD can be plugged with small implants inserted through a cut in the leg and anchored in the heart; however, these implants have been known to cause additional damage to surrounding heart tissue. A miniature device will be developed which can perform surgery on ASD through the same small cut in the leg without the need for implants or open-heart surgery.