Intraoperative Aortic Valve Visualization Test Device

Stanford researchers in the Woo Lab have developed a novel device that allows for direct visual assessment of the aortic valve apparatus under physiologic pressure in aortic valve procedures. The funnel shaped device with a cantilevered edge on the proximal end fits a wide range of graft or aorta sizes without distortion and is secured to the distal end of a graft or the aorta without slippage or fluid leakage. Two standard luer lock ports provide clear fluid injection (pressurization) and de-airing for a clear view. With continued clear fluid injection, the surgeon can clearly assess the aortic valve under physiologic pressure via the transparent top. Given the reversible attachment mechanism, this device enables surgeons to assess aortic morphology, cusp symmetry, and coaptation before and after aortic valve repair in an iterative process without the need to come off bypass (See video.)

Post aortic valve repair, surgeons often test valve competency via saline injection test, which provides inadequate pressurization. Graft clamping test only provides subjective information and does not allow a direct view of the valve. Transesophageal echocardiogram evaluation remains the primary mode of intraoperative assessment of the aortic valve, but the results are highly operator dependent and also do not provide direct visualization of the aortic valve. If the repair is unsuccessful deemed by echocardiogram, the surgeon would have to re-cross clamp, re-arrest the heart, and re-repair the aortic valve, all of which can significantly increase intraoperative and postoperative risk, such as stroke and heart attack.

The Woo Lab device mimics the physiologic pressure that the aortic valve experiences in diastole, allows surgeons to visually inspect the valve before aortic closure and complete any additional repairs without re-arresting the heart, and thereby provides a safer and more effective outcome than current techniques.

Stage of Development
Researchers in the Woo Lab at Stanford Medicine has completed a preliminary first in man testing, demonstrating safety and efficacy of the device.