A surgical apparatus is disclosed for delivering a therapeutic device to a desired location within the vasculature of a patient, which includes an elongated tubular body defining a longitudinal axis and having opposed proximal and distal end portions, the tubular body including an outer wall surrounding an interior lumen, wherein an elongated target opening is formed through the outer wall of the tubular body within the distal end portion thereof in communication with the interior lumen. At least one distal sensing electrode is provided on the tubular body adjacent a distal side of the target opening, and at least one proximal sensing electrode is provided on the tubular body adjacent a proximal side of the target opening, wherein the sensing electrodes allow placement of the target opening within the vasculature of a patient for the delivery of a therapeutic device to a desired location.
