Surgical depth measuring instrument and method

Abstract

A device for measuring the depth below skin level of a blood vessel that has been punctured in the course of a catheterization or other interventional vascular procedure comprises a tubular member having a proximal end and a distal end portion that is preferably tapered to a small outer diameter. The lumen may have a stepped diameter extending between the proximal and distal ends. A first portion of the lumen is distally located and is of a diameter generally equal to the diameter of a guidewire with which the measuring device is used. The second segment of the lumen is of a substantially larger diameter. A side entry port is made through the wall of the tubular member at the distal base of the larger diameter section of the lumen. Graduated markings on the side wall of the tubular member extend from the side entry port toward the proximal end of the instrument. When the instrument is fed over a guidewire into a puncture wound formed through the skin and into an artery, the wall of the artery can be accurately located relative to the skin's surface by noting the graduated markings on the exterior of the tube at the point where blood flow enters the side entry port and fills the larger diameter lumen. Rather than having two coaxially disposed lumens as above, the tubular member may have a double lumen, one extending the entire length for accommodating the guidewire and the other extending between the tube's proximal end and the side entry port.