Patent EA-002415-B1 (EA)
Title: Sizing catheter for measuring septal defects
Inventor: AMPLATZ KURT
IPC: A61F2/958
Filed: 1999-07-30
Abstract: 1. A sizing catheter for measuring the size of an intracardiac opening, said sizing catheter including: a tubular shaft having a longitudinal axis extending between a proximal end and a distal end thereof, said tubular shaft further having a lumen extending between the proximal end and a region short of the distal end and terminating into a series of ports extending through the tubular shaft from the lumen to an outer surface of the tubular shaft, wherein an elongated dilation balloon affixed to the tubular shaft proximate the distal end of the tubular shaft encloses the series of ports, said dilation balloon being constructed of a thin expandable plastic and having an inflation threshold, wherein when the dilation balloon is positioned within a predetermined opening and inflated, said dilation balloon resists deformation up to the inflation threshold such that when the inflation threshold is reached the dilation balloon deforms about the predetermined opening and a size of the dilation balloon adjacent the predetermined opening approximates a stretched diameter of the predetermined opening. 2. The sizing catheter as recited in claim 1, further including radiopaque markings affixed to the tubular shaft proximate the dilation balloon. 3. The sizing catheter as recited in claim 1, wherein the distal end of the tubular shaft is bent at a 45 degree angle relative to the longitudinal axis of the tubular shaft. 4. The sizing catheter as recited in claim 1, wherein the dilation balloon is constructed of an expandable polymer. 5. The sizing catheter as recited in claim 1, wherein the dilation balloon is constructed of polyurethane. 6. The sizing catheter as recited in claim 1, wherein the series of ports are aligned in a spiral fashion around the circumference of the tubular shaft. 7. A method of determining a size of an intracardiac opening, said method including the steps of: a) providing a sizing means for sizing a predetermined internal opening of a patient, said sizing means including an elongated dilation balloon being constructed of a thin expandable plastic and being inflatable to thereby approximate a size of the predetermined opening; b) providing a viewing means for viewing the internal position of the elongated dilation balloon positioned within a patient's body; c) positioning the dilation balloon of the sizing means within the predetermined opening; d) inflating said dilation balloon to an inflation threshold, such that the dilation balloon deforms about the predetermined opening and a size of the dilation balloon adjacent the predetermined opening approximates a stretched diameter of the predetermined opening; and e) determining the size of the dilation balloon adjacent the predetermined opening. 8. The method as recited in claim 7, wherein the step of positioning the dilation balloon further includes positioning a longitudinal axis of the balloon relatively perpendicular to a plane of the predetermined opening. 9. The method as recited in claim 7, wherein said sizing means includes markers viewable by said viewing means, wherein said sizing means is advanced through the predetermined opening such that said markers may be utilized to determine a thickness dimension of the predetermined opening. 10. The method as recited in claim 8, wherein said sizing means includes markers viewable by said viewing means, wherein said sizing means is advanced through the predetermined opening such that said markers may be utilized to determine a thickness dimension of the predetermined opening. 11. The method as recited in claim 7, wherein the viewing means utilizes echocardiography to view the internal position of the elongated dilation balloon.