Wire Guide Canalization
In order to determine if an infertile woman has blocked fallopian tubes, an x-ray test known as an HSG is performed. If blockage of the fallopian tubes is suspected, a catheter may be advanced into the opening of the tube. This technique, known as selective salpingography, may be able to open a blocked tube. Occasionally, selective salpingography alone is insufficient to remove an obstruction. In that case, additional techniques are needed in order to attempt to achieve a patent fallopian tube. A thin, flexible wire can be carefully threaded through a selective salpingography catheter and passed directly inside a fallopian tube. This technique (which is analogous to using a plumber’s “snake” to open a blocked drain) is another technique doctors can use to try to open a blocked tube.
The initial image shows a normal uterus. The right fallopian tube (seen on the left side) is open. The left tube is blocked. A selective salpingography catheter has been placed into the opening of the tube to try to open it. however, it remained blocked.

This image shows that a wire has been passed through the selective salpingography catheter. the obstruction has been dislodged and the wire can move freely within the fallopian tube.
The wire has been withdrawn. The dye can now flow through the fallopian tube.