In-vitro fertilization (cf) is amazing. But it is also a palaver. It involves drugs, injections, early morning vaginal ultrasound monitoring, sedation, minor surgeries, medical skills, high-tech machines and luck. And at several thousand dollars a pop, it’s expensive. Not to mention it’s more likely than not to fail.
In cases where infertility is caused by blockage of the fallopian tubes, which carry eggs from the ovaries to the uterus, an obvious option may seem to be to try to unblock the tubes in question. If the blockage is simply the result of dried mucus, it can be done quite simply using a procedure called fallopian tube recanalization. This involves pushing a fine guide wire out through the end of a catheter and up the blocked tube. It is not a new approach. But it is, in the view of Lindsay Machan, an interventional radiologist at the University of British Columbia, in Vancouver, an underused one. According to Dr Machan, many reproductive endocrinologists and interventional radiologists do not know about it. And he thinks they should.
Between 2015 and 2021, as they reported June 13 at the Society of Interventional Radiology’s annual meeting in Boston, Dr Machan and his team examined 951 women who had been diagnosed with at least one blocked fallopian tube using a procedure called a x-ray hysterosalpingogram (hsg). This involves sending dye into the uterus to check, among other things, whether the tubes are clear.
For each woman, the team first repeated one hsg, under light sedation. Almost a quarter of their patients, they found, actually had two normal, unblocked tubes. Dr Machan’s explanation for this is that without sedation a hsg can trigger a spasm that causes the tubes to constrict again. This can be mistaken for a blockage.
For the remaining 725 women, while still under sedation, the team performed a more focused procedure called a selective salpingogram. This involves pushing a fine catheter up through the cervix, over the uterus and into the opening of one of the tubes, and then injecting dye through it directly into that tube.
Results from the selective salpingograms showed that many of the women had a blockage of a type that appeared treatable with fallopian tube recanalization, which the team then performed through the catheter already in place. In all, they were able to open a blocked tube this way in 539 of their patients—more than half of those who originally presented.
The acid test, of course, is how many of these women have become pregnant in more natural ways than cf. Dr Machan has no answer to that question. His responsibility as a radiologist does not extend to asking that. But with about 2.5m cycles off cf performed around the world every year, someone should. If fallopian tube recanalization routinely enables pregnancy, and if the numbers Dr Machan found in his study are anything like typical, it suggests fertility clinics may be missing an important trick. ■
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