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In some infertile women, the fallopian tubes are blocked at the uterine ( cornual) end. Recanalization is a minimally invasive procedure used to open the blocked fallopian tubes in these patients. The diagnosis of cornual block or proximal tubal occlusion ( PTO) is made usually by doing a X-ray of the uterus and tubes, called a hysterosalpingogram ( HSG) or a laparoscopy.

Fallopian tube recanalization is a relatively new reproductive technique , in which an X-ray of the uterus is performed, using a dye to visualise the uterine cavity and the site of the block, with the help of an advanced X-ray machine called an image intensifier. In patients who demonstrate a tubal block on X-ray, a guide wire or a balloon is passed to the area of tubal blockage & the block is opened up. In women whose tubes are blocked because of a mucus plug or debris, it's possible to open the block successfully. Of course, if the block is because of fibrosis, the technique will not work. The success rate of fallopian tube recanalisation is about 50%, depending upon how well the patients are selected. About 20 -30 % of these women will achieve a pregnancy at the end of 6 months.

It is also possible to recanalise a cornual block while doing a hysteroscopy. The principle is exactly the same, the only difference being that the guidewire is passed into the cornual end under hysteroscopic guidance, rather than fluoroscopic guidance.

Please remember that this technique is not a panacea for all tubal blocks. Thus, is cannot be used for women whose tubes are blocked because of tuberculosis ( TB ); or for those with a mid-tubal or isthmic block or hydrosalpinx. Also, sometimes the tubes can get re-blocked after a few months. If a pregnancy is not achieved within 6 months of the FTR, the next step is in vitro fertilization ( IVF) .

Blocked fallopian tubes are one of the commonest causes of infertility. The fallopian tubes project out from each side of the body of the uterus and form the passages through which the egg is conducted from the ovary into the uterus. The fallopian tubes are about 10 cms long and the outer end of each tube is funnel shaped, ending in long fringes called fimbriae. The fimbriae catch the mature egg and channel it down into the fallopian tube when released by the ovary .

The tube itself is a muscular highly movable structure capable of highly coordinated movement. The egg and sperm meet in the outer half of the fallopian tube, called the ampulla. Fertilization occurs here, after which the embryo continues down the tube toward the uterus. The uterine end of the tube, called the isthmus, acts like a sphincter, and prevents the embryo from being released into the uterus until just the right time for implantation, which is about 4 to 7 days after ovulation.The fallopian tube enters the uterus at its cornual end.

The tube is much more complex than a simple pipe, and the lining of the tube is folded and lined with microscopic hair like projections called cilia which push the egg and embryo along the tube. The tubal lining also produces a fluid that nourishes the egg and embryo during their journey in the tube.

Fig 1. Normal tube and ovary, as seen during laparoscopy

Remember that a doctor cannot judge if your fallopian tubes are open or closed either by an internal examination; or a vaginal ultrasound scan. Unfortunately, this is a very common mistake many patients make, and they assume that if the scan is normal, this means their tubes are open. This is not true. Sadly, many doctors also make the assumption that the fallopian tubes are open, without bothering to test them. Thus, some doctors will assume that a young woman with polycystic ovarian disease must have open tubes, and they start treating her with clomid, without bothering to test the tubal status. This can sometimes be a very expensive mistake ! Just because you have had no symptoms of a pelvic infection does not mean that your tubes cannot get blocked; and if the tubes are blocked, this means the eggs and sperm cannot meet, no matter what medicines you take. This is why it is essential that you ask the doctor to formally test your tubal status before starting any treatment.

The only reliable ways of testing if your tubes are open or closed is by doing either a HSG or a laparoscopy. Personally, I prefer a HSG, because it is much less expensive and provides hard copy documentation.

If a tubal block is found, then what are the next steps ?

The first question is - Are both the tubes blocked ? If only one tube is blocked, then there is no need to take any action at all ! One normal tube is enough for normal fertility. If one tube is open and your doctor advises you to have surgery to open the other tube, please do not agree !

The next question is - Where is the block ? The block could be at the terminal ( fimbrial) end of the fallopian tube. This often causes the tube to get swollen with fluid, and form a hydrosalpinx. In the past, doctors would perform tubal surgery to open this kind of blocked tubes. However, the results were very poor. The tube would usually close down again; or would never function properly, because its inner lining was damaged - damage which cannot be repaired by surgery. Some of these patients would then go on to have tubal ( ectopic) pregnancies.

If the tube is blocked at the cornual end, it's sometimes possible to repair these tubes. Sometimes the block is not a real block, but just an apparent block because of tubal spasm . Sometimes the block is because of a mucus plug or debris, and this can sometimes be cleared with the help of FTR ( fluoroscopic tubal recanalisation). This is a bit like doing an " angioplasty " for the fallopian tube ! ?

Remember that it's impossible for a doctor to judge tubal function. While we know that a blocked tube will not work, it does not follow that an open tube ( which may look perfectly normal anatomically on the HSG or the laparoscopy) is in fact capable of functioning normally ! Sometimes the doctor says the spill of dye is "sluggish"; or that "the tubes filled slowly"; or that they have a beaded appearance. These are just descriptive terms, and often cause more confusion rather than clarity !

Finding out your tubes are blocked can be quite a blow. Because tubal disease is often silent, there is no way of suspecting tubal blockade prior to doing the tests. Blocked tubes will not affect your menstrual cycle, your health or your sexual life, but they will prevent you from having a baby !

While the results of tubal surgery to repair blocked tubes is poor, the good news is that it is possible to offer very effective treatment for this problem today, thanks to IVF, which allows us to bypass the problem completely ! In IVF, the test tube in the IVF lab performs the role the fallopian tube would normally perform in the bedroom !

If you have a hydrosalpinx , some doctors will want to surgically remove this prior to performing IVF. I do not think this is a good idea at all !

Many patients do not understand the difference between embryo transfer and implantation and will often confuse these terms.

Embryo transfer is a simple mechanical process in which the doctor inserts the embryos into the uterus, using a catheter ( a plastic hollow tube).

This is usually an easy procedure which takes about 10 minutes to do. It is done by the doctor, and is usually performed using clinical touch ( where the doctor guides the catheter through the cervix into the uterine cavity with his sense of touch: or with ultrasound guidance).

In some patients ( for example, those with cervical stenosis ( a narrow cervix) or with an angulated cervix, the procedure may be technically challenging, and the catheter may not pass through the cervix easily. There are many ways of solving this problem , based on the difficulty and the doctor's experience and expertise. The doctor may use dilators or special catheter sets, which are designed to help him negotiate the cervical canal; or do the procedure under general anesthesia; or
do a ZIFT, thus bypassing the cervix altogether and transferring the embryos directly into the fallopian tubes.

Implantation, on the other hand, is a biological process , and involves three phases - apposition, adhesion and invasion. This is not in a doctor's control, and while most doctors are very good at making embryos in the IVF lab and then transferring them into the uterus, whether these embryos will finally implant or not is not in anyone's control.

Unfortunately, implantation is not an efficient process, whether done in the bedroom or in the clinic , and only about 30% of apparently perfect embryos will finally become babies. The commonest reason why embryos do not implant is that they have a genetic abnormality , and this is Nature's defense mechanism, to prevent the birth of an abnormal baby. While these defects are often random, they are commoner in older women. This is because the eggs of older women have more genetically abnormalities, because they have "aged" and have genetic defects, which we still cannot screen for efficiently. However, as PGD technology improves, our ability to do so will also improve !

So if your doctors makes good quality embryos and transfer them into your uterus, this means he has done a good job. Now whether these embryos will become babies or not you will find out only after the dreaded 2 week wait !