Are my fallopian tubes blocked?

Patients are often interested in the status of their fallopian tubes and quite understandably are concerned as to whether they may be blocked or not. Superficially this sounds like a very reasonable and logical question. Indeed, one of the tests often performed by fertility specialists is to demonstrate tubal patency. Simplistically it is easy to imagine that the fallopian tubes are somewhat like a drain pipe that is either hollow or blocked. Like many things in life, the real issue behind this line of questioning is much more complex and nuanced. The situation can be likened somewhat to a blocked nose. We all appreciate that one can have a mucous plug and that a blocked nose is not abnormal and does not require any form of surgery.
The fallopian tube is much more than a simple pipe. It is lined by a delicate hair or carpet-like structure called cilia. The tube needs to collect eggs from the distal end and then move these towards the uterus whilst moving sperm in the opposite direction. Fertilisation of the egg occurs in the tube and the embryo will remain within the tube for some 5 days before being transported to the uterus prior to implantation. We are unable to test any of these functions and patency is a very coarse test. In the same way that a nose can be blocked with a mucous plug the probability is the same can occur within the tube and that there can be a degree of spasm of the muscular component of the tube such that it may appear blocked whilst in fact being normal. Under laparoscopic control it is regularly appreciated that blue dye introduced into the uterus under pressure may not always be seen spilling from the ends of the fallopian tubes despite being of a pristinely normal appearance. Most of these cases will be normal and do not at all indicate that some form of surgery or IVF is required to conceive.
Prior to the current high success rates of IVF, surgery was used at times to improve obvious abnormally blocked tubes. The surgical results however were woeful and in current times surgery is rarely performed with the exception of reversing ligation of otherwise normal tubes. It is certainly possible to make tubes patent, although if the tubes have truly been blocked and dilated (hydrosalpinx) the underlying cilia is likely significantly damaged and poorly functioning such that normal pregnancy is not possible and there is an increased risk of ectopic pregnancy. One could liken the situation to a plush carpet in a high end hotel compared with the beer stained dance floor of the local pub where your shoes stick to the floor as you attempt to move.
A true hydrosalpinx is when the fallopian tube is blocked and dilated. In most circumstances this involves clubbing or closure of the distal (fimbrial) end of the tube. Hydrosalpinx is associated with infertility, ectopic pregnancy, failed IVF and pelvic infection which can result (happily rarely) in septicaemia, multiorgan failure and even death. For these reasons it is reasonably standard practice to recommend removal of the tube if it is a hydrosalpinx.
My own suggestion to patients is that if a fallopian tube looks normal although not patent to dye it should be left in situ. Failure to conceive after an appropriate time may require resort to IVF but not removal of the fallopian tube. I also prefer to retain tubes that may be mildly dilated with intact fimbriae.
Fallopian tubes are not simply drain pipes and a finding of a “blockage” should be carefully thought through before recommending surgery or IVF.