What Are Fallopian Tubes?
The fallopian tubes, also called uterine tubes, salpinx, or oviducts, are j- shaped muscular structures found in the reproductive tract of females. It is present bilaterally between the uterus and the ovaries in the pelvis region. The main function of the fallopian tubes is the transportation of eggs from the ovaries to the uterus. For permanent contraception or sterilization, the fallopian tubes are blocked.
What Are the Functions of Fallopian Tubes?
The main function of the fallopian tubes is to transport eggs (ovum) from the ovary to the uterus. The fimbriae pick up the egg and then sweep towards the uterus. The movement of the egg is facilitated by the beating of the cilia and by peristalsis (contraction of certain muscles), which occurs with the rhythmic contractions of the muscles of the tubes.
During fertilization, the sperm moves from the uterus into the tubes. In the fallopian tubes, the fertilization of an egg happens. This fertilized egg then moves towards the uterus. When the fertilized egg implants in the uterus, it becomes a uterine pregnancy. So, the fallopian tube is essential for the successful transportation of an egg to become pregnant.
What Is the Anatomy of the Fallopian Tube?
The fallopian tube is a muscular organ and they are two tubes that begin from the uterine horn. It is 11 to 12 centimeters long and the diameter of the lumen is less than one millimeter. The other ends of the fallopian tubes lie very close to the ovaries but not directly attached. They generally have four sections.
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Fimbriae - It is a finger-like, ciliated project, which helps in capturing the egg from the surface of the ovary.
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Infundibulum - It is a funnel-shaped opening seen near the ovary, where fimbriae are attached.
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Ampulla - It is the widest section of the uterine tubes with thin walls. Usually, fertilization occurs here.
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Isthmus - It is a narrow section of the uterine tube that connects the ampulla to the uterine cavity.
The fallopian tubes consist of several layers. Serosa is the outer membrane-like layer and the inside muscle layers, known as the mesosalpinx. The number of layers depends on the portion of the tube. The innermost of the fallopian tubes consist of a deeply folded mucosal surface with cilia. They are hair-like structures and help to move the ovulated egg from the ovary to the uterus. Additionally, they help in distributing tubal fluid throughout the tube.
Do the Structural Variations in the Fallopian Tube Cause Infertility?
Fertility can be caused due to the presence of an accessory fallopian tube that can form during development, and it is a very rare case. The accessory tube usually ends near the ovary, but they do not extend into the uterus. So, if an egg is taken up by the accessory fallopian tube, the fertilization and implantation do not happen. Additionally, the risk of ectopic pregnancy in cases of an accessory tube is high. Therefore, when a woman experiences infertility the doctors may screen for an accessory fallopian tube. Other structural variations include closed sacs, extra openings, and functional changes to the fimbria. These cases occur when any developmental anomaly occurs in one or both fallopian tubes.
What Are the Diseases Affecting the Fallopian Tubes?
Fallopian tube diseases can affect the function of the fallopian tubes, which serve as pathways for the fertilization of eggs.
The diseases affecting the fallopian tubes are,
1) Salpingitis - It refers to an inflammatory disease that leads to the thickening of the tubes. There are two types of salpingitis. Nodular salpingitis involves the formation of nodules inside the isthmus. These nodules make it hard for the eggs to pass through the tubes and also increase the risk of ectopic pregnancy. In non-nodular salpingitis is caused by an infection, which can be associated with pelvic inflammatory diseases. It can also cause tubal blockages and scarring.
2) Ectopic Pregnancy - If the fertilized egg cannot pass into the uterus, and if it implants in the fallopian tube it is known as an ectopic pregnancy. The fertilized egg can not grow in the fallopian tube and so miscarriage occurs. It is a medical emergency condition, if it is not diagnosed early, the implanted embryo can cause rupture and hemorrhage of the fallopian tube.
3) Tubal Infertility - It is a general term, used to describe when a woman is not able to conceive a pregnancy due to fallopian tube issues. It can occur due to multiple causes, from congenital abnormalities to infections. Infection due to chlamydia is one of the most common causes of tubal infertility. Tubal infertility is responsible for a large number of cases of female infertility.
4) Tubal Torsion - It is also called adnexal torsion. It occurs due to the twisting of the fallopian tube, which in turn affects its blood supply. This usually happens along with ovarian torsion, but in some conditions, it can happen on its own. If it is treated, it can affect fertility.
5) Hydrosalpinx - It occurs when one or both fallopian tubes become blocked, swollen, and filled with fluid. Usually, hydrosalpinx can be the result of an infection. But it can also be due to an obstruction in the ends of the fallopian tube.
6) Cancer of the Fallopian Tube - It occurs very rarely, less than one percent of gynecologic cancers happen in the fallopian tubes.
What Are the Tests Used to Detect Fallopian Tube Anomalies?
The diagnostic tests for fallopian tube abnormalities include:
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Hysterosalpingography (HSG) - It is the most commonly used imaging technique to check for structural abnormalities in the fallopian tubes. This test is usually done a few days after the menstrual period ends. A dye is injected through the cervix into the fallopian tubes. Then X-rays are taken that produce an image of the fallopian tube outlined by the dye.
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Sonohysterography -This test also detects fallopian tube problems. In this technique, a saline solution is injected into the uterus through the cervix to expand and allow ultrasound imaging to reveal abnormalities. The proper flow of saline solution through the fallopian tubes indicates the tubes are not blocked.
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Hysteroscopy - It is used to identify suspected fallopian tube disease or damage. A lighted, thin tube called a hysteroscope is inserted into the vagina and into the uterus to view any growths that block the fallopian tubes. If any blockage such as a polyp or fibroid is found, instruments are inserted through the tube, and the blockages are removed.
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Laparoscopy - Laparoscopy also helps to identify and remove blockages in the tubes. A laparoscope is a thin tube with a camera and light. It is inserted through a small incision into the uterus so that the doctors can see into the fallopian tubes and check for blockage. If present, it is removed using special instruments.
What Is the Treatment for Fallopian Tube Diseases?
The treatment of fallopian tubules involves hysteroscopy or laparoscopy to remove any abnormal tissues. Both are minimally invasive methods. In the case of infections or severe damage, surgery may be required.
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Surgery - In some cases, surgery is required to repair the damage to the fallopian tube by infection or by an ectopic pregnancy. In most instances, women need IVF (In Vitro Fertilization) to conceive after surgery. However, the surgery is helpful to remove the infection or other blockages. The procedures involve complications like pain, blood loss, and tissue damage.
Conclusion -
Fallopian tubules are important structures for reproduction. The main function of the fallopian tube is to transport eggs from the ovaries to the uterus. So any infections, structural or developmental anomalies in the fallopian tube can cause infertility. There are many diagnostic tests to find out the blockage or damage of the fallopian tubes. Hysteroscopy, laparoscopy and surgery are treatment options for fallopian tube disorders.
