Hysterosalpingography is a specialized radiologic procedure used in the evaluation of female infertility. Specifically, its purpose is to assess the shape and function of the uterine cavity and the fallopian tubes.
Hysterosalpingography involves the use of fluoroscopy, an X-ray technique used in real-time to visualize organs within the body.
During this technique, an appropriate contrast medium is injected through a special catheter (a slender tube) into the uterus through the cervix. The tube is made in such a way that the dye will not leak back into the vagina. The introduction of the tube and the dye is under fluoroscopic guidance so that complications are minimized.
A preliminary X-ray is taken first. Following dye injection, four more timed X-rays are taken to assess the contour of the endometrial lining of the uterine cavity, the tubes, and the patency of the tubes. If the tubes are open, they allow the dye to spill out into the peritoneal cavity at the ovarian end. Hysterosalpingography is a safe procedure in most patients, but it does have some risks which are, luckily, rare.
Along with infection, pain is the most common complication of hysterosalpingography. It may be in the form of uterine contractions as the catheter and contrast medium is introduced into the uterus. It is mostly lower abdominal pain, if caused by uterine contractions.
The contrast medium occasionally causes irritation of the peritoneal cavity following spillage, which is felt as a more generalized discomfort in the abdomen. A slow rate of contrast injection will allow time for the agent to spread through the uterine cavity without causing undue distension. Furthermore, using agents with the same osmolarity as body fluids also represents a helpful practice in minimizing pain.
If the tubes are chronically infected or dilated (which is called a hydrosalpinx, when a bulbous portion of the damaged tube contains serous fluid), the procedure may precipitate pelvic infection. This may also be a pointer to traumatic catheter insertion causing uterine injury.
Vasovagal reactions are fainting attacks caused by the sudden manipulation of the cervix or by the insertion of the catheter. In some cases vasovagal reactions may act as an indicator of the premature inflation of the terminal retaining balloon of the catheter before it has entered the uterine cavity and is still within the cervix.
The catheter may pierce and tunnel under the endometrial lining of the uterus. If minor, this is usually not serious. However, the examination maneuver should always be appraised prior to the examination in order to minimize the potential trauma.
While extremely serious, tubal perforation is rare because the technique is carried out under fluoroscopic guidance. If the tube is blocked, weakened by infection, or the contrast is pushed in with extreme force, the thin-walled tube may rupture causing hemorrhage. Uterine perforation may happen if the catheter is pushed too far or too fast through the cervix.
The contrast medium may escape out of the uterine and tubal cavities into the lymphatic or blood vessels. Water-based media do not usually cause significant problems in the case of intravasation, but oil-based media may cause more reactions.
This type of complication is more likely if the contrast is injected with too great force, if the endometrium is traumatized by the catheter, or if the patient is still having her periods and still has open blood vessels. Inflammation of the endometrium is another risk factor.
While technically possible, this is avoided by the use of appropriate precautions and the right technique. It is most serious when the woman is pregnant, because it causes the fetus to be exposed to radiation. Hence it is important to observe the precautionary measures detailed above.
Both oil-based and water-based contrast media have been used historically. However, oil-based media enjoyed a brief popularity due to some reports suggesting that they reduced the time to conception. This was not confirmed by later studies, and moreover, their use was linked to granuloma formation within the tubes in the presence of inflammation or infection.
For this reason, almost all centers performing this procedure now use water-based contrast. Very recent research shows, however, that about 40% of women without pelvic infection conceived within 6 months of having this procedure an oil-based iodine-containing agent known as ethiodized oil, as against almost 30% with a water-based contrast medium. Hypersensitivity to the contrast medium is very rarely observed today.