Patient Information
Hysterosalpingography (HSG), Lipiodol Flush, and Fallopian Tube Recanalisation
Information for patients
This guide explains three closely related procedures that are often performed together when investigating fertility: Hysterosalpingography (HSG), Lipiodol flush, and fallopian tube recanalisation. These procedures can be offered with sedation according to patient preference. They are performed through the cervix, usually in a single appointment, and use X‑ray guidance to assess whether the fallopian tubes are open and, in some cases, to improve tubal function. This guide complements – not replaces – conversations with your specialist/medical team.
1) Hysterosalpingography (HSG)
An HSG is an X‑ray test that looks at the shape of the uterus and checks whether the fallopian tubes are open. During the test, a small catheter is placed through the cervix and contrast is gently injected into the uterus. X‑ray images are taken as the contrast fills the uterus and flows into the tubes.
If the contrast passes freely through the tubes and spills into the pelvis, the tubes are considered open. If it does not, this may indicate a blockage or temporary tubal spasm.
Some women have already had a HyCoSy (hysterosalpingo-contrast-sonography, an ultrasound-based tubal test) before being referred. An HSG can be performed after a HyCoSy has suggested a possible blockage, to confirm the finding. There is then the option of treatment during the same sitting.
Most women experience period‑like cramping during the procedure. The discomfort is usually brief and settles quickly once the test is complete.
2) Lipiodol flush
A Lipiodol flush is a variation of an HSG that uses an oil‑based contrast agent rather than a water‑based dye. It is performed at the end of the HSG and does not require a separate procedure.
The strongest evidence for this effect comes from a large randomised controlled trial comparing oil‑based (Lipiodol) and water‑based contrast during HSG. In this study, the live birth rate associated with pregnancies occurring within 6 months from the procedure was 39% in women who underwent a (Lipiodol) flush, compared with 28% in those who had a water‑based contrast flush (Dreyer et al., New England Journal of Medicine, 2017).
The reason for this benefit is not fully understood. It is thought to be due to a combination of gently clearing minor debris or mucus from the tubes and possible biological effects of the oil‑based contrast within the reproductive tract.
Performing a Lipiodol flush under X‑ray guidance allows Dr Hillhouse to see exactly where the contrast is flowing and helps reduce the risk of contrast entering small blood vessels (intravasation). This visual control is an advantage compared with blind or non‑fluoroscopic flushing techniques.
A Lipiodol flush is only offered to selected patients. It is not suitable if you have an iodine allergy or if the tubes are completely blocked.
3) Fallopian tube recanalisation
If the HSG shows that a fallopian tube appears blocked close to where it joins the uterus (a proximal or ostial blockage), it may be possible to reopen it using fallopian tube recanalisation.
The procedure is usually performed in a stepwise manner. First, a small catheter is positioned at the opening of the tube and gently flushed under X‑ray guidance using contrast. In a proportion of cases, this selective flushing alone is enough to displace the mucus plug and restore flow.
If the tube does not open with flushing, Dr Hillhouse may proceed to wire recanalisation. Very fine guidewires are then used to carefully cross the blocked segment under continuous X‑ray guidance. Contrast is injected at the end to confirm whether the tube has been successfully reopened.
Technical success rates for reopening at least one tube is approximately 85–95%. Recanalisation is most effective for blockages close to the uterus and is not suitable for all types of tubal disease.
Complications are uncommon. Tubal perforation has been reported in a small percentage of cases (generally <1–3%) and is usually recognised immediately under X‑ray guidance. In most instances, this is managed conservatively and does not result in long‑term problems. Infection and significant bleeding are rare.
4) Timing and preparation
These procedures are performed when you are not pregnant and are usually scheduled after your period has finished but before ovulation. You will have a urine pregnancy test the morning of your procedure. The best time to perform the tests are between day 6 and day 11 of a typical 28‑day cycle.
We advise you to avoid intercourse from the start of your period until after the test, to reduce the chance of an early pregnancy at the time of the procedure.
We recommend taking paracetamol and an anti‑inflammatory pain relief (such as ibuprofen) about one hour beforehand if you are able to do so.
The procedure typically lasts around 45 minutes to 1 hour, including preparation and excluding recovery.
5) After the procedure
Most women are able to go home shortly after the procedure and return to normal activities the next day.
It is common to experience mild cramping for a day or two. You may notice vaginal loss of fluid or light bleeding for several days as the contrast drains; using a sanitary pad rather than a tampon is recommended.
If you feel well, trying for pregnancy in the same cycle after the procedure is generally considered safe.
6) Risks and when to seek help
These procedures are considered low risk. Complications include infection, tubal spasm causing pelvic pain, or a vasovagal response (feeling light‑headed or faint during or shortly after the procedure).
You should seek medical advice if you develop worsening pelvic pain after the first few days, fever above 38°C, offensive vaginal discharge, or feel generally unwell.
7) Frequently asked questions
Can all these procedures be done together?
Yes. In many cases, an HSG, Lipiodol flush, and fallopian tube recanalisation (if required) can all be performed in a single sitting, avoiding the need for multiple appointments.
Will this improve my chances of pregnancy?
These procedures help identify whether the tubes are open and guide fertility planning. In some women, particularly those having a Lipiodol flush, studies show a modest but meaningful improvement in pregnancy rates in the months following the procedure.
What if both tubes remain blocked?
If blockages cannot be reopened, your fertility specialist will discuss alternative options with you, such as assisted reproductive treatments.
Will I need time off work?
Most women return to work the following day, depending on how they feel.
Prepared for patients of Dr James Hillhouse, Interventional Radiologist.
This information is general and should be discussed with your treating clinicians.
For clinicians: X‑ray‑guided Lipiodol flushing allows real‑time visualisation of tubal filling and spill, enables immediate treatment of proximal tubal occlusion if identified, and reduces the risk of unrecognised Lipiodol intravasation/fat embolism compared with blind or non‑fluoroscopic techniques.