Hysterosalpingogram

Hysterosalpingogram (HSG) is a fluoroscopic examination of the uterus and the Fallopian tubes, most commonly used in the investigation of infertility or recurrent spontaneous abortions.

Indications

• Infertility to assess uterine morphology and tubal patency.

Contraindications

• pregnancy
• active pelvic infection
• recent uterine or tubal surgery

Technique

• the procedure should be performed during the proliferative phase of the patient’s menstrual cycle (days 6-12), when the endometrium is thinnest 
  • this improves visualization of the uterine cavity, and also minimizes the possibility that the patient may be pregnant ¹
  • if there is any uncertainty about the patient’s pregnancy status, a beta hCG is warranted prior to commencing.
• after an antiseptic cleaning of the external genital area, a vaginal speculum is inserted with the patient in the lithotomy position; the cervix is cleaned with an aseptic solution.
• catheterization of the cervix is then performed; the type of device used depends on local practice preferences
  • e.g.  6 Fr Foley catheter with balloon inflation, or
  • any one of a range of available HSG catheters or metal cannulas ³.
• Foley catheter has several technical disadvantages, such as difficulty in inserting the catheter in angulated or problematic cervix. Other conditions that increase the difficulty of Foley catheter insertion are: acute anteverted or retroverted uterus, cervical stenosis, highly positioned cervix due to pelvic adhesions, previous surgery or uterine leiomyoma. Foley catheter should be placed just beyond the internal os of the cervix. If the catheter is placed within the cervical canal, it can be easily dislodged. Inadequate seal of the balloon with the internal os will result in leakage of the contrast through the cervical canal, generating inadequate intrauterine pressure to push the contrast out of the bilateral fallopian tubes. This results in false positive result of fallopian tube blockage ⁹.
• whatever the device, it should be primed with contrast prior to commencing to avoid the introduction of gas bubbles which may provide a false positive appearance of a filling defect.
• water soluble iodinated contrast is subsequently injected slowly under fluoroscopic guidance.
• some radiologists use iodinated oil (Lipiodol) as contrast when the indication is for lack of fertility. Some authors report increased fertility after its use: this remains controversial however ⁸.
• a typical fluoroscopic examination includes a preliminary frontal view of the pelvis, as well as subsequent spot images that demonstrate uterine endometrial contour, filled Fallopian tubes and bilateral intraperitoneal spill of contrast, to establish tubal patency.

Complications

Common but self-limiting

• abdominal cramping
• per vaginal spotting
• venous intravasation

Rare but serious

• pelvic infection
• contrast reaction

Detectable pathology 

Conditions which may be detected with HSG include:

Uterine

• uterine congenital anomalies
• submucosal uterine fibroids
• uterine malignancy
• adenomyosis
• intrauterine adhesions
• uterine (endometrial) polyps

Tubal

• obliteration of fallopian tubes : usually secondary to previous pelvic inflammation.  It must be differentiated from incomplete tubal opacification due to tubal spasm, or underfilling of the uterus with contrast ²
• tubal polyps ⁶
• tubal malignancy
• hydrosalpinx
• salpingitis isthmica nodosa (SIN) ⁴
• tubal spasm ⁶: can be physiological
• salpingectomy