CHAPTER 144 Hysterosalpingography and Sonohysterography
Hysterosalpingography (HSG) is a radiologic examination of the female genital tract. It allows for the evaluation of the cervical canal, endometrial cavity, tubal lumen, and the periadnexal area. The basic infertility work-up includes HSG, although some physicians feel that it has been superseded by laparoscopy with hysteroscopy. However, it remains an integral part of many other diagnostic work-ups. HSG is a relatively easy procedure, requires no anesthesia, and has a low complication risk. Its use as a therapeutic procedure for enhancing fertility is promoted by some clinicians. The addition of selective cannulation of the cornual ostia has eliminated many false positives (or blockage) and opened new therapeutic options. These additions, however, require special training and currently limit the use of HSG in this manner to an infertility specialist or an interventional radiologist. The radiation exposure is usually minimal, in the 50 to 500 mrem ranges.
Saline infusion sonohysterography (SIS) is a technique for visualization of the reproductive tract using ultrasound and the injection of sterile normal saline as an ultrasonic contrast medium. The ease of this procedure and the availability of ultrasound in the office have been responsible for its rapid growth. The discomfort involved is usually less than that of HSG, but the complications and contraindications are similar. A vaginal probe ultrasound and catheter-injected normal saline (or ultrasonic contrast medium, not yet FDA [Food and Drug Administration] approved for gynecology) are used for imaging of the anatomy. The procedure itself is simple, but the expertise and experience needed for interpretation require specialized training. The decreased accuracy in visualizing the fallopian tubes limits its use for this purpose. However, these limitations are compensated for by the ability to identify endometrial pathologic changes and to define uterine anomalies.
Many clinicians start their work-up of a patient with abnormal uterine bleeding with a transvaginal ultrasonic measurement of the thickness of the endometrial stripe to rule out endometrial cancer. Ultrasonic evaluation of the endometrial stripe thickness in the work-up of abnormal uterine bleeding has been enhanced greatly by using SIS in combination. Endometrial thickness of 5 mm or less is thought to represent dysfunctional uterine bleeding. However, ethnic variations exist and cancer has been found in Japanese women with stripes only 3 to 4 mm thick. SIS is performed in patients with double layer endometrium thicker than 5 mm. Single layer endometrium of 3 mm or less, with no focal abnormalities on SIS, is also treated as dysfunctional uterine bleeding (Fig. 144-1). Symmetrical thickening of the single layer endometrium greater than 3 mm, with no focal lesions, is evaluated by an office endometrial biopsy. A newly available SIS catheter allows an immediate endometrial biopsy, if indicated, through the same catheter. Endometrium with focal lesions or asymmetry requires hysteroscopy and directed biopsy (Fig. 144-2). Hormone replacement and the use of tamoxifen also affect uterine lining, requiring the use of different discrimination thicknesses.
Many types of HSG cannulation devices are available. The choice of catheters used may depend on procedure indication and physician preference. Three general types are in common use, with multiple modifications (the flexible balloon cannulas are also used for SIS):
Figure 144-4 Saline infusion sonohysterography using EZ-HSG.
(Courtesy of CooperSurgical, Trumball, CT.)
(Courtesy of CooperSurgical, Trumball, CT.)
Special selective cannulation catheterization systems are available from Cook Medical (see the “Suppliers” section). These catheters are used to selectively cannulate and evaluate a fallopian tube in special circumstances (e.g., unilateral or bilateral nonvisualization, salpingitis isthmica nodosa, or prior ectopic pregnancy). They may also be used therapeutically in some patients to open a blockage in the proximal tubes (Fig. 144-7).
Figure 144-7 Selective cannulation of the fallopian tube. A, Preassembled Mencini double balloon catheter. B, Balloon cervical cannula (BCC) in uterus. C, Selective salpingography catheter (SSC) passes through BCC. D, Inner catheter through SSC.
(Courtesy of Cook Ob/Gyn, Spencer, IN.)
SIS catheters with and without cervical sealing balloons and sponges are used for these procedures. In addition, an infusion/endometrial biopsy catheter makes it possible to biopsy at the same time (Box 144-1).
Box 144-1 Common Cannulas by Brand Names
(Courtesy of Cook Medical, Bloomington, IN.)