Evaluation of Tubal Patency (HyCoSy, Doppler)

Abstract

Tubal pathology is a significant contributor to subfertility; therefore, assessment of the fallopian tubes forms an important and integral part of the fertility workup. An ideal method of tubal assessment should be sensitive and specific, relatively safe, widely available and inexpensive. Laparoscopy and dye testing is the gold standard method of tubal assessment. However, this is associated with operative risks as well as financial implications. Hysterosalpingography was classically the first-line investigation; however, this too has its associated risks such as exposure to radiation. More recently, HyCoSy, which involves ultrasonographic tubal assessment using contrast media, has become more widespread. This involves a transvaginal scan, injection of contrast media through the cervix and observation of bilateral spill from the fimbrial ends of the fallopian tubes. Some investigators have used air as an inexpensive alternative to contrast media. The use of colour flow Doppler, which demonstrates flow of medium through the fallopian tube (as opposed to simply detecting spill from the fimbrial ends), has also been described. In this chapter, we aim to outline the assessment of tubal patency using ultrasound examination. Subfertility affects one in ten couples worldwide. Tubal pathology is thought to be a contributor in up to 40% (Steinkeler et al. Radiographics 29:1353–1370, 2009; Lim et al. Hum Reprod 26:967–971, 2011; Watrelot et al. Best Pract Res Clin Obstet Gynaecol 17:187–209, 2003) of cases of subfertility, making tubal pathology the leading female cause. Assessment of the fallopian tubes forms an important and integral part of the fertility workup. Tubal patency will determine subsequent treatment as well as assisted conception options. If tubal assessment does reveal tubal blockage, then the couple may be referred for in vitro fertilisation or tubal surgery. If the tubes are patent, then alternative causes and consequent treatment options will be investigated. The question of “are the tubes patent” is one of the most important clinical questions that must be answered when performing a subfertility workup. Any ideal modality of tubal assessment will be sensitive, specific, safe, widely available, inexpensive and diagnostically accurate. Laparoscopy and dye testing is the accepted gold standard for assessment of tubal pathology. Hysterosalpingography (HSG) was classically the first-line investigation used in the assessment of tubal pathology (Lanzani et al. Fertil Steril 92:1158–1161, 2009). Advances in ultrasonography have resulted in the development of techniques using ultrasound to diagnose tubal pathology. Hysterosalpingo-contrast-sonography (HyCoSy) is the name given to a technique that combines the use of ultrasound and contrast media to delineate tubal pathology. HyCoSy can be combined with 3D imaging as well as advanced computer software to enhance diagnostic imaging. Contrast media employed include air, saline, albumin with micro air bubbles and galactose with micro air bubbles. The supplementary use of colour flow Doppler has also been employed as a reliable and accurate alternative modality. In this chapter, we aim to provide an outline of the currently employed methods used in the evaluation of tubal patency.