Imaging of obstructive azoospermia

Abstract

Obstructive azoospermia represents approximately 10 % of cases of male hypofertility. It is classified according to the volume of ejaculate. When the latter is normal a proximal obstruction is suspected. Scrotal sonography can help to detect dilation of the epididymal head when clinical findings are equivocal. Ejaculatory duct obstruction (EDO) is suspected when the volume of ejaculate is low. The use of transrectal ultrasonography (TRUS) plays a major role in the investigation of these patients, and endorectal MRI is a very useful adjunct in selected cases. The most common cause of EDO is congenital bilateral absence of vas deferens, which is now thought to be a genital form of cystic fibrosis in 80 % of cases. Consequently, a definitive diagnosis must be made before any attempt at in vitro fertilization. TRUS accurately visualizes abnormalities of the caudal junction of the vas deferens and seminal vesicles, yielding a definitive diagnosis without scrototomy. Other causes of EDO are congenital cysts compressing the distal part of the ejaculatory ducts and inflammatory distal stenosis. The former are accurately identified by TRUS, but the latter give more or less marked signs of obstruction which are only of value in azoospermic patients with a low-volume ejaculate. More invasive imaging is required to diagnose partial obstruction of the ED. Surgical vasography is still the reference, but puncture of the seminal vesicles under TRUS guidance is an attractive alternative, as it permits aspiration of seminal fluid (to seek motile sperm) and vasography without scrototomy. Lastly, endorectal MRI well assesses the relationships between the proximal prostatic urethra and the posterior wall of the ejaculatory ducts, which need to be precisely known when endoscopic resection of the ejaculatory ducts is planned.

Normal and variant appearances of the adult epididymis and vas deferens on high-resolution sonography

“…1 Any obstruction of the epididymis, VD, or ejaculatory duct (eg, obstructive azoospermia) can lead to decreased quality of the sperm and infertility. 2,3 Since the introduction of high-frequency ultrasound transducers, exploration of the epididymis and VD sonographically has become common practice in infertile men. [4][5][6][7][8][9][10] Although the normal sonographic appearance of the testis is well documented in the literature, the sonographic appearance, anatomic position, and size of the normal epididymis and VD have rarely been described.…”

Was Fine-Needle Vasography an Obsolete Diagnostic Method to Evaluate Ejaculatory Duct Obstruction? Report of 37 Cases

“…All the more, the diagnostic accuracy of TRUS also remains disputable. Among all the auxiliary diagnostic techniques of imageology on EDO, seminal vesicle puncture, aspiration as MRI and TRUS were used mostly to obtain the static information of the spermatic transfer duct near the prostate, while vasography and seminal vesiculography were regarded as more full-scale dynamic techniques of imageology [3,[18][19][20][21][22][23][24] . Therefore, vasography, the standard technique of imageology, was the best choice to confirm our doubts.…”

Imagerie de l’hypofertilité masculine : technique et résultats

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