Diagnostic ultrasound ( PDFDrive )

CHAPTER 10 The Prostate and Transrectal Ultrasound 393
SV
SV
V
RSV
A
B
C
C
LSV
FIG. 10.10 Infertility. (A) Bilateral dilated seminal
vesicles (SV) (>1.5 cm). This is presumptive evidence
of mechanical obstruction to the ejaculatory ducts, which
may be the cause of the infertility. The inding is not
speciic because this degree of enlargement can also
be seen in normal, fertile men. (B) Unilateral agenesis
of left seminal vesicle and vas deferens (V). Only the
right side is intact. (C) Unilateral right seminal vesicle
cyst (C); transvesical scan. This patient also had absence
of the ipsilateral right kidney. LSV, Left seminal vesicle;
RSV, right seminal vesicle.
4. Detection of genetic abnormalities (e.g., cystic ibrosis) that
may afect the health of children if afected sperm are harvested
or used for assisted reproductive techniques.
Male factors can be categorized as pretesticular, testicular, and
posttesticular. Pretesticular factors include conditions such as
faulty reproductive behavior and genetic abnormalities (e.g., CFTR
gene of cystic ibrosis, Y chromosome microdeletions). Testicular
factors include congenital and acquired intrinsic disorders of
spermatogenesis (e.g., infections, trauma, and treated cryptorchidism)
that, except for varicocele, are generally irreversible.
Also tumors and testicular microlithiasis are more common in
infertile men. Posttesticular causes of azoospermia (no sperm
in ejaculate) and oligospermia (low numbers of sperm in ejaculate)
generally relate to obstructive issues and are found in about 40%
of infertile men, although only 1% to 5% have ejaculatory duct
obstructions that are amenable to surgical therapies such as
prostate cyst unrooing or transurethral resection of ejaculatory
ducts. 50 his excludes vasectomy reversal, which is successful in
70% to 95% of patients and results in achievement of pregnancy
in 30% to 70% of couples. In 100 consecutive azoospermic men,
the causes of azoospermia were genetic abnormalities, 27%; diseases
or external inluence (orchitis, radiotherapy, infections, surgery,
trauma), 22%; corrected cryptorchidism, 27%; and unexplained,
22%. 51 his illustrates the broad spectrum of disorders apart from
ejaculatory duct obstructions that relate to azoospermia and that
are part of the investigation of infertile men. 48,49
Imaging investigations—ultrasound and MRI—are used to
evaluate for abnormalities and focus on the scrotum and testes,
prostate, and seminal ducts and occasionally the developmentally
related urinary tract. 50,52,53
he role of TRUS and increasingly MRI is to identify anatomically
correctable ejaculatory duct obstructions and anomalies in
men who are azoospermic or oligospermic and who have VD on
palpation. Obstructions can result from calculi in the vas, müllerian
or wolian duct cysts, postsurgical or inlammatory scars, calculi,
or atresia of the ejaculatory ducts (see Fig. 10.10). Note that the
presence or absence of the VD is diagnosed clinically by palpation
of the spermatic cord and not through imaging. Vasography has
been used to demonstrate obstruction, but this generally has been
discontinued because of the risk of injury to the VD. On occasion,
TRUS can be used to inject SVs with ultrasound or x-ray contrast
agents to demonstrate patency of the ejaculatory ducts or to retrieve
sperm from the SVs for assisted reproduction. 50,52,53
here are no speciic symptoms associated with ejaculatory
duct obstruction. he diagnosis is suggested in infertile males
with azoospermia or oligospermia who have low ejaculate volume,
normal secondary sex characteristics and testes, pain during or
ater ejaculation or orgasm, or history of prostatitis. he relative
frequencies of TRUS indings in infertile men with low-volume
azoospermia are as follows: normal appearance (25%); bilateral
absence of VD (34%); bilateral occlusion of the VD, SVs, and
ejaculatory ducts by calciication or ibrosis (16%); unilateral