ENVIRONMENTAL FACTORS
In addition to the maternal factors predisposing to
cryptorchidism presented in the guideline, a more
recent large case-control study evaluating 16,433
cases with isolated male genital malformations and
population based controls linked the endocrine dis-
rupting pesticide atrazine to an increased risk of
cryptorchidism, as well as hypospadias and small
penis.
7
Another study noted a positive association
between endocrine disrupting organotin compounds
and
cryptorchidism
when
comparing
placental
organotin compound levels and cryptorchidism risk.
8
USE OF IMAGING
The AUA guideline recommends against the use of
ultrasound (US) or other imaging in evaluation of
cryptorchidism, in large part due to the low sensi-
tivity (45%) and specificity (78%) of US in localizing
nonpalpable testes. A recent study examining the use
of US in 49 cryptorchid boys with 60 UDTs revealed
that US identified 97% of UDTs located in the
inguinal canal, with 77% of these being palpable, but
could not identify intra-abdominal testes, largely
echoing the consensus findings of the AUA report.
9
Another prospective study used high resolution US
to examine 40 boys with 52 UDTs, comparing the
findings to those at surgical exploration, and up to
91% of palpable and 87% of nonpalpable testes were
identified.
10
In contrast to other studies evaluated
by the AUA, this study had an overall sensitivity of
90%, specificity 33%, positive predictive value 96%
and negative predictive value 17%. Despite this
finding in support of the use of US, it may behoove
physicians in litiginous climates to avoid such imag-
ing, given that a false finding of an intra-abdominal
testis, which on laparoscopy was determined to be
a blind-ending vas, has resulted in litigation.
11
Furthermore, other imaging modalities do not
appear to fare any better. In line with the consensus
AUA findings, a recent meta-analysis on the use of
magnetic resonance imaging to identify nonpalpable
UDT also showed low sensitivity and specificity,
with poor results locating intra-abdominal testes
and only modestly better results at locating inguino-
scrotal testes.
12
CRYPTORCHIDISM TREATMENT
Hormonal
The AUA guideline recommends against the use of
hormone therapy to induce testicular descent, given
low response rates and lack of long-term efficacy.
A systematic review evaluating 14 clinical trials of
hormone therapy for hypospadias before surgical
correction determined that it was not possible to
currently
define
an
appropriate
neoadjuvant
regimen due to the diversity and overall scarcity of
clinical trials, similar to the conclusions of the
guideline panel.
13
A second systematic review
evaluating 26 surgical and 14 hormonal treatment
studies for UDT found a marginal benefit of hor-
monal therapy, with an approximately 10% benefit
over placebo, and efficacy of surgical treatments
in line with those outlined in the guideline.
14
Surgical
Overall success rates for 1 or 2-stage Fowler-Stephens
orchiopexy were found by the AUA guideline panel
to be approximately 79% for the 1-stage and 86% for
the 2-stage approach, with an overall testicular at-
rophy rate of 2.2% after orchiopexy of nonpalpable
testes. A recent study evaluating longer term (up to
20 years) followup for 2-stage Fowler-Stephens
orchiopexy in 62 patients with 79 testes revealed
complete testicular viability based on US evaluation
in 71% of patients, with relative (15%) or complete
(15%) testicular atrophy in the remaining patients,
indicating that while Fowler-Stephens orchiopexy
remains an effective treatment modality in the short
term, longer term results show fewer viable testes.
15
Single incision orchiopexy is considered a viable
option for UDT treatment by the AUA guideline
panel, and a recent systematic review of 1,558
orchiopexies further supports this conclusion, with
a need for an inguinal incision in only 3.5% of cases,
recurrence in 9, testicular atrophy in 3 and hypo-
trophy in 2, and overall efficacy rates ranging from
88% to 100%.
16
Natural Course of Cryptorchidism
While significant work has been performed exam-
ining the effects of various hormones and treatments
on testicular descent, to our knowledge, no pro-
spective studies have evaluated the natural course
and growth of spontaneously descended testes in
boys with prior cryptorchidism. A recent prospective
study evaluated testicular size in 91 boys with
congenital unilateral cryptorchidism followed from
birth to 5 years, finding that 82% of spontaneous
descent occurred by age 2 months, and that sponta-
neously descended testes were significantly smaller
than their descended counterparts.
17
A study eval-
uating long-term post-orchiopexy testicular size in
155 patients 5.1 to 26.6 years old revealed that testes
are significantly smaller than normative values
(50th percentile) for a given age after orchiopexy
and also smaller than the contralateral testis.
18
FERTILITY
The AUA guideline focused on patients who had
undergone orchiopexy in their youth when assessing
DIAGNOSIS AND TREATMENT OF CRYPTORCHIDISM
347