patients after prostatectomy.
The value added by
offering PDE-5 inhibitors to post-RP patients is
twofold: it supports a patients’ ability to achieve
an erection after surgery and contributes to the long-
term recovery of erectile function. While the former
property of PDE-5 inhibitors has been clearly
established, the latter has only begun to be eluci-
dated. This review will summarize the compelling
evidence to support PDE-5 inhibitors for both these
objectives, making it the cornerstone of our EP
have examined daily
inhibitor therapy for post-RP patients. McCullough
et al.
demonstrated the return of normal nocturnal
penile tumescence and unassisted erectile function
in patients who were treated with nightly sildenafil
after RP. For the sildenafil group of patients, there
was a dose-dependant improvement in recovery of
nocturnal penile rigidity. Importantly, the larger trial
from which this subgroup analysis is based suggests
that this outcome in fact correlates with the recovery
of natural erectile function (see below).
tionally, there was a substantial difference in the
rate of recovery of erections satisfactory for sexual
intercourse (for example a rate of 5
) for
patients taking 50–100 mg of sildenafil nightly.
However, the study was very small (
54) and
represents a subgroup analysis of a larger trial. The
authors remark that, since only one patient in the
placebo recovered nocturnal erectile function, the
small sample size limits comparisons between
groups. However, the consistent performance of
the two sildenafil groups versus the control supports
this therapeutic strategy in this patient population.
In a complementary study, Bannowsky
et al.
reported the impact of nightly sildenafil on the
progression of international index of erectile func-
tion (IIEF) scores after RP. In this small controlled
study, patients were randomized based on pre-RP
IIEF scores, nocturnal erectile function, age and NS
status. After surgery, patients experienced a decline
in IIEF scores of over 75% on average at the 6-week
assessment. Steady increases in IIEF scores were
observed in both groups thereafter, with a statisti-
cally significant increases in IIEF scores observed at
36 and 52 weeks for PDE-5 inhibitor patients over
control. The fact that a small study was able to show
a statistically significant difference in outcomes
suggests that the effect of sildenafil on sexual health
is very favorable. However, a larger study would
improve confidence in these results.
Definitive evidence to support use of nightly PDE-
5 inhibitor therapy has been derived from the above-
referenced randomized, placebo-controlled trial by
et al
In the study, the authors
compared natural erectile function after an 8-week
washout period subsequent to 36 weeks of nightly
sildenafil therapy. Patients reported a return of
normal ‘spontaneous’ erections at a 7
rate over
control patients (4% versus 27%) based on IIEF
scores (for questions 3 and 4)
8 when also
responding positively to the question ‘were erec-
tions good enough for satisfactory sexual activity?’.
In general, IIEF scores for the sildenafil patients
were just below 50% greater than placebo patients
(13.1 versus 8.8). Interestingly, the rate of recovery
for patients in the control arm was surprisingly
low and the authors were unable to clearly explain
why. Irrespective of this absolute observation, the
relative performance of the study group is very
impressive and compelling. Of note, the doses of
sildenafil were between 50 and 100 mg over the
course of therapy.
Montrosi and McCullough
performed a compre-
hensive and elegant meta-analysis examining the
role of PDE-5 inhibitor therapy after surgery. The
authors reviewed studies of post-RP patients, where
PDE-5 inhibitor therapy was an independent vari-
able in the analysis. Pooling all results together
yielded an overall response rate of 35% with
considerable variability (95% confidence interval:
24–48%). Noting that these data include patients
sustaining varying degrees of NS during their
surgery, the authors independently assessed this
factor to describe responses to PDE-5 inhibitor
therapy. The authors noted NS to be a very
important factor in segmentation, where patients
undergoing NS RP had a response rate ranging from
35 to 75% and patients whose surgery was non-NS
ranged from 0 to 15%. The combined odds ratio for
this result was determined to be 12.1. Careful
analysis of the degree of NS demonstrated statisti-
cally comparable rates of response between uni-
lateral and bilateral NS, but the range of outcomes
was more variable in the unilateral NS group
compared with the bilateral NS group. While this
study demonstrates the remarkable effectiveness of
PDE-5 inhibitors after RP, particularly in patients
who undergo NS surgery, there are some important
weaknesses inherent in the studies comprising this
meta-analysis. Only seven studies were included in
the primary response analysis and only five of those
commented on NS. More so, the authors’ ability to
distinguish between the extent of NS relied on only
four studies. As is a common problem in this body of
literature, the results of the study would be more
compelling if a standard measure of erectile func-
tion was included in all studies. Regardless, this
study was successful in definitively establishing the
value of PDE-5 inhibitors for post-RP patients.
Perhaps, the least established concept is the idea
that pre-RP PDE-5 inhibitor therapy adds value to
EP. While no formal published data are available,
some have described improvement in recovery of
post-operative erectile function in animal models
when PDE-5 inhibitors are used before injury.
Interestingly, the value of a formal EP program
versus on-demand dose PDE-5 inhibitor therapy has
not been definitively elucidated. Whereas the above-
referenced studies rely on some regularity in dosing
Review and treatment protocol: erectile preservation for RP patients
DJ Moskovic
et al
International Journal of Impotence Research