(for example nightly, four time per week and so on),
a study by Montorsi
et al.
was unable to demon-
strate a difference in functional outcomes between
patients on demand-dose PDE-5 inhibitors versus a
formal EP program schedule in a three-arm con-
trolled study. However, this study neither assessed a
comprehensive EP program nor did it document
compliance with regular PDE-5 inhibitor dosing.
Additionally, it was composed of numerous treat-
ment sites and did not control for surgeon skill
in preserving the cavernosal nerves. Thus, this
outcome cannot be extrapolated to all formal
EP regimens. Despite the statistical equivalence
between these two groups, each showed a dramatic
improvement in erectile function compared with
the control group.
inhibitors can also be observed histologically.
et al
observed the role of sildenafil in
preservation of erectile function after cavernous
nerve crush injury. In a rat model for cavernosal
nerve injury, the authors demonstrated maintenance
of cavernosal smooth muscle integrity and observed
a trend in favor of improved erectile function
outcomes. The authors attribute this to improved
penile hemodynamics immediately after injury, thus
preventing smooth muscle apoptosis with perma-
nent damage to the tissues. Schwartz
et al.
demonstrated the dose-dependant impact of silde-
nafil on corporal smooth muscle after RP. In this
study, two groups (50 and 100 mg of sildenafil every
other night) were biopsied at the time of RP and 6
months post-operatively. While their small study
21) lacks a control group because of concern for
the psychological trauma associated with the 6-
month post-RP biopsy, the patients in the 50-mg
group maintained pre-RP corporal smooth muscle
levels, whereas the patients in the 100-mg actually
had a significant increase in post-RP corporal
smooth muscle (as a percent of the histologic section
assessed by a computer-based analysis tool). At 6
months, the overall prevalence of veno-occlusive
disease in both groups was
5% (one patient). The
authors comment on other reports of the chronology
of post-RP veno-occlusive disease where evidence of
disease is present in at least 50% of post-RP
impotent patients, if not all post-RP patients, at
approximately 6 months.
Furthermore, a study
by Mulhall
et al.
suggested that rates of veno-
occlusive disease increased through 18 months
from 14 to 50% post-RP. Vascular status was also
predictive of the likelihood the patient had recov-
ered erectile function sufficient for sexual activity;
47% of men with normal penile vascular status had
recovered erections, while only 8% of patients with
venous leak reported sufficient erectile function
after 1 year post-RP. These two studies offer insight
into the pathophysiology of post-RP ED and suggest
that EP may offset some of the detrimental effects of
the procedure.
For this reason, PDE-5 inhibitor therapy is the
backbone of our institution’s EP program. Pharma-
cotherapy with PDE-5 inhibitors is initiated prior to
surgery given the aforementioned anecdotal reports
and, consistent with many of the case series and
trials reported herein, is continued throughout the
duration of recovery. Low-dose PDE-5 inhibitor
therapy (25 mg) is utilized given the multiple
modality approach that is described below.
Intrauretheral alprostadil suppositories
Alprostadil, a PGE1 analog, is administered to
patients to increase corporal oxygenation by pro-
moting blood flow. This drug is not only most
commonly administered through intracavernosal
injection (ICI), but is also available in the form of
an intrauretheral suppository (MUSE
, Vivus Inc.,
Mountain View, CA, USA). Montorsi
et al.
ported that recovery of spontaneous erections was
250% more likely for a patient receiving alprostadil
ICI compared with an untreated control. Thus, the
concept of localized (for example non-systemic)
penile therapy demonstrated dramatic efficacy with-
out concern for the systemic consequences of oral
The use of intrauretheral alprostadil suppository
therapy was documented in 1997, although early
results were inconsistent and not reproducible.
et al.
were the first to demonstrate the long-
term effectiveness of this type of therapy in post-RP
patients. Their analysis consisted of a retrospective
review of post-RP patients 6 months after surgery
who subjectively reported ED (defined as the
inability to achieve vaginal penetration). Patients
were told to use MUSE (titrated up to 1000
g based
on efficacy) on demand. Overall, 55% were able to
achieve erections sufficient for penetration with
61% of partners reporting satisfaction with this
modality of therapy. Sexual health inventory in men
(SHIM) scores after MUSE use were comparable
with pre-RP scores in these patients.
et al.
adapted the concept of
nightly low-dose PDE-5 inhibitor therapy to com-
pare the effectiveness of this commonly used
approach with nightly MUSE. Patients were rando-
mized into groups using nightly sildenafil or MUSE
g titrated to 250
g within 1 month if toler-
able). The study included only men with IIEF scores
of at least 26. Treatment was initiated upon catheter
removal and was continued for 9 months. After a
1-month washout
period where
patients were
instructed to attempt sexual intercourse without
medication to assist with erections, demand-dose
patients. The final assessment was conducted
11 months after initiating the protocol. IIEF score
rose sequentially and were approximately 50–75%
higher after treatment than at baseline. Intercourse
success rates nearly doubled from the 3 months visit
Review and treatment protocol: erectile preservation for RP patients
DJ Moskovic
et al
International Journal of Impotence Research