The influences of anatomical changes of urethra and urethral sfincter on stress urinary incontinence and erectile dysfunction after a laparoscopic radical prostatectomy with 2D and 3D ultrasound

Radical prostatectomy (RP) is one of the treatments of organ confined prostate
cancer . Stress urinary incontinence (SUI) and Erectyle Dysfunction(ED) could
be a consequence of this treatment . SUI is the complaint of involuntary loss
of urine on effort or physical exertion (e.g. sporting activities), or on
sneezing and coughing . In literature, the incidence of early SUI after a RP
varies from 0.8 % - 87 %. This wide range indicates the difficulty involved in
the accurate assessment of urinary control after RP. The precise aetiology of
post-prostatectomy urinary incontinence (UI) has not been completely understood
until now. Dysfunction of the bladder neck as well as intra operative damage of
the nerves and sphincter may play a causative role. In this regard, damage of
the urethral sphincter can result not only from direct muscle damage but also
from damage of the neuronal innervation .
Several predictors of post-prostatectomy UI have been investigated, such as
age, prostate volume, disease stage, body weight, co morbidities, history of
previous lower urinary tract dysfunctions, surgical techniques and urine loss
ratio. Nevertheless, few of these studies reached a high level of evidence.
The incidence of erectile dysfunction after radical prostatectomy varies wide
in literature. They range from 11% to over 90% patients with good erectile
function postoperative. One meta-analysis shows an overall erectile function
rate of 58% after radical prostatectomy, but also states that most data does
not meet the strict criteria for reporting erectile dysfunction. The
discrepancy in al these results is following Mulhall because of a wide variety
in study populations, population demographics, means of data acquisition,
variability in questionnaires, temporal considerations, baseline erectile
dysfunction status, defining adequate erectile dysfunction and the concepts of
quality and consistency of erections used in literature.This makes it difficult
for urologists to counsel patients correctly about their postoperative sexual
functioning and could cause false expectations.

To detect the differences in the length of the urethra in healthy volunteers
and in men after laparoscopic radical prostatectomy.
To detect the degree of erectiel dysfunction before and after laparoscopic
radical prostatectomy.
To detect the cause of stressincontinence and erectyle dysfunction after
laparoscopic radical prostatectomy.

This study concerns a longitudinal study in which patientes diagnosed with
local prostate cancer and who will have a laparoscopic radical prostatectomy
will be followed before and 2 years after the laparoscopic radical
prostatectomy.

This study will consist of 3 parts.

1) 3D Ultra sound. Before surgery patients will have once a 3D ultrasound
examination of the anal canal. In this manner the thickness of the musculus
levator ani and the diafragm urogenitalis can be detected just like the
functionig of the urethral sfincter complex. Postoperative: This examination
will be repaeted at 6 months, 1 year and 2 years postoperativeliy to observe
the anatomical changes.
2) Questionairres with the use of validated questionairres: the KIngs Health
Questionairre, the International Index of Erectile dysfunction, the Pelvic
Floor Inventories Leiden (PeLFis), in order to map the sfincter function en
erectyle function
3) In the dissecting room 3 laparoscopic radical prostatectomies will be
performed, in order to study the anatomical changes thouroughly.

Of great importance is the analyzing of the relationship resection margin in
relation to the nervus levator ani and the autonom nervus system.
Also the anatomical changes after a laparoscopic radical prostatectomy will be
studied

We hypothesized that there will be a relationship between the length of the
urethra preoperative and postoperative after a LARP. an earlier study showed
that the incidence of SUI is 42% after a LARP with a follow up of one year
Logistic regression analysis showed that 78 patients are needed to reach a
power of 80 % with p of < 0.05 to detect a difference in having incontinence
between 42% for the mean length of the urethral sphincter and 57.9% if the
length of the urethral sphincter is a standard deviation lower. this difference
will be a ODDs ratio of 1.90 per SD Dit verschil komt overeen met een odds
ratio van 1.90 per SD decrease of the length of the urethral sfincter.

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