The immunohistochemical characteristics of the obstructed human bladder

The overactive bladder syndrome (OAB) is a symptom complex of urgency
accompanied by frequency with or without urgency urinary incontinence. It is a
highly prevalent disorder with a profound impact on quality of life and has
many potential causes and contributing factors. One of these factors is an
outlet obstruction of the bladder due to benign prostatic hyperplasia (BPH).
Despite the projected demand for treatment, many patients with symptoms of an
overactive bladder are inadequately treated. Moreover, if outlet obstruction
and detrusor overactivity coincide, the treatment algorithm is still obscure.
Nowadays antimuscarinic drugs are used for treatment of OAB symptoms.
During the last decade studies concerning detrusor overactivity have been
performed in animals to investigate the causes. As the rat and the guinea pig
are the most frequently used species in this research field, it is important to
point out that they show both from a structural and functional point of view,
major differences compared to the human bladder. Rats specifically differ from
humans in micturation behavior, as the guinea pig bladder differs in the effect
of certain drugs like prostaglandines on the bladder. Therefore, it is of
upmost importance to start with this immunohistochemical study in human bladder
tissue and to compare this to bladder function. In particular, we aim to
compare these characteristics in different phases of obstruction (OAB vs.
complete urinary retention).

The primary objective of this study is to describe the immunohistochemical
characteristics of the bladder wall and urethra and to investigate possible
microanatomical connections between nerves, ganglia and interstitial cells in
the human bladder. Secondary, we want to investigate whether the
immunohistochemical characteristics of the bladder wall are different in
obstructed normo-active compared to obstructed overactive bladders and bladders
after complete urinary retention. Furthermore, we aim to image these
microanatomical characteristics of the bladder by using two-photon microscopy.

In this multicenter study the immunohistochemical characteristics of human
bladder and urethra will be described. Bladder and urethra tissue from patients
undergoing open suprapubic prostatectomy according to Hryntschak because of
benign prostate hyperplasia will be used. During the operation in which the
bladder is opened anyhow through an anterior incision, a full thickness bladder
sample from the anterior wall with a diameter of 5mm and a length of 15mm will
be taken. This will occur from one of the sides of the bladder incision needed
to perform the operation. Only histologically normal regions of the bladder,
not showing any signs of cancer or prominent inflammation, will be examined in
this study.

Patients that participate in this study are not expected to be exposed to
serious adverse events and no site visits are presumed. They will be asked to
fill in an ICS male LUTS questionnaire taking approximately 5 minutes. Patients
will not have benefits of this study.