Clinical and histologic effect of transrectal intraprostatic injections with botulinum toxin A in patients with lower urinary tract symptoms caused by benign prostatic hyperplasia.

Rationale:
The standard treatment of lower urinary tract symptoms due to benign prostatic hyperplasia, not responding to medication, is transurethral prostatic resection. This is an invasive procedure requiring general or regional anestesia. Intraprostatic injection of Botox causes relaxation of smooth muscle tissue and causes cellular apoptosis. Therefore it is possibly effective for treatment of benign prostatic hyperplasia. Transrectal prostatic injection is minimally invasive and can be performed without anestesia in the outpatient clinic.

Objective:
To determine the subjective effect on lower urinary tract symptoms and to determine objective urodynamic and histologic changes after intraprostatic botulinum toxin injection.

Study design:
Prospective.

Study population:
Male patients with lower urinary tract symptoms due to benign prostatic hyperplasia, not responding to medication.

Intervention:
Transrectal injection of botulinum toxin into the prostate.

Main study parameters/endpoints:
Symptom relief (IPSS).

Urodynamic obstruction (according to Schafer)

Post void residual

Decrease of prostate volume

Histologic changes after 1 month.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness:
At least 8 visits to the outpatient clinic are necessary. Four urodynamic studies will be performed (in total 4 hours). Patients will be asked to fill out questionnaires and voiding diaries with every visit.
There is a risk for prostatitis and a risk for hemorrage due to the prostatic biopsy and after the intraprostatic injection. Furthermore there is a risk for side effects of the botulinum toxin like allergy (infrequently), aritmia and respiratory problems in case of overdose.

Botulinum toxin type A injection of the prostate causes relaxation and cellular apoptosis and by this way will relieve lower urinary tract symptoms in patients with benign prostatic hyperplasia.

Transrectal intraprostatic injection with botulinum toxin type A