Anatomical study of the prostatic urethra using vinyl polysiloxane casts.

Area of Science:

• Urology
• Anatomy
• Medical Device Design

Background:

• Limited studies exist on the detailed nonhistologic anatomy of the prostatic urethra.
• This study describes ex vivo anatomical details of prostatic urethra shape and size.

Purpose of the Study:

• To provide detailed ex vivo anatomical descriptions of the prostatic urethra.
• To correlate prostatic urethral dimensions with prostate size.

Main Methods:

• An observational study using vinyl polysiloxane casts of prostatic urethras from radical prostatectomy specimens.
• Measurements included anterior/posterior length, maximal diameter, bladder neck to verumontanum, verumontanum to apex length, and prostate urethral angle (PUA).
• Prostate volume was calculated using the ellipsoid formula.

Main Results:

• Thirty-three prostatic urethral casts were analyzed, with a mean prostate volume of 38.59 cc and mean PUA of 127.6°.
• Anterior length, posterior length, and maximum diameter of the prostatic urethra increase with prostate size.
• The distance from the verumontanum to the apex remained uniform (mean 1.2 cm) regardless of prostate size.

Conclusions:

• Prostatic urethral dimensions, excluding the verumontanum-to-apex length, correlate with prostate size.
• This anatomical data is valuable for designing prostatic stents and devices for benign prostatic hyperplasia (BPH).
• Urethral angulation showed a non-significant trend to decrease with increasing prostate size.