Bulkamid(R) injection in men: Cadaver study of operative technique and putative mechanism of action

Objective: Post-prostatectomy incontinence (PPI) is relatively common and of variable degree. Treatment of small-volume persistent PPI with a male sling or an artificial urinary sphincter is overly invasive, and the concept of intraurethral injection is very appealing in this situation. Bulkamid(R) is a nanoparticulate polyacrylamide and water polymer gel which is being used successfully in female stress urinary incontinence. We assessed the feasibility and effects of a four-point intraurethral technique on maximum urethral pressure (MUP) in male cadavers. Methods: Urethral pressure profile (UPP) was measured twice on two male fresh-frozen cadaver models before and after a four-point injection of 2 mL of Bulkamid(R) intraurethrally at the level of the sphincter in 0.5 mL aliquots using a 21Ch cystoscope with a 12 degrees telescope and a 23G needle. Results: A clear UPP trace was recordable in both cadavers. The mean MUP at baseline was 38 cm H2O, and the mean MUP following Bulkamid(R) intraurethral injection increased to 55 cm H2O. Conclusions: Bulkamid(R) intraurethral injection in male cadavers is a simple technique that increases MUP. This increase in MUP may allow for treatment of low-volume PPI in men following prostate cancer treatment and warrants further study in the clinical situation.