The Mode of Action of Adjustable Transobturator Male System (ATOMS): Intraoperative Urethral Pressure Measurements

Abstract

(1) Background: The Adjustable Transobturator Male System (ATOMS) device is increasingly used to treat post-prostatectomy incontinence as it enhances residual urinary sphincteric function and allows continence recovery or improvement by dorsal compression of the bulbar urethra through a fixed transobturator mesh passage. The mode of action and the profile of the patients with best results are not totally understood. (2) Methods: Intraoperative urethral pressure measurements at different filling levels of the ATOMS device show increased urethral resistance and enhanced residual sphincteric activity. We evaluated whether the pattern of urethral pressure change secondary to serial progressive intraoperative filling of the cushion can predict postoperative results after ATOMS placement. (3) Results: The regression analysis showed a significant direct relationship between cushion volume and intraurethral pressure (p = 0.000). The median intraurethral pressure at atmospheric pressure was 51 ± 22.7 cm H2O, and at atmospheric pressure plus 4 mL was 80 ± 23.1 cm H2O). Cluster analyses defined a group of patients (n = 6) formed by patients with a distensible urethra and 100% continence after adjustment in contrast to another group (n = 3) with rigid urethras and 33% continence after adjustment. (4) Conclusions: As a part of its continence mechanism, the ATOMS device leads to continence by increasing intraurethral pressure owing to the stretching effect on the urethral wall caused by cushion filling that increases urethral resistance.