Hydraulic occluders for the treatment of USMI: the future?

The hydraulic occluder (HO) is a medical-grade silicone cuff connected by tubing to a titanium injection port placed subcutaneously (Norfolk Vet Products, IL, USA). It has been used recently in the treatment of USMI in dogs (1 – 4) and some other causes of incontinence (3,4). They are an alternative to existing surgical treatments where medical management has failed, such as colposuspension, urethropexy, or a combination (6), urethral submucosal injections and transobturator tape (7). The unique feature of the HO is that postoperative adjustments to pressure exerted by the cuff can be made by percutaneous injection of sterile saline.

Routine investigations to diagnose USMI are the same as for all surgical techniques, including diagnostic imaging and urine culture and sensitivity.

The HO comes in a range of diameters to fit different sizes of dog and cat, and this is assessed at the time of surgery. 10 to 12mm diameter cuffs are typically used for the medium to large breed dogs that are commonly diagnosed with USMI; typically one size larger in the male. Sizing is not well defined and results may improve once this happens. [...]