Does bulk injection therapy improve the symptoms of patients with stress urinary incontinence?

This study investigated the effectiveness of bulk injection therapy with polydimethylsiloxane Urolastic (PDSU; Urogyn) in the treatment of stress urinary incontinence (SUI). Researchers suggested that some patients treated with PDSU were cured 2 years after treatment.

Urinary incontinence (UI) consists of leakage of urine that cannot be controlled. It is a common disorder and can affect the quality of life. In SUI the urine leakage is a result of bladder pressure that happens when coughing or sneezing. There is a variety of different therapies available to treat this disorder.

The urethral bulk injection is a non-invasive therapy that consists of injecting a bulk material in the urethra. This material gives resistance to urine flow and prevents urine leakage. However, studies have suggested that bulk injection has a lower response rate when compared to standard therapies.

PDSU is one of the most recent bulking agents which consist of a smooth material that is not absorbed by the body. Prior studies showed that the PDSU success rate at 6 months was between 59 and 89% and at 12 months is between 35 and 90%. However, this comes at the expense of side effects with studies showing that PDSU is associated with complications such as pain. It is still not clear if patients remain satisfied with PDSU therapy after 2 years of follow-up.

This study included information about 110 patients with UI. All patients had been treated with PDSU. The average follow-up was 25 months.

The rate of satisfaction among patients was 51% and the cure rate was around 47%. 85% of patients still experienced some degree of UI symptoms.

The most common side effects were urinary retention (22%), pain (15%), and pain during sexual intercourse (15%). PDSU exposure happened in 7% of the patients and damage in 5%. 6% repeated the surgery and 18% had a re-injection of the bulk material.

This study concluded that half of the patients treated with PDSU were satisfied and cured 2 years after therapy, although still experiencing some symptoms.

Some patients did not participate in all follow-up visits. Also, some information regarding urinary symptoms was missing. This may have influenced the results. Further studies are needed for stronger evidence.