Rigi10™ Malleable Penile Prosthesis
Also Known As
Urethral bulking, Periurethral bulking, Transurethral injection therapy, Injectable bulking agents for incontinence, Urethral injection therapy
Definition
Periurethral injection is a minimally invasive surgical procedure that involves the injection of bulking agents around the urethra to treat urinary incontinence, particularly stress urinary incontinence.1 The procedure works by artificially inflating the submucosal tissues of the bladder neck and urethra, increasing urethral resistance to urinary flow.2 These injections compress, support, or narrow the bladder neck, improving urethral coaptation and restoring the mucosal seal mechanism of continence.1,3 Various injectable compounds have been developed for this purpose, including synthetic materials (such as polyacrylamide hydrogel, calcium hydroxylapatite, and polydimethylsiloxane), bovine collagen, and autologous substances.2 The procedure can be performed using either transurethral or periurethral injection techniques, often as an outpatient procedure under local anesthesia.1
Clinical Context
Periurethral injection is primarily used in the treatment of stress urinary incontinence, particularly in cases of intrinsic sphincter deficiency.1,3 The most suitable candidates for this procedure include elderly women, patients who constitute high operative risk, and those with stress incontinence due to intrinsic sphincter failure.1 Additionally, patients with stress incontinence due to a combination of urethral hypermobility and intrinsic sphincter deficiency with failure of suspension procedure may also benefit from the procedure.1
The procedure offers an alternative to the current main method for surgical treatment of stress incontinence in women, which is a polypropylene sling placed without tension below the mid-urethra.4 Periurethral injection is considered when the main method is not suitable or desired.4 Clinical experience has shown that it can be well suited for lighter degrees of leakage, in women with low urethral closure pressure (urethral incompetence), and in women with low urine flow and/or incomplete bladder emptying.4 It has also been shown to produce good outcomes in older women and in women who have undergone radiation therapy.4
The reported long-term (more than 24 months) success rates vary according to the substances used.1 For example, studies on polyacrylamide hydrogel have found that 45–86% of patients are defined as ‘responders’ (defined as continent or with more than 50% improvement, alternatively ‘satisfied’) and 24–43% became fully continent with follow-up of up to three years.4
Periurethral injection is generally considered a more gentle method with a lower risk of complications than tension-free vaginal tape.4 In contrast to tension-free vaginal tape, injection therapy does not result in any notable obstruction, meaning that there is less risk of postoperative bladder voiding problems.3 The procedure is quicker and simpler to perform, and the recovery period is short, rarely requiring more than one or two days of sick leave.4