Urethral bulking agents for SUI: Rethinking their indications
Rising interest in alternatives to sling procedures and increasing evidence of successful outcomes for urethral bulking agents make them a potential primary treatment option for patients with SUI
Complications and safety issues
Adverse events. Reported adverse effects associated with urethral bulking include mild pain, transient urinary retention (typically resolving within 1-2 days after injection), dysuria, hematuria, and urinary tract infection (UTI).4,12
In a 12-month RCT involving 355 women treated with Durasphere or bovine collagen, adverse events were reported in 178 Durasphere-treated women; dysuria (24.7%) and temporary urinary retention (16.9%) were the most commonly reported adverse events.20
An RCT of Coaptite injection (n = 296) found that temporary urinary retention (41%) was the most common adverse event.14
In a 12-month comparative study of Macroplastique versus Contigen (n = 122), UTI was reported as the most common adverse event (23.8%), followed by dysuria (9%) and urgency (9%).15 In addition, in a meta-analysis involving 958 patients in 23 cohorts, Ghoniem and Miller reported that the median rates for adverse events were temporary dysuria, 50%; hematuria, 45%; urge incontinence, 7%; temporary urinary retention, 7%; and UTI, 3%.16
A 3-year summary outcome of 256 patients who received Bulkamid injection reported that only 1 patient developed infection, abscess, or allergic reaction at the injection site and 1 patient had a UTI.10 In an 8-year follow-up of patients who received Bulkamid injection, 1 patient experienced stranguria and 7 patients had recurrent cystitis.18
It appears that transient dysuria, urgency, and urinary retention occur more frequently after urethral bulking with particulate agents.12
Complications. Few delayed but serious complications after urethral bulking have been reported, including suburethral abscess, urethral prolapse, and particle migration.4 Cases of urethral prolapse have been reported with both Coaptite and Durasphere. Notably, all cases of urethral prolapse occurred in patients with a history of pelvic surgery and/or previous urethral bulking.21,22 Cases also have been reported of Durasphere carbon bead particles migrating to regional and distant lymph nodes, and pseudoabscess also has been reported.12,23 A single case of periurethral abscess was reported after Bulkamid injection in a patient who had prior vaginal hysterectomy and a transobturator tape procedure after a total vaginal mesh repair.24
Bulking agent use: Time to go mainstream?
Historically, urethral bulking agents have had limited utility, largely due to the inaccurate and unsubstantiated perceptions of them being indicated only in women with ISD and a well-supported urethra. More recently, urethral bulking agents are commonly being used in patients who: have recurrent SUI after a surgical intervention, have infrequent but bothersome SUI symptoms, are not ideal candidates to undergo anesthesia, or wish to avoid mesh.
Some data suggest that objective and subjective success rates are lower with bulking agent treatment compared with the gold standard MUS procedure. However, in the appropriately selected patient, urethral bulking agents may be considered primary treatment due to their associated low morbidity and, as recently reported with newer nonparticulate agents, high subjective success rates. If the patient is not satisfied with the results of bulking treatment, surgical repair with any type of sling remains a subsequent option. This feature adds to the potential viability and appropriateness of considering a bulking agent as a primary treatment. ●
