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Urethral Bulking Agents

Urethral bulking improves mucosal coaptation by injecting material into the urethral wall. It offers a less invasive option for women with stress urinary incontinence (SUI) who prioritize a shorter procedure or wish to avoid more invasive surgery. AUA/SUFU 2023 considers bulking agents viable treatments for SUI, notes that retreatment is common, and advises counseling women on the expected need for repeat injections. Improvement is more common than durable complete dryness.[1]

For product composition, labeling and device details, see the Bulkamid, Macroplastique and other device pages. See Female SUI for the evaluation and treatment pathway.

Patient selection​

SituationDecision
Patient prefers a less invasive procedure or declines meshDiscuss bulking alongside nonmesh surgery and nonsurgical options. The lower procedural burden comes with a lower chance of dryness
Anesthetic risk, frailty or anticoagulation complexityOffice treatment under local anesthesia may be feasible, but retention and infection still require reliable access to follow-up
Recurrent SUI after a slingEstablish the cause of leakage and assess for obstruction or mesh complications before adding outlet resistance
Fixed, poorly mobile urethraAUA/SUFU states that clinicians may offer pubovaginal slings, retropubic midurethral slings, bulking agents or adjustable retropubic slings . The panel prefers autologous pubovaginal sling in this setting because of suboptimal bulking outcomes.[1] The 2024 AUGS clinical practice statement also notes that ISD does not predict bulking outcomes.[27]
Mixed symptoms or incomplete emptyingSeparate stress leakage from urgency and voiding dysfunction before choosing an outlet procedure

Bulking is a poor match for a patient who expects a sling-like dry rate, has severe leakage, untreated obstruction or a high PVR, has active UTI, or has a urethral diverticulum, erosion or fistula that needs anatomic management first. AUA/SUFU finds inadequate data to recommend one injectable agent over another.[1]

For Bulkamid specifically, the US indication is SUI due to ISD in adult women with SUI or stress-predominant mixed incontinence. The current manufacturer summary contraindicates acute UTI and warns against use before correction of urethral or bladder-neck strictures.[2] The IFU lists populations in which safety and effectiveness have not been established: urethral hypermobility with a straining angle above 30 degrees, predominant urge incontinence, detrusor overactivity, polyuria of 3 L/24 h or more, unevaluated hematuria, prolapse above stage II, BMI above 35 kg/m² and neurogenic bladder. These are gaps in evidence and not absolute contraindications. The IFU also states that only women with well-controlled diabetes should be considered; safety and effectiveness are unestablished with fragile urethral mucosa or active genital herpes, and it advises caution with immunosuppressive therapy while autoimmune-disease safety is unestablished.[2][3]

Review prior bulking products and injection sites. Bulkamid labeling advises against injecting a site previously treated with another agent, or placing another agent into a Bulkamid-treated site. It also warns not to use Bulkamid in men.[2]

Procedural workflow​

Use the current instructions and training for the exact product. Needle, access system, injection depth, location and volume differ between agents. Bulkamid injection can be performed in the office under local anesthesia in selected patients; recovery includes a voiding assessment and management of any retention.[18][3] Injection may be transurethral or periurethral. In the Cochrane review, transurethral and periurethral injection had similar outcomes, with numerically more early complications after the periurethral route without statistical significance. EAU 2026 additionally notes a possible higher urinary-retention risk with periurethral injection (level of evidence 2b).[5][26]

  1. Confirm the stress-leakage target, baseline emptying and relevant prior procedures. Test urine and treat infection before injection.
  2. Review anticoagulants and bleeding risk with the prescribing team. Choose an anesthesia plan and antimicrobial prophylaxis according to the product and local protocol.
  3. Inspect the urethra and bladder and confirm tissue suitability before injection.
  4. For endoscopically administered systems, place deposits under direct vision in the product-specified plane, aiming for coaptation while preserving perfusion. Follow the exact instructions for other delivery systems.
  5. With Bulkamid, stop if superficial mucosal capillaries fade. Avoid intravascular injection, damaged tissue and overcorrection that can obstruct the outlet.
  6. Empty the bladder with a soft catheter when needed, without disrupting the deposits. An indwelling urethral catheter is avoided after bulking because it may disrupt the injected material; if retention persists, intermittent catheterization (one description uses an 8-12 Fr catheter) or, if needed, temporary suprapubic drainage has been advised instead.[20]
  7. Assess voiding and residual urine before discharge. Give a clear retention-management and urgent-contact plan.[3][2]

The January 2020 FDA-hosted Bulkamid IFU (manufacturer instructions) describes the following sequence. It differs from the current manufacturer summary, which references a later revision, so the IFU supplied with the device governs.[3][2]

  • Anesthesia. The cited IFU describes urethral anesthetic gel or local anesthetic at 3 and 9 o'clock 5 to 10 minutes before injection, with antibiotic prophylaxis according to local protocol.[3] In a small randomized office PAHG trial (n = 23; stopped early), combined topical anesthesia and periurethral block lowered mean procedural pain (4.5 versus 7.4/10); 3/12 topical-only patients needed rescue block.[31]
  • Site 1. The rotatable sheath is positioned with the needle at the first site (for example 6 o'clock), about 2 cm from the bladder neck, pressed parallel to the urethral wall so the needle enters submucosa to its 1 cm mark. Angling the system risks a deposit that is too deep or too superficial.
  • Deposit. Hydrogel is injected to the midline of the lumen while superficial vessels stay visible, under water inflow that dilates the urethra.
  • Further sites. Two more sites (for example 2 and 10 o'clock, or 3 and 9 o'clock) are treated in the same plane. Retract the needle before rotating or removing the rotatable sheath, and limit puncture holes to reduce extravasation.[3]
  • Volume. The typical volume is 1.5 to 2.0 mL, with a maximum of 2 mL per session.[3] A top-up is possible at least 4 weeks later, and safety and effectiveness are demonstrated for up to three sessions.
  • Finish. The bladder is emptied with a 10 to 12 Fr catheter. The patient may be discharged if the residual after the first void is 100 mL or less.[3] Intermittent catheterization at home is the fallback for voiding difficulty.

Available agents​

AUA/SUFU 2023 notes longer-term persistence of effect for calcium hydroxyapatite, polydimethylsiloxane and polyacrylamide hydrogel (PAHG) at 73.2, 83 and 96 months, and that erosion was not reported with PAHG in multiple studies. A 2021 systematic review supports Bulkamid and Macroplastique as the best-supported agents. Older trials directly compared injectable agents, but they did not establish a reliable efficacy ranking for currently available products.[1][9][5] In a 2026 retrospective cohort of 623 women, PAHG was associated with less retreatment at two years than other approved agents (24.4% versus 44.3%; adjusted HR 0.53), although agent choice was not randomized and 332/355 comparators received calcium hydroxyapatite.[32] EAU 2026 strongly recommends offering bulking to women seeking surgical treatment for SUI after discussion of other options.[26] For women requesting a low-risk procedure, it advises counseling that efficacy is lower than with other operations, repeat injections are likely, and long-term durability and safety are not established. It strongly recommends against autologous fat (fatal embolism risk) and hyaluronic acid (local abscess risk).[26]

AgentCompositionShort-term efficacyLonger-term dataMain safety signal
BulkamidPolyacrylamide hydrogel (PAHG)30-90% cure or improvement across series42-70%; 7-year dataNo erosion or migration in the 2021 review[9]
MacroplastiquePolydimethylsiloxane40-85%21-80%; 24-month multicenter durability study of 12-month responders[17]; in a prospective 22-center ISD cohort, 70/147 (47.6%) five-year completers improved Stamey grade after their last injection, with 147/274 (54%) completing follow-up[33]Erosion reported; largest historical evidence base[9][16]
CoaptiteCalcium hydroxyapatiteVariable60-75% in selected seriesHigher transient retention (mean 34.2%) and erosion reported[9]
DurasphereOriginal: pyrolytic carbon-coated zirconium; current EXP: pyrolytic carbon-coated graphite[28]VariableLimitedLymph-node migration reported with the historical formulation[9]; urinary urgency of any attribution in 44/178 (24.7%) in the original trial[28]
UrolasticIn situ polymerizing polydimethylsiloxane elastomerVariableLimitedA 65-woman series reported 17 combined exposures or erosions and 14 partial or complete implant removals (17/65, 26.2%; 14/65, 21.5%); three women lacked complication follow-up, so a later review recalculated exposure or erosion as 17/62 (27.4%).[9][21][29][30]
ContigenCross-linked bovine collagenHistorical comparatorNo longer commercially availableComparator in the pivotal Bulkamid trial[11]

Efficacy and the most useful comparison​

Pivotal randomized PAHG versus collagen trial​

In the North American trial of 345 women (229 hydrogel, 116 collagen), 47.2% of PAHG recipients and 50.0% of Contigen recipients reported zero stress incontinence episodes at 12 months, and 77.1% versus 70.0% considered themselves cured or improved. Bulkamid was not inferior to Contigen, and major adverse events were rare.[11]

Five-year randomized PAHG versus TVT trial​

The Helsinki noninferiority trial randomized 223 women; 212 received the assigned treatment and 195 attended five-year follow-up. High satisfaction (score at least 80/100) occurred in 74/99 PAHG recipients (74.7%) and 89/96 TVT recipients (92.7%). The difference was 18.0 percentage points (95% CI 7.7–28.0); PAHG did not meet the prespecified 20-point noninferiority margin.[4]

Among the 195 women attending five-year follow-up, perioperative or postoperative complications before crossover were reported in 22/99 (22.2%) after PAHG and 42/96 (43.8%) after TVT.[4] The trial shows a tradeoff between higher satisfaction with TVT and fewer recorded complications with PAHG.[4]

Other evidence​

The 2017 Cochrane review included 14 trials and 2,004 women, but its reported search date was November 2010. It found limited and heterogeneous evidence, generally greater improvement with surgery, and no reliable ranking of agents or injection locations. Two trials favored surgery for objective cure, although one comparison was not statistically significant in an intention-to-treat analysis. Saline injection produced improvement similar to bulking agent in one trial.[5]

A six-study meta-analysis (710 patients overall) pooled five studies for subjective symptom improvement at 12 months and favored surgery (bulking-versus-surgery RR 0.70, 95% CI 0.53–0.92).[6] Its Clavien-Dindo grade 3 complication estimate from three of six studies was imprecise (RR 1.30, 95% CI 0.30–5.66), leaving comparative safety unresolved.[6] A modeling analysis estimated 1.86 QALYs for midurethral sling and 1.82 QALYs for PAHG; the annualized difference was 0.02 QALY/year, below the stated minimally important utility difference of 0.03 per year, with PAHG cost-effective when more than 58% of procedures are done in the office.[13]

An older, smaller randomized trial directly compared pubovaginal sling with transurethral Macroplastique in 45 women with SUI and ISD (22 sling, 23 Macroplastique). At the 6- and 12-month assessments, symptomatic and satisfaction success were similar, but objective success favored sling (81% versus 9%, p < 0.001); Macroplastique had lower morbidity (shorter operating time, less blood loss, shorter catheterization and hospital stay) but was more expensive. At mean 62-month telephone follow-up, 60% of each arm responded, with reported continence success of 69% versus 21% and satisfaction of 69% versus 29% (p = 0.057 for satisfaction).[22]

Longer-term observational data support persistence of benefit for some women. Brosche's single-center series included 388 seven-year completers from 1,200 treated patients; among 261 receiving PAHG as their primary procedure, 175 (67.1%) reported cure or improvement and 51 (19.5%) underwent another continence procedure.[7] Among the 388 patients who completed seven-year follow-up, the study’s postoperative complication table records transient prolonged emptying in 48 and UTI in 11.[7] A French two-center retrospective series of 320 women (median follow-up 24 months) reported 63.7% cured and 21.9% improved at last follow-up.[12]

Recurrent SUI after a sling​

Bulking may suit a patient who has persistent stress leakage and wishes to avoid further dissection. An 11-study review reported a pooled 75% cure-or-improvement estimate with substantial heterogeneity, and pooled failure and reoperation rates of 32% and 25%.[8] Subgroup estimates were 84% for Macroplastique and 80% for Bulkamid.[8] A broader 2025 review of 20 salvage-bulking studies pooled objective cure or improvement at 56% and patient satisfaction at 77%, with reintervention ranging from 9.8% to 42%; its prior-treatment mix and endpoints differ from the post-sling review.[34]

A retrospective cohort directly comparing the two retreatment options after a failed midurethral sling found a lower failure rate with a repeat sling than with urethral bulking (11.2% of 98 repeat slings versus 38.8% of 67 bulking procedures, p = 0.004), with no difference in perioperative complications between the groups. Bulking spares a repeat dissection while the repeat sling had a lower failure rate in this cohort.[19]

Persistent urgency, obstruction, urethral erosion, fistula or other structural complications require their own treatment. A later sling or other reconstruction may remain possible. The injected permanent material must be documented for future surgery, and the effect of prior injection on later operations is not established.[1][3]

Safety and follow-up​

Counseling covers dysuria, hematuria, infection, pain, transient retention, persistent obstruction, new urgency and treatment failure. Agent-specific problems include erosion, extrusion, granuloma and migration. The 2021 systematic review found no PAHG erosion or migration, but current labeling includes them among potential adverse events.[9][2]

ComplicationReported range
UTIThe 2021 review reported 4-10.6% in its included studies; the original Durasphere zirconium-bead trial recorded UTI of any attribution in 53/178 (29.8%) and treatment-related UTI in 16/178 (9%). Postoperative UTI occurred in 11/388 Bulkamid seven-year completers and 7/320 (2.2%) in the French Bulkamid series.[9][28][7][12]
Retention10/320 (3.1%) acute retention in the French Bulkamid series; postoperative transient prolonged emptying in 48 of 388 seven-year Bulkamid completers; mean 34.2% temporary acute retention with Coaptite[12][7][9]
Transient hematuria7.2% in the French Bulkamid series[12]
Urinary urgencyReported across agents; 44/178 (24.7%) of Durasphere recipients in the original trial reported urgency of any attribution[9][28]
Erosion or extrusionReported with Macroplastique, Coaptite and Urolastic[9]
MigrationLymph node migration reported with Durasphere[9]

After discharge, inability to void, worsening pain, fever or substantial bleeding warrants prompt assessment. Reassess persistent leakage before repeating treatment: the target may be residual SUI, urgency, incomplete emptying or another problem. Record the material, lot, volume, location and date so later clinicians can interpret cystoscopy or imaging correctly.[3] In a retrospective radiology review of 528 patients who had undergone periurethral bulking, 79 (15%) had subsequent abdominal or pelvic imaging with abnormal periurethral findings, and in 72 of 111 such studies (65%) the bulking agent was not correctly identified; the most common misdiagnoses were bladder or periurethral calcification, a urethral diverticulum with stone, an indeterminate pelvic density, and a mass suspicious for malignancy.[23]

Persistent retention after injection can reflect over-bulking or outlet obstruction, but other causes, including evolving detrusor weakness in an older patient, should also be considered. A delayed periurethral pseudocyst or abscess can present as a palpable anterior vaginal-wall mass with irritative or obstructive urinary symptoms, sometimes with negative cultures despite reported infection; imaging can help distinguish retained bulking material or a fluid collection from another pelvic mass. Case reports and small series describe transurethral aspiration or unroofing for an obstructing deposit, though aspiration alone may recur, and removing or decompressing the material can restore stress leakage. For a larger or loculated collection not reachable transurethrally, complete transvaginal drainage with preservation of periurethral fascia and watertight closure has been described; a transurethral approach is generally favored when feasible because of a theoretical urethrovaginal-fistula risk with transvaginal excision, and fistula or diverticulum formation has also been reported after spontaneous or procedural drainage. These case reports and small series describe rescue approaches without a standard protocol or product-risk comparison.[24]

Vaginal estrogen may be appropriate for a separate GSM indication; it has not been shown to be required preparation for bulking. Vaginal/topical estrogen and duloxetine have separate indications and jurisdiction-specific considerations.

Men and investigational injections​

AUA/GURS/SUFU 2024 recommends that clinicians counsel men with incontinence after prostate treatment that efficacy is low and cure is rare with bulking agents .[10] A systematic review of 8 studies (mostly Macroplastique; one randomized study against AUS) reported dry rates from 0% to 83%, with short follow-up and small samples.[14] A narrative review of 25 studies reported success from 13% to 100% with deterioration over time.[15] Bulkamid labeling warns against male use.[2]

Male slings and AUS are separate surgical pathways. Regenerative cell injections, including autologous adipose-derived and muscle-derived cells, aim to regenerate sphincter function and not merely bulk the urethra. Studies are few, small and heterogeneous, with success rates that appear comparable to conventional bulking. AUA/SUFU recommends against offering stem cell therapy outside investigative protocols .[1][16] A multicenter, double-blind, placebo-controlled trial of autologous muscle-derived cells for urinary sphincter repair (AMDC-USR) in women with stress or stress-predominant mixed incontinence planned a sample of 246 women, randomized 2:1 to cells or placebo; enrollment halted after 150 women were biopsied (61% of the plan), of whom 143 received cells or placebo, because of an unexpectedly high placebo response on the prespecified composite primary outcome, which prevented assessment of the intended treatment effect.[25] A post hoc analysis using a more stringent response threshold suggested a possible treatment effect in a subgroup.[25] This trial is inconclusive on its primary endpoint.[25]

Counseling points​

  • Bulking is minimally invasive and can be done in the office under local anesthesia.
  • It is less effective than midurethral or fascial sling surgery.
  • Repeat injection is common.
  • The 2021 systematic review reported no PAHG erosion or migration, although current labeling lists both as potential adverse events.[1][9][2]

Device and treatment references​

Podcasts​

Midurethral Slings vs Bulkamid: What Clinicians Need to Know
BackTable Urology, Ep. 140 (2023) · Tamsin Greenwell, Suzette Sutherland
backtable.com
SUFU 23: Panel Periurethral injections in SUI
SUFU Podcast (2024)
podcasts.apple.com

References​

1. Kobashi KC, Vasavada S, Bloschichak A, et al. "Updates to Surgical Treatment of Female Stress Urinary Incontinence (SUI): AUA/SUFU Guideline (2023)." J Urol. 2023;209(6):1091-1098. doi:10.1097/JU.0000000000003435

2. Boston Scientific. Bulkamid Urethral Bulking System: current US indications, safety and warnings summary, referencing IFU110-0303rB. Manufacturer safety summary.

3. Contura / US Food and Drug Administration. Bulkamid Urethral Bulking System: Instructions for Use,10078-001, January2020. FDA physician labeling.

4. Itkonen Freitas AM, Isaksson C, Rahkola-Soisalo P, Mentula M, Mikkola TS. Tension-Free Vaginal Tape versus Polyacrylamide Hydrogel Injection for Stress Urinary Incontinence — 5-Year Follow-Up. NEJM Evid. 2025;4(5):EVIDoa2400216. doi:10.1056/EVIDoa2400216.

5. Kirchin V, Page T, Keegan PE, et al. "Urethral Injection Therapy for Urinary Incontinence in Women." Cochrane Database Syst Rev. 2017;7:CD003881. doi:10.1002/14651858.CD003881.pub4

6. Pivazyan L, Kasyan G, Grigoryan B, Pushkar D. "Effectiveness and Safety of Bulking Agents Versus Surgical Methods in Women With Stress Urinary Incontinence: A Systematic Review and Meta-analysis." Int Urogynecol J. 2022;33(4):777-787. doi:10.1007/s00192-021-04937-1

7. Brosche T, Kuhn A, Lobodasch K, Sokol ER. "Seven-year Efficacy and Safety Outcomes of Bulkamid for the Treatment of Stress Urinary Incontinence." Neurourol Urodyn. 2021;40(1):502-508. doi:10.1002/nau.24589

8. Braga A, Caccia G, Papadia A, et al. "Urethral Bulking Agents for the Treatment of Recurrent Stress Urinary Incontinence: A Systematic Review and Meta-analysis." Maturitas. 2022;163:28-37. doi:10.1016/j.maturitas.2022.05.007

9. Hoe V, Haller B, Yao HH, O'Connell HE. "Urethral Bulking Agents for the Treatment of Stress Urinary Incontinence in Women: A Systematic Review." Neurourol Urodyn. 2021;40(6):1349-1388. doi:10.1002/nau.24696

10. American Urological Association / GURS / SUFU. Incontinence After Prostate Treatment Guideline. Amended2024. Statement25 and discussion. Guideline.

11. Sokol ER, Karram MM, Dmochowski R. "Efficacy and Safety of Polyacrylamide Hydrogel for the Treatment of Female Stress Incontinence: A Randomized, Prospective, Multicenter North American Study." J Urol. 2014;192(3):843-849. doi:10.1016/j.juro.2014.03.109

12. Lamblin G, Boix S, Moret S, et al. "Effectiveness and Safety Profile of Urethral Bulking With Bulkamid for Stress Urinary Incontinence: A French Multi-center Cohort Study." Int Urogynecol J. 2025;36(1):205-211. doi:10.1007/s00192-024-06005-w

13. Chang OH, Shepherd JP, Cadish LA, et al. "Urethral Bulking With Polyacrylamide Hydrogel Compared With Other Treatments for Stress Urinary Incontinence: A Cost-effectiveness Analysis." Obstet Gynecol. 2024;143(3):428-430. doi:10.1097/AOG.0000000000005503

14. Toia B, Gresty H, Pakzad M, et al. "Bulking for Stress Urinary Incontinence in Men: A Systematic Review." Neurourol Urodyn. 2019;38(7):1804-1811. doi:10.1002/nau.24102

15. Nguyen L, Leung LY, Walker R, et al. "The Use of Urethral Bulking Injections in Post-prostatectomy Stress Urinary Incontinence: A Narrative Review of the Literature." Neurourol Urodyn. 2019;38(8):2060-2069. doi:10.1002/nau.24143

16. Hillary CJ, Roman S, MacNeil S, et al. "Regenerative Medicine and Injection Therapies in Stress Urinary Incontinence." Nat Rev Urol. 2020;17(3):151-161. doi:10.1038/s41585-019-0273-4

17. Ghoniem G, Corcos J, Comiter C, Westney OL, Herschorn S. "Durability of Urethral Bulking Agent Injection for Female Stress Urinary Incontinence: 2-year Multicenter Study Results." J Urol. 2010;183(4):1444-1449. doi:10.1016/j.juro.2009.12.038

18. Lukanović D, Blaganje M, Rhazi I, Deval B. "Urethral Bulkamid Injection After Failed Midurethral Sling: A Step-by-step Video." Int Urogynecol J. 2023;34(11):2843-2845. doi:10.1007/s00192-023-05608-z

19. Gaddi A, Guaderrama N, Bassiouni N, Bebchuk J, Whitcomb EL. "Repeat Midurethral Sling Compared With Urethral Bulking for Recurrent Stress Urinary Incontinence." Obstet Gynecol. 2014;123(6):1207-1212. doi:10.1097/AOG.0000000000000282

20. Brown ET, Dmochowski RR. Bulking agents for incontinence. In: Smith JA Jr, Dmochowski RR, Thomas JC, Preminger GM, eds. Hinman's Atlas of Urologic Surgery. 5th ed. Elsevier; 2025:789-790.

21. Alimi Q, Bouchard B, Corcos J. Urethral bulking agents. In: Martins FE, Holm HV, Sandhu JS, McCammon KA, eds. Female Genitourinary and Pelvic Floor Reconstruction. Springer; 2023:437-447. doi:10.1007/978-3-031-19598-3_25

22. Maher CF, O'Reilly BA, Dwyer PL, Carey MP, Cornish A, Schluter P. Pubovaginal sling versus transurethral Macroplastique for stress urinary incontinence and intrinsic sphincter deficiency: a prospective randomised controlled trial. BJOG. 2005;112(6):797-801. doi:10.1111/j.1471-0528.2005.00547.x

23. Gaines N, Gupta P, Khourdaji AS, et al. Radiographic misdiagnoses after periurethral bulking agents. Female Pelvic Med Reconstr Surg. 2018;24(4):312-314. doi:10.1097/SPV.0000000000000440

24. Lightner DJ, Knoedler JJ, Linder BJ. Periurethral bulking agent injection in the treatment of female stress urinary incontinence. In: Goldman HB, ed. Complications of Female Incontinence and Pelvic Reconstructive Surgery. 2nd ed. Springer (Humana Press); 2017:297-306. doi:10.1007/978-3-319-49855-3_27

25. Jankowski RJ, Tu LM, Carlson C, et al. A double-blind, randomized, placebo-controlled clinical trial evaluating the safety and efficacy of autologous muscle derived cells in female subjects with stress urinary incontinence. Int Urol Nephrol. 2018;50(12):2153-2165. doi:10.1007/s11255-018-2005-8

26. European Association of Urology. EAU Guidelines on Non-neurogenic Female LUTS. 2026. Section 4.2.4.c.2.c.1. Guideline.

27. Fleischmann N, Chughtai B, Plair A, et al. "Urethral Bulking." Urogynecology (Phila). 2024;30(8):667-682. doi:10.1097/SPV.0000000000001548

28. Carbon Medical Technologies, Inc. Durasphere EXP Injectable Bulking Agent: Directions for Use. 51013(1), March 2026. Manufacturer DFU.

29. de Vries AM, van Breda HMK, Fernandes JG, Venema PL, Heesakkers JPFA. "Para-Urethral Injections with Urolastic for Treatment of Female Stress Urinary Incontinence: Subjective Improvement and Safety." Urol Int. 2017;99(1):91–97. doi:10.1159/000452450

30. Capobianco G, Azzena A, Saderi L, et al. "Urolastic, a New Bulking Agent for Treatment of Stress Urinary Incontinence: A Systematic Review and Meta-Analysis." Int Urogynecol J. 2018;29(9):1239–1247. doi:10.1007/s00192-018-3703-6

31. Gaddam NG, Marantidis J, Ahmed NT, et al. "Optimal Anesthesia for Polyacrylamide Hydrogel Injection: A Randomized Trial." Urogynecology (Phila). 2026;32(8):919-927. doi:10.1097/SPV.0000000000001757

32. Pfeuti CK, King KS, Gebhart JB, et al. "Real-World Results of Urethral Bulking With Polyacrylamide Hydrogel Versus Legacy Injectables: A Retrospective Study." Neurourol Urodyn. Published online September 1, 2026. doi:10.1002/nau.70435

33. Ghoniem G, Lane F, Farhan B, Gilliam K, Shobeiri SA, Salah A. "Five-Year Follow-up Study on Safety and Efficacy of Macroplastique® in Female Patients with Stress Urinary Incontinence (the ROSE Study)." Int Urogynecol J. 2025;36(8):1663-1670. doi:10.1007/s00192-025-06163-5

34. Hoffman O, Jiang J, Rashid S, Yao HH, O'Connell HE, Gani J. "Urethral Bulking Agent as a Salvage Procedure for Female Stress Urinary Incontinence: A Systematic Review and Meta-Analysis." Int Urogynecol J. 2025;36(10):1921-1933. doi:10.1007/s00192-025-06373-x