In a patient with a history of bladder or urethral mesh placement for stress urinary incontinence or pelvic organ prolapse who now has recurrent urinary tract infections, what is the most likely etiology and what diagnostic and therapeutic steps should be taken?

Mesh Erosion into the Bladder is the Most Likely Cause of Recurrent UTIs

In a patient with bladder or urethral mesh and recurrent UTIs, mesh erosion into the urinary tract is the primary concern and requires immediate cystoscopic evaluation to identify and remove the eroded material.

Most Likely Etiology

The recurrent UTIs are most likely caused by mesh erosion into the bladder or urethra, which creates a nidus for bacterial colonization and biofilm formation 1, 2, 3.

• Synthetic mesh placed at the bladder neck has a 5% urethral/bladder erosion rate and 10% UTI rate, with erosions creating persistent infection sources 1
• Midurethral synthetic slings have lower but still significant erosion rates (1% into urinary tract) with 11% UTI rate 1
• Any mesh encountered within the urinary tract must be fully excised as conservative management fails 2

Other Contributing Factors

Beyond direct erosion, mesh complications that promote recurrent UTIs include 4, 2, 3:

• Incomplete bladder emptying from voiding dysfunction caused by mesh tension or urethral obstruction
• Vaginal mesh exposure (most common mesh complication) allowing ascending bacterial colonization
• Foreign body effect even without frank erosion, creating bacterial biofilm substrate
• Bladder outlet obstruction from mesh placement increasing post-void residual volumes

Diagnostic Algorithm

Step 1: Clinical Assessment

Obtain specific history for mesh-related complications 2, 3, 5:

• Vaginal discharge, bleeding, or pain (suggests vaginal exposure)
• Dyspareunia (vaginal mesh exposure)
• Persistent pelvic or urethral pain (mesh contraction or erosion)
• Irritative voiding symptoms (bladder/urethral erosion)
• Hematuria (urinary tract erosion)
• Recurrent UTIs with same organism (biofilm on mesh) 4

Step 2: Physical Examination

• Vaginal examination to identify mesh exposure through vaginal epithelium 2, 3, 5
• Palpable mesh on anterior vaginal wall examination suggests exposure
• Small asymptomatic exposures (<0.5cm) may be managed conservatively, but larger exposures require excision 2

Step 3: Mandatory Cystoscopy

Cystoscopy is essential to visualize mesh erosion into the bladder or urethra 2, 3, 5:

• All urethral and bladder erosions are detected by cystoscopy 5
• Look for white/yellow foreign material protruding into bladder lumen or urethra
• Assess for stone formation on eroded mesh (common with chronic erosion) 6, 7
• Evaluate bladder neck and urethral integrity

Step 4: Urine Culture

• Obtain culture before each treatment to guide antimicrobial therapy and track resistance patterns 8
• Urea-splitting organisms (Proteus) suggest possible stone formation on mesh 4

Step 5: Imaging Studies

Consider imaging when structural abnormalities beyond mesh are suspected 4:

• Post-void residual measurement to assess for incomplete emptying
• CT urogram or ultrasound if stone formation suspected on eroded mesh
• Imaging helps identify concurrent structural problems (fistula, obstruction) 4

Therapeutic Management

Immediate Management

Complete surgical excision of any mesh within the urinary tract is mandatory 2:

• Conservative management of urinary tract erosions fails universally
• Partial excision is insufficient—complete removal of eroded segment required 2, 3
• Leave urethral catheter for 2-3 weeks post-excision to allow healing 1

Surgical Approach

For confirmed mesh erosion 2, 3, 5:

• Transvaginal approach for accessible urethral erosions
• Combined cystoscopic and vaginal approach for bladder neck erosions
• Open surgical excision may be required for extensive erosions or fistula formation
• Excise eroded mesh with primary closure of bladder/urethral defect
• Remove any calcifications or stones formed on mesh 7

Antimicrobial Therapy

Treat acute UTI episodes while planning definitive surgical management 8:

• Nitrofurantoin 100mg twice daily for 5-7 days (first-line)
• Trimethoprim-sulfamethoxazole 160/800mg twice daily for 7 days (alternative)
• Culture-directed therapy based on sensitivities
• Do not use prophylactic antibiotics as long-term solution—this only delays definitive treatment and promotes resistance 8

Post-Excision Considerations

After mesh removal 2, 5:

• Recurrent stress incontinence occurs in ~60% of patients after mesh excision for erosion
• Persistent pain may continue in up to 50% despite complete mesh removal
• Wait 3-6 months before considering repeat incontinence surgery 1
• Use autologous fascial sling if repeat surgery needed—synthetic mesh is contraindicated after erosion 1

Critical Pitfalls to Avoid

• Never treat recurrent UTIs with chronic suppressive antibiotics without investigating for mesh erosion—this masks the underlying problem and promotes resistance 8
• Never assume UTIs are "simple cystitis" in a patient with mesh history—always perform cystoscopy 4, 2, 3
• Never attempt conservative management of mesh eroded into bladder or urethra—complete excision is required 2
• Never place synthetic mesh in patients with prior mesh erosion, urethral injury, or fistula—this is contraindicated 1
• Do not treat asymptomatic bacteriuria in these patients, as it does not prevent symptomatic episodes 8

Prognosis

• Symptoms resolve dramatically after complete mesh excision 5
• However, stress incontinence recurs in majority of patients requiring alternative management 2, 5
• Pain may persist despite complete removal in up to half of patients 2