What is the best approach to manage bladder frequency following a pelvic fracture?

Management of Bladder Frequency Following Pelvic Fracture

Bladder frequency following pelvic fracture is most commonly a long-term complication of urethral or bladder injury, and should be managed based on the underlying anatomic injury pattern identified during initial trauma evaluation and subsequent follow-up imaging. 1

Initial Assessment and Injury Classification

The first step is determining whether bladder or urethral injury occurred at the time of pelvic fracture, as 6-8% of pelvic fractures involve bladder injury and posterior urethral injuries occur in 1.5-5% of anterior pelvic fractures. 1

Key Diagnostic Considerations:

• CT scan with delayed phase imaging is the method of choice for evaluating bladder injuries and should be performed if not done during initial trauma workup 1
• Uretroscopy or urethrogram are the methods of choice for urethral injury assessment 1
• Patients should be monitored for complications including stricture formation, erectile dysfunction, and incontinence for at least one year following urethral injury 1

Management Algorithm Based on Underlying Pathology

If Urethral Stricture is Present:

Urethral stricture is the most common cause of obstructive voiding symptoms (including frequency) after pelvic fracture urethral injury, occurring in the majority of cases regardless of initial management approach. 1

• Definitive surgical treatment with urethroplasty should be performed after healing of the pelvic ring injury 1
• Conservative endoscopic approaches should be attempted before proceeding to formal urethroplasty 1

If Bladder Neck Injury Occurred:

Bladder neck injuries associated with pelvic fractures represent complex extraperitoneal injuries that require surgical exploration and repair, as they do not heal reliably with catheter drainage alone. 1, 2

• Open bladder neck before or after urethroplasty may herald incontinence and frequency symptoms 3
• Radiographic bladder neck opening greater than 1.68 cm is associated with higher risk of postoperative incontinence 3
• Bladder neck reconstruction provides good continence rates when performed sequentially after urethral repair 3

If Overactive Bladder Symptoms Predominate:

When frequency is due to detrusor overactivity rather than anatomic injury, anticholinergic therapy with oxybutynin is first-line pharmacologic treatment. 4

• Oxybutynin increases bladder capacity, diminishes frequency of uninhibited detrusor contractions, and delays initial desire to void 4
• Starting dose is 5 mg two to three times daily in adults; 2.5 mg two to three times daily in frail elderly 4
• Pediatric patients aged 5-15 years may receive 5-15 mg total daily dose 4

Critical Pitfalls to Avoid

• Do not assume frequency is simply "overactive bladder" without imaging follow-up, as unrecognized stricture or bladder neck injury will not respond to anticholinergics and requires surgical intervention 1
• Avoid repeated catheterization attempts if urethral injury is suspected, as this increases injury severity 1
• Do not attempt conservative management of bladder neck injuries with catheter drainage alone, as failure to repair can result in chronic incontinence and frequency 2
• Operative repair of concurrent bladder rupture is associated with lower rates of pelvic hardware infection (5.6% versus 33.3%) compared to conservative management when internal fixation is required 5

Follow-Up Protocol

• CT scan with delayed phase imaging should be repeated if symptoms persist or worsen 1
• Urodynamic testing may be considered to assess bladder contractility and evaluate for detrusor dysfunction 6
• Reassessment 2-4 weeks after initiating anticholinergic therapy if pharmacologic management is pursued 6
• Annual follow-up is recommended to detect symptom changes or complications 6