Urinary Tract Injuries

Introduction

Welcome to this comprehensive MCCQE1 study guide on Urinary Tract Injuries. This resource is tailored for Canadian medical students preparing for the Medical Council of Canada Qualifying Examination Part I (MCCQE1). Understanding urinary tract injuries is crucial for success in your MCCQE1 and future medical practice in Canada.

Epidemiology in the Canadian Context

Urinary tract injuries are relatively uncommon but can have significant morbidity if not recognized and treated promptly. In Canada:

• Approximately 10% of patients with abdominal trauma have genitourinary injuries
• Males are more commonly affected than females (3:1 ratio)
• Blunt trauma accounts for 90% of renal injuries in Canada, with motor vehicle accidents being the leading cause

Classification of Urinary Tract Injuries

Understanding the classification of urinary tract injuries is essential for MCCQE1 preparation. The American Association for the Surgery of Trauma (AAST) grading system is widely used in Canada:

Clinical Presentation and Diagnosis

For MCCQE1 success, focus on recognizing the key signs and symptoms of urinary tract injuries:

1. Renal Injuries:

   • Flank pain or tenderness
   • Hematuria (gross or microscopic)
   • Abdominal distension or mass
   • Hypotension (in severe cases)

2. Ureteral Injuries:

   • Often asymptomatic initially
   • Flank pain
   • Fever
   • Ileus

3. Bladder Injuries:

   • Lower abdominal pain
   • Inability to void
   • Gross hematuria
   • Suprapubic tenderness

Diagnostic Approach

Management of Urinary Tract Injuries

Understanding the management principles is crucial for MCCQE1 preparation:

Renal Injuries

• Grades I-III: Generally managed conservatively with bed rest, analgesia, and monitoring
• Grades IV-V: May require surgical intervention, especially if hemodynamically unstable

Ureteral Injuries

• Early diagnosis: Primary repair with stenting
• Delayed diagnosis: Nephrostomy tube placement followed by delayed repair

Bladder Injuries

• Extraperitoneal: Catheter drainage for 10-14 days
• Intraperitoneal: Surgical repair with catheter drainage

Complications and Follow-up

Be aware of potential complications for MCCQE1 questions:

• Urinoma formation
• Delayed bleeding
• Hypertension
• Urinary fistula
• Chronic pyelonephritis

Follow-up should include:

• Regular imaging (ultrasound or CT) to monitor healing
• Blood pressure monitoring
• Renal function tests

Canadian Guidelines for Urinary Tract Injury Management

The Canadian Urological Association (CUA) provides guidelines for managing urinary tract injuries. Key points include:

1. Hemodynamic stability is the primary determinant of management approach
2. Non-operative management is preferred for most renal injuries
3. Early urological consultation is recommended for all suspected urinary tract injuries
4. Follow-up imaging is crucial to detect and manage delayed complications

Key Points to Remember for MCCQE1

• Hematuria is the most common sign of urinary tract injury but may be absent in severe cases
• CT with contrast is the gold standard for diagnosing renal and ureteral injuries
• Retrograde cystogram is essential for diagnosing bladder injuries
• Most low-grade renal injuries (I-III) can be managed conservatively in Canada
• Intraperitoneal bladder ruptures require surgical repair
• Ureteral injuries often present late and may require staged repair
• Canadian guidelines emphasize minimally invasive approaches when possible

Sample Question

A 35-year-old man is brought to the emergency department after a motor vehicle accident. He complains of right flank pain and gross hematuria. Vital signs are stable. CT scan reveals a 2 cm deep laceration of the right kidney with a small perinephric hematoma. Which one of the following is the most appropriate next step in management?

• A. Immediate surgical exploration
• B. Angiographic embolization
• C. Placement of a nephrostomy tube
• D. Conservative management with bed rest and monitoring
• E. Retrograde pyelogram

Explanation

The correct answer is:

• D. Conservative management with bed rest and monitoring

This patient presents with a Grade III renal injury (deep cortical laceration >1 cm) following blunt trauma. The patient is hemodynamically stable, and there is no evidence of collecting system or vascular involvement. In the Canadian healthcare context, where conservative management is preferred when safe and appropriate, the most suitable approach for this injury is non-operative management.

Conservative management typically involves:

• Bed rest
• Analgesia
• Serial hemoglobin measurements
• Monitoring of vital signs
• Follow-up imaging to ensure proper healing

Surgical exploration (A) is not indicated for stable Grade III injuries unless there are signs of ongoing bleeding or other complications. Angiographic embolization (B) might be considered for higher-grade injuries with active bleeding. A nephrostomy tube (C) is not routinely used for this type of injury. Retrograde pyelogram (E) is not necessary when CT imaging has already provided adequate information about the injury.

This question tests your knowledge of the AAST renal injury grading system, the principles of managing renal trauma, and the Canadian approach to favoring conservative management when appropriate.

References

1. Buckley JC, McAninch JW. Selective management of isolated and nonisolated grade IV renal injuries. J Urol. 2006;176(6 Pt 1):2498-2502.

2. Bryk DJ, Zhao LC. Guideline of guidelines: a review of urological trauma guidelines. BJU Int. 2016;117(2):226-234.

3. Canadian Urological Association. (2019). Genitourinary Trauma Guidelines. https://www.cua.org/guidelines (opens in a new tab)

4. Morey AF, Brandes S, Dugi DD 3rd, et al. Urotrauma: AUA guideline. J Urol. 2014;192(2):327-335.

5. Santucci RA, Wessells H, Bartsch G, et al. Evaluation and management of renal injuries: consensus statement of the renal trauma subcommittee. BJU Int. 2004;93(7):937-954.