1 Why are children more likely to sustain renal injuries than adults?

ce:anchor id=”p0010″/>A child’s kidneys are disproportionately larger in relation to body size and have less perinephric fat, more lobulations, and a more intra-abdominal location. Because children have a weaker anterior abdominal wall and a less well-ossified thoracic cage with a more flexible thoracolumbar spine, the kidneys and other genitourinary structures are more susceptible to blunt trauma. Preexisting congenital renal abnormalities have been documented in 10–15% of patients evaluated for renal trauma. Approximately 10% of trauma patients have urogenital injuries. Common associated injuries include head injuries, fractures (extremities, pelvis, ribs, spine, and skull), spinal cord injuries, and liver or spleen injuries. Blunt trauma accounts for up to 90% of renal injuries.

Abou-Jaoude WA, Sugarman JM, Fallat ME, et al: Indicators of genitourinary tract injury or anomaly in cases of pediatric blunt trauma. J Pediatr Surg 31:86–90, 1996.

2 Describe the immediate and delayed complications of renal trauma

Contusions and minor cortical lacerations usually heal without sequelae. More severe injuries may be associated with delayed bleeding, renal failure, abscess formation, urinary extravasation with sepsis, and ureteral obstruction secondary to clot formation. Late complications include hypertension, arteriovenous fistulas, hydronephrosis, pseudocyst formation, and renal calculi. Children with renal trauma (radiologically or operatively confirmed) should be followed closely with serial scans for at least 1 year after injury to evaluate renal anatomy and to ensure prompt diagnosis and treatment of possible complications.

Gotschall CS, Eichelberger MR: Predictors of abdominal injury in children with pelvic fracture. J Trauma 31:1169–1173, 1991.

McAleer IM, Kaplan GW: Pediatric genitourinary trauma. Urol Clin North Am 22:177–188, 1995.

3 Which is the cardinal laboratory marker of renal injury?

Hematuria is the most important laboratory evidence of renal injury. Gross hematuria is the hallmark sign of severe injury. However, this finding may be absent in up to 50% of patients with vascular pedicle injuries and in 29% of patients with penetrating injuries. Radiographic evaluation is needed for children with gross hematuria, hematuria of more than 20 red blood cells/high-powered field, microscopic hematuria with shock, or clinical findings indicative of renal trauma.

Garcia CT: Genitourinary trauma. In Fleisher GR, Ludwig S, Henretig FM (eds): Textbook of Pediatric Emergency Medicine, 5th ed. Philadelphia, Lippincott Williams & Wilkins, 2006.

4 How are renal injuries classified?

The Organ Injury Scaling Committee of the American Association for Surgery of Trauma developed a new scaling system that unifies previous classifications for research purposes:

Moore EE, Shackford SR, Pachter HL, et al: Organ injury scaling: Spleen, liver, and kidney. J Trauma 29:1664–1666, 1989.

5 Which imaging modality is considered the diagnostic test of choice for evaluation of renal injuries in stable pediatric patients?

Contrast-enhanced computed tomography (CT) is considered the diagnostic test of choice for detection of renal injury in stable pediatric patients with trauma. It not only delineates the degree of renal parenchymal injury with high accuracy (98%) but also assesses other intra-abdominal, retroperitoneal, and pelvic injuries simultaneously. However, this test is relatively expensive and requires a hemodynamically stable patient who can tolerate transport to the radiology suite. CT is useful for identifying genitourinary injury in children with penetrating trauma to the abdomen or other significant injuries.

Stubbs DM: Emergency radiology of urinary tract injuries. Am J Emerg Med 10:242–250, 1992.

6 Which diagnostic modality should be used in unstable patients?

Traditionally, IV pyelography has been used for the evaluation of renal trauma or isolated urogenital trauma in unstable patients. It is available in most institutions and is relatively inexpensive, and it provides evidence of renal function (including contralateral function in patients with penetrating injuries) and visualization of the calyceal system or extravasation. One-shot IV pyelography usually is indicated for unstable patients and can be performed in the emergency department or operating room. However, results of this study may be falsely negative in patients with pedicle injuries and, in general, correlates in only 50–75% of patients with injuries found at exploratory laparotomies.

Stevenson J, Battistella FD: The “one-shot” intravenous pyelogram: Is it indicated in unstable trauma patients before celiotomy? J Trauma 36:828–833; discussion, 833–834, 1994.

7 Which are the most commonly found symptoms in bladder injuries?

Hematuria and dysuria are usually present in patients with blunt or penetrating trauma to the pelvis. During childhood, the bladder has a higher abdominal location, which renders the organ more susceptible to injury. Radiologic evaluation is indicated in patients with pelvic or lower abdominal trauma who experience difficulty in voiding or gross hematuria. However, catheterization must be avoided if physical examination reveals blood at the urethra or a high-riding prostate on rectal examination.

Corriere JN Jr, Sandler CM: Bladder rupture from external trauma: Diagnosis and management. World J Urol 17:84–89, 1999.

8 What clinical findings should make you suspect ureteral injury?

Signs and symptoms of ureteral injuries are nonspecific and often overlooked. Fewer than 50% of patients are diagnosed within 24 hours because the presentation may develop gradually. An enlarging flank mass in the absence of retroperitoneal bleeding suggests the possibility of urinary extravasation. Hematuria is not a reliable sign because it may be absent in > 40% of patients with urethral injuries. Common symptoms in delayed presentation include fever, chills, ileus, lethargy, pyuria or bacteriuria, and flank pain. Ureteral injuries usually are discovered during evaluation of other traumatic injuries.

9 Describe the most common mechanisms for ureteral injuries

Ureteral injuries are uncommon in children, accounting for < 1–3% of patients with genitourinary tract injury. They may result from blunt trauma (involving the ureteropelvic junction) or penetrating trauma (gunshot wounds), but most ureteral injuries are iatrogenic (urologic, gynecologic, colonic, and vascular surgery procedures). Iatrogenic injury is less common in children than adults because of the nature of the procedures and easier identification of the ureters because of lack of retroperitoneal fat.

Tarman GJ, Kaplan GW, Lerman SL, et al: Lower genitourinary injury and pelvic fractures in pediatric patients. Urology 59:123–126, 2002.

10 What clinical findings indicate urethral injuries?

The presence of blood at the meatus has been reported in more than 90% of patients with anterior urethral injury. Such injuries are commonly due to motor vehicle crashes, straddle injuries (bulbar urethra), or instrumentation. Patients may present with hematuria, difficulty or inability to void, swelling, and ecchymosis or hematoma of the perineum or penis. Anterior urethral injuries may produce extravasation of blood and urine into the abdominal wall, scrotum, or perineum.

11 What are the indications for urethrography in pediatric trauma patients?

Retrograde urethrography is the radiologic method of choice for diagnosis. It should be performed in any child with penetrating trauma and suspected genitourinary injuries; perineal trauma with hematuria; inability to void or to advance a urinary catheter; vaginal laceration or bleeding; swelling, hematoma, or ecchymosis of the perineum; blood at the urethral meatus; and high-riding or boggy prostate.

Kotkin L, Brock JW: Isolated ureteral injury caused by blunt trauma. Urology 47:111–113, 1996.

12 How does traumatic testicular dislocation present?

Forceful displacement of the testicle from its anatomic position is uncommon in children because of their brisk cremasteric reflex; however, a straddle-type injury may produce enough force to dislocate the testicle. Patients may present with nausea, vomiting, scrotal pain, and absence of the testicle in the involved hemiscrotum or a testis palpated in another location. Dislocation may be found in various ectopic locations: superior inguinal, pubic, abdominal, penile, acetabular, or perineal. Associated injuries, such as pelvic fractures, are common.

13 How does testicular rupture present?

The tunica albuginea ruptures, and testicular contents extravasate into the scrotal sac. It is a surgical emergency because there is a higher chance of testicular salvage if exploration is done within 24 hours from the injury.

14 Describe the management for zipper entrapment of the penis or foreskin

Using a bone or wire cutter, split the median bar of the zipper. With the fastener intact, the zipper falls apart, freeing the foreskin or penis (Fig. 60-1). Warm soaks may be used after the procedure to control edema. Some children may require conscious sedation and, in severe cases, a penile block. Alternatively, mineral oil can be applied liberally to the entrapped tissue and allowed to soak for 15 minutes. The trapped skin may then be easily released.

Figure 60-1 Release of entrapped foreskin from zipper.

Fein J, Zderic SA: Management of zipper injuries. In Henretig FM, King C (eds): Textbook of Pediatric Emergency Procedures, Baltimore, Williams & Wilkins, 2007.

15 When should I consider the possibility of sexual abuse in a child with vaginal injury?

Young girls frequently suffer straddle injuries on a bicycle or a fall. However, injury to the perineum in which the history fails to explain the findings, a history of possible abuse from the child or another source, or presence of other suspicious injuries on physical examination obligates a report to appropriate agencies.

16 What is the best predictor of abdominal injury in children with pelvic fractures?

Several classifications for pelvic fractures have been devised, but none has been used extensively in children. Several reviews of pelvic fractures in children have found that stable pelvic ring fractures and unstable fractures with anterior and posterior ring fractures were associated with urologic injury rates of 12–42%. However, the best predictor of abdominal injury in children with pelvic fractures is the presence of multiple fractures to the pelvic ring.

Livne PM, Gonzales ET Jr: Genitourinary trauma in children. Urol Clin North Am 12:53–65, 1985.

17 What are the most common diagnostic findings in children with pelvic fractures?

Most patients have a history of a major mechanism of injury and associated multiple trauma. Some patients present with unstable vital signs due to internal hemorrhages and massive retroperitoneal hematomas. This presentation is most common in older children and adults. Pain and instability elicited by pelvic rocking (while holding the anterior iliac spines) suggest fractures in the pelvic ring. Pressure over the pubis also may produce pain and crepitus. Other findings, such as obturator, femoral, and sciatic nerve injuries, are infrequent in children because of the flexibility of the pelvic ring.

Straddle injury is the most common mechanism and it is usually the cause of vulvar hematomas and lacerations. Vaginal lacerations must always be suspected in patients with severe trauma to the external genitalia. Sedation or general anesthesia may be required for a complete evaluation that may include endoscopic evaluation.

Hendren WH, Peters CA: Lower urinary tract and perineal injuries. In Touloukian RJ (ed): Pediatric Trauma, 2nd ed. St. Louis, Mosby, 1990, pp 371–398.