Upper Genitourinary Trauma 

Updated: Jan 24, 2017
Author: Imad S Dandan, MD; Chief Editor: Trevor John Mills, MD, MPH 

Overview

Background

Because trauma is a multisystem disease, multiple injuries may be present in the trauma patient. Other injuries often take priority over injuries to the genitourinary (GU) system and may initially interfere or postpone a complete urologic assessment. Coordinated efforts between various services caring for the patient are crucial to ensure comprehensive care, and evaluation of the injured patient with possible GU trauma should not differ from that of other trauma patients. Follow the protocols of the Advanced Trauma Life Support (ATLS) program of the American College of Surgeons to provide total patient care.[1, 2] See the images below.

Ruptured left kidney. Ruptured left kidney.
Contrast-filled urinoma. Contrast-filled urinoma.
Avulsed left renal artery with thrombosis. Avulsed left renal artery with thrombosis.

Pathophysiology

The kidneys, pelvocaliceal system, and ureters comprise the upper GU tract. The adult kidneys are well protected by the rib cage and vertebral column, but lateral forces can compress them between these structures, leading to injury. Sudden deceleration can cause avulsion injuries to the renal pedicle and pelvocaliceal system.

Only 6% of patients with GU trauma have ureteral injuries, probably due to its small size and mobility, and the protection provided by the psoas muscle posteriorly, the abdominal viscera anteriorly, and the vertebral column medially.

Epidemiology

From 3 to 10% of patients with multiple trauma have GU involvement; 10 to 15% of trauma patients with abdominal injuries have GU involvement. Renal injuries constitute 45% of all GU injuries; ureteral injuries constitute 6%.

Mortality from upper GU tract injuries is attributed primarily to other associated injuries, and morbidity is 26%. Trauma is the leading cause of death in persons aged 1-40 years and is the third-ranked cause of mortality in all age groups.

According to the National Trauma Data Bank, most renal trauma in children is low grade, is blunt in nature, and occurs in children older than 5 years. Although most pediatric patients are treated conservatively, the rate of nephrectomy has been found to be 3 times higher at adult hospitals than at pediatric centers. Of the injuries, 79% were found to be grade I, II or III, and penetrating injuries accounted for less than 10% of all pediatric renal injuries.[3]

Patient Education

For patient education resources, see the Kidneys and Urinary System Center, as well as Blood in the Urine.

 

Presentation

History

In blunt trauma, history is obtained regarding the time and mechanism of injury, position of the patient, speed of the vehicle, and use of restraints.

In penetrating trauma, knowing the size of the stabbing weapon or the caliber of the gun and the distance from which it was discharged aids assessment.

Question the paramedics as to the condition of the patient immediately after injury occurred and during transport to the hospital.

In patients with GU trauma, symptoms are nonspecific and may be masked by or attributed to other injuries.

Renal injuries are most commonly from motor vehicle accidents (MVAs). Renal injuries occur in 3% of patients hospitalized with trauma and in 10% of patients with abdominal trauma. Most renal injuries (80%) are minor and do not require surgical intervention.

Suspect renal injury when fractures of lower ribs and/or spinal processes are observed and/or when a history of sudden deceleration or significant lateral force on the patient exists. In penetrating trauma, the trajectory of the bullet or the penetrating object helps indicate the possibility of renal injury.

Iatrogenic ureteral injuries are much more frequent than violent ones. A high incidence of associated organ injuries with ureteral injuries exists (90% in gunshot wounds, 60% in stabbings). Diagnosis of ureteral injury depends mainly on clinical suspicion. History and physical examination are unreliable and often are not sensitive.

Iatrogenic injury to the ureter can be a devastating complication of modern surgery. Most often, such injuries to the ureters occur during gynecologic, colorectal, and vascular pelvic surgery.[4]

Physical

Flank ecchymosis or mass indicates a retroperitoneal process but is not specific to renal injuries and rarely occurs acutely. The most important indicator of renal trauma is gross or microscopic hematuria. The absence of hematuria, although rare, does not exclude renal injury. Hematuria is absent in 5% of patients.

Presence of abdominal, visceral, solid organ, or vascular injury may indicate the presence of concomitant renal injury, as these injuries often coexist with renal injury in 34% of patients with blunt trauma and in up to 80% of patients with penetrating trauma.

In suspected ureteral injury, physical examination is of minimal use except in diagnosis of associated injuries.

Perform a rectal examination to help establish the presence or absence of a urethral injury prior to Foley catheter insertion. Look for a high-riding prostate, rectal tear, bony abnormality, or frank blood.

Causes

 The most common cause of renal injury is blunt trauma, followed by penetrating trauma.[5] MVAs and gunshot wounds account for 80% of renal injuries. Conversely, the etiology of ureteral trauma is mostly iatrogenic (82%). In noniatrogenic causes of ureteral injury, penetrating trauma accounts for 90% of cases (missile injury in 90%, stabbing injury in 10%) with a blunt avulsing-type mechanism causing the remaining 10% of injuries.

Blunt trauma includes the following:

  • MVAs

  • Motorcycle accidents

  • Falls from high elevations

  • Bicycle accidents

  • Assaults with blunt weapons

Penetrating trauma includes the following:

  • Missile injury: Differentiate between low- and high-velocity missiles.

  • Shotgun wounds: Close-range injuries are equivalent to high-velocity injuries.

  • Stabbings

  • Impalements

Iatrogenic trauma is also reported.

 

DDx

Differential Diagnoses

 

Workup

Laboratory Studies

Lab studies include the following:

  • Complete blood count (CBC) to obtain hematocrit level and platelet count

  • Prothrombin time (PT) and activated partial thromboplastin time (aPTT) to check for coagulopathy; may be unnecessary in young, otherwise healthy patients

  • BUN and serum creatinine: Elevation of BUN without elevation in creatinine indicates urine reabsorption.

  • Urinalysis to diagnose hematuria

  • Blood type and crossmatch

Imaging Studies

Use of diagnostic imaging techniques is crucial in functional and anatomic assessment of the injured and uninjured kidney.

Perform urologic imaging only when indicated, as persistent low yield occurs when imaging patients with microscopic hematuria, patients with no associated injuries, and patients who are hemodynamically stable.

Indications for imaging include the following:

  • Gross hematuria

  • Microscopic hematuria with hemodynamic instability

  • Persistent microscopic hematuria (serial urine analysis)

  • Hemodynamic instability with history of significant deceleration mechanism

CT scan of the abdomen and pelvis with IV contrast

CT scan is preferred over intravenous pyelogram (IVP) in renal injuries because of its superiority in providing anatomic and functional details, its higher sensitivity, and improved time to results with the advent of the spiral CT techniques. Multidetector CT scanners offer even greater image resolution and the ability for a CT angiogram of the kidneys.[6]

CT scanning allows visualization of the rest of the abdomen for detection of urinomas. Microscopic hematuria without hemodynamic instability or significant mechanism is not an indication for CT scan in patients with blunt trauma. Perform CT scan if a history of hypotension; gross hematuria; or penetrating abdominal, flank, or back injury is present in the stable patient. Renal pedicle thrombosis may present without hematuria, but associated injuries or findings usually mandate CT scan or laparotomy.

In collecting system injuries, many may not be detected on initial CT, which suggests the need for repeat imaging in patients with large perinephric hematomas.[7]

See the image below.

CT scan of abdomen and pelvis showing a urinoma. CT scan of abdomen and pelvis showing a urinoma.

Intravenous pyelogram

IVP provides information about the function of both kidneys; when performed with a double dose, it is the preferred test in suspected ureteral injuries. In renal injuries, CT scanning is preferred due to the relatively poor sensitivity of IVP.

If CT scan is not readily available and renal imaging is required, IVP is a good imaging study to perform as a first-line modality. CT scan or laparotomy should follow an abnormal IVP finding.

Renal arteriography

Use renal arteriography when therapeutic embolization is needed and to determine regional blood flow to the affected kidney if considering exploration.[8]

Transcatheter arterial embolization (TAE) has been shown to be an alternative therapeutic modality for blunt renal injury in children who have contrast medium extravasations in the kidney on angiography.[9]

Ultrasonography

Ultrasonography is inferior to CT scan in anatomic detail and sensitivity. It may be helpful in follow-up care of renal injuries and in detection of urinomas.[10]  Ultrasonography may also be useful in the acute setting of abdominal trauma as part of the focused abdominal sonography in trauma (FAST) examination of the injured patient in detecting perirenal hematomas and other injuries to the abdomen.

Other

Radionuclide scan is not helpful in diagnosis of renal injury but is useful in follow-up treatment regarding the function of the injured kidney.

Retrograde ureterogram is useful in diagnosing ureteral injury, especially in missed injury. It is invasive and requires a cystoscopy suite.

See the image below.

Retrograde urethrogram showing a leak in the dista Retrograde urethrogram showing a leak in the distal right ureter with an element of obstruction.

Procedures

Insert a Foley catheter only after urethral injury is excluded.

A suprapubic cystostomy may be performed in a percutaneous or open manner when a Foley catheter cannot be inserted and urine output measurement or detection of hematuria is required.

Use a suprapubic cystostomy when Foley catheter insertion is contraindicated.

 

Treatment

Prehospital Care

Advancement of prehospital care for trauma patients is one of the biggest leaps forward in trauma care. Principles do not change with different organ injuries.

Paramedics quickly assess the patient and mechanism of injury, with special attention to patency of ABCs.

  • Establish an airway if needed and/or administer oxygen.

  • Establish 2 large-bore IVs.

Take cervical spine precautions (eg, hard collar, back-board).

Quickly transport the patient to the trauma center.

Emergency Department Care

Adherence to ATLS principles is necessary for proper care of the trauma patient.

  • Administer oxygen and ventilatory support if needed.

  • Resuscitate with crystalloids (lactated Ringer solution or isotonic sodium chloride solution) and blood (O-negative or type-specific blood if known) if indicated.

  • Treat life-threatening injuries (eg, tension pneumothorax, open pneumothorax, cardiac tamponade) should be addressed emergently in the ED.

Assess capabilities of the ED to handle the patient with multiple injuries that include upper GU trauma; the decision to transfer is based on that assessment.

Treat life-threatening injuries prior to transfer; stabilize and resuscitate the patient.

The responsibility for transfer, choice of transfer modality, and selection of accepting facility lies with the transferring physician.

The receiving physician confirms the ability of the receiving institution to handle the patient's condition.

Institutional transfer protocol facilitates the process.

Patients with upper GU trauma benefit from transfer when the following conditions exist at the transferring center:

  • CT scan not available

  • No staff urologist

  • Multiple injuries that surpass hospital's resources

  • Unavailability of specialized care required by patient's injuries

Consultations

Consultations include the following:

  • Trauma or general surgeon for management of associated abdominal injuries

  • Urologist for management of specific GU injuries

  • Other specialists as injuries dictate

Medical Care

Management of renal injuries depends on the grade of injury and is linked to management of associated injuries.[11, 12]  Grade of renal injury is best depicted in the scale developed by the American Association for the Surgery of Trauma[13, 14, 15]

Grade I

Grade I injuries include the following:

  • Contusion - Microscopic or gross hematuria with normal urologic studies

  • Hematoma - Subcapsular, nonexpanding without parenchymal laceration

Grade II

Grade II injuries include the following:

  • Hematoma - Nonexpanding and confined to the renal retroperitoneum

  • Laceration - Less than 1 cm parenchymal depth of renal cortex without urinary extravasation

Grade III

Grade III injuries include the following:

  • Laceration more than 1 cm parenchymal depth of renal cortex without collecting system rupture or urinary extravasation

Grade IV

Grade IV injuries include the following[15] :

  • Laceration - Extending through the renal cortex, medulla, and collecting system

  • Vascular - Main renal artery or vein injury with contained hemorrhage

Grade V

Grade V injuries include the following:

  • Laceration - Completely shattered kidney

  • Vascular - Avulsion of renal hilum that devascularizes the kidney

Treat grades I, II, and III conservatively. Monitor vital signs, hematocrit level, and progression of hematuria. Most patients heal without intervention. Rarely, radiologic selective embolization is needed to control hematuria that does not subside spontaneously.

In grade IV injuries, expectant treatment of the extravasation has a 60% success rate if ureteral outflow is not impeded. Correct flow obstruction with stenting. If urinary extravasation does not improve, perform percutaneous drainage. Vascular injury indicates surgical intervention for repair, provided the warm ischemia time does not exceed 4 hours. Hemorrhage control also indicates surgical exploration.

Most children with grade IV renal injury are treated using a conservative approach with a high success rate, but some may require urologic intervention because of symptomatic urinomas. According to one study, the need for transfusion and the presence of specific image features on initial CT (eg, main laceration location in the anteromedial portion of kidney), intravascular contrast extravasation, and a large perinephric hematoma may serve as useful predictive factors for urologic intervention in grade IV pediatric blunt renal trauma patients who were initially treated with a conservative approach.[16]

In grade V injuries, completely shattered kidneys require excision for control of hemorrhage. Kidneys with pedicular avulsion do not require removal unless a laparotomy already is being performed for a different pathology. Avulsed kidneys do not result in late sequelae if left in situ. Attempt revascularization of the kidney only if warm ischemia time is less than 4 hours, as failure rates are extremely high when warm ischemia time is more than 4 hours. High rates of infection and hypertension occur in kidneys with failed revascularization. Make exceptions for patients with solitary kidneys and decreased renal capacity.

Management of acute ureteral injury primarily involves repair. Debridement is performed until a healthy bleeding ureter is reached and a repair is performed at this point by the surgeon. The type of repair depends on the level of ureter injury and the length of ureter lost to injury and debridement.

Treatment of ureteropelvic junction injuries is by reimplantation of the ureter into the renal pelvis. Ureteroureteral or ureterovesicular anastomoses are used for distal injuries and bladder flaps may be required for a tension-free anastomosis. Transureteroureterostomy (anastomosis of the injured ureter to the contralateral ureter) has lost favor because of danger to the normal ureter. Management of missed ureteral injuries includes drainage of urinomas (preferably percutaneously) with a nephrostomy. The inflammation is allowed to subside (3-6 wk), then a definitive surgical repair is performed.

Most children with grade IV/V renal injury following blunt trauma can be managed nonoperatively. Management can be properly planned and executed based on clinical features, CT imaging, and staging of renal injuries.[17]

Complications

Renal trauma

Renal trauma includes the following:

  • Hemorrhage

  • Urinoma

  • Loss of function of kidney

  • Pseudoaneurysm formation

  • Arteriovenous fistula (rare)

  • Renal hypertension

  • Obstruction of the collecting system and renal artery aneurysm (pseudo)

Ureteral injury

Ureteral injury includes the following:

  • Urinary extravasation

  • Urinoma

  • Infection and stricture formation leading to hydronephrosis

Long-Term Monitoring

Outpatient care depends upon the associated injuries and need for rehabilitation (eg, orthopedic or neurologic injuries).

A follow-up CT scan is indicated in patients with renal injuries to assess the progress of healing; IVP is required as follow-up care for ureteral repairs.

 

Medication

Medication Summary

Medications for patients with upper GU injuries relate to the management of patients as critically injured rather than management specific to the GU injury.

Antibiotics

Class Summary

Used in prophylaxis of infections of the injured GU tract. Empiric antimicrobial therapy must be comprehensive, covering all likely pathogens in the clinical setting.

Ampicillin and sulbactam (Unasyn)

Drug combination of beta-lactamase inhibitor with ampicillin. Covers skin, enteric flora, and anaerobes. Not ideal for nosocomial pathogens.

Cefotetan (Cefotan)

Second-generation cephalosporin indicated for infections caused by susceptible gram-positive cocci and gram-negative rods.

Dosage and route of administration depend on condition of patient, severity of infection, and susceptibility of causative organism.

Analgesics

Class Summary

Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and have sedating properties, which are beneficial for patients who have sustained trauma.

A review of opioid equivalents and conversions may be found in the following reference article:

 http://emedicine.medscape.com/article/2138678-overview

Fentanyl (Sublimaze, Abstral, Actiq, Duragesic, Fentora, Ionsys, Lazanda, Onsolis, Subsys)

A synthetic opioid that is 75-200 times more potent and much shorter half-life than morphine sulfate. Has less hypotensive effects and is safer in patients with hyperactive airway disease than morphine because of minimal-to-no associated histamine release. By itself, it causes little cardiovascular compromise, although addition of benzodiazepines or other sedatives may result in decreased cardiac output and blood pressure.

Highly lipophilic and protein-bound. Prolonged exposure leads to accumulation in fat and delays weaning process.

Consider continuous infusion because of the short half-life of fentanyl.

Parenteral form is DOC for conscious sedation analgesia. Ideal for analgesic action of short duration during anesthesia and immediate postoperative period.

Excellent choice for pain management and sedation with short duration (30-60 min) and easy to titrate. Easily and quickly reversed by naloxone.

After initial parenteral dose, subsequent parenteral doses should not be titrated more frequently than q3h or q6h thereafter.

Transdermal form is used only for chronic pain conditions in opioid tolerant patients. When using transdermal dosage form, majority of patients are controlled with 72-h dosing intervals; however, some patients require dosing intervals of 48 h.

Easily and quickly reversed by naloxone.

Morphine sulfate (Astramorph, Duramorph, MS Contin, Avinza, Infumorph, Kadian, MorphaBond, Arymo ER)

DOC for analgesia because of reliable and predictable effects, safety profile, and ease of reversibility with naloxone.

Various IV doses are used; commonly titrated until desired effect obtained.

Postoperatively, oral morphine sulfate extended-release formulations may be prescribed for severe pain, with immediate release preparations used for breakthrough pain. Arymo ER is a morphine sulfate abuse-deterrent derivative.