Genitourinary injury occurs in 2–5% of all trauma patients and in at least 10% of patients with abdominal trauma, emphasizing the need for a close collaboration between the general and urologic trauma surgeon. This unique relationship that the urologist and general trauma surgeon share in the management of urologic injuries requires common philosophies of management to be applied.

Controversies exist in the approach to urologic trauma and recent efforts to achieve a broad consensus in the management of diverse urologic injuries have resulted in numerous publications. One such effort, sponsored by the World Health Organization (WHO) and the Societe Internationale d’Urologie, involved a 25-year review of world literature focusing on levels of evidence and the development of evidence-based management recommendations.^1,2,3,4 Another effort through the European Association of Urology (EAU) had a similar focus.⁵ Both produced useful syntheses of a large body of literature. The current discussion will offer a broadly applicable approach to the management of urologic trauma based on current literature, local experience, and local perspective.

The contemporary surgical approach to the injured kidney is through an anterior midline abdominal incision. Access to the kidneys and ureters is generally obtained by reflecting the colon medially on either side and exposing Gerota’s fascial envelope. The exposure of an injured kidney may be achieved after obtaining vascular control of the renal vessels prior to entering the perirenal hematoma or by expeditious exploration of the retroperitoneum and manual renal vasculature. Parenchymal compression is necessary in cases of hemorrhagic unstable patients. The important step of either approach is to access the pedicle and apply atraumatic vascular clamping while damage is assessed and treated. Vascular control can be accomplished through individual dissection and “looping” of the renal vessels through an incision in the posterior peritoneum over the aorta (which can allow access to either the left- or right-sided artery and the left-sided vein) or by first reflecting the colon on the side of the injury and then obtaining vascular control or access to the pedicle. This surgical step has been successful in experienced hands but it may increase the exploration time. In cases of low suspicion of a renovascular injury and depending on the urologic trauma surgeons’ comfort level, another successful approach to the kidney and renal hilum can be achieved by first reflecting the colon and then by manual compression, the surgeon can achieve vascular control while the assistant can evaluate and apply a “en bloc” atraumatic vascular clamp if necessary.

The kidney is located high and posterior in the retroperitoneum. The midline incision may need to be extended to the xiphoid process and additional upper abdominal retraction may need to be inserted for proper exposure. The kidney overlies the diaphragm, transversus abdominis aponeurosis, and quadratus lumborum muscle laterally and psoas major muscle medially. Significant bleeding from these muscles and the deep muscles of the back can occur following penetrating trauma and may be misinterpreted in the imaging as a kidney injury when it may be brisk bleeding occurring in the renal fossa. The kidney is enclosed in a thin but strong fibrous capsule which should be left intact during renal dissection and mobilization. As the capsule is typically lifted off the parenchyma by an underlying hematoma, the entire capsule may inadvertently be stripped off the kidney by using a sweeping finger to quickly mobilize the kidney. Ideally, the kidney should be mobilized through sharp and blunt dissection working from a normal area toward the area of parenchymal injury to keep the capsule on the kidney. Stripping the capsule complicates the repair of the kidney and should be avoided.

Recognizing patterns of injury is important; the trauma surgeon should anticipate injuries to adjacent organs based on the relational anatomy of the kidney and ureter as well as the trajectory of a penetrating injury (Fig. 36-1).⁶ The left kidney is crossed anteriorly in its upper portion by the tail of the pancreas and lies behind the lower portion of the spleen. On the right, the duodenum is immediately anterior to the hilar region. In the case of a renal injury on the right side, the right colon, liver, and duodenum are commonly injured in penetrating trauma. With blunt trauma, an associated hepatic laceration is most common. On the left side, injuries to the left colon, stomach, spleen, and pancreas are common in penetrating trauma, and lacerations of the spleen are particularly common with blunt trauma to the left upper quadrant. Injuries to the diaphragm are also common with penetrating renal injury and less common with blunt injury. The left adrenal gland is located medial to the upper pole of the left kidney, while the right adrenal gland is located in a more cephalad position relative to the right upper renal pole and may be in a retrocaval position.

At the level of the renal pedicle, there are commonly single renal arteries and veins present bilaterally. The renal vein, artery, and renal pelvis are organized in an anterior-to-posterior orientation. On the right side, the gonadal vein arises from the vena cava at or slightly below the level of the renal pedicle. A lumbar vein, which may be quite large, often arises from the posterior aspect of the right renal vein near the connection with the inferior vena cava. The right adrenal vein enters directly into the vena cava, often on its posterolateral aspect. On the left, the main branches of the renal vein include the left gonadal, the adrenal, and one or more lumbar veins. This asymmetry of the collateral branches of the renal veins explains why the left renal vein can be safely ligated near the vena cava with an 85% chance of renal preservation. In contrast, the right kidney will most likely develop venous thrombosis and become nonviable if the right renal vein is ligated.

For the urologic trauma surgeon who engages in intrarenal surgery and renal reconstruction, knowledge of the intrarenal anatomy is important (Fig. 36-2). The renal arterial supply consists of the following five segments: apical, superior (anterosuperior), middle (anteroinferior), lower (inferior), and posterior. The posterior branch crosses cephalad to the renal pelvis to reach its segment. About 25% of kidneys receive accessory arterial branches directly from the aorta. These may enter through the renal sinus or at the upper or lower poles. Certain anomalies of the upper urinary tract, such as horseshoe kidney and congenital obstructive and duplicated systems, must be familiar to the trauma surgeon as they may impact management.

The blood supply to the ureter is particularly important in surgery for urologic trauma (Figs. 36-3 and 36-4). The main sources are the renal artery from above, the aorta or common iliac arteries, and the vesical arteries from below. Branches approach the upper and mid-ureter primarily from the medial side while in the lower pelvis, the blood supply to the ureter enters primarily from a lateral direction. These branches form a long, predictable anastomotic chain usually with a single longitudinal vessel that runs the length of the ureter in the plane between the ureteral adventia and muscularis.

The anatomy of the urethra, perineum, and external genitalia may be less familiar to the general trauma surgeon. The gross anatomy and fascial layers of the genitalia and perineum are important in trauma as they largely determine the manner in which blood and urine extravasate following urethral or genital trauma (Fig. 36-5).

The American Association for the Surgery of Trauma (AAST) Injury Scaling Committee has devised a staging system for urologic injuries. The system, originally published in 1989 and since amended, addresses injuries to the kidney, ureter, bladder, urethra, testis, scrotum, and penis (Table 36-1).⁷ For some organs, such as the kidney, the system has proven highly applicable and has come into common use. For other organs, such as bladder and ureter, the AAST system has been less commonly utilized for a variety of reasons, largely relating to lack of specificity of available imaging approaches to provide the necessary data for assignment of a grade. The grading systems for the urethra and external genitalia are becoming more commonly used and are of value when addressing outcomes following such injuries. Several aspects of the staging system have received attention regarding their clinical significance and impact on decision making, complication rates, and patient outcomes.^8,9

As noted in the table, the renal Organ Injury Scale utilizes five grades of injury, ranging from contusion or subcapsular hematoma (I) to shattered kidney or avulsion of the hilum (V) (Fig. 36-6). It is valuable to specifically distinguish the parenchymal lacerations from renovascular trauma in the group IV and V injuries when reporting experience, as management and outcomes differ between these entities. The varying degrees of renal injury as described in the scaling system are depicted diagrammatically in Fig. 36-6. Recent data have shown support for the clinical utility and validity of the renal injury scale, indicating that this system is predictive of morbidity in blunt and penetrating renal injury, of mortality in blunt injury,⁹ and of the risk of nephrectomy with exploration for renal trauma.

The determination of ureteral injury type and classification can be challenging without surgical exploration, intraluminal endoscopic view, or use of radiopaque intraluminal contrast. Other indirect signs, such as the presence of ipsilateral hydronephrosis, can determine ureteral injury but will not determine the percentage of the ureteral circumference damaged. For the bladder, the distinction of intraperitoneal from extraperitoneal rupture is important and is addressed in the scaling system, but whether the length of the laceration in the bladder wall truly has clinical significance has not been demonstrated.

For urethral injuries, the scaling system addresses anatomic factors that can often be determined from retrograde urethrography (RUG) and provide advantages over the earlier system described by Colapinto and McCallum.¹⁰ The current AAST system addresses urethral disruption based on whether the injury is complete or incomplete (eg, whether contrast enters the bladder), on the length of the urethral defect, and the presence of extension into the prostate or vagina. Endoscopic assessment indicates that cases where the retrograde urethrogram may suggest a complete disruption; however, partial circumference continuity may exist which may allow for insertion of a catheter into the bladder. Despite some lack of specificity (anterior versus posterior injury), the AAST organ injury scaling system has substantial usefulness.

The scaling system for organ-specific injuries as applied to genitourinary trauma (Tables 19-22 and 29-31 from AAST Web site) has introduced a much-needed advance in the field.⁷ The designations of the AAST system provide an universal language among clinicians to describe injuries and enact the right protocol and management of genitourinary trauma among different specialties.

Incidence and Patterns of Injury

Renal injuries occur in approximately 1–3% of all trauma patients and up to 10% of patients with abdominal trauma. The percentage of blunt and penetrating trauma varies dramatically depending on the health care institution and the population served. In some urban trauma centers, penetrating injuries predominate.^6,11,12,13 Overall, approximately 90% of significant renal injuries are due to blunt trauma in the United States.¹⁴

For penetrating trauma, nearly all renal gunshot wounds are associated with injuries to other intra-abdominal organs; for renal stab wounds, approximately 60% of cases occur in combination with another intra-abdominal injury.

Interestingly, minor mechanisms of blunt abdominal trauma may cause significant renal injury and hematuria in kidneys with preexisting anatomic abnormalities (renal cysts, ureteral pelvic junction obstruction with hydronephrosis, renal neoplasm).^15,16

Clinical Presentation and Evaluation

Any history of blunt and/or penetrating trauma to the chest, abdomen, and pelvis may increase the probability of a renal injury.

The physical examination of patients at risk for renal injury should include careful assessment of the abdomen, back, flank, and chest as well as a complete genitourinary examination. Findings suggestive of a renal injury include tenderness in the flank, costovertebral angle or abdomen, palpable flank mass, or ecchymosis in the flank, back, or abdomen. Complete inspection of the torso for a penetrating injury is critical. Stab wounds posterior to the anterior axillary line carry a risk of renal injury with only about 12% of such injuries being associated with an injury to another organ. Hematuria is the most common sign of renal trauma although the magnitude of the hematuria correlates poorly with the magnitude of injury.^15,16

Laboratory assessment should include urinalysis by dipstick, as well as a microscopic examination for blood or infection in the urine. The first specimen assessed in the emergency room should be analyzed for hematuria to optimize diagnostic accuracy. The determination of serum electrolytes, blood urea nitrogen (BUN) and serum creatinine, lactate level, and hemoglobin is important. A blood sample should be obtained to screen, determine blood type, and cross-match when clinically appropriate.

Radiographic Imaging for Renal Trauma

Traditionally, all patients with abdominal trauma and any degree of hematuria were imaged in the emergency room on presentation, yielding minor injuries in 90% of imaged patients without requiring intensive monitoring or intervention. Therefore, in order to be cost-effective and minimize potential morbidity of unnecessary imaging, more selective approaches toward renal imaging in the trauma setting have been proposed without increasing the risk of missed injuries and delay in diagnosis.¹⁷ In 1985, a group from San Francisco General Hospital analyzed their renal trauma experience and identified that the only findings that were predictive of significant renal injury were the presence of penetrating trauma, blunt trauma with gross hematuria, or blunt trauma with microhematuria and shock. Shock was defined as a systolic blood pressure less than 90 mm Hg at any time post-injury, including during transport by EMS. In a review of 812 patients with microhematuria without shock, no significant renal injuries were detected. All 44 injuries in this original series were found among the 195 patients with gross hematuria or microhematuria and shock. This series has been extended over the years, and in the expanded patient group of 2254 patients with renal trauma, it was found that approximately one-third were imaged and two-thirds were not. Within this group, no major renal injuries were missed when using the established criteria.^18,19,20

Other investigators have modified imaging criteria according to their own experience and judgment. Some have suggested including standard imaging for patients with injury to the brain, loss of consciousness, or altered mental status, with the belief that the loss of information on a physical examination and the magnitude of trauma in such patients may create a higher risk of a missed injury. Some have suggested extending imaging indications to patients with mechanisms of injury consistent with deceleration trauma. This approach avoids missing injuries to the renal pedicle (eg, intimal disruption in the renal artery and renal devascularization), which may present with no hematuria in 20–33% of patients. The presence of fractures of long bones, lower ribs, or transverse spinous processes has also been suggested as an indication to modify the previous imaging restrictions, possibly predicting a higher risk of occult renal injury. In the pediatric population (addressed in the section “Pediatric Renal Trauma”), imaging for patients with only microhematuria has been more liberally utilized.

Conversely, patients with penetrating trauma with any degree of hematuria, injury proximity, or suspicion are appropriate candidates for imaging of the urinary tract, regardless of the presence or magnitude of hematuria. Significant penetrating injuries can present without hematuria, particularly if trauma to the major collecting system causes all urine from the injured kidney to exit into the retroperitoneum, preventing ureteral peristalsis.

In penetrating trauma, imaging would generally be obtained while assessing a patient’s candidacy for nonoperative management in the appropriate clinical setting. The concept of obtaining preoperative renal imaging solely to demonstrate the presence of two functioning renal units prior to surgical intervention has become less popular in recent years. Instead, careful intraoperative palpation of the kidneys, and on occasion, intraoperative intravenous pyelogram (IVP), may be used selectively during a trauma laparotomy to demonstrate renal presence or function.²¹ The selection of imaging modalities has evolved greatly since the advent and availability of computed tomography (CT) scanning in emergency center evaluation.¹⁷ While the bolus IVP with nephrotomography was previously the standard imaging approach, the CT scan has, over the years, become the gold standard for precise staging of renal injuries (Fig. 36-7), and has largely replaced intravenous pyelography in most clinical settings.

Although the IVP was considered an accurate tool for clinical staging purposes in 60–85% of patients, CT scanning also offers a number of important advantages.²² Nevertheless, trauma surgeons and urologists should maintain familiarity with the findings suggestive of renal injury on IVP because the use of CT for trauma assessment is not consistently available, especially when considering variations in international practice and infrastructure. These IVP findings that indicate renal trauma include the presence of a transverse process fracture on the scout film, presence of a mass effect in soft tissue, loss of the psoas margin on the involved side, and alteration of the longitudinal axis or vertical displacement of the kidney. Loss of a clear renal cortical outline, gross extravasation of contrast, ipsilateral decrease in renal excretory function, and loss of opacification in portions of the collecting system should all be noted. The IVP allows confirmation of the presence of two renal units, gives general information of the extent of injury, and may show significant extravasation.

Estimates of the accuracy of IVP in detection of renal injury vary. In general, the IVP should be viewed as a crude means of detection rather than as a process to obtain precise staging. Some studies indicate that as many as 20% of patients with significant renal injuries may have a normal IVP. Renal arterial occlusion may not always be the cause of reduced function or nonfunction of a kidney on IVP. In up to 50% of patients, other factors including contusion, hypotension or hypoperfusion may lead to a reduced/nonfunctional kidney when viewed through IVP.

Advantages of CT over IVP include identification of contusion and subcapsular hematoma, definition of the location and depth of parenchymal lacerations, more reliable demonstration of extravasation of contrast, and identification of injuries to the pedicle and artery (“rim sign,” “cutoff sign,” etc) with or without three-dimensional reconstruction. There is also enhanced imaging of the perinephric space, other solid viscera (liver, spleen, pancreas), and delineation of many cases of hollow viscus perforation and identification of free intraperitoneal fluid. For these and other reasons, the contrast-enhanced CT scan has largely replaced the IVP for trauma imaging. One may be extremely cautious to obtain correct CT scan sequences and obtain delayed, excretory images to avoid missing extravasation from the collecting system or ureter which may not be apparent from early nephrogenic and vascular phases.²³

Often, interventional radiographic studies are obtained when vascular injury is diagnosed after CT scan and treatment is needed. Precise delineation of arterial anatomy, interventions to control hemorrhaging, or placement of a vascular Palmaz stent mandate the continued use of renal arteriography on a selective basis (Fig. 36-8). In several places including the United States, the Focused Assessment for the Sonographic Evaluation of the Trauma Patient (FAST) study is performed to assess for free intra-abdominal fluid rather than for the delineation of an injury to parenchyma of solid organs. The evolvement of high-resolution ultrasound and Doppler techniques for the assessment of renal perfusion and vascular anatomy can be used intra and perioperatively in cases of renal trauma.²⁴

Currently, retrograde ureteropyelogram plays a limited role in defining renal injury but can be performed to evaluate and treat concomitant ureteral injuries when ureteral stents may decrease urinary extravasation and/or assist the passage of blood clots from the upper collecting system.

The pediatric kidney may be more vulnerable to trauma than the adult kidney due to the relatively larger size of the kidneys to the body, the relative lack of perinephric fat in the child, and because of their association with congenital renal abnormalities. One recent review found that 8.3% of pediatric renal injuries occurred in patients with preexisting renal abnormalities¹⁵ with other estimates of preexisting renal abnormality described in up to 23% of major pediatric renal injuries due to blunt trauma. Some data suggests that the kidney is the most commonly injured intra-abdominal organ in children.

It is commonly agreed that the presence of gross hematuria after trauma in the pediatric patient warrants further investigation with imaging of the urinary tract. As in the adult, the CT scan plays a major role in staging such injuries for the same reasons as described earlier. Several studies suggest that only about 5% of pediatric patients with major renal injuries will develop signs of shock, further emphasizing the importance of an aggressive diagnostic approach. Pediatric patients can maintain normal blood pressure despite significant blood loss, and persistent tachycardia is a particularly important parameter to note in the pediatric patient as a potential sign of significant blood loss.

Many authors suggest that all pediatric patients with any degree of hematuria after significant trauma should undergo renal imaging while some have suggested modified criteria. One study has suggested that microscopic hematuria with greater than 50 red blood cells per high-power field in the pediatric setting should be considered an imaging criterion, regardless of hemodynamic parameters.²⁵

Certain types of renal injuries are more common in the pediatric patient. These include laceration of the renal pelvis, avulsion of the ureteropelvic junction, and forniceal avulsion. When extensive medial extravasation is noted and/or the ureter does not opacify with contrast despite adequate excretion into the renal collecting system, a disruption of the major collecting system should be considered. In such cases, retrograde pyelography with ureteral stent placement may be necessary to define the anatomy, diagnosis, and treatment.

Much like in the adult, the use of the rapid spiral CT scanner can lead to a pitfall in diagnosis if a delayed sequence is not requested. Limiting the study to a nephrographic or early excretory phase may fail to demonstrate extravasation or asymmetrical opacification of the ureters which would be readily visible on later images.

Overall, approximately 85% of pediatric renal injuries from blunt trauma are minor (contusions, superficial parenchymal lacerations) and are managed with bed rest and observation. Pedicle injuries comprise about 5% of renal injuries while major parenchymal injuries occur in 10–15% of patients. As in the adult, it is these latter groups for which management is somewhat controversial; however, it is largely agreed among pediatric urologists that operative decisions are based mainly on hemodynamic status rather than imaging criteria. The potential for successful management of kidneys that appear severely injured in imaging studies is remarkable in the pediatric population, and a nonoperative approach is the norm. Surgical treatment is generally reserved for patients with ongoing bleeding or hemodynamic instability, for those who have clearly failed an attempt at nonoperative management, and for penetrating injuries.²⁶

Ureter

Ureteral injuries are relatively uncommon, occurring in approximately 4% of patients with penetrating abdominal injuries and in less than 1% of those with blunt abdominal trauma. Concomitant visceral injury occurs in the majority of patients with ureteral injuries from penetrating trauma. While hematuria is an important sign of ureteral injury, it may be absent 15–45% of the time. As such, a high index for suspicion of ureteral injury is critical.^27,28,29 In fact, the ureter is one of the most common sites of missed injury during laparotomy, with one recent report noting a missed injury rate of 11%.¹³ While direct visualization of the ureter is the mainstay of detection of ureteral injury at the time of laparotomy, imaging modalities useful for detection of ureteral trauma also include an IVP and contrast-enhanced CT scan with excretory phase.¹⁶ Failure of the distal ureter to opacify or the presence of ipsilateral hydronephrosis on a CT scan should raise concern for a potential injury.^30,31 When noninvasive imaging fails to provide sufficient detail regarding ureteral anatomy or the specific nature of an injury, cystoscopy with retrograde pyelography and possible ureteral stent placement may be indicated.

Bladder

Sudden compression of the full bladder, shear forces, or a pelvic fracture may result in a blunt rupture, especially when the bladder is full. Rupture may be accompanied by lower abdominal pain, an inability to void, and suprapubic or perineal ecchymosis. The cardinal sign of injury to the bladder is gross hematuria, present in greater than 95% of cases, while only about 5% of patients will only have microscopic hematuria.³² Over 80% of patients with a bladder rupture have an associated pelvic fracture in health care centers with a high percentage of blunt trauma. An association of bladder rupture with disruption of the posterior urethra, along with the occurrence of a pelvic fracture, may occur in 10–20% of patients.^33,34 Overall, recent data indicate that genitourinary injury occurs in approximately 15% of pelvic fractures in the pediatric setting¹⁵ and that the incidence of injury to a pelvic organ is fairly comparable between adult and pediatric patients.^35,36

Voiding cystogram with post-void film is the standard method for diagnosis of injury to the bladder (Fig. 36-9).³⁷ It is important that the bladder be adequately filled to avoid false-negative studies. For the adult bladder, the standard volume of filling is 300–400 mL of iodinated contrast (30% iodine commonly utilized) which is infused through the indwelling Foley catheter by gravity. Alternatively, the bladder can be filled by gravity to a point at which the patient describes a sense of bladder fullness. If the patient is unable to indicate that there is a sense of fullness, using a standard filling volume is a useful methodology. A vertically oriented abdominal filling film image, designed to show the entire abdomen, should be obtained. Postdrainage films are necessary to avoid false-negative cystograms in which extravasated contrast may be missed if located only anterior or posterior to the distended bladder on an anteroposterior film. Patterns of contrast extravasation have been described for intraperitoneal, extraperitoneal, and combined ruptures (Fig. 36-10). Hematuria of the bladder without contrast extravasation on a properly performed voiding cystogram is consistent with a contusion or minimal mucosal injury, which is uniformly managed nonoperatively.

Currently, cystogram is most commonly obtained using a CT technique (Fig. 36-11).³⁸ The advantages of CT cystograms are the speed to obtain the images, accuracy of extravasation detection, and the lack of need for voiding images (Fig. 36-11B and C). Studies comparing the accuracy of standard radiographic stress cystography with CT cystography suggest equivalent capability in defining and staging bladder injuries. Simply clamping a bladder catheter following intravenous contrast administration, with the expectation that passive filling with contrast-opacified urine will suffice, is not adequate and will result in an unacceptably high percentage of false-negative examinations, with either the standard radiographic or the CT technique.⁴² In selected cases, flexible cystoscopy may aid in the acute diagnosis of bladder injury and placement of a urinary Foley catheter.³⁹

Urethra

Trauma to the anterior urethra may result from straddle injuries with sudden compression at the level of the midurethra to deep bulbar urethra against the inferior pubic arch. Urethral distraction injuries or posterior urethral disruption may accompany pelvic fracture in 4–10% of patients. Bilateral fractures of the pubic rami, especially when accompanied by an open pelvic ring (abnormally distracted sacroiliac joint), may also be present in patients who have suffered posterior urethral disruption. The classification system used to further describe urethral trauma is discussed in the section “Injury Grading and Scoring Systems for Genitourinary Injuries.” It is important to determine from the urethrogram if an injury is partial (contrast passes proximal to the point of extravasation, filling the more proximal urethra or bladder) or complete (all contrast extravasates and none enters the urethra proximal to injury or bladder) as this factor has an impact on selection of management.⁴⁰

Blood appearing at the urethral meatus, inability to void, presence of a perineal hematoma, and inability to clearly palpate the prostate on rectal examination should make one suspicious of urethral injury (Fig. 36-12). When urethral injury is suspected, a retrograde urethrogram should be performed (Fig. 36-13). Approximately 30 mL of iodinated contrast is instilled via a catheter inserted just within the urethral meatus, and then a plain radiograph is obtained. A normal retrograde urethrogram should demonstrate contrast filling an intact urethra and entering the bladder without extravasation. No attempt at insertion of a bladder catheter should be pursued until a negative retrograde urethrogram is obtained to avoid further complicating a urethral rupture (Fig. 36-14).

Following placement of either a urethral catheter (if the urethra proved normal or by a urologist using direct vision techniques in selected incomplete injuries) or a suprapubic catheter (if urethral disruption was revealed), a stress cystogram should still be performed if hematuria is present. This is because 10–15% of patients with urethral disruptions from a pelvic fracture will have a concomitant injury to the bladder.

External Genitalia

Genital injuries represent a diverse group of traumatic events.⁴¹ These include the classic blunt penile fracture (which occurs from forceful bending of the erect penis, often during intercourse), crushing injuries with rupture of the testis, penetrating injuries, and industrial accidents. Amputation injuries of the penis or testicle can occur due to assaults, self-mutilation, or industrial trauma. After major blunt trauma to the scrotum, the risk of testicular rupture is approximately 50%. An ultrasound examination of the scrotum may be valuable to distinguish testicular rupture from a hematoma of the scrotal wall or hematocele (blood within the tunica vaginalis compartment).

While nonoperative management for many urologic injuries has become well-established, the selection of operative versus nonoperative management for certain genitourinary injuries remains controversial. Recent reviews of urologic management based on careful assessment of levels of evidence reveal a notable paucity of level 1 prospective management studies.^1,2,3,4,5 The relatively recent efforts to accurately and uniformly describe and stage the nature of injuries and the lack of long-term follow-up leave many questions regarding the best way to manage many forms of genitourinary trauma.

Kidney

It has long been accepted that low-grade renal injuries can be managed nonoperatively with a high success rate. Renal contusion and subcapsular hematomas are routinely managed expectantly and only rarely would require surgical or other interventions in such cases. These injuries heal spontaneously with few exceptions as do low-grade parenchymal lacerations. Depending on the institutional bias and experience, some urologic trauma surgeons may limit operative management of renal injuries to those in which the patient is hemodynamically unstable, almost regardless of imaging findings. Alternatively, others would include high-grade injuries, presumably translating into a higher incidence of post-injury complications with nonoperative management. A number of indications for renal exploration following injury have been suggested by McAninch and Carroll.⁴² These include hemodynamic instability, an ongoing hemorrhage requiring significant transfusion, pulsatile or expanding hematoma upon exploration, and avulsion of the pedicle. These strong indications for surgical or other procedural intervention remain widely accepted. Relative indications for surgical intervention have included high-grade injuries, large perirenal hematoma, presence of urinary extravasation on contrast studies, significant devitalized fragments of parenchyma, and findings in the operating room during laparotomy with an incompletely staged injury. While there is lack of consensus regarding these relative surgical indications, there is a general trend toward nonoperative management in many of these situations as long as hemodynamic stability is maintained.²⁶

Proponents of the nonoperative management approach suggest that many high-grade injuries will heal without surgery, complications can frequently be managed with nonsurgical techniques (percutaneous drainage, stenting, angiographic embolization), and renal salvage rates are better overall when renal exploration is avoided. This school of thought would maintain that, with few exceptions, it is only hemodynamic instability that should prompt surgical intervention for the injured kidney, not injury stage or other predetermined imaging criteria.

In contrast, proponents of a more aggressive surgical approach would suggest that higher grades of renal injury carry an unacceptably high complication rate and that such complications, when they occur, have a high likelihood of resulting in otherwise avoidable morbidity or nephrectomy (Fig. 36-15). Proponents would suggest that early exploration offers the advantages of early debridement of devitalized tissue, definitive hemostasis, repair of injuries to the collecting system, and early utilization of appropriate drainage. As such, post-injury infection, urinoma, and hemorrhage risk are minimized. The descriptions of “absolute” and “relative” indications for renal exploration of trauma have been suggested to attempt to provide assistance in this decision-making process.^42,43,44