Surgical Management of Urologic Trauma and Iatrogenic Injuries Leonard N. Zinman, MD*, Alex J. Vanni, MD* KEYWORDS Trauma Kidney Bladder Urethra Ureter Genitalia KEY POINTS Trauma patients requiring urologic-specific evaluation must be identified. The most efficient means of diagnosing urologic trauma should be determined based on the mechanism of injury. The optimal management strategy is based on the location and degree of urologic injury and patient stability. INTRODUCTION Genitourinary injuries may be seen as a sequel to both blunt and penetrating trauma occurring in approximately 10% of all patients admitted to an emergency department. Trauma is the number one cause of death in patients aged 1 to 44 and accounts for more than 120,000 deaths per year in the United States, 10% of which have a concomitant component of genitourinary origin with the kidney as the most frequently involved organ.1,2 These injuries may be quite elusive, concealed anatomically in the relatively nonresponsive retroperitoneal and pelvic locations where even intravenous (IV) contrast computed tomography (CT) might not identify them clearly. Urogenital trauma is rarely fatal, but may ultimately become the basis for significant short- and long-term morbidity, if not recognized early during its course. The major causes of genitourinary trauma are motor vehicles accidents, deceleration injuries, and pene- trating firearm assault violence, all of which are on the increase.3 Blood in the urine signifies a urogenital injury. However, this is neither specific for location of injury nor a prognosticator for the severity of injury.4,5 Blunt trauma with associated hematuria requires evaluation of both the upper and the lower genitouri- nary system, as forces associated with high-speed motor vehicle collisions can Disclosures: The authors have nothing to disclose. Department of Urology, Lahey Hospital and Medical Center, Tufts University School of Medi- cine, 41 Mall Road, Burlington, MA 01805, USA * Corresponding authors. E-mail addresses: [email protected]; [email protected] Surg Clin N Am 96 (2016) 425–439 http://dx.doi.org/10.1016/j.suc.2016.02.002 surgical.theclinics.com 0039-6109/16/$ – see front matter Ó 2016 Elsevier Inc. All rights reserved. 426 Zinman & Vanni produce significant injury to the entire genitourinary system. Hematuria in patients suffering penetrating abdominal trauma indicates possible urologic injury to the kid- neys, ureters, or bladder. Genitourinary trauma usually occurs in the setting of multisystem trauma. Timely evaluation and management of the trauma patient have the potential to minimize uro- logic morbidity and mortality. In what follows, each of the major urogenital organs is treated separately. New imaging modalities and a growing emphasis on nonoperative expectant management of both upper and lower urinary tract injuries have changed the field of urologic trauma. Concomitant injury to both the upper and the lower urinary tract is rare, but careful evaluation is critical to identify these devastating injuries. RENAL INJURY Initial Evaluation Blunt renal trauma constitutes the most common genitourinary organ injury and is the result of motor vehicle collision, falls from heights, a sustained direct blow to the flank, lower rib fractures, or a complication of elective renal surgery from percutaneous stone surgery or partial nephrectomy. In a large population study, the incidence of trauma patients in the United States who had renal injuries was 1.2% with 14,000 pa- tients hospitalized in the United States with renal trauma alone.2 In addition, 24% of all solid abdominal organ injuries involve the kidneys.6 The presenting signs and symptoms of blunt trauma may include flank or abdominal pain and bruising, hematuria, hemodynamic instability, flank hematoma (expanding and pulsatile), and sepsis or ileus from urinary extravasation, which may not be recog- nized initially and may require delayed recognition and intervention. Penetrating abdominal injuries as a result of gunshot or stab wounds should always alert the physician to possible renal injury. A thorough physical examination of the abdomen, chest, and back must be performed because gunshot wounds may be misleading because of the small entrance defects and may not initially reveal the extent of tissue dam- age. To identify the location and extent of the penetration with imaging, a paper-clip marker may be placed at the entrance and exit sites to help define the damage during all imaging techniques, because most penetrating injuries will require surgical exploration.7 Contrast CT with delayed imaging of the ureters is the gold-standard imaging mo- dality to evaluate the entire urinary tract as well as the anatomy and function of the kid- ney. The American Association for the Surgery of Trauma (AAST) Organ Injury Scale is used to classify blunt and penetrating renal injuries and corresponds closely to the appearance of the kidney on CT (Table 1).8 Renal injuries may be classified as renal contusions, renal lacerations with or without collecting system injury, renal pedicle avulsion, and vascular disruption, renal artery thrombosis, injury to the renal pelvis or ureteropelvic junction disruption. CT should be performed in all cases of suspected renal trauma in hemodynamically stable patients. The standard protocol includes helical (spiral) CT with a portal venous phase (from the diaphragm to the ischial tuberosities) to survey lower genitourinary structures or the presence of active arterial bleeding, followed after 10 minutes by delayed images to identify the presence of urinary contrast extravasation. CT should not be used as the primary evaluation tool in hemodynamically unstable patients, because these patients should be managed operatively, and other diagnostic tests, such as diagnostic peritoneal lavage or ultrasound, should initiate the evaluation because the critical need of immediate surgical control of bleeding is crucial. Most blunt renal injuries are minor with contusions that account for 64% to 81% of cases. Wessels9 in a multicenter study of 6892 patients with renal trauma found Surgical Management of Urologic Trauma 427 Table 1 American Association for the Surgery of Trauma organ injury scales for renal injury AAST Grade Characteristics of Injury AIS-90 Score I Contusion with microscopic or gross hematuria, urologic 2;2 studies, normal, nonexpanding subcapsular hematoma without parenchymal laceration II Nonexpanding perirenal hematoma confined to renal 2;2 retroperitoneum; laceration <1 cm parenchymal depth of renal cortex without urinary extravasation III Laceration >1 cm parenchymal depth of renal cortex without 3 collecting system rupture or urinary extravasation IV Parenchymal laceration extending through renal cortex, 4;4 medulla, and collecting system; injury to main renal artery or vein with contained hemorrhage V Completely shattered kidney; avulsion of renal hilum that 5;5 devascularizes kidney Abbreviation: AIS, abbreviated injury scale. contusion or hematomas in 64.2%, grade II or III lacerations in 24.8%, grade IV injury in 7.7%, and grade V injury in 3.3% of cases.10 Contemporary CT imaging with support of the grading system has provided a plat- form for the management of renal trauma and helps dictate the options of nonopera- tive and angiographic approaches and has been pivotal in decreasing surgical intervention and nephrectomy.11 Angiography is rarely performed, but can be a valuable tool to both diagnose and treat renal injury via transcatheter embolization for active arterial bleeding, a pseudoa- neurysm, or an arteriovenous fistula. Because the most common form of surgical man- agement of renal injury is nephrectomy, angioembolization, when feasible, has been shown to decrease the rate of nephrectomy and increase renal salvage.9,12–14 A rare but serious complication of renal arterial thrombosis and embolization with ischemic parenchyma is the development of renovascular hypertension. Development of renovascular hypertension has been documented in 0.2% of cases and is mediated by the renin-angiotensin system and can be managed by a delayed laparoscopic ne- phrectomy. Long-term follow-up is critical to identify this systemic event, which may develop in a delayed fashion. Management The goal of renal trauma management is to preserve the maximal number of renal units in as safe a manner as feasible. Thus, the management of blunt and penetrating renal injury varies greatly. Nonoperative There is an established and sustained shift in the renal injury therapeutic paradigm with an increasing nonoperative approach that involves close monitoring, bed rest, se- rial hemoglobin/hematocrit measurement with transfusions if necessary, and selective repeat CT imaging. Virtually all grade I–IV renal injuries and a select group of grade V injuries are now initially managed conservatively.13,15 The accuracy and rapidity of he- lical CT, combined with improvement in renal reconstruction, have decreased the number of renal explorations and nephrectomies performed over past 2 decades.12 Fewer than 5% of blunt injuries and 36% of all penetrating renal injuries are 428 Zinman & Vanni undergoing operative management.9 Ongoing arterial bleeding in hemodynamically stable patients may be treated with angiography and selective embolization.16,17 Thrombosis of the renal artery or its branches is managed expectantly. Bed rest is maintained until the urine becomes grossly clear. The urethral catheter can be removed when the patient is stable and