Injury to the Urinary Tract (Bladder Injuries· Kidney Injuries·Ureteral Injuries, Urethral Injuries

Introduction

The kidneys and the rest of the urinary tract may become injured in a number of ways. Examples include injuries from a blunt force (most commonly motor vehicle collisions, falls, or sports injuries) or a pentrating force (most commonly gunshot or stab wounds), or surgery. Injuries to the urinary tract often occur with injuries to other organs, especially abdominal organs. In men, the penis and testes may also be injured (see Penile and Testicular Disorders: Injuries to the Penis and Scrotum).

Because the function of the kidneys is to continuously filter out metabolic wastes from the blood and remove them from the body through the urinary tract, injuries to the kidneys or urinary tract can lead to the inability to perform these functions (kidney failure). Other complications of injury include bleeding, leakage of urine from the urinary tract into surrounding tissues, and infection. Preventing permanent damage to the urinary tract and even death may depend on prompt diagnosis and treatment.

Bladder Injuries A bladder injury often occurs when the pelvis is injured, as in a high-speed motor vehicle collision or a fall. Penetrating wounds, usually from gunshots, also can injure the bladder. In addition, a bladder injury may occur unintentionally during surgery involving the pelvis or lower abdomen (such as hysterectomy, cesarean section, or colectomy). If bladder injuries are not promptly treated, complications, such as frequent and urgent urination, uncontrollable loss of urine (urinary incontinence), and infection, may develop. Symptoms and Diagnosis The most common symptoms of a bladder injury are blood in the urine, difficulty in urinating, and pain in the pelvis and lower abdomen. If the lowermost portion of the bladder (where the muscle that helps to control urination is located) has been injured, the person may experience frequent urination or urinary incontinence. The diagnosis of a bladder injury is best established by cystography, a procedure in which a radiopaque dye (contrast agent), which is visible on x-rays, is injected into the bladder and a computed tomography (CT) scan or x-rays are taken to look for leakage. Bladder injuries that occur during a surgical procedure are usually recognized promptly and imaging tests are not needed. Treatment Minor bladder injuries, either bruises or tears (lacerations), may be treated by inserting a catheter into the urethra for 5 to 10 days while the bladder heals. For more extensive bladder injuries or any injury resulting in leakage of urine into the abdominal cavity, surgery should be performed to determine the extent of the injury and to repair all tears. The urine can then be more effectively drained from the bladder using two catheters, one inserted through the urethra (a transurethral catheter) and one inserted directly into the bladder through the skin over the lower abdomen (a suprapubic catheter). These catheters are removed in 7 to 10 days or once the bladder has healed satisfactorily. If complications develop, they must be treated. When a bladder injury is recognized during a surgical procedure, it is treated at that time.

Kidney Injuries The kidney is injured more often than any of the organs along the urinary tract. Blunt force due to motor vehicle collisions, falls, or sports injuries is the usual cause of injury. Penetrating kidney injuries can result from gunshot or stab wounds. Less commonly, injuries can occur during diagnostic tests, such as a kidney biopsy, or during various treatments, such as those for kidney stones, including extracorporeal shock wave lithotripsy. Most blunt kidney injuries are minor. However, some are serious. If serious blunt or penetrating kidney injuries are not treated, complications, such as kidney failure, high blood pressure, delayed bleeding, and infection may result. Symptoms and Diagnosis Symptoms of a blunt kidney injury may include pain in the upper abdomen or flank (the area between the ribs and hip), bruising of the flank, blood in the urine, marks near a kidney made by a seat belt, or pain resulting from fractures of the lower ribs. With severe kidney injuries, low blood pressure (shock) and anemia may occur if the person loses a significant amount of blood. Kidney Injuries: Minor to Severe The severity of kidney injuries varies widely. When an injury is minor, the kidney may be only bruised. When an injury is more severe, the kidney may be cut or torn (lacerated), and urine and blood may leak into the surrounding tissue. If the kidney is torn from its attachment to blood vessels, bleeding may be profuse, resulting in shock or death. Most kidney injuries result in blood in the urine. The history of events that led to the injury, the person's symptoms, and a physical examination help doctors recognize kidney injuries. A sample of urine is taken and examined to see if blood is present. Blood in the urine in a person with an injury to the trunk suggests that the injury involves the kidney. The blood may be visible with the naked eye (gross hematuria) or visible only using a microscope (microscopic hematuria). With penetrating injuries, the location of the wound (whether in the upper or mid part of the abdomen, back, or flank) may help doctors determine if the kidney is involved. Adults who have mild symptoms and blood in the urine that is visible only with a microscope probably have a minor bruise that will heal on its own. Further tests are usually not needed. For children, and for adults in whom doctors suspect a more serious injury, computed tomography (CT) with radiopaque dye (contrast agent) is done. Occasionally, additional imaging tests may be needed to confirm the diagnosis. Treatment For minor kidney injuries, careful control of fluid intake and bed rest are often the only treatment needed, because these measures allow the kidney to heal itself. For more serious injuries, treatment begins with steps to control blood loss and to prevent shock. Fluids and sometimes blood are given intravenously to help keep blood pressure within a normal range and stimulate urine production. Only the most serious injuries, such as when the kidney is torn from its attachments to blood vessels, require surgical repair. Rarely, the injured kidney needs to be removed. Most people recover from even serious kidney injuries, provided the injuries are diagnosed and treated promptly. Kidney failure, when it develops, may require lifelong treatment. Other complications of kidney injuries that require treatment include high blood pressure, delayed bleeding, and infection. Ureteral Injuries Most injuries to the ureter occur during pelvic or abdominal operations, such as removal of the uterus (hysterectomy) or the colon (colectomy) or repair of an abdominal aortic aneurysm, or during ureteroscopy (an examination of the ureter with a rigid or flexible viewing tube). Another cause of ureteral injury is penetration by either a gunshot or stab wound. A ureteral injury from a direct blow to the body is uncommon. Rarely, blunt injuries, particularly those that cause the trunk to bend backward, can separate the upper part of the ureter from the kidney. If ureteral injuries are untreated, complications, such as formation of a fistula (abnormal connection to another abdominal structure), stricture (narrowing of the ureter), or persistent urinary leakage and infection, may result. Symptoms and Diagnosis People may complain simply of pain in the abdomen or flank (the area between the ribs and hip), or they may notice urine leaking from their wound. Fever may accompany an infection caused by persistent urinary leakage. Blood may appear in the urine. Because ureteral injury is rarely the most likely cause of such symptoms, an injury to the ureter may not be recognized promptly. Usually, doctors suspect an injury when a person who has symptoms has had a recent surgical procedure or when a person has a wound that has penetrated the abdomen. When a ureteral injury is suspected, imaging tests are needed. The initial test is often computed tomography (CT) with radiopaque dye (contrast agent) or intravenous urography. Occasionally, retrograde urography (an x-ray taken after a radiopaque dye is instilled directly into the end of the urethra) may be done. Sometimes, ureteral injuries are identified during surgery. Treatment Some minor ureteral injuries can be treated by placing a flexible tube (stent) in the ureter either through the bladder or through the kidney via a small incision in the side (percutaneous nephrostomy). These treatments divert urine from flowing through the ureter, usually for 2 to 6 weeks, allowing the ureter to heal. If the ureteral injury does not heal despite the use of a stent, additional surgery may be needed. In people with more severe injuries, surgery may be required to reconstruct the ureter. Treatment helps to prevent complications of ureteral injuries. If complications occur despite efforts to prevent them, they must be treated. Urethral Injuries Most urethral injuries occur in men. Common causes include pelvic fractures and straddle injuries (injuries to the area between the legs). The urethra can also be injured unintentionally during surgical procedures performed directly on the urethra or during procedures in which instruments are passed into the urethra, such as bladder catheterization or cystoscopy (passing a flexible viewing tube through the urethra into the bladder). Occasionally, injuries result from gunshot wounds. Rarely, urethral injuries can be self-inflicted when a person inserts a foreign object directly into the urethra. Some injuries to the urethra are limited to bruising. Injury to the urethra can also tear the lining, resulting in leakage of urine into the tissues of the penis, scrotum, abdominal wall, or perineum (the area between the anus and vulva or scrotum). Complications that can result from urethral injuries include infection, bleeding, permanent narrowing (stricture), erectile dysfunction, and uncontrollable loss of urine (urinary incontinence). Symptoms and Diagnosis The most common symptoms include blood at the tip of the penis in men or the urethral opening in women, blood in the urine, an inability to urinate, and pain during urination. Bruising may be visible between the legs or in the penis. Other symptoms may arise when complications develop. For example, if urine leaks into surrounding tissues, infection may result. In addition, the injury may cause the urethra to narrow (stricture) near or at the site of injury. Men may also experience impairment in the ability to have an erection (erectile dysfunction), caused by damage to the nerves or blood supply to the penis. The diagnosis of a urethral injury is usually confirmed by retrograde urography, an x-ray taken after a radiopaque dye (contrast agent) is instilled directly into the end of the urethra. Retrograde urography is done before a catheter is passed through the urethra into the bladder. Treatment For urethral bruises that do not result in any leakage of urine, a doctor can place a catheter through the urethra into the bladder for several days to drain the urine while the urethra heals. For urethral tears, the urine should be diverted from the urethra using a catheter placed directly into the bladder through the skin over the lower abdomen. The urethra is repaired surgically after all other injuries have healed or after 8 to 12 weeks (when inflammation has resolved). Rarely, urethral tears heal without surgery. Treatment helps to prevent some complications of urethral injuries. Complications that cannot be prevented are treated .