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Pediatric Genitourinary Trauma
Douglas A. Husmann
1.Which of the following signs or symptoms noted after a traumatic insult is suggestive of a preexisting renal abnormality?
a.Microscopic hematuria with shock
b.Gross hematuria with shock
c.Gross hematuria with clot formation
d.Hematuria disproportionate to severity of trauma
e.Hematuria in the absence of coexisting injuries to the thorax, spine, pelvis/femur or intra-abdominal organs
2.The radiographic study that is the most sensitive for the presence of a renal injury is:
a.intravenous pyelogram (IVP).
b.magnetic resonance imaging (MRI) of abdomen.
c.focused assessment with sonography for trauma (FAST) ultrasound.
d.triphasic abdominal computed tomography (CT).
e.monophasic abdominal CT.
3.Following a traumatic injury, a CT of the abdomen reveals a renal laceration that extends into the collecting system with urinary extravasation. The injury is associated with a devitalized fragment. The grade of renal injury is:
a.1.
b.2.
c.3.
d.4.
e.5.
4.An 11-year-old boy sustained a renal laceration that extended into the collecting system 2 weeks previously. He has been at home for the past week with grossly clear urine. He presents to the emergency room with the sudden onset of gross hematuria with clots. His blood pressure is normal and his vital
signs in the emergency room are stable. The best next step is:
a.continued observation.
b.abdominal ultrasound.
c.a single-phase CT scan.
d.cystoscopy and stent placement.
e.angiography.
5.A 9-year-old boy sustained a renal laceration associated with a functional renal fragment that was completely dissociated from the kidney. He has a persistent symptomatic urinary fistula despite combined treatment with a nephrostomy tube, double J stent, and urethral catheter. The best next step is:
a.angiographic embolization of functional renal fragment.
b.radio frequency ablation (RFA) of functional renal fragment.
c.cryotherapy of functional renal fragment.
d.laparoscopic partial nephrectomy.
e.open partial nephrectomy.
6.An 8-year-old boy on IV prophylaxis with cefazolin undergoes angiographic embolization of a traumatic arteriovenous fistula (AV) fistula associated with a grade 4 traumatic renal injury. His urine is clear, but on postembolization day 2 he is having febrile temperature spikes to 40° C; blood pressure is stable. Acetaminophen is given for fever and blood and urine cultures are obtained. The best next step in management is:
a.continued observation.
b.change in antibiotic coverage to piperacillin.
c.addition of metronidazole.
d.CT of abdomen and aspiration of perinephric hematoma/urinoma.
e.percutaneous nephrostomy drainage of urinoma.
7.A 2-year-old boy sustains a major renal laceration with a tear into his collecting system secondary to child abuse. He has persistent gross hematuria with clots and ileus 5 days following his injury. CT scan reveals a clot filling his renal pelvis, and there is a significant perinephric urinoma. However, good flow of contrast is seen into the patient's ipsilateral distal ureter, findings essentially unchanged from a CT scan done 48 hours earlier. Vital signs and hemoglobin are normal and stable. The best next step is:
a.continued observation.
b.angiography.
c.percutaneous nephrostomy.
d.cystoscopy, retrograde pyelogram, and stent placement.
e.surgical exploration and renorrhaphy.
8.Follow-up CT imaging for a grade 2 renal injury should be performed:
a.only if a patient develops systemic of localized signs or symptoms.
b.2 to 3 days after traumatic injury.
c.3 to 4 weeks after traumatic injury.
d.3 months after traumatic injury
e.1 year after traumatic injury.
Answers
1.d. Hematuria disproportionate to severity of trauma. The classic patient history that should make the physician think of a preexisting renal anomaly is that the degree of hematuria present is disproportionate to the severity of trauma. None of the other options have been found to be associated with the presence of a preexisting renal abnormality during the evaluation of trauma.
2.d. Triphasic abdominal computed tomography (CT). A triphasic CT study (precontrast study, followed by a study immediately following injection and then a 15-to 20-minute delayed study) is the most sensitive method for diagnosis and classification of renal trauma. A single-phase CT study is beneficial in determining renal perfusion and major renal fractures, but may on occasion miss the presence of urinary extravasation and will miss the vast majority of ureteral injuries. FAST sonographic evaluations are operator and experience dependent. It is noteworthy, however, that a normal FAST sonographic evaluation coupled with a serial normal physical examinations during 24 hours will reliably detect all clinically significant genitourinary (GU) injuries.
3.d. 4.
Grade
of
Renal Description Injury
1Renal contusion or subcapsular hematoma
2Less than 1-cm parenchymal laceration, all renal fragments viable, no urinary extravasations
3Greater than 1-cm parenchymal laceration, includes renal segmental injuries resulting in devitalized fragments,
no urinary extravasation
4Laceration extending into the collecting system, includes renal segmental injuries resulting in devitalized
fragments, urinary extravasation is present. Grade 4 includes shattered kidney, renal pelvic lacerations, and complete ureteropelvic junction disruption.
5Injury to the main renal vasculature: major renal vessel laceration or avulsion resulting in uncontrollable
hemorrhage or renal thrombosis of the major renal vessels
4.e. Angiography. Approximately 25% of patients with a grade 3-or 4 renal trauma managed in a nonoperative fashion will have persistent or delayed hemorrhage. Classically, delayed hemorrhage will present 10 to 14 days postinjury, but it may occur as long as 1 month after the insult. Delayed hemorrhage arises from the development of AV fistulas, will not spontaneously resolve, and may be associated with life-threatening hemorrhage. The patient may have had a significant blood loss despite normal vital signs. Shock in a child may be one of the later signs of severe bleeding. IV access should be obtained in the emergency room, and the patient should immediately be transported to the angiography suite for evaluation and embolization of the bleeding site.
5.a. Angiographic embolization of functional renal fragment. Persistent urinary fistulae associated with a viable renal fragment that is separate from the remaining portions of traumatically injured kidney are initially managed with percutaneous nephrostomy tube drainage and double J stent placement. If persistent fistula drainage continues, it may be managed by angiographic infarction of the isolated functional segment which may prevent the need for open surgical excision of the functional segment.
6.a. Continued observation. Postembolization syndrome is well recognized and self-limiting. It is manifested by pyrexia as high as 40° C, flank pain, and adynamic ileus. Symptoms should resolve within 96 hours after the embolization. When pyrexia develops, blood and urine cultures to rule out bacterial seeding of the necrotic tissue are necessary. Consideration for a repeat CT scan with possible aspiration, culture, and drainage of a perinephric hematoma/urinoma should be given if febrile response persists for longer than 96 hours or if the patient’s clinical course should rapidly worsen.
7.c. Percutaneous nephrostomy. Most posttraumatic urinomas are asymptomatic and have a spontaneous resolution rate approaching 85%. They will occasionally persist and be associated with continued flank pain, adynamic ileus, and/or low-grade temperature. Frequently these patients are managed via endoscopic intervention, with cystoscopy, retrograde pyelography, and placement of a ureteral stent. It should be noted that both percutaneous nephrostomy drainage and internal stenting are equally efficacious. The advantage of an internal stent is that it prevents possible dislodgment of the draining tube and the need for external drainage devices.
The two major disadvantages of internal drainage are that both stent placement and removal, in the pediatric patient population, require general anesthesia. In addition, the small ureteral stents (4 to 5 Fr) placed in young children may become blocked with blood clots from the dissolving hematoma, resulting in persistence of the urinoma. In this young child with large perinephric clots, the best way to manage the problem is with percutaneous nephrostomy. This will allow the physician to externally irrigate the system if the tube becomes blocked with clots.
8.a. Only if a patient develops systemic of localized signs or symptoms. Follow-up renal imaging is not recommended for grade 1 or 2 renal injuries or for grade 3 lacerations where all fragments are viable. In patients with grade 3 renal lacerations associated with devitalized fragments, and those with grade 4 or salvaged grade 5 renal injuries, a repeat CT scan with delayed images should be obtained 3 months following the injury. This latter study is obtained to verify resolution of any perinephric urinoma and to define the anatomic configuration and determine the extent of the residual functioning renal parenchyma.
Chapter review
1.Preexisting renal anomalies are commonly found in children who present with traumatic injuries of the kidney.
2.In children, there is a poor correlation between the presence of hematuria and a renal injury.
3.A single-shot IVP intraoperatively is only useful in determining the presence of a contralateral kidney when an ipsilateral nephrectomy is anticipated.
4.The vast majority of AV fistulas that occur after trauma will not spontaneously resolve, unlike AV fistulas following a renal biopsy, where spontaneous resolution is the rule.
5.Most posttraumatic urinomas are asymptomatic and will resolve spontaneously.
6.When there is a coexistence of an intra-abdominal injury adjacent to the urinary tract injury, the two should be separated by interposing tissue such as omentum.
7.Posttraumatic hypertension in children is usually due to a small, poorly functioning kidney; it is renin mediated and nephrectomy is generally the best option.
8.CT findings associated with ureteropelvic junction disruption include medial extravasation, absence of parenchyma lacerations, and no visualization of the distal ureter. Immediate surgical repair is preferred.
9.Traumatic bladder lacerations in children are likely to extend through the bladder neck and require surgical exploration and repair.
10.When a urethral injury is found with a pelvic fracture, a concurrent rectal injury is present in 15%; in females, urethral injuries associated with pelvic fractures are associated 75% of the time with vaginal lacerations and 30% of the time with rectal injury.
11.A diverting colostomy is appropriate in traumatic injuries of the urethra associated with rectal injuries.
12.Penile strangulation caused by hair should be suspected when circumferential edema and/or necrosis is noted from a circumferential point distally.
13.The CT findings following trauma that indicate a need for interventional therapy are: (1) medial extravasation of contrast suggesting a renal pedicle injury, (2) lateral extravasation of contrast with no visualization of the ureter suggesting a ureteral injury, and (3) a large perinephric hematoma that may require angiographic embolization.
14.Radiographic assessment for a genitourinary injury is indicated if the patient has any one of the following: (1) deceleration or high-velocity injury, (2) significant fractures, (3) gross hematuria, and (4) microscopic hematuria with a systolic pressure less than 90 mm Hg.
15.Major renal artery injuries are rarely salvageable.
16.Intraperitoneal bladder injuries require open repair.
17.A triphasic CT study (precontrast study, followed by a study immediately following injection and then a 15-to 20-minute delayed study) is the most sensitive method for diagnosis and classification of renal trauma.
18.Shock in a child may be one of the later signs of severe bleeding.
19.Follow-up renal imaging is not recommended for grade 1 or 2 renal injuries or for grade 3 lacerations where all fragments are viable. In patients with grade 3 renal lacerations associated with devitalized fragments and those with grade 4 or salvaged grade 5 renal injuries, a repeat CT scan with delayed images should be obtained 3 months following the injury.
SECTION G
Oncology