Renal trauma imaging: Diagnosis and management. A pictorial review

Renal Arteriovenous (AV) Fistula after High-Grade Blunt Renal Trauma Caused by Traffic Accidents

PURPOSE

To report a series of three patients with traumatic renal AV fistulas after blunt renal laceration.

METHODS

We retrospectively analyzed the renal trauma cases treated in the Department of Urology of Salzburg University Clinic during a time period of 10 years concerning traumatic AV fistula formation and other clinical parameters.

RESULTS

In total, 3 cases of traumatic AV fistula formation were identified in 106 blunt renal trauma patients (2.8%), with a mean age of 39 (17-56) years. All renal traumas were classified as American Association for the Surgery of Trauma (AAST) grade IV. Two patients were primarily treated with ureteral stent; one was managed conservatively. All AV fistulas were diagnosed after a mean time of 7 (1-13) days. Two patients were symptomatic with gross hematuria, and the mean time between trauma and onset of symptoms was 11 (9-13) days. All cases were managed via coil embolization after a mean of 10 (8-13) days. Two patients received a second intervention after a mean of 18 (11-25) days. The mean AV fistula size was 18.7 (12-24) mm. Mean hemoglobin loss was 3.6 g/dL. One patient received one erythrocyte concentrate. Discharge was after a mean time of 13.3 (7-12) days, with the mean time of intensive care treatment being 2.3 (1-3) days.

CONCLUSIONS

Traumatic renal AV fistula is a rare but severe complication associated with higher-grade renal trauma. It can become evident through hematuria or blood loss several days after the initial trauma. The availability of coil embolization in a trauma center can help kidney preservation management.

Endovascular management of vascular renal injuries: outcomes and comparison between traumatic and iatrogenic settings

PURPOSE

To evaluate the efficacy of endovascular treatment for vascular renal injuries (VRIs) like bleeding, pseudoaneurysm and artero-venous fistula (AVF) and to compare patients with blunt trauma (T-VRIs) with those with iatrogenic damage (I-VRIs).

METHODS

We retrospectively assessed 49 renal artery embolizations performed to treat T-VRIs (26.5%) and I-VRIs (73.5%). Different embolic materials were used based on the type of lesion. Technical success was defined as the complete occlusion of target arteries with no further visualization of VRIs. Clinical success was defined if no recurrence was present and if renal function (difference between creatinine after and before treatment <0.5 mg/dl) was preserved after 1 month.

RESULTS

Angiography showed bleeding in 27 patients, pseudoaneurysm in 29 and an AVF in 6. Embolic agents used were coils in 39 procedures, coils with sponge in four and others in six. Technical success was 100% while clinical success was 85.7% due to seven patients with recurrence. The group I-VRIs showed a higher rate of clinical success than the group T-VRIs (94.4% vs 61.5%; p < 0.05). Moreover, the group I-VRIs had a higher incidence of pseudoaneurysms and AVFs compared with the group T-VRIs (69.4% vs 30.8% and 16.7% vs 0%; p < 0.05).

CONCLUSION

Endovascular treatment for VRIs showed satisfactory results and no patient had a worsening of renal function. I-VRIs had better clinical success and more frequently appeared as pseudoaneurysms compared to T-VRIs: probably iatrogenic injury is localized and pseudoaneurysm is easily identifiable and treatable with endovascular treatment.

A Case of Arteriovenous Fistula After Kidney Trauma Mimicking Tumor

Renal arteriovenous fistulas are rare complications of kidney injury that are usually caused by penetrating or blunt abdominal trauma, percutaneous or open biopsy, or surgery. We report a case of renal arteriovenous fistula after blunt abdominal trauma of a male patient who had traffic accidents. Computed tomography images show arteriovenous fistula lesion mimicking the tumor of the renal pelvis. Through this case, we present how to identify and avoid being confused in diagnosis as well as introduce its clinical manifestations, imaging, and treatment.

Kidney and uro-trauma: WSES-AAST guidelines

Renal and urogenital injuries occur in approximately 10-20% of abdominal trauma in adults and children. Optimal management should take into consideration the anatomic injury, the hemodynamic status, and the associated injuries. The management of urogenital trauma aims to restore homeostasis and normal physiology especially in pediatric patients where non-operative management is considered the gold standard. As with all traumatic conditions, the management of urogenital trauma should be multidisciplinary including urologists, interventional radiologists, and trauma surgeons, as well as emergency and ICU physicians. The aim of this paper is to present the World Society of Emergency Surgery (WSES) and the American Association for the Surgery of Trauma (AAST) kidney and urogenital trauma management guidelines.

Nationwide Procedural Trends for Renal Trauma Management

OBJECTIVE

To characterize national trends in procedural management of renal trauma.

BACKGROUND

Management of renal trauma has evolved to favor a more conservative approach. For patients requiring intervention, there is a paucity of information to characterize the nature of procedural therapy administered.

METHODS

A retrospective cross-sectional analysis was performed using data contained within the National Trauma Data Bank. The National Trauma Data Bank is a voluntary data repository managed by the American College of Surgeons, containing data regarding trauma admissions at 747 level I to V trauma centers throughout the United States and Canada. Participants included any patient with renal trauma requiring intervention from 2002 to 2012. They were identified according to International Classification of Diseases, Ninth Revision (ICD-9) diagnosis codes, with codes 866.00 through 866.03 for blunt renal trauma, and codes 866.10 through 866.13 for penetrating trauma. Cases were separated into those requiring nephrectomy, renorrhaphy, or endovascular repair based on ICD-9 procedure code. The number of cases performed each year and yearly trends as measured by linear regression.

RESULTS

A total of 4296 cases were reported during the study period. Of these cases, 2635 involved blunt trauma and 1661 involved penetrating injury. There was a significant increase in the percentage of cases managed by endovascular means for both blunt and penetrating trauma (R = 0.92, P < 0.01; and R = 0.86, P < 0.01, respectively). This was primarily at the expense of nephrectomy, with cases showing significant decline in both groups.

CONCLUSIONS

National trends for procedural management of renal trauma are toward less invasive interventions. These trends suggest favorable change towards renal preservation and decreased morbidity, potentially facilitated, in part, by improved radiographic staging and endovascular techniques, and also increased provider awareness of the safety and value of conservative management.

Bilateral Renal Hypoperfusion Following Motor Vehicle Accident

Renal hypoperfusion noted on abdominal computed tomography (CT) scan without any underlying comorbid condition is a rare finding. Most reported cases of renal hypoperfusion have an association with an underlying cardioembolic problem, such as atrial fibrillation, endocarditis, cardiomyopathies, or artificial valve thrombi. We present a case of transient renal hypoperfusion evident on abdominal CT scan following blunt trauma. An 18-year-old male without any significant past medical history presented to the emergency department with the complaint of abdominal pain. The patient reported history of motor vehicle accident 1 week prior to his presentation. He was a front seat passenger wearing a seatbelt when the car went into a ditch. Airbags were deployed and the patient briefly lost consciousness. He presented 1 week later with complaints of generalized abdominal pain, more on the left side that started a few days after his accident, nonradiating, constant, 4/10 intensity. He denied dysuria, hematuria, groin pain, fever, chills, nausea, vomiting, abdominal pain, diarrhea, constipation, decreased oral intake, joint pain, leg swelling, or redness. He denied any medication use or any history of intravenous drug abuse. There was no reported family history of kidney disease or blood clots. Initial laboratory tests, including complete blood count, basic metabolic panel, erythrocyte sedimentation rate, and urinalysis were unremarkable except trace protein on the urinalysis. Contrast-enhanced CT of the abdomen showed multiple, confluent, focal areas of hypoperfusion of the renal parenchyma bilaterally. Given the CT findings of bilateral renal hypoperfusion, the patient was admitted to the hospital and an extensive workup was performed to rule out cardioembolic etiology. Echocardiogram, renal ultrasound, magnetic resonance angiogram of the abdomen, vasculitis panel, and hypercoagulable workup was unremarkable. The CT findings of renal hypoperfusion were considered secondary to transient hypoperfusion from blunt trauma. Abdominal pain resolved with nonsteroidal anti-inflammatory drugs and he was discharged to home. Follow-up abdominal CT scan with contrast obtained a few months later showed normal kidneys with resolution of previously noted renal hypoperfusion. Our case highlights a benign incidental finding of bilateral renal hypoperfusion following motor vehicle accident (with airbag injury), which resolved on follow-up imaging. On literature search, such CT scan findings of transient renal hypoperfusion of unclear significance have not been previously reported. Even though our patient underwent extensive workup to rule out cardioembolic etiology, it may be reasonable to forego such workup following blunt abdominal trauma.

Challenging case of horseshoe kidney double fracture

INTRODUCTION

Renal injuries occur in 10% of blunt abdominal traumas, 7% of these occur in kidneys with congenital or acquired disorders. Trauma of horseshoe kidney is an uncommon finding.

PRESENTATION OF A CASE

We present the case of 31 year-old caucasian man with no remarkable personal records, who was brought to our Trauma Unit soon after being involved in a motorcycle collision. A Contrast Enhanced - Multi Detector Computed Tomography (ce-MDCT) revealed a double disconnection of a horseshoe kidney. The patient was not aware of bearing such abnormality.

DISCUSSION

Trauma of horseshoe kidney is an uncommon finding. The abdominal ce-MDCT scan is the diagnostic tool of choice since the renal anatomy, injury grading and vascular or urinary tract abnormalities are well depicted and easily identified. The conservative management of these injuries is associated with a lower rate of nephrectomies and kidney failure while selective trans-catheter renal embolization is a challenging treatment option. However surgery can be a treatment of choice and should be aimed to preserve renal function.

CONCLUSION

the interest in our case lies in the rarity and particular anatomical aspect of such injuries and the implication related to its management in an emergency setting.

The diagnosis and management of renal trauma

Background:

Renal trauma is less common but often occurs in polytrauma. Most trauma is blunt and the severity of the injury varies in different circumstances.

Assessment:

There is a series of features that should prompt investigation but none are reliably seen in all trauma cases and a low threshold for suspecting renal injury should be taken. A urine dip is essential.

Investigation:

Computerised tomography is the main modality. Follow-up imaging may be used if complications arise and ultrasound may be used in some cases.

Management:

Approaches include surgical, radiological and conservative. The latter has been achieved in all grades but intervention will be required in haemodynamic instability.

Complications:

Haemorrhage, infection and urine extravasation are common and require intervention. There are many long-term complications and hypertension can occur by a variety of mechanisms.

A case of renal vein branch injury identified by multidetector computed tomography

A 39-year-old male fell from a forklift and was urgently transported to our hospital. His vital signs were stable at the initial visit. Contrast imaging computed tomography (CT) showed extravasation (Ev) of contrast medium emigrating outside of the renal capsule and hematoma around the right kidney, and he was diagnosed with traumatic right renal injury, Grade IV laceration [American Association for the Surgery of Trauma classification]. When imaging the inferior renal artery branch extremity perfusing the area where Ev was found in the following blood vessel contrast imaging, obvious Ev was not found in the arterial phase; however, massively spreading Ev was found in the area adjacent to the renal laceration in the venous phase after taking a contrast image of the renal parenchyma. Thus, he was diagnosed with a renal vein branch injury. The transcatheter arterial embolization (TAE) was performed to the area, resulting in the disappearance of Ev. The effectiveness of TAE for renal injury has been established; however, it is only performed for arterial hemorrhage. TAE for venous injury has not previously been considered because a tamponade is supposedly effective for hemostasis of venous hemorrhage due to the anatomy surrounding Gerota's fasciae. This is an extremely rare case in which only venous injury was identified, without obvious arterial hemorrhage. Gerota's fasciae were broken and hemostasis treatment was required. Because the renal artery is the end artery, the venous hemorrhage was controlled with arterial embolization. In our case, renal vein branch injury was identified on CT and hemorrhage was terminated using TAE for the renal artery branch. TAE can be used as a non-operative management for the successful treatment of renal vein branch injury.

[Ultrasound of the urinary system]

Ultrasound techniques are able to provide a fairly complete examination of the urinary system, achieving a high sensitivity in relevant-pathology detection, especially in the kidney, bladder and prostate. Early detection of pathologies such as tumors or urinary tract obstructions, sometimes even before their clinical manifestation, has improved their management and prognosis in many cases. This, added to its low cost and harmlessness, makes ultrasound ideal for early approaches and follow-up of a wide number of urinary system pathologies. In this article, the ultrasound characteristics of the main urinary system pathologies that can be diagnosed by this technique, are reviewed.

"Management of blunt renal injury: what is new?"

The diagnosis, workup and management of blunt renal injury have evolved greatly over the past decades. Evaluation and management of blunt renal injury echoes the increasing success of nonoperative management in other blunt abdominal solid organ injury, such as liver and spleen. Decision-making difficulties still remain regarding the optimal imaging, grading and degree of interventional or operative exploration used. Increasingly, initial nonoperative management has gained acceptance and appears to be applicable even high-grade injuries. Emerging techniques in highly sensitive imaging as well as interventional angiography have allowed safe nonoperative management in the appropriate patient. This review will focus on the contemporary workup and management of blunt renal injury while focusing on some of the emerging literatures in regard to refined imaging and grading of injuries as well as techniques to increase the success of nonoperative management.