Scarring following renal trauma in children

Renal ultrasound to evaluate for blunt renal trauma in children: A retrospective comparison to contrast enhanced CT imaging

INTRODUCTION

The standard imaging modality for hemodynamically stable blunt abdominal trauma patients is a contrast enhanced CT scan, which is reflected in the current AUA urotrauma guidelines. This comes, however, with radiation exposure and the potential sequalae of IV contrast administration in the pediatric patient.

OBJECTIVE

We hypothesize that ultrasound imaging would be able to diagnose and rule out clinically significant renal injuries when compared to the gold standard of CT scan in the setting of pediatric blunt abdominal trauma.

STUDY DESIGN

All children <18 years of age who were evaluated for blunt abdominal trauma who had a CT scan and ultrasound imaging of kidneys were identified. The ultrasound images were reviewed by four reviewers who were blinded to CT results and all clinical information. The ability of ultrasound to diagnose and rule out clinically significant renal injury was evaluated by diagnostic test performance characteristics including sensitivity, specificity, negative predictive value and positive predictive value.

RESULTS

There were 76 patients identified, 24 of which had a renal injury (1 bilateral) diagnosed by CT scan for a total of 25 injuries in 152 renal units. There were six grade I-II injuries and 19 grade III-V injuries. The sensitivity of the four blinded reviewers by ultrasound alone to detect the 19 grade III-V injuries ranged from 79 to 100% with NPV between 97 and 100%. Three of the four reviewers identified all 19 grade III-V injuries by ultrasound. When combined with significant hematuria, all 19 grade III-IV injuries were identified. Of note, all patients with a grade III-V injury of the kidney had significant hematuria. Of the grade I-II renal injuries, all reviewers identified 1/5 or 2/5 by ultrasound alone.

DISCUSSION

The limitations of this study include: its retrospective nature, limited number of patients and reviewers, quality of the ultrasound machine. and experience of technologist, radiologist and urologist. A major limitation is the inability to assess other solid organ injuries during this initial study.

CONCLUSIONS

When compared to a CT scan as the gold standard, kidney ultrasound images had a sensitivity of 79-100% to detect grade III-V injuries and NPV of 97-100% by four blinded reviewers. All grade III-V injuries had either an episode of gross hematuria or microscopic hematuria >50 RBC/hpf. A prospective study that includes full abdominal imaging is needed to confirm that ultrasound can safely be used in place of CT scan for evaluation of hemodynamically stable blunt trauma patients.

Management of paediatric high-grade blunt renal trauma: a 10-year single-centre UK experience

OBJECTIVE

To report the management and outcome of paediatric patients sustaining high-grade blunt renal trauma.

PATIENTS AND METHODS

Medical records were examined for all American Association for the Surgery of Trauma (AAST) grade III-V blunt renal trauma cases admitted to a paediatric trauma centre from 2005 to 2015. Data collected and analysed included: demographics, imaging modalities, management, length of hospital stay (LOS), complications, and follow-up outcomes.

RESULTS

In all, 18 children (12 boys, six girls) with mean (range) age 11 (4-15) years were included. According to the AAST grading criteria, 39% (seven of 18) of the patients had grade III, 50% (nine of 18) grade IV, and 11% (two of 18) grade V injuries; 44% (eight of 18) had concomitant injuries. Most of the patients were managed conservatively (89%, 16 of 18), although two of the 16 subsequently needed JJ-stent insertion during inpatient stay for symptomatic urinoma(s). In all, 11% (two of 18) of the patients required interventional radiology service(s), involving selective embolisation for life-threatening renal tract haemorrhage. Blood transfusion for renal injury exclusively was required in 11% (two of 18) of the patients. In all, 89% (16 of 18) of the patients had at least one follow-up imaging study before hospital discharge; most (13 of 16) had ultrasonography and three required computed tomography. The median (range) LOS was 11 (4-31) days. In all, 17% (three of 18) of the patients required hospital re-admission within 30 days for complications and all required interventional procedures: JJ stent for urinoma (one), embolisation of renal arterio-venous fistula (one), and embolisation for a post-traumatic pseudoaneurysm (one). Overall, the median (range) follow-up was 6 (2-60) months. In all, 78% (14 of 18) of the patients had dimercaptosuccinic acid studies, with 11 showing reductions in renal function (range 3-44%).

CONCLUSIONS

This study supports a care pathway strategy advocating conservative management of high-grade renal injuries in children. However, patients may experience a relative decline in renal function with higher grade injuries indicating the need for monitoring and follow-up.

Late evaluation of the relationship between morphological and functional renal changes and hypertension after non-operative treatment of high-grade renal injuries

Objective

To evaluate the anatomical and functional renal alterations and the association with post-traumatic arterial hypertension.

Methods

The studied population included patients who sustained high grades renal injury (grades III to V) successfully non-operative management after staging by computed tomography over a 16-year period. Beyond the review of medical records, these patients were invited to the following protocol: clinical and laboratory evaluation, abdominal computed tomography, magnetic resonance angiography, DMSA renal scintigraphy, and ambulatory blood pressure monitoring. The hypertensive patients also were submitted to dynamic renal scintigraphy (^99mTc EC), using captopril stimulation to verify renal vascular etiology.

Results

Of the 31 patients, there were thirteen grade III, sixteen grade IV (nine lacerations, and seven vascular lesions), and two grade V injuries. All the patients were asymptomatic and an average follow up post-injury of 6.4 years. None had abnormal BUN or seric creatinine. The percentage of renal volume reduction correlates with the severity as defined by OIS. There was no evidence of renal artery stenosis in Magnetic Resonance angiography (MRA). DMSA scanning demonstrated a decline in percentage of total renal function corresponding to injury severity (42.2 ± 5.5% for grade III, 35.3 ± 12.8% for grade IV, 13.5 ± 19.1 for grade V). Six patients (19.4%) had severe compromised function (< 30%). There was statistically significant difference in the decrease in renal function between parenchymal and vascular causes for grade IV injuries (p < 0.001). The 24-hour ambulatory blood pressure monitoring detected nine patients (29%) with post-traumatic hypertension. All the patients were male, mean 35.6 years, 77.8 % had a familial history of arterial hypertension, 66.7% had grade III renal injury, and average post-injury time was 7.8 years. Seven patients had negative captopril renography.

Conclusions

Late results of renal function after conservative treatment of high grades renal injuries are favorable, except for patients with grades IV with vascular injuries and grade V renal injuries. Moreover, arterial hypertension does not correlate with the grade of renal injury or reduction of renal function.

[Thoracic and abdominal trauma in children]

Knowledge of the characteristics of thoraco-abdominal trauma in children is important to optimize the imaging work up while keeping radiation exposure to a minimum. Because of the plasticity of the pediatric rib cage, rib fractures are infrequent, and severe parenchymal injuries may be present in the absence of rib fracture. Mediastinal injuries are unusual. The increased mobility of solid intraabdominal organs combined with a weaker abdominal wall are specific to pediatric patients. First-line imaging typically includes chest radiograph and abdominal US with Doppler imaging. Contrast-material enhanced CT is used as a second-line technique, with delayed imaging in patients with urinary tract lesions. Dedicated pediatric acquisition protocols are mandatory. Follow-up is obtained mainly with US.

At the bottom of the differential diagnosis list: unusual causes of pediatric hypertension

Hypertension affects 1-5% of children and adolescents, and the incidence has been increasing in association with obesity. However, secondary causes of hypertension such as renal parenchymal diseases, congenital abnormalities and renovascular disorders still remain the leading cause of pediatric hypertension, particularly in children under 12 years old. Other less common causes of hypertension in children and adolescents, including immobilization, burns, illicit and prescription drugs, dietary supplements, genetic disorders, and tumors will be addressed in this review.

Management of high-grade renal injuries in children after blunt abdominal trauma: experience of 40 cases

OBJECTIVE

We present our experience of management of high-grade renal trauma in a pediatric population, including assessment of the long-term function and morphology of the ipsilateral kidney.

PATIENTS AND METHODS

From 1997 to 2005, 40 children with high-grade renal injury (III, IV, V) after blunt abdominal trauma were managed. Initial evaluation included vital signs, color of urine, hemoglobin (Hb%), hematocrit, serum creatinine and computed tomography (CT). Follow up included vital signs, urine analysis, Hb%, CT, +/-intravenous pyelogram and renogram.

RESULTS

One patient needed superselective embolization due to continuing hemorrhage in spite of conservative treatment. Internal stenting plus percutaneous tube drain was indicated in three cases due to progressive extravasation. Exploration was indicated in four cases, one at presentation due to hemodynamic instability which ended in nephrectomy; the other three were successfully repaired. Conservative treatment was successful in 32 cases (80%). Blood transfusion was indicated in 16 cases (40%). Length of hospital stay was 4-20 days (mean 12.1). At the last follow up (range 1-8 years, mean 3.5), scars were detected in 10 cases, while all showed normal levels of Hb% and creatinine. No patient developed hypertension. Apart from in the nephrectomy case, the ipsilateral kidney showed split function of 40-50%.

CONCLUSION

After exclusion of hemodynamic instability and continuing hemorrhage, conservative treatment is successful in 80% of patients. Internal stenting with or without percutaneous drainage is indicated if there is progressive urinoma. Angioembolization is successful in selected cases.

[Kidney trauma in children: state of the art medical imaging]

Traumatic renal lesions have some particularities in the pediatric age group, especially for anatomic reasons. Imaging is very important for diagnosis and staging. Ultrasonography with Doppler is the first line examination performed in children and frequently allows initial diagnosis. From the Doppler-ultrasonographic results and the type of trauma, renal Computed Tomography (CT) is complementary performed. The association of these imaging techniques allows comprehensive work-up of traumatic renal lesions, and also of associated or pre-existing lesions. Conservative management is the rule in most cases. Interventional imaging techniques are sometimes used for therapeutic care of renal pedicular vascular lesions or lesions of the collecting system. Far from the traumatic event, imaging allows to follow up the morphologic and functional evolution of major renal lesions, in particular lesions of excretory renal ducts.

Late renal functional and morphological evaluation after non-operative treatment of high-grade renal injuries in children

OBJECTIVE

To assess the long-term results in children with high-grade renal trauma who were managed without surgery, as such treatment was initially successful but little is known about the late ipsilateral renal function and morphology.

PATIENTS AND METHODS

The study included 13 children (nine boys and four girls; mean age 8 years, sd 5) with high-grade renal injury who were managed without surgery between 1997 and 2001, and followed for a mean (sd, range) of 3 (2, 0.5-7) years. The trauma was caused by a motor-car accident in five and falling from a height in eight children, and was on the right in 10 and on the left in three. There was gross and microscopic haematuria in 10 and three patients, respectively. The trauma was graded according to the American Association for Surgery of Trauma, with grades III, IV and V renal injury in six, four and three children, respectively. All patients were treated initially by observation; one required super-selective embolization because of continuing haemorrhage. Three children with progressive urinary extravasation were treated with a percutaneous tube drain and JJ stent for 6 weeks. Patients were discharged after a mean (sd) hospital stay of 9 (6) days. Ultrasonography then showed resolving haematoma in all patients with a mean (sd) size of 7 (2) cm(2). At the last follow-up patients were re-evaluated by a clinical examination, renal scintigraphy and computed tomography angiography.

RESULTS

None of the children was hypertensive nor had any abnormality on urine analysis; all had normal serum creatinine levels, and scintigraphy and angiography showed normal contralateral kidneys in all. Ipsilateral abnormalities were detected in 12 patients, and included a single scar in five, multiple scars in six and a cystic lesion with multiple septa in one. There was no vascular complication or hydronephrosis, and no significant functional loss, with all affected kidneys having a split function of 41-50% at the last follow-up.

CONCLUSION

Although there is no late functional loss there are residual morphological changes in almost all children with high-grade renal injury. This study provides objective support for the non-operative management of high-grade renal injury in children, but a prolonged follow-up is warranted to assess the risk of progression of these abnormalities.

Ureteric injuries: diagnosis, management, and outcome

OBJECTIVES

To define the current causes and the optimal methods of early diagnosis and management of ureteric injuries, both iatrogenic (excluding endourologic) and traumatic, and to determine the outcome of these injuries and which identifiable factors affect this outcome.

METHODS

A retrospective analysis was performed of all the 35 patients who sustained 40 ureteric injuries over a 5-year period (1991-1996). The methods used for diagnosis and management were reviewed. The outcome was assessed in terms of preservation of renal function.

RESULTS

The study group was composed of 28 patients with 32 iatrogenic injuries and 7 patients with 8 injuries caused by external trauma. Gynecologic procedures accounted for 63% (20 of 32) of the iatrogenic injuries, whereas motor vehicle crashes accounted for 75% of the external injuries (6 of 8 injuries). The successful diagnostic rate for direct inspection (intraoperatively), intravenous urogram, retrograde pyelogram, and anterograde pyelogram were 33% for the former two and 100% for the latter two. Treatment consisted of primary open repair in 26 cases, a staged procedure in 7 cases, and endoscopic stenting in 5 cases. Of 36 cases with follow-up, complications developed in 9 cases (25%), 7 cases of which were corrected surgically. Overall incidence of nephrectomy was 8%, and the factors that seemed to affect the outcome adversely were pediatric age (< or =12 years), injury to upper ureter, delay in recognition, the presence of a urinoma, and/or associated organ injury.

CONCLUSION

Iatrogenic trauma is the leading cause of ureteric injuries. The single controllable factor adversely affecting the outcome of this rather uncommon injury seems to be delayed diagnosis. Wound inspection and intravenous urogram are not reliable for early and accurate diagnosis, and a retrograde pyelogram or an anterograde pyelogram may be needed. Uncontrollable factors adversely affecting the outcome include young age, injury to upper ureter, and associated injuries all seen in association with external trauma rather than iatrogenic injuries.