(Paediatric) magnetic resonance urography: just fancy images or a new important diagnostic tool?

Laparoscopic pyeloplasty in children with horseshoe kidney

PURPOSE

Laparoscopic pyeloplasty for ureteropelvic junction obstruction associated with horseshoe kidney has been described in adults but seldom in young children. We describe our experience in 10 children treated successfully with laparoscopic dismembered pyeloplasty.

MATERIALS AND METHODS

Eight boys and 2 girls with a mean age of 8 years (range 0.7 to 16.5) underwent laparoscopic dismembered pyeloplasty for ureteropelvic junction obstruction associated with horseshoe kidney between 2002 and 2012. Presenting symptoms were abdominal pain (3 patients), urinary tract infection (2), abdominal mass (1) and hematuria (1). Horseshoe kidney was diagnosed preoperatively in all cases but 1. The anastomosis was done by running or interrupted 5-zero or 6-zero resorbable sutures and drained by a Double-J® stent.

RESULTS

Laparoscopic dismembered pyeloplasty was feasible in all cases. Mean operating time was 220 minutes (range 180 to 260). Anatomical abnormalities included anteriorly crossing vessels at the ureteropelvic junction in 6 cases (polar vessels in 4, ureteropelvic junction posterior to an abnormal branch of vena cava in 1 and renal vein in 1) and high ureteral insertion in 4. Two children underwent an extensive reduction pyeloplasty. Mean hospital stay was 3.2 days (range 1 to 8). Mean followup was 50 months (range 4 to 132). All patients were asymptomatic with significant improvement of dilatation.

CONCLUSIONS

The transperitoneal laparoscopic approach is adapted for pyeloplasty in children with horseshoe kidney. This procedure allows global exploration of the upper tract and efficient identification of anatomical anomalies, especially crossing vessels. Although our series is small, it is the first known description specific to horseshoe kidney in children and demonstrates that this approach has lasting effectiveness in young children.

[Primary megaureter]

A primary megaureter is an anomaly with a prevesical or overall dilated ureter of more than 6 mm in diameter. It is important to distinguish between cases of primary non-refluxing and primary obstructive-refluxing megaureters, as the treatment of both is completely different. The basic diagnostic work-up includes ultrasonography and voiding cystourethrography. Diuretic renography is used to detect split renal function and the degree of upper urinary tract obstruction. In most cases of primary non-refluxing megaureter surgical treatment is unnecessary due to the high remission rate, whereas obstructive refluxing megaureters commonly only need to be corrected. Antibiotic prophylaxis may be indicated in infants with a primary obstructive megaureter during the first 6 months of life due to a higher risk of complications due to pyelonephritis especially in this age group.

Imaging chronic renal disease and renal transplant in children

At Great Ormond Street Hospital we have the highest number of paediatric renal transplant patients in Europe, taking cases from across the United Kingdom and abroad. Our caseload includes many children with rare complicating medical problems and chronic renal failure related morbidity. This review aims to provide an overview of our experience of imaging children with chronic renal failure and transplants.

High resolution MR for evaluation of lower urogenital tract malformations in infants and children: feasibility and preliminary experiences

INTRODUCTION

This retrospective study aimed to assess the value of supplementing heavily T2-weighted, high resolution MR-imaging for detailed anatomic assessment in paediatric lower urogenital tract (UGT) malformations.

PATIENTS/METHODS

Sixteen patients (6 male and 10 female, median age=1.8 years, range=0-9 years) with suspected malformations of the lower UGT who were retrospectively identified from the PACS underwent a clinically indicated standard MR-urography study. In order to facilitate a better anatomic assessment of questioned specific lower UGT structures, an additional three-dimensional Constructive Interference in Steady State-sequence (3D-CISS) had been acquired in these patients. The final diagnosis was established by all imaging results and surgical or laprascopic findings. The findings from the CISS-sequence were compared to the results from standard MR-urography for complementary anatomic information and conspicuity.

RESULTS

Diagnostic 3D-CISS image quality was achieved in all patients. The 3D-CISS confirmed an ectopic ureteral insertion in six patients and reliably excluded ectopic insertion in 10 patients, whereas conventional MR-urography showed an ectopic insertion of the ureter in one case. In six patients with retrovesical complex formations (suspicious for an ectopic cystic renal bud or a cystic genital structure) the 3D-CISS showed increased conspicuity scores for image quality.

CONCLUSION

The additional 3D-CISS-sequence increases the diagnostic yield in the pelvis in children with complex malformations of the lower UGT such as ectopic ureteral insertion or suspected cystic renal or genital malformations at only minimal additional time, compared to standard MR-urography.

Value of comprehensive renal ultrasound in children with acute urinary tract infection for assessment of renal involvement: comparison with DMSA scintigraphy and final diagnosis

The aim of this study was to evaluate the value of comprehensive renal ultrasound (US), i.e., combining greyscale US and amplitude-coded color Doppler sonography (aCDS), for assessment of urinary tract infection (UTI) in infants and children, compared to (1) (99m)Tc DMSA scintigraphy and (2) final diagnosis. Two hundred eighty-seven children with UTI underwent renal comprehensive US and DMSA scintigraphy. The results were compared with regard to their reliability to diagnose renal involvement, using (1) DMSA scintigraphy and (2) final diagnosis as the gold standard. Sixty-seven children clinically had renal involvement. Sensitivity increased from 84.1% using only aCDS to 92.1% for the combined US approach, using DMSA scintigraphy as the reference standard. When correlated with the final diagnosis, sensitivity for DMSA scintigraphy was 92.5%; sensitivity for comprehensive US was 94.0%. Our data demonstrate an increasing sensitivity using the combination of renal greyscale US supplemented by aCDS for differentiation of upper from lower UTI. Sensitivity for DMSA and comprehensive US was similar for both methods compared to the final diagnosis. Comprehensive US should gain a more important role in the imaging algorithm of children with acute UTI, thereby reducing the radiation burden.