Hydronephrosis and crossing vessels in children: Optimization of diagnostic-therapeutic pathway and analysis of color Doppler ultrasound and magnetic resonance urography diagnostic accuracy.

INTRODUCTION: Ureteropelvic junction obstruction (UPJO) is one of the most frequent urological diseases affecting the pediatric population. It can be due to both intrinsic stenosis of the junction and extrinsic causes such as the presence of crossing vessels (CVs), which can be detected by color Doppler ultrasound (CD-US). Magnetic resonance urography (MRU) is a good alternative, but sedation and infusion of a contrast agent are required. OBJECTIVE: The aim of this study was to analyze the diagnostic accuracy of CD-US and MRU in visualizing CVs in pediatric hydronephrosis, in order to decide the correct diagnostic pathway in the pre-operative phase. MATERIAL AND METHODS: A retrospective review was performed of medical records for all patients who underwent surgical treatment for hydronephrosis from August 2006 to February 2016. Ultrasound and scintigraphy had been performed on all patients. Data about CD-US and MRU were collected. A high-level technology ultrasound scanner and a 1.5 T MR scanner were used. The presence of CVs at surgery was considered the gold standard. Sensitivity, specificity, positive and negative predictive values (NPV) were calculated and reported for both of the imaging techniques. RESULTS: A total of 220 clinical charts were reviewed. Seventy-three CVs were identified at surgery (33.2% of UPJO). The median age was statistically higher in the group with CVs compared to the group without CVs (P < 0.001). The sensitivity and NPV of CD-US in detecting CVs were higher than MRU (sensitivity 93.3% vs. 71.7%, NPV 95.7% vs. 77.6%, respectively). DISCUSSION: According to the data, CD-US had higher sensitivity and NPV than MRU, resulting in superior detection of CVs. It is important for a surgeon to know that a child has a CV, especially in older children in which the incidence of extrinsic UPJO is higher. The main limitation of this study was the presence of incomplete data, due to the retrospectivity. CONCLUSIONS: In the pre-operative phase, the CD-US should be considered as the investigation of choice to detect CVs in children with hydronephrosis (Summary Fig). Moreover, CD-US has lower costs than MRU, and sedation with infusion of contrast agent is unnecessary. For the future, it could be useful to lead a prospective comparison between the two imaging techniques.

Horseshoe kidney and uretero-pelvic-junction obstruction in a pediatric patient. Laparoscopic vascular hitch: A valid alternative to dismembered pyeloplasty?

Horseshoe kidney (HSK) is a congenital defect of the urinary tract that occurs in 0.25% of the general population. Laparoscopic Vascular Hitch (LVH) according to Hellstrom-Chapman represent an alternative approach in treatment of extrinsic hydronephrosis by crossing vessels (CV) in pediatric age. In our Department from 2006 to 2016, 36 children with extrinsic-Uretero-Pelvic-Junction (UPJ)-Obstruction (UPJO) underwent laparoscopic vessels transposition. Over the last 4years, we have treated three patients with extrinsic hydronephrosis in HSK; two males and one female respectively of 6, 7 and 8years. The side affected was the left in all patients; symptoms of onset: recurrent abdominal pain, vomiting with associated intermittent hydronephrosis at ultrasonography. The preoperative examinations performed were: ultrasound/Doppler scan, MAG3-renogram, functional-magnetic-resonance-urography (fMRU). Mean operative time was 120'; median hospital stay 3- days. Intraoperative diuretic-test (DT) confirmed an extrinsic-UPJO in all patients. No JJ-stents and drain were used and there were no perioperative complications. Clinical and ultrasound follow-up (18 months-4 years) show resolution of symptoms and decrease in hydronephrosis grade in all patients. Our series is the largest in pediatric population by a revision of the literature. We believe that LVH is feasible in patients with symptomatic hydronephrosis by CV in HSK. Intraoperative-DT and the correct selection of patients are crucial to the success of the technique. According to us, this procedure is appropriate in those cases where the UPJ-anatomy is disadvantageous to a resection/re-anastomosis between ureter and renal pelvis. Our initial results are encouraging, although long-term follow- up and a more significant patient sample are required.

Extraperitoneal laparoscopic pyeloplasty: a multicenter study of 55 procedures.

PURPOSE: We assessed the feasibility, reproducibility and morbidity of retroperitoneal laparoscopic pyeloplasty for ureteropelvic junction obstruction. MATERIALS AND METHODS: A total of 55 retroperitoneal laparoscopic pyeloplasties were performed at 3 institutions between September 1996 and May 2000 in 33 women and 21 men. Results were analyzed in regard to radiological assessment by excretory urography at 3 months, complications and hospital stay. RESULTS: We performed dismembered pyeloplasty in 48 cases and Fenger plasty in 7 cases. Crossing vessels were noted in 23 patients. The conversion rate was 5.4%. Mean operative time was 185 minutes (range 100 to 260), mean hospital stay was 4.5 days (range 1 to 14) and mean followup was 14.4 months (range 6 to 43.6). The overall complication rate was 12.7%. Complications in 7 patients included hematoma in 3, urinoma in 1, severe pyelonephritis in 1 and anastomotic stricture in 2 requiring open pyeloplasty at 3 weeks and delayed balloon incision at 13 months, respectively. Excretory urography in 50 patients and ultrasound in 4 showed decreased hydronephrosis in 88.9% at 3 months. Normal physical activity and absent pain were reported by 47 patients (87%) 1 month after surgery. CONCLUSIONS: Retroperitoneal laparoscopic pyeloplasty seems to be a valuable alternative to open pyeloplasty for ureteropelvic junction obstruction. The long-term outcome must be assessed before this procedure may be definitively validated.

Outpatient ureteric procedures: a new method for retrograde ureteropyelography and ureteric stent placement.

OBJECTIVE: To evaluate a new method for retrograde ureteropyelography and retrograde ureteric stent placement. PATIENTS AND METHODS: Procedures were undertaken using a flexible cystoscope and digital C-arm fluoroscopy in outpatients under sedoanalgesia. The flexible cystoscope was used to identify the ureteric orifice and a straight 0.9 mm hydrophilic guidewire inserted and passed into the renal pelvis under fluoroscopic guidance. A 4 F general-purpose catheter was then passed over the wire and ureteropyelography performed. To place the stent the hydrophilic guidewire was exchanged for an ultra-stiff wire, over which the stent was passed directly. RESULTS: Over a 47-month period, 723 procedures were carried out in 472 patients. The clinical indications were ureteric obstruction in 229 (32%), stone disease in 165 (23%), unexplained hydronephrosis in 150 (21%), haematuria in 94 (13%) and others in 85 (12%). Of the 723 procedures, 643 (89%) were technically successful. Failure was most commonly caused by failure to cannulate the ureteric orifice (51, 7%). Just over half the procedures (366, 51%) involved stent placement or replacement. Immediate complications occurred in 17 patients (3%). Of those who were questioned, 94% (282 of 300) reported the procedure to be acceptable. CONCLUSION: Retrograde ureterography and ureteric stent placement may be satisfactorily undertaken with the patient under sedoanalgesia on an outpatient basis. This technique can reduce costs, hospital admissions, general anaesthetic use, demands on theatre time and complication rates.

Urografía por RM: un método alternativo en la evaluación en pediatría del aparato urinario / MR urography: imaging alternative procedure of the urinary tract in childhood

Tomando como base las secuencias conocidas como RARE, las RM urográficas, se ha planteado como un método alternativo en la evaluación del aparato urinario. Se evaluaron 16 pacientes pediátricos, 11 niñas y 5 varones, con edades entre 4 meses y 14 años. Se investigaron: a) dilatación de la vía excretora, (6 pacientes); b) evaluación de estenosis pieloureterales, 2; c) evaluación postquirúrgica de estenosis pieloureterales, 1; d) riñón en herradura, 1; e) doble vía excretora, 3; f) en reemplazo de U.E., 2 y g) síndrome de regresión caudal, 1 paciente. Se evaluaron en forma adecuada las uropatías obstructivas, determinándose en forma exacta el punto de obstrucción, no así su causa; se logró con las imágenes obtenidas, adecuada discriminación anatómica córtico medular; también fueron satisfactorios los resultados en la evaluación de malformaciones del tipo riñón en herradura y síndrome de regresión caudal. Contrariamente no fueron buenos los resultados en la evaluación de la vía excretora. En conclusión, la RM urográfica actualmente puede ser considerada, un método válido para el estudio del tracto urinario, llegando a reemplazar al U.E. en situaciones específicas; las principales objeciones al método son su costo, las dificultades que presenta en la evaluación de vía excretora no dilatada y la necesidad de anestesiar a los menores de 5 años (AU)

[Pelvic lipomatosis. A case with ureteral and venous obstruction]. / Lipomatose pelvienne. A propos d'un cas avec obstruction urétérale et veineuse.

The authors report a case of pelvic lipomatosis in a 62 year old man associated with venous obstruction (third case reported in the literature), diagnosed after bilateral ureteric obstruction, and review of the literature on this subject. The diagnosis was suggested by the radiological triad of hyperlucency of the pelvis on plain abdominal X-ray, "hot air balloon" appearance of the bladder on IVU and a rigid and ascended rectosigmoid on barium enema, and was confirmed by CT and MRI. Treatment combining corticosteroids and urinary tract disinfection was partially effective. A double J ureteric stent resolved the problem of persistent right ureteric obstruction.

[Significance of a nonionic renographic contrast medium (Iopamidol 300) in the roentgen diagnosis of the kidneys and urinary tract in children]. / Die Bedeutung eines nichtionischen nierengängigen Kontrastmittels (Iopamidol 300) in der Röntgendiagnostik der Nieren und Harnwege bei Kindern.

The ionic contrast media used so far have been associated with considerable risks in infants and children. The high osmolality of these media did not always permit a dosage sufficient for kidney imaging in the nephrographic and in the pyelographic phase. The new non-ionic contrast media have largely reduced these risks so that their general application in infants and young children should be recommended. Intravenous urographies using the non-ionic contrast medium Iopamidol 300 (Solutrast 300) were performed in 195 children aged one day to 12 years. Good to superior urograms were obtained in 85% of the investigations. No adverse reactions caused by the osmolality of the contrast media had been observed in spite of the relative high dosage. As a result of their low osmolality and non-ionic property a safe application of high doses was possible.

Radionuclide evaluation of renal function.

The renal scintillation camera study and the excretory urogram should be considered to be complementary studies. The renal scintillation camera study provides an accurate evaluation of changes in total, differential, and segmental renal function but affords only a gross assessment of anatomic changes. The excretory urogram provides superior information about renal anatomic changes but only inferior information about functional changes of the kidney. The advantages of a renal scintillation camera study with regard to the patient are that it is done in a state of normal hydration, it requires no bowel preparation, it is not associated with allergic reactions, it provides a low radiation exposure, and it is a noninvasive procedure for differential renal function which requires no ureteral catheters.

Kidney scintigraphy with 99mTc-DMSA and 131I-hippurate.

43 patients underwent an extended scintigraphic procedure with 99mTc-dimercaptosuccinylic acid in order to investigate its proper use for diagnosing morphological and functional kidney abnormalities. The group was comprised of patients without renal disease, and patients with diffuse parenchymal disease, obstructive uropathy, renal cysts and renal tumors. The study was followed by 131I-hippurate renography. We propose a simplified routine procedure with scintiphotos taken 10-15 min after injection for topographic information and 120 min after injection for renal morphology. This procedure allows excellent case finding of diffuse parenchymal disease of a special value in cases of radiological non-visualization. The technique is indicated, when iodine contrast media cannot be used for radiological examinations. DMSA studies, however, do not allow safe functional evaluation in all categories of patients. Neither can obstructive nephropathy be diagnosed unless the renal pelvis is dilated. Renal perfusion studies are contaminated by the perfusion of liver and spleen. Nevertheless, a tentative differentiation between cysts and tumours is possible, the former being hypoperfused the latter hyperperfused. When supplemented with gamma camera 131I-hippurate renography, the total scintigraphic procedure will also include split function determination and run-off evaluation.

Radiology of the urinary tract: some physiological considerations. Annual oration in memory of John S. Bouslog, M.D., 1890-1973.

This paper reviews some of the fundamental technical and diagnostic problems in clinical uroradiology, such as (a) the reason for the obstructive nephrogram; (b) why high-dose urography gives better studies than low-dose; (c) why the Trueta phenomenon has not been demonstrated in man; (d) the case for an intrarenal arterial collateral pathway via the pericalyceal network (these vessels can be demonstrated in man and must not be misinterpreted as tumor vessels or vascular malformations). One of the most baffling problems sometimes occurs with the sudden partial block of a single segmental vessel: the kidney ceases to excrete urine and eventually becomes atrophic even though some excretory function returns. To date, there is no satisfactory explanation for this course of events.