Diuretic Renography Research Articles

Is One Early Renographic Follow-Up Adequate to Measure the Success of Robotic Pyeloplasty?

Diuretic renography (DRG) is commonly used to diagnose ureteropelvic junction obstruction (UPJO) and to evaluate the success of surgical repair (pyeloplasty). Duration, frequency, and interpretation of renographic follow-ups are still under dispute. We retrospectively reviewed 94 consecutive patients diagnosed with UPJO who underwent a minimally invasive, robotically assisted laparoscopic pyeloplasty at our institution between January 2009 and September 2015. DRG was carried out preoperatively and again routinely 4 to 6 weeks postoperatively the day after stent removal (early DRG). Patients were scheduled for repeat (late) DRG and follow-up examinations, including clinical status and ultrasonography. Nineteen patients with missing preoperative DRG were excluded from the study; the remaining 75 patients were eligible for statistical evaluation. At follow-up, 98.7% reported no or only very mild and rare symptoms. On early DRG, 52.5% had T1/2 ≤ 10 min (unobstructed), 39.3% had T1/2 between 10 and 20 minutes (equivocal), and 8.2% had T1/2 ≤ 20 minutes (obstructed). At late follow-up, the DRG results had improved to 80.8% unobstructed with 19.2% remaining equivocal, and no patients were obstructed; thus, the overall success rate was 80.8%. There was only one patient who worsened from unobstructed to equivocal from early to late DRG assessment. In case of complete symptom resolution, a nonobstructive diuretic half-time of ≤10 minutes on early DRG following stent removal suggests that further routine renographic follow-up is unnecessary. Patients with an equivocal early DRG (T1/2 between 10 and 20 minutes) require further scintigraphic follow-up, as they have a 42.1% chance of staying equivocal.

Functional and Morphological Outcomes of Pyeloplasty at Different Ages in Prenatally Diagnosed Society of Fetal Urology Grades 3-4 Ureteropelvic Junction Obstruction: Is It Safe to Wait?

To evaluate changes in functional and morphological outcomes in children with prenatally diagnosed Society of Fetal Urology (SFU) grades 3-4 ureteropelvic junction obstruction (UPJO) who underwent pyeloplasty at different ages. We also examined the effect of surgical wait time on recovery of renal function. All patients (aged 0-12 months) with prenatally diagnosed SFU grades 3-4 UPJO who underwent pyeloplasty in a single center between January 2013 and December 2015 were reviewed. One hundred thirty-three children were enrolled in this study. The children were divided into 2 groups according to their age at the time of surgery (group I: 0-3 months, group II: 3-12 months). We evaluated changes in parenchymal thickness, anteroposterior diameter (APD), and differential renal function (DRF) using ultrasound and diuretic renography. Functional and morphological outcomes were compared using Student t test. A total of 133 patients were included in the study. We found a significant difference in the change of DRF (difference between before and after pyeloplasty) between the 2 groups (P < .05). There were no significant differences in changes in parenchymal thickness and APD. Patients who waited 1-2 months had a significantly lower functional improvement compared with those who waited less than 1 month. Early surgery leads to a significant improvement in DRF. Wait times greater than 1 month can decrease functional improvement. For patients with prenatally diagnosed SFU grades 3-4 UPJO, early pyeloplasty is recommended in those with increasing renal pelvic APD and an obstructed renogram with differential renal function <40%.

Laparoscopic Pyeloplasty: Always Dismembered?

To compare three laparoscopic surgical techniques for the treatment of ureteropelvic junction obstruction (UPJO), assessing their difficulty, operating time, effectiveness, and complications. The clinical histories of 54 patients with UPJO who underwent a laparoscopic procedure between June 2003 and September 2013 were reviewed. Anderson-Hynes (A-H) pyeloplasty was performed on 34 patients, nondismembered pyeloplasty on 11 cases (8 Y-V Foley plasty and 3 Fenger plasty), and cephalad vascular displacement or Hellström technique (HT) on 9 patients. The patients were selected for the different techniques depending on the findings during the procedures, according to renal pelvic size and the presence of crossing vessels. We compared the techniques according to intraoperative and postoperative outcomes. Complications were interpreted following the Clavien-Dindo classification. The success rate was defined as the absence of clinical symptoms and normal diuretic renography. Analysis of variance and chi-square tests were used for the statistical analysis. Mean follow-up was 55.58 months. The success rate achieved was 88.5% for A-H pyeloplasty, 90.9% for nondismembered pyeloplasty, and 100% for HT (p > 0.05). HT was the least time-consuming: 124 ± 30 vs 202 ± 44 minutes of A-H pyeloplasty and 147 ± 27 minutes of nondismembered plasty (p < 0.005). Mean hospital stay was 6.7 ± 1.4 days for A-H pyeloplasty, 6.6 ± 2 days for nondismembered pyeloplasty, and 3.42 ± 1.5 days for HT (p < 0.05). The postoperative complication rate was 21.1% for A-H pyeloplasty, 18.8% for nondismembered pyeloplasty, and 12.5% for HT (p > 0.05). None of the cases required open surgery, and urinary fistula was the most frequent complication. Intraoperative observation of ureteropelvic junction allows selecting cases to undergo nondismembered pyeloplasty techniques, achieving similar results to A-H pyeloplasty, reducing operating time, complication rate, and hospital stay.

Benefit of F-15 protocols in equivocal F + 20 MAG3 renography in children with upper tract dilatation and symmetric split function: Results and outcomes

In children with upper tract dilatation, diuretic renography, which includes application of mercaptoacetyltriglicin-99mTc (MAG3), is the standard examination. Ordinarily, furosemide is applied 20min after tracer injection (F+20). In children with persistent hydronephrosis and preserved split function, this protocol may lead to further examinations with repeatedly equivocal washout curves. The present study evaluated the potential of MAG3 (F-15) scans in this subgroup of children to achieve a conclusive result avoiding additional equivocal MAG3 (F+20) scans. To evaluate whether the washout curve using the F-15 protocol is a helpful criterion with which to clarify results in patients with equivocal patterns in the F+20 protocol. 31 children (male/female 22/9, median age at time of examination 42 months, mean anterioposterior diameter 2.1cm, left/right 14/18) underwent MAG3 F-15 renography at the present department because of upper urinary tract dilatation and (repeatedly n≥2F+20=28) equivocal results in MAG3 F+20 examinations. In 10/31 children (32.2%), MAG3 F-15 revealed an obstructive pattern, indicating a pyeloplasty in 9/10 of them (90%). In 16/31 children (51%), the F-15 protocol showed a non-obstructive curve, leading to further uneventful follow-up in 15/16 of them (93.7%). In 5/31 children (16%), MAG3 F-15 led to equivocal results, resulting in no pyeloplasty and further uneventful follow-up in all the children (mean follow-up 1.46 years). In children with persistent high-grade hydronephrosis on ultrasound and preserved split function, multiple scans were prompted and further management was sometimes difficult. Although there was proven evidence that the F-15 protocol reduced the frequency of equivocal pattern, there was no indication for primary F-15 investigation, due to the risk of over diagnosis of obstruction. The F-15 scan was considered to be a stress test of the upper tract leading to a diuretic challenge without any opportunity to investigate normal washout curve. In these cases, partial obstruction could lead to false positive obstructive results. A stepwise approach, in which the traditional F+20 technique allows observation of the rate of washout of radiopharmaceuticals before forced diuresis followed by a F-15 protocol, could reduce the child's additional radiation burden and stress. After equivocal results in MAG3 F+20 protocols, performing a MAG3 F-15 exam lead to a conclusive result in 80.6% (25/31 patients) of the cases. Thus, performing a MAG3 (F-15) exam can be recommended in children with persistent hydronephrosis and preserved split function after equivocal results on MAG3 (F+20) scans.

Early mercaptoacetyltriglycine(MAG-3) diuretic renography results after pyeloplasty.

To describe the drainage and functional outcome of paediatric pyeloplasty, 1 week after stent removal 7-9 weeks after pyeloplasty using diuretic renography. Between 2009 and 2014, we assessed the functional and drainage outcomes according to mercaptoacetyltriglycine MAG-3 diuretic renograms from 66 children (69 kidneys) who underwent modified dismembered Anderson-Hynes pyeloplasty for pelvi-ureteric junction (PUJ) obstruction. Stents were left in place for 6-8 weeks and postoperative renal units were evaluated with MAG-3 renogram 1 week after stent removal. Surgical success was defined by improvement of drainage (half clearance time [T/2] < 20 min), stable or improved function on the postoperative MAG-3 renogram and by decreased pyelocaliceal dilatation on ultrasonography (US) at 1 year. Of the 69 kidneys with a preoperative median range T/2 of 33.4 (7.6-200) min, 60 (87%) had improved drainage curves, with a median (range) T/2 of 6.9 (1.6-19) min. Thirteen percent (9/69) had persistent impaired drainage, with a median (range) T/2 of 36 (24-108) min. Of these nine children, one girl was found to have a persistent obstructive pattern (T/2 = 30 min) associated with a decreased split renal function (SRF; from 42 to 33%) and persistent hydronephrosis (at 28 mm). Redo pyeloplasty was performed 2 months after the initial procedure (and 18 days after stent removal) and renal function recovered to 47%. The remaining eight patients were free of symptoms; hydronephrosis improved at 1 year (anteroposterior diameter decreased from 28 to 18.5 mm; P = 1.94) and SRF remained stable (44.5 vs 48.5% after repair; P = nonsignificant). In the 29% of kidneys (20/69) that had preoperative impaired SRF, postoperative renal function improved in 75% (from 27.5 to 43%; P < 0.001), remained unchanged in 2% and one kidney (0.2%) deteriorated. The median (range) postoperative follow-up was 18 (12-90) months. There is no agreement regarding the 'gold standard' investigation to use after pyeloplasty for PUJ obstruction. Improvement in hydronephrosis on US is slow and often takes > 12 months. Based on animal studies, it is possible that missed recurrent obstruction will cause irreversible loss of renal function after 6 weeks; therefore, early postoperative assessment is desirable, but there have been few reports on urinary drainage changes with early diuretic renography after pyeloplasty. Most of the renal units had improved drainage on diuretic renography 7 weeks after pyeloplasty and 1 week after stent removal. An early diuretic renogram is a reliable method of documenting surgical success after pyeloplasty.

Gravity-assisted drainage imaging in the assessment of pediatric hydronephrosis.

As early detection of hydronephrosis increases, we require better methods of distinguishing between pediatric patients who require pyeloplasty vs. those with transient obstruction. Gravity-assisted drainage (GAD) as part of a standardized diuretic renography protocol has been suggested as a simple and safe method to differentiate patients. Renal scans of 89 subjects with 121 hydronephrotic renal units between January 2004 and March 2007 were identified and analyzed. Of all renal units, 65% showed obstruction. GAD maneuver resulted in significant residual tracer drainage in eight renal units, moderate drainage in 12 renal units, and some improvement in 40 units after the GAD maneuver. Of the eight renal units with significant residual tracer drainage, only two proceeded to pyeloplasty. After pyeloplasty, nine children had improved time to half maximum (T(1/2) Max) and 13 were unchanged. Our study was limited due to its retrospective design and descriptive analyses, but includes a sufficient number of subjects to conclude that GAD as part of a diuretic renography protocol is an effective and simple technique that can help prevent unnecessary surgical procedures in pediatric patients.

Robotic-assisted Laparoscopic Pyeloplasty: Analysis of Symptomatic Patients With Equivocal Renal Scans

To review the objective and subjective success rates of robotic-assisted laparoscopic pyeloplasty in symptomatic patients with radiographic findings suggestive of uretero-pelvic junction obstruction (UPJO), but equivocal renal scans (diuretic T1/2 <20 minutes). We reviewed 77 patients with symptomatic UPJO, who underwent robotic-assisted laparoscopic pyeloplasty between August 2006 and March 2013. We grouped patients by renal scan findings into 1 of 2 groups, obstructed (diuretic T1/2 ≥20 minutes) or equivocal (diuretic T1/2 <20 minutes). All patients were symptomatic and had radiographic findings suggestive of UPJO (eg hydronephrosis). Mean age was 40.7 years (range 17-80) with 70% female. UPJO occurred 44% left and 56% right, with 92% presenting with flank pain. Of 77 patients, 45 had obstruction on renal scan, with 41 (91%) having resolution of obstruction postoperatively and 44 of 45 (98%) having complete resolution of their initial symptoms. Thirty-two patients had equivocal findings with mean diuretic T1/2 of 12.6 minutes (range: 5.5-19.26) on renal scan. In this latter group, patients had significantly less of a decrease in their diuretic T1/2 postoperatively (4 vs 64 minutes, P = .018) and reported less pain resolution (53% vs 98%, P ≤.001) than group 1. Many studies have demonstrated excellent success of pyeloplasty, with most series including patients meeting strict diagnostic criteria for obstruction. Our study examines outcomes in patients with clinically symptomatic UPJO and equivocal diuretic renography. In our cohort, equivocal patients were significantly less likely to have subjective resolution of symptoms than patients in the obstructed group.

Initially Asymmetrical Function on MAG3 Renography Increases Incidence of Adverse Outcomes

To discriminate pathological from physiological hydronephrosis (99m)Tc-mercaptoacetyltriglycine (MAG3) diuretic renography is a fundamental imaging modality. Initial asymmetrical differential function or decreasing function on serial MAG3 scans is a classic surgical indication. However, prognostic evidence supporting this is limited. Therefore, we examined the association between initial function and outcomes. We hypothesized that patients with initially asymmetrical function would have higher odds of functional decline, and experience symptoms and surgical intervention compared to patients with initially symmetrical scans. We retrospectively reviewed the charts of 1,124 pediatric patients with hydronephrosis seen at Stollery Children's Hospital from 2000 to 2014. A total of 387 cases of unilateral ureteropelvic junction obstruction were grouped by initial postnatal differential function with asymmetrical defined as a greater than 10% difference in relative function. Postnatal surveillance, followup MAG3 results, pyeloplasty rates and post-pyeloplasty outcomes were compared. Of 387 patients 143 (37%) had initially asymmetrical function. Of those undergoing MAG3 scan surveillance 17% experienced a 10% or greater decline in ipsilateral differential function vs a 6% rate of function loss in the initially symmetrical group (OR 3.2, 95% CI 1.6-6.4, p = 0.0008). The overall pyeloplasty rate in patients with asymmetrical and symmetrical function was 27% and 16%, respectively (OR 1.9, 95% CI 1.1-3.2, p = 0.013). Patients with initially asymmetrical function had an increased rate of pyeloplasty secondary to symptoms compared to those with initially symmetrical function (16% vs 8%, OR 2.1, 95% CI 1.1-4.0, p = 0.019). Mean time to functional decline and pyeloplasty was 19and 17 months, respectively. Patients with initially asymmetrical differential function had increased ORs for subsequent renal decline, symptom onset and pyeloplasty.

Comparison Between Diuretic Urography (IVP) and Diuretic Renography for Diagnosis of Ureteropelvic Junction Obstruction in Children.

Background:Ureteropelvic junction obstruction (UPJO) is one of the most common causes of urinary tract obstruction in children. Several methods are used to diagnose upper urinary tract obstruction including renal ultrasonography (US), intravenous pyelogram (IVP), diuretic renography (DR), magnetic resonance urography (MRU) and antegrade or retrograde pyelography. Nowadays it is suggested to use diuretic renography as the best method for diagnosing of UPJO. There is no comparative study between IVP and DR scan for diagnosis of UPJO in children.Objectives:The aim of the present study was to compare IVP with furosemide injection and diuretic renography in diagnosis of clinically significant UPJO.Patients and Methods:This was a cross sectional study performed in 153 UPJO suspected children (121 boys, 32 girls) based on US findings in cases presented with urinary tract infection (UTI), prenatal hydronephrosis, abdominal/flank pain, abdominal mass and hematuria. Renal ultrasound was used as an initial screening tool for detection of urinary tract abnormality. Vesicoureteral reflux (VUR) was ruled out by voiding cystourethrography (VCUG). Serum creatinin, blood urea nitrogen, urinalysis and urine culture was screened in all cases. IVP with furosemide and DR were performed as soon as possible after the mentioned workup.Results:During a five year period, 46 out of 153 patients were diagnosed as UPJO based on diuretic renography: the age ranged from 4 months to 13 years (mean: 3.1 ± 0.78 years). There was a significant higher (76%) proportion of UPJO in the boys and in the left side (78%). The sensitivity of IVP with furosemide injection in diagnosis of UPJO was 91.3% whereas DR was accepted as standard for diagnostic procedure in diagnosis of UPJO.Conclusions:Although DR is accepted as the best method for diagnosis of UPJO, we found a small sensitivity difference between IVP and DR in kidneys with normal or near normal function. In many settings such as small cities lacking facilities for advanced isotope imaging technology, use of IVP with diuretic maybe an acceptable procedure for diagnosis of UPJO.

Late outcomes of laparoscopic pyeloplasty: a single institution study with follow-up longer than 5 years.

IntroductionAlthough most urologists agree that failures after laparoscopic pyeloplasty occur usually within a year after the operation, late failures are also reported.AimTo assess late results of laparoscopic pyeloplasty.Material and methodsSeventy-eight of ninety-five patients who had been operated on between November 2001 and September 2009 were notified about the possibility of diuretic renography (DR). Excluded from the study were 3 patients who failed within 1 year after surgery, 2 others with late recurrences at 1.5 and 2.5 years postoperatively, 8 patients who were lost to follow-up immediately after the operation, 2 patients with equivocal DR after pyeloplasty and 2 cases with open conversion. Twenty-six (33.3%) patients responded to the notification. Mean follow-up was 89 months. In all patients DR, ultrasound, serum creatinine concentration, estimatated glomerular filtration rate and the assessment of symptoms were carried out. Success was defined as T1/2 ≤ 12 min and improved or stable differential renal function on DR.ResultsDiuretic renography revealed no obstruction in 25/26 (96%) patients. One woman was not appropriately hydrated, which rendered the result of the investigation unreliable. Mean half time to tracer clearance was 6.74 min. Mean split renal function on the operated side was 44.62%. Mean pain strength according to the VAS scale was 1.54.ConclusionsOur study seems to indicate that recurrence after laparoscopic pyeloplasty in the follow-up period longer than 5 years is very unlikely. However, until more data are available, patients should undergo long-term follow-up to receive the benefit of the operation.

Morphological and functional outcome of dismembered pyeloplasty in children with unilateral ureteropelvic junction obstruction

ObjectiveTo evaluate the morphological and functional outcome of dismembered pyeloplasty in children with unilateral ureteropelvic junction obstruction (UPJO). Patients and methodsWe retrospectively reviewed the medical records of all children subjected to dismembered pyeloplasty in the department of urology at Al-Azhar University hospitals between January 2004 and December 2011. The preoperative data included the personal history and imaging. Furthermore, the details of surgery and the postoperative course were evaluated. Only children with primary unilateral UPJO were included in this study. Preoperative radiological assessment included renal ultrasonography, magnetic resonance urography (MRU) and diuretic renography for all patients. All cases showed hydronephrosis with an obstructive renal pattern. Dismembered pyeloplasty (Andersen-Hynes) was performed via an open or laparoscopic approach. All cases were followed up clinically and radiologically at regular intervals for the assessment of both morphological and functional outcome. Success was defined as both symptomatic relief and radiographic resolution of obstruction at the last follow-up visit. ResultsDuring the study period, 83 children were subjected to dismembered pyeloplasty for the treatment of UPJO. Two thirds of the cases were boys. The median age was 4 years (range: 2 months to 17 years). Mean follow-up was 53 (range 14–96) months. The overall success rate was 94% with success being defined as stability or improvement of split renal function (SRF) with no further symptoms. Secondary procedures were needed in 5 patients (6%) showing deterioration of SRF. One patient underwent redo pyeloplasty, whereas endopyelotomy was done in 4 cases. In the remaining 77 patients (94%), radiological follow-up revealed stability or improvement of SRF with no further symptoms. Postoperative diuretic renography showed normal drainage in 52 (62.7%) and prolonged drainage in 31 cases (37.3%). Stability or improvement of hydronephrosis was seen in 75 (90.4%) cases. ConclusionDismembered pyeloplasty is a safe and effective treatment of UPJO in children, not only relieving obstruction but also improving renal function.

Delayed renal tissue tracer transit in Tc-99m-DTPA renography correlates with postoperative renal function improvement in UPJO patients.

The aim of the study was to explore the potential parameters for evaluating the improvement in relative renal function (RRF) in patients with unilateral ureteropelvic junction obstruction (UPJO) who underwent surgery. In this regard we observed the RRF expressed as the obstructed kidney's percentage contribution to overall renal function in technetium-99m diethylenetriaminepentaacetic acid (Tc-99m-DTPA) diuretic renography. Data on 47 patients, who underwent Anderson-Hynes pyeloplasty for diagnosed unilateral UPJO during the period of February 2003 to October 2014, were retrospectively collected. Tc-99m-DTPA diuretic renography was performed on all patients before and after surgery, and no morphological or functional abnormalities were detected on the contralateral kidney. Several parameters, especially renal tissue tracer transit (TTT), the response to furosemide stimulation, and RRF, were evaluated. All data were analyzed with the statistical software SPSS, 17.0, and a value of P less than 0.05 was considered statistically significant. Data on 42 patients were eventually retained for further analysis; five patients were excluded because of indeterminate TTT. All patients showed obstructive response to furosemide stimulation with a preoperative RRF of 41±12%. Postoperative RRF of the obstructed kidneys was 47±11%, significantly higher than the preoperative RRF (P<0.05). Postoperative RRF improvement (absolute increment≥5%) was seen in 18/42 (43%) patients, and 24/42 (57%) of them manifested with postoperative drainage improvement. After surgery, both the RRF increment and the percentage of patients with postoperative RRF improvement in the preoperative delayed TTT group were significantly higher than those in the normal TTT group (12±7 vs. 2±4%, and 81 vs. 19%, respectively; P<0.05), but no significant difference in postoperative drainage improvement was detected between the two groups (56 vs. 54%, P>0.05). None of the other factors, including the preoperative RRF, obstructed kidney location, surgical method, sex, and age, had a significant influence on postoperative RRF improvement (P>0.05). Preoperatively delayed TTT of Tc-99m-DTPA diuretic renography was an independent factor that correlated with RRF improvement of unilaterally hydronephrotic kidneys, and might provide valuable information for surgical decisions pertaining to UPJO patients.

Laparoscopic repair of congenital midureteric strictures in infants and children

PurposeCongenital midureteric strictures (CMUS) are an uncommon cause of obstructive uropathy. There are only a few case reports of laparoscopic management of CMUS. We present our experience with laparoscopic repair of CMUS in 7 children. Patients and methodsThe records of all children (n=7, 5 infants) undergoing laparoscopic reconstruction for CMUS were reviewed. Preoperative imaging included ultrasound (US) and diuretic renography (DR) in all children. Intravenous urography or magnetic resonance urography was performed in 3 children when a dilated ureter was seen on the ultrasound. Retrograde pyelography was performed in 6 children before definitive surgery. All children underwent transperitoneal laparoscopic excision of the stricture with ureteroureterostomy. Follow-up included clinical examination and US in all children, with DR in 5 children. ResultsOver a 3-year period, 7 children underwent laparoscopic repair of CMUS. Six children had antenatally diagnosed hydronephrosis, while one child presented with infected hydronephrosis, underwent nephrostomy and was later referred to us. The diagnosis of CMUS was suspected preoperatively in 4 children; in 3 children, diagnosis of CMUS was confirmed on retrograde pyelography. Laparoscopic repair was successfully completed in all children; there were no significant intraoperative or postoperative complications. At a median follow-up of 18months, all children are asymptomatic, with US (7) and DR (5) confirming significant reduction in the hydronephrosis and improved drainage. The cosmetic results have been excellent. ConclusionTo our knowledge, this is the first report of laparoscopic repair of CMUS in children. Laparoscopic repair of CMUS can be safely and successfully performed even in small infants, with good results.

Evaluation and Management of Antenatal Hydronephrosis

Antenatal hydronephrosis (ANH) is one of the most common abnormal findings detected on prenatal ultrasound (US), and it has been reported in 1-5% of all pregnancies. The likelihood of significant postnatal pathologic abnormality in the urinary tract correlates with the degree of anterior-posterior diameter (APD) according to the gestational age. Detection of urologic anomalies prenatally permits fetal interventions that avoid complications in rare cases of bladder outlet obstruction with oligohydramnios even though their final benefits still remain controversial. There is no clear consensus on the extent and mode of postnatal imaging after a diagnosis of ANH. US is the mainstay of the postnatal evaluation and helps guide further testing with voiding cystourethrography (VCUG) and diuretic renography. Although most algorithms continue to recommend generous VCUG for identification of lower urinary tract anomalies, VCUG may be safely reserved for high grade ANH cases or any grade of ANH with dilated distal ureter without increasing the risk of urinary tract infection (UTI). There are conflicting studies about efficacy of postnatal prophylactic antibiotics. It still seems reasonable to consider use of a prophylactic antibiotic to prevent infant UTIs in high-risk populations, such as females and uncircumcised males with high grades of hydronephrosis, hydroureteronephrosis, or vesicouretral reflux.

Use of Self-Expanding Metallic Ureteral Stents in the Secondary Treatment of Ureteral Stenosis Following Kidney Transplantation.

To evaluate the safety and efficacy of self-expanding metal stents in the treatment of ureteral stenosis following kidney transplantation. Seven patients who developed benign stenosis after kidney transplantation were treated by a self-expanding metallic stent implantation from June 2007 to March 2014. All patients had undergone at least one open surgical procedure and one endourologic procedure for treatment of the stenosis. The extent of stenosis varied from 1.2 to 3.7 cm. Ultrasonography, urography, diuretic renography, and urine culture were performed every 3 months after stent insertion. Ureteroscopic examination was performed when needed. Stent placement was technically effective in all cases. The mean operative time was 37 minutes (range, 26-59 minutes). Lower urinary-tract symptoms and the ipsilateral flank pain were common early-stage complications and were greatly relieved after an average of 3 months. The mean follow-up duration was 38 months (range, 13-86 months), and no stent migration or fragmentation was observed. Urothelial hyperplasia occurred in only one patient and was effectively managed with a Double-J stent. Five patients had normal stable renal function; the remaining two had impaired renal function, including one patient with a preoperative renal failure who required dialysis at the end of the follow-up period (36 months). As an alternative to open surgery, implantation of a self-expanding metal stent is a safe and effective treatment for ureteral stenosis in patients who have undergone kidney transplantation.

National Trends in Followup Imaging after Pyeloplasty in Children in the United States

Radiographic followup after pyeloplasty for the correction of ureteropelvic junction obstruction is not well defined in children. We characterize trends in frequency and modality of postoperative imaging after open and minimally invasive pediatric pyeloplasty. Using the MarketScan® database, we identified patients 0 to 18 years old undergoing pyeloplasty between 2007 and 2013. Followup imaging was classified as functional (diuretic renography, excretory urography) or nonfunctional (ultrasound, computerized tomography, magnetic resonance imaging). We excluded patients with less than 24 months of postoperative enrollment in MarketScan. Multivariate logistic regression was performed to determine associations between demographic variables and imaging use patterns. We identified 926 patients with a mean ± SD followup of 3.6 ± 1.3 years, of whom 30% underwent minimally invasive pyeloplasty. Overall 5.9% of patients had no postoperative imaging available. Within the first 6 months postoperatively 853 patients (91%) underwent at least 1 imaging study and 192 (24%) underwent renography. Within the first 12 months postoperatively 91% of patients underwent at least 1 imaging study, most commonly ultrasound. After 12 months almost a third of the patients were not followed with imaging. Of the 71% undergoing imaging most underwent ultrasound. Younger age and female gender were independently associated with frequent imaging (at least yearly) on multivariate logistic regression. Following pediatric pyeloplasty there is variation in modality and frequency of imaging followup. The majority of patients are followed with renal ultrasound, with less frequent use of functional imaging. Almost a third of patients do not undergo followup imaging after 1 year.

Sonographic Evaluation of Hydronephrosis in the Pediatric Population

Standardized protocols exist for diuretic renography. There are no specific guidelines regarding hydration before renal sonography. This study assessed the importance of the hydration status by sonographic measurements of the anteroposterior diameter and its effect on Society for Fetal Urology (SFU) hydronephrosis grading. Children aged 6 weeks to 16 years (mean age, 22 months) with unilateral SFU grade 3 or 4 hydronephrosis requiring diuretic renal scintigraphy were recruited to undergo prehydration and posthydration renal sonography. Hydrated diuretic renal scintigraphy, or "well-tempered" renography, was then performed. Renal sonograms were reviewed by a blinded pediatric radiologist and pediatric urologist. Two-sided statistical tests assessed whether SFU grades and the anteroposterior diameter changed significantly after hydration. Among 67 kidneys, the pediatric urologist (L.P.M.) and pediatric radiologist (V.J.R.) reported no SFU grade change in 45 (67%) and 52 (78%) kidneys after hydration. In kidneys that changed, the posthydration grade was more likely to be higher. This difference was statistically significant (14 of 22 and 13 of 15 differences were higher grades after hydration for L.P.M. and V.J.R., respectively; P= .06; P= .007). Most kidneys that changed with hydration differed by only 1 SFU grade. Differences greater than 1 grade were seen in 5 control kidneys, which increased from SFU grade 0 to 2. The mean anteroposterior diameter increased significantly between prehydration and posthydration sonography for both hydronephrotic kidneys (1.46 versus 1.72 cm; P< .001) and control kidneys (0.22 versus 0.39 cm; P= .019), but did not correlate with increased SFU grades. Hydration does have a substantial effect on the anteroposterior diameter, but it does not correlate with a substantial effect on the SFU grade; therefore, well-tempered sonography seems unnecessary.

Does the histopathologic pattern of the ureteropelvic junction affect the outcome of pyeloplasty.

To investigate the effects of the histopathologic pattern of obstructed ureteropelvic junction (UPJ) specimens, including collagen type 3, elastin, fibrosis and Cajal cells, on the outcome of pyeloplasty. Histopathological specimens obtained following Anderson-Hynes pyeloplasty from 52 patients with intrinsic ureteropelvic junction obstruction (UPJO) between January 2005 and January 2008 were evaluated histopathologically. Patients with extrinsic or secondary UPJO were excluded. Preoperative and postoperative radiographic evaluations were performed either via diuretic renography or intravenous pyelography, or both. Six months post-surgery the patients were divided into 2 groups, as successful surgery (group 1) and unsuccessful surgery (group 2). Histopathological findings (collagen type 3, elastin, fibrosis and Cajal cells) in each group were statistically compared. The study included 52 patients (21 female and 31 male). Mean age of the entire study population was 39.42 ± 14.5 years, versus 39.63 ± 14.9 years in group 1 (n = 47) and 37.4 ± 10.0 years in group 2 (n = 5). Median follow-up was 18 months. There weren't any significant differences in collagen type 3, elastin, fibrosis, or Cajal cells between the 2 groups (P > .05). The histopathologic pattern of UPJ was not a factor associated with the success of pyeloplasty. Based on the present findings, we conclude that surgical technique is more important than the histopathologic pattern of UPJ for the successful treatment of UPJO.

Novel augmentation ileocystoplasty technique to manage non-compliant bladders in the presence of obstructed megaureters: the "fez procedure".

To show the efficacy and safety of a novel modification of Studer's neobladder, herein defined as the "fez procedure." The medical records of 21 children (mean age 9.4 ± 1.3 years) who underwent the "fez procedure" at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, to manage refractory poorly-compliant bladders and concomitantly obstructed megaureters were retrospectively reviewed. The patients had been previously managed by either preliminary cutaneous ureterostomy (17 patients) or temporary nephrostomy (four patients) to improve and stabilize the renal functions. The "fez procedure" entailed augmentation ileocystoplasty and the use of an afferent tubularized ileal loop for direct ureteroileal anastomosis. The augmented bladder together with the tubularized loop were fashioned as a "fez" with its tassel. The outcome measures were changes in cystometric capacity, bladder compliance, glomerular filtration rate, serum creatinine, technetium 99m-diethylene triamine pentaacetic acid diuretic renography (T1/2), ureteral diameter, vesicoureteral reflux, febrile urinary tract infections, continence and complications. The mean study follow-up period was 52.5 ± 12.8 months. Means of changes of cystometric capacity (273.2 ± 60.9 mL) and bladder compliance (15.6 ± 4.2 mL/cm H2 O) were significant (P < 0.0001). Resolution of ureteral obstruction was documented with improved T1/2 and ureteral diameter (P < 0.0001, each) of all patients. The initially improved renal functions after ureterostomies or nephrostomies were maintained after "fez surgery," with non-significant changes in the improved glomerular filtration rate (P = 0.22) and serum creatinine (P = 0.18). None of the patients experienced ureteral restenosis, vesicoureteral reflux, febrile urinary tract infections, incontinence or significant complications. The "fez procedure" represents a versatile and successful surgical option for these selected patients, as it offers improved bladder capacity/compliance, resolution of ureteral obstruction and vesicoureteral reflux, preservation of the renal function, control of urinary tract infections and urinary continence, and acceptable morbidity.

Diagnostic accuracy of neonatal kidney ultrasound in children having antenatal hydronephrosis without ureter and bladder abnormalities

To determine the diagnostic accuracy of anteroposterior renal pelvic diameter (APD) measurement and the society for fetal urology (SFU) grading in neonatal ultrasonography (USG) for detecting uropathy in newborns having antenatal isolated hydronephrosis (IH), characterized by hydronephrosis without ureter and bladder abnormalities, and to study time to resolution and factors predicting resolution of insignificant hydronephrosis. Ninety-six healthy newborns (129 kidneys) with IH, who underwent USG at age 7-30 days and voiding cystourethrography (VCUG) in conjunction with diuretic renography (DR) if APD > 10 mm or SFU grade 3-4 in neonatal USG, and at least a 12-month follow-up were divided into significant and insignificant hydronephrosis using the combined data of sequential USG, VCUG, and DR as the reference standard. Areas under the receiver operating characteristic plots (95 % CI) were 0.86 (0.79-0.94) versus 0.81 (0.73-0.89); p = 0.08, and 87.6 versus 79.8 % of cases were correctly classified, for APD ≥ 16 mm versus SFU grade 4, respectively. Ureteropelvic junction obstruction (UPJO) was the most common uropathy diagnosed. Of 85 kidneys with insignificant hydronephrosis, 57 underwent spontaneous resolution. The resolution rates were 24, 40, and 68 % at age 6, 12, and 24 months, respectively. APD was the only independent factor predicting resolution with the hazard ratio of 0.83 (95 % CI 0.74-0.92; p = 0.001). In IH, neonatal USG was a useful diagnostic tool to detect uropathy, mainly UPJO. Further investigation should be recommended when APD ≥ 16 mm or SFU grade 4.