Hydronephrosis: Comparison of extrinsic vessel versus intrinsic ureteropelvic junction obstruction groups and a plea against the vascular hitch procedure

Ureteropelvic Junction Obstruction Caused by Crossing Vessels in Infants and Young Children

BACKGROUND

To analyze the clinical characteristics of ureteropelvic junction obstruction (UPJO) caused by crossing vessels (CV) in infants and young children.

METHODS

A retrospective analysis was performed on children with UPJO who underwent primary surgery. Patients were classified into laparoscopic pyeloplasty (LP) and open pyeloplasty (OP) groups and classified as ≤3 or >3 (years old) groups. Children with CV-caused UPJO were identified.

RESULTS

A total of 747 patients were included. Ninety cases of CV were identified. The CV discovery rate was higher in the LP group (78/457, 17.1%) than in the OP group (12/290, 4.1%) (P < 0.001). In the ≤3 group, the CV discovery rate in the LP group (27/144, 18.8%) was higher than that in the OP group (11/274, 4.0%) (P < 0.001). In the LP group, there was no significant difference between ≤3 (27/144, 18.8%) and >3 (51/313, 16.3%) groups in the CV discovery rate. The rate in children with UPJO was not significantly different at any age (P > 0.05). Progressive aggravation of hydronephrosis (21/27, 77.8%) and symptomatic hydronephrosis (44/51, 86.3%) were the main surgical indications in the ≤3 and > 3 groups, respectively. There were no preoperatively confirmed cases of CV in the ≤3 group. In the OP group, five patients underwent reoperation, three of whom were due to failure to detect CV during the initial operation.

CONCLUSIONS

The CV distribution is similar in children with UPJO across all ages; CV in infants and young children are not rare. LP should be considered as CV are prone to being missed during OP.

LEVELS OF EVIDENCE

III.

Utility of F-15 diuretic MAG3 renography in assessment of paediatric hydronephrosis

INTRODUCTION

Diuretic renography is crucial in evaluation of paediatric hydronephrosis. Furosemide is conventionally given 15-20 min after radiolabelled tracer (F+15/F+20 protocol), however this is equivocal in around 15% of patients. Giving furosemide 15 min prior to tracer (F-15 MAG3 protocol) has been suggested as an additional tool in the investigation of patients with suspected upper urinary tract obstruction. However, the role of this method in assessment and management of paediatric hydronephrosis is not widely reported.

OBJECTIVE

To investigate utility of F-15 renograms in children with hydronephrosis being assessed for Pelvi-Ureteric Junction Obstruction (PUJO).

STUDY DESIGN

Retrospective review of patients <16 years old undergoing F-15 MAG3 renogram between 2018 and 2021 in our tertiary paediatric surgical centre. Data collected included patient demographics, mode of presentation, investigations, management and outcomes.

RESULTS

Eighteen patients were included. Median age at F-15 renogram was 7.3 years. Eleven patients presented with antenatal hydronephrosis, 5 with symptoms in childhood and 2 with incidental hydronephrosis on trauma imaging. Fourteen patients were symptomatic. Ten had a prior non-obstructed F+20 renogram but persisting symptoms suggestive of PUJO. Seven had previous equivocal F+20 renograms. One symptomatic patient directly underwent an F-15 renogram. A conclusive result was obtained in 16/18 (89%); 11 patients had obstructed curves and 5 non-obstructed. Two asymptomatic patients' scans were inconclusive. All symptomatic patients had conclusive scans. Of 11 patients with an obstructed F-15, 9 have undergone pyeloplasty to date. All have had post-operative resolution in symptoms and static or improved post-operative ultrasound. One patient with an inconclusive scan underwent pyeloplasty due to persisting hydronephrosis and parent preference. Three patients with non-obstructed F-15 renograms have been discharged. One symptomatic patient with a non-obstructive F-15 had a ureteric stent inserted due to persistent flank pain; 1 continues under surveillance.

DISCUSSION

It is known that conventional F+20 MAG3 renograms can give equivocal results. Published experience suggests that F-15 renograms are conclusive in the majority of patients. Routine primary use is, however, discouraged as they can 'over diagnose' obstruction and limit the study of tracer transit under physiological flow rates. This study indicates that the F-15 renogram is a useful adjunct in the assessment of patients with symptoms suggestive of PUJO who have previously had an equivocal or a non-obstructed F+20 renogram.

CONCLUSION

F-15 renogram was conclusive in 89% of patients. We recommend using F-15 renograms to aid surgical decision-making in children with equivocal F+20 renograms, especially in the presence of symptoms.

Sex differences in children operated with pyeloplasty for pelvoureteric junction obstruction

PURPOSE

Pelvoureteric junction obstruction (UPJO) is a common cause of hydronephrosis in children but no previous studies have evaluated differences between boys and girls operated with pyeloplasty. This study aimed to evaluate potential differences between sexes in children operated with pyeloplasty for PUJO in terms of presentation, surgery, and long-term results.

METHODS

Data was retrospectively collected from all children operated on with pyeloplasty between January 2002 and December 2020. Data contained several variables covering presentation, surgery, and long-term results.

RESULTS

In total, 194 patients were included of which 126 (64.9%) were boys. There were no significant differences in prenatal findings, pelvic dilation on ultrasound, function of the affected kidney, surgical method, obstruction type, resolution of hydronephrosis, or improvement of function. Boys presented with pain more often than girls (47.4 vs 25.0%, p < 0.01) while girls were more prone to infections preoperatively (17.2 vs 7.0%, p = 0.04). All nine patients requiring reoperation were boys (p = 0.03).

CONCLUSION

Girls with UPJO seem to experience infections as presenting symptoms more often than boys, while boys significantly more often present with pain. There is also a higher percentage of boys needing reoperation.

Association between intraoperative anatomical variation and histopathological parameters in cases of ureteropelvic junction obstruction in children: A cross-sectional study

Introduction

The intraoperative anatomical findings (IOAF) of all ureteropelvic junction obstruction (UPJO) cases are not identical. Moreover, there is also controversy in the literature regarding histopathological (HP) findings in cases of UPJO. In the present study, we evaluated different IOAF and assessed their association with specific HP parameters.

Materials and Methods

This was a cross-sectional study set-up, which was carried out in a tertiary care centre. Children with UPJO who underwent surgery between 2017 and 2020 were enrolled. The following IOAF were noted: Type of pelvis (extrarenal or intrarenal), insertion of the ureter (high or normal), presence of lower pole crossing vessel (CV), negotiation of UPJ segment with double J stent (3 Fr) and length of internal narrowing (LIN) at UPJ. The resected segment of UPJ was assessed at three levels (pelvis, UPJ and ureter) for various HP parameters including fibrosis, oedema, inflammation and smooth muscle hypertrophy (SMH).

Results

Thirty-nine children were included in the study with a mean age of 31 months. The summary statistics of IOAF were intrarenal pelvis in 5 cases, high insertion of the ureter (HIU) in 9, CV in 6, negotiable UPJ in 23, and 16 cases showed LIN >1 cm. All cases showed SMH at the pelvis region and SMH with fibrosis at the UPJ region. At the pelvis region, there was an association between (1) HIU with oedema and chronic inflammation (CIF), (2) CV with CIF and (3) LIN with CIF and SMH. At the UPJ region, there was an association between (1) CV and negotiable UPJ with less fibrosis and (2) LIN with SMH. At the ureteric end, CV showed an association with less fibrosis and more CIF.

Conclusion

All UPJO cases have some common HP findings. Although, some particular IOAF, i.e., presence of CV, negotiable UPJ, HIU and LIN showed association with specific HP parameters.

Functional Magnetic Resonance Urography in Ureteropelvic Junction Obstruction: Proposal for a Pediatric Quantitative Score

BACKGROUND

Ureteropelvic junction obstruction (UPJO) is one of the most frequent causes of congenital hydronephrosis. It is essential to distinguish UPJO which needs surgical treatment. fMRU combines high quality morphological details of the kidney and excretory pathways with functional data.

OBJECTIVE

This study aims to introduce a new radiological score based on fMRU findings to be able to differentiate surgical from non-surgical kidneys.

MATERIALS AND METHODS

We retrospectively selected patients with hydronephrosis due to UPJO who underwent fMRU (January 2009-June 2018). A multidisciplinary team identified a list of fMRU morpho-functional predictive variables to be included in the analysis. To evaluate the role of different independent variables in predicting the outcome, a multivariable logistic regression model has been performed; the outcome variable was the surgical intervention. For each predictive variable, Odds Ratio and 95% Confidence Intervals were calculated. The likelihood ratio test was used to assess the significance of the variables. Using the regression model, we assigned a numerical value to each predictive variable, rounding up the beta-coefficients. The cut-off value of the total score was obtained from the ROC curve analysis.

RESULTS

A total of 192 patients were enrolled, corresponding to 200 pathological kidneys. All of them underwent fMRU; 135 were surgically treated, while 65 underwent ultrasound or MRU follow-up. Predictive variables significantly associated with surgery resulted to be the urographic phase, the presence of abnormal vessels, and a baseline anterior-posterior pelvic diameter >23 mm. Beta coefficients of the logistic regression model were then converted in scores. The ROC curve of the score showed high sensitivity (84.3%) and specificity (81.3%) with a cut-off > 2.5.

CONCLUSIONS

We propose a new fMRU score able to identify surgical vs. non-surgical kidneys with UPJO.

Transposition and fixation of lower pole crossing vessel in children with ureteropelvic junction obstruction: A STROBE-compliant study

Chapman and Hellstrom techniques are typically employed to transpose renal lower pole crossing vessels (LPCVs). Both procedures have certain limitations. We investigated the midterm outcomes in pediatric patients in whom LPCV-induced ureteropelvic junction obstruction was treated with either dismembered Anderson-Hynes pyeloplasty or upward transposition coupled with a new technique to fix the LPCV.We retrospectively compared Anderson-Hynes pyeloplasty to the new technique in terms of outcome. LPCV transposition was considered feasible in patients in whom the diuretic loading test revealed a decrease in the pelvic volume after correction of vascular compression as well as absence of structural changes in the ureteropelvic junction (UPJ) and hemodynamic compromise of the lower renal pole. The fascial flap was passed below the LPCV to form a "hammock". The free edge of the flap was sutured to its base.Group 1 consisted of 102 (69.9%) patients (median age: 7.9 years) undergoing dismembered Anderson-Hynes pyeloplasty, while group 2 included 44 (30.1%) patients (median age: 8.4 years) treated with upward transposition and the new technique to fix the LPCV. No intra-operative complications or conversions occurred in either group. Redo-pyeloplasty was performed in 3 (2.9%) children of group 1 and 1 (2.3%) child of group 2. Renal ultrasonography conducted 12 months after surgery revealed similar anteroposterior diameters of the renal pelvis in groups 1 (7.9 ± 8.1 mm) and 2 (6.0 ± 2.9 mm). Patients in both groups showed a non-significant median increase in differential renal function at follow-up after at least 1 year after surgery (group 1: 36% [33.3; 40.5] vs 36.5% [35.3; 41.0]; group 2: 41% [37.5; 46.0] vs 43% [39; 46]).In our patients, the new technique for laparoscopic or open fixation of the obstructing vessel after transposition was effective, reproducible, and devoid of limitations typical for the Chapman and Hellstrom techniques. We recommend Anderson-Hynes pyeloplasty in children with a history of hydronephrosis diagnosed antenatally, recurrent abdominal pain, intra-operative absence of peristalsis across the UPJ, high location of the UPJ at the renal pelvis, or intra-operative absence of volume reduction of the renal pelvis upon furosemide testing.

Asymptomatic obstructive hydronephrosis associated with diabetes insipidus: a case report and review

The treatment of asymptomatic hydronephrosis due to ureteropelvic junction obstruction (UPJO), as well as the timing and indications for surgical intervention, remain controversial. Diabetes insipidus (DI) is a rare disease in infants that is known to cause non-obstructive hydronephrosis, while its association with obstructive hydronephrosis has not been reported. Some studies have found that increased water intake is a predisposing risk factor of developing hydronephrosis. However, there are no studies or guidelines that indicate the specific follow-up intervals and surgical indications for mild hydronephrosis if predisposing risk factors persist. A 46-month-old boy was admitted to our Urology Department with a history of Society of Fetal Urology (SFU) Grade 2 prenatal left hydronephrosis, which was stable at SFU Grade 1-2 at regular postnatal follow-ups. The patient developed polydipsia and polyuria three months prior to admission, then he was considered as primary polydipsia by endocrinology and was treated with fluid restriction while the examination was negative. Renal ultrasound at follow-up demonstrated severe left hydronephrosis with an anterior-posterior diameter (APD) of 6.25 cm three months after symptom onset. Diuretic renography (DR) revealed a renal function of 13.7% with a glomerular filtration rate (GFR) of 11.25 mL/min. The patient was otherwise asymptomatic without any abdominal pain or vomiting. He underwent left pyelostomy immediately as well as laparoscopic left dismembered ureteropelvioplasty after three months, and a diagnosis of UPJO was confirmed. The patient had an uncomplicated postoperative recovery and the result of follow-up renal ultrasound was stable. However, the symptoms of polydipsia and polyuria did not improve significantly. He underwent pituitary magnetic resonance imaging (MRI) and pathological examination, the results of which were consistent with central DI caused by Langerhans cell hyperplasia four months postoperatively. This case indicates the need to pay attention to children with mild hydronephrosis undergoing regular observation and conservative treatment, as a sudden aggravation of the hydronephrosis and a rapid decline of renal function may occur if DI persists.

Laparoscopic pyeloureterostomy for ureteropelvic junction obstruction occurring in incomplete ureteral duplication of the solitary kidney

INTRODUCTION

Ureteropelvic junction obstruction associated with ureteral duplication is rare, with prevalence reported to be around 2-7%. Ureteropelvic junction obstruction of the lower pole with both complete and incomplete duplex systems is a common cause of obstruction. Here, we report a case of ureteropelvic junction obstruction associated with incomplete ureteral duplication of the solitary kidney successfully treated by pyeloureterostomy.

CASE PRESENTATION

The patient was a 39-year-old woman who presented with right hydronephrosis, right back pain, and deteriorated renal function. The patient was referred to our department from the rheumatology department. Her medical history included congenital left renal hypoplasia, Sjogren's syndrome, and hyperphospholipid antibody syndrome.

CONCLUSION

We encountered a case of hydronephrosis occurring in a solitary kidney with incomplete ureteral duplication. This case was successfully managed after pyeloureterostomy.

Management of ureteropelvic junction obstruction in children-a roundtable discussion

The investigation, management and follow-up of paediatric ureteropelvic junction obstruction is not standardized. The Young Pediatric Urology Committee of the European Society of Pediatric Urology interviewed five experts in the field on various aspects of management and compared this with published literature.

Surgical validation of functional magnetic resonance urography in the study of ureteropelvic junction obstruction in a pediatric cohort

INTRODUCTION

Ureteropelvic junction obstruction (UPJO) is one of the most common urological diseases in children. The etiology can be intrinsic, extrinsic (crossing vessel [CV] or adhesions), or mixed. To date, ultrasonography and scintigraphy are considered gold-standard imaging techniques for the study of UPJO. Functional magnetic resonance urography (fMRU) combines anatomical and functional information and has been recently evaluated for the detection of CVs in UPJO.

OBJECTIVE

The objective of the study was to evaluate the concordance between fMRU and surgery in determining the etiology of UPJO and the presence of obstructing/non-obstructing CVs.

STUDY DESIGN

Patients with unilateral hydronephrosis who underwent surgery after an fMRU were included in the sample. Surgical data regarding the etiology of UPJO were compared with radiological results. The etiology was divided into intrinsic, extrinsic due to CV, extrinsic due to adhesions, and mixed or cicatricial (postoperative). The concordance was calculated by means of the Cohen's kappa coefficient.

RESULTS

The observed agreement between fMRU and surgical findings regarding the etiology and the presence of CV were 83.2% and 89.4%, respectively (with substantial Cohen's kappa coefficient). The sensitivity and specificity of fMRU were 0.84 and 0.93, respectively; the positive predictive value (PPV) and negative predictive value (NPV) were 0.889 and 0.897, respectively. The observed agreement regarding the type of vessel was 88.3% with a Cohen's kappa coefficient of 0.787 (substantial).

DISCUSSION

In children with hydronephrosis, it is very important for the surgeon to quantify the extent of dilation, define the etiology of the obstruction, and the presence or absence of CVs. fMRU is a 'one-stop-shop' technique which provides both anatomical and functional information showing a high concordance with surgical findings, avoiding radiation exposure.

CONCLUSIONS

fMRU should be considered a valid imaging technique in the study of pediatric UPJO, as it provides the surgeon with important information regarding the etiology of the obstruction for the preoperative planning.

Hydronephrosis in Children Caused by Lower Pole Crossing Vessels-How to Choose the Proper Method of Treatment?

Objectives: Assessment of the efficacy of intraoperative diagnosis between extrinsic and intrinsic UPJO in children. Assessment of the efficacy of laparoscopic vascular-hitch procedure in UPJO caused by lower pole crossing vessels (CV). Materials and Methods: Between 2008 and 2017, 47 laparoscopic procedures were performed with the CV discovered intraoperatively. CV were translocated cephalad, and the UPJ was carefully inspected. The Chapman's vascular hitch procedure was accomplished in the case of decreasing sizes of the pelvis and clear, visible peristalsis of the UPJ (31 patients). In the other cases, Anderson-Hynes (A-H) pyeloplasty with posterior translocation of the CV was performed (16 patients). Results: The median age at operation was 6 years (range 1-16) in VH and 6 years (range 2-17) in A-H (p = 0.4635). Prenatal dilatation of kidney was diagnosed in 18.7% of VH and 10% of A-H cases (p = 0.5474). Success was achieved in 16 (100%) patients in the A-H and in 29 (93.54%) in the VH groups. Two patients (6.5%) in VH required repeated surgery because of a misdiagnosed intrinsic obstruction. Median operation time in VH was 80 min (range 40-105) and was 105 (range 70-225) in A-H (p < 0.05). Conclusions: The intraoperative selection based on intraoperative pelvis and UPJ appearance after vessel transposition is sufficient in majority of cases. Laparoscopic vascular hitch seems to be effective and safe procedure, but can only be performed on carefully selected patients. In case of misdiagnosis, reoperation is possible with the same laparoscopic access.

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.

Computed tomography angiography with 3D reconstruction in diagnosis of hydronephrosis cause by aberrant renal vessel: A case report and mini review

BACKGROUND

Congenital hydronephrosis is often caused by aberrant renal vessel and it is difficult to be diagnosed and treated at the early stage due to lack of the significant symptoms. Although current medical diagnosis tools are widely used, the aberrant renal vessel cannot be displayed very well in the images.

OBJECTIVE

To investigate whether applying computed tomography (CT) angiography with 3D reconstruction can improve efficacy in diagnose of this congenital hydronephrosis.

MATERIALS AND METHODS

A male patient of 18 years old was diagnosed as hydronephrosis of left kidney. A CT angiography with 3D reconstruction was evaluated in diagnosis of the prenatal hydronephrosis compared to ultrasound (US) and intravenous urogram (IVU).

RESULTS

US and IVU images were able to display the dilation of left pelvic and the dilated calyces, and the thinner of renal parenchyma on the left kidney (Grade II-IV), but failed to detect the causing of hydro-nephrosis. CT angiography with 3D reconstruction provided accurate images of the dilated renal pelvic, upper segment of the ureter, and an aberrant vessel bundle overcrossing at the left renal pelvic-ureter junction as well. The aberrant vessel could be revealed during surgery.

CONCLUSIONS

A CT angiography with 3D reconstruction provides a more accurate diagnostic approach for the congenital hydronephrosis caused by aberrant renal vessel. Thus, it can offer surgeons very important information in the pre-surgery planning.

Pelviureteric Junction Obstruction with Crossing Lower Polar Vessel: Indicators of Preoperative Diagnosis

Introduction:

A crossing lower polar vessel (CLPV) is found in 11%–20% of children of pelviureteric junction obstruction (PUJO). Preoperative imaging (Doppler or magnetic resonance angiography (MRA)) may help but does not form a part of routine diagnostic workup. An attempt has been made here to evaluate clinical and imaging features (ultrasound and renal dynamic scan [RDS]) in children of PUJO with CLPV and define variables that could provide a diagnostic clue to its presence.

Materials and Methods:

Records of children having PUJO with CLPV over 10 years (2006–2015) were reviewed retrospectively. Their demographic profile, clinical presentation, imaging features, management, and outcomes were evaluated.

Results:

Of 372 children with PUJO, 21 (5.6%) had a CLPV. Median age at presentation was 7 years (range 4 months–11 years). Presenting features included pain (66.6%), urinary tract infection (14.3%), antenatally diagnosed fetal hydronephrosis (14.3%) and lump (4.8%). All had an obstructive drainage on RDS and mean split renal function (SRF) of the affected kidney was 32.5% ± 15.65%. The majority had mild-moderate hydronephrosis with intrarenal pelvis. None of the ultrasound images suggested the presence of a CLPV. Diagnosis of a CLPV was made intraoperatively in all. Dismembered pyeloplasty anterior to the vessel was done in the majority (80.9%). Mean SRF on postoperative RDS improved to 36.6% ±17.76% with nonobstructive drainage. All were asymptomatic at a mean follow-up of 34.5 ± 17.5 months (range 2–56 months).

Conclusions:

Pain is the predominant presenting feature in these patients who present at an older age. Despite older age at presentation, these patients have well-preserved renal function and mild hydronephrosis. No specific RDS or ultrasound findings can predict the presence of a CLPV. As the incidence of CLPV is <10% and management is essentially same as PUJO with intrinsic obstruction, preoperative Doppler or MRA are extraneous.

Advances in paediatric urology

Paediatric urological surgery is often required for managing congenital and acquired disorders of the genitourinary system. In this Series paper, we highlight advances in the surgical management of six paediatric urological disorders. The management of vesicoureteral reflux is evolving, with advocacy ranging from a less interventional assessment and antimicrobial prophylaxis to surgery including endoscopic injection of a bulking agent and minimally invasive ureteric reimplantation. Evidence supports early orchidopexy to improve fertility and reduce malignancy in boys with undescended testes. A variety of surgical techniques have been developed for hypospadias, with excellent outcomes for distal but not proximal hypospadias. Pelvi-ureteric junction obstruction is mostly detected prenatally; indications for surgery have been refined with evidence, and minimally invasive pyeloplasty is now standard. The outlook for patients with neurogenic bladder has been transformed by a combination of clean intermittent catheterisation, algorithms of diagnostic investigations, and innovative medical and surgical therapies. Posterior urethral valves are associated with considerable mortality; fetal diagnosis allows stratification of candidates for intervention, but ongoing bladder dysfunction in patients after valve ablation remains a cause of long-term morbidity.

Outcome analysis of pediatric pyeloplasty in units with less than 20% differential renal function

OBJECTIVE

This study was conducted to assess ureteropelvic junction obstruction (UPJO) units with differential renal function (DRF) ≤20%, 3 months post-pyeloplasty as well as complications and stability of function in long term follow up.

MATERIAL AND METHODS

In this prospective study, children below 12 years age with unilateral UPJO and DRF ≤20% undergoing open Anderson-Hynes dismembered pyeloplasty from 2002-2014 excluding associated vesicoureteric reflux were included. Drainage and function were assessed with isotope [ethylene di-cysteine (EC)] scan at 3 months and later during yearly follow-up as well as by intravenous urography (IVU).

RESULTS

Of a total 744 patients with UPJO in the study period, 112 had DRF ≤20%. Thirty four (30%) underwent percutaneous nephrostomy. Ten with no function underwent nephrectomy. 102 (mean age 4.7 years) with DRF 0-9% (n = 40) and 10-20% (n = 62) formed the study group. Hypertension (3), small kidney (13) and crossing vessels (9) were associated. Follow up ranged from 1-8 years (4.6 ± 1.34 years). Six patients were lost to follow up. There was significant improvement in drainage in the remaining 96 patients. Mean DRF and IVU function showed highly significant improvement (p < .001) in those with clinical signs and symptoms (n = 85), compared to asymptomatic patients in preoperative 0-9% and 10-20% group. The mean rise in DRF was significantly more in the preoperative 0-9% group, palpable mass presentation and by age at 5-12 years in the 0-9% group and 1-5 years in the 10-20% group. In the symptomatic group, except for intermittent UTIs (n = 8) and pain (n = 3) which subsided 1-2 years after surgery, all patients had resolution of initial complaints. Hypertension resolved in two patients with crossing vessels. No patient required re-do pyeloplasty or developed hypertension during followup. There was no significant difference (p = 1.000) in mean DRF between 3 month and 1-8 years post-operative scans (n = 53).

CONCLUSIONS

This study which appears to be the largest in the literature of pediatric UPJO with DRF ≤20%, conclusively shows that there is statistically significant improvement in function after pyeloplasty which remains stable during the period of growth with no long term complications. Nephrectomy should be considered only in patients with nil or <5% uptake on isotope imaging with associated (a) no parenchyma on imaging or on exploration, (b) pyonephrosis, (c) hypertension or (d) minimal urine output on percutaneous nephrostomy.