Effect of emergent nephrostomy on long-term total and split renal function in patients with upper urinary tract obstruction due to pelvic malignant tumors.

PURPOSE: This study aimed to investigate the impact of nephrostomies on the outcome of total renal function (TRF) and split renal function (SRF) in patients with malignant pelvic tumors associated with upper urinary tract obstruction (UUTO). METHODS: Patients with pelvic tumors suffering severe unilateral hydronephrosis treated at our hospital from 2000 to 2022 were included. Data for nephrostomy placement, short- and long-term renal function, and radiological and nuclear imaging studies were collected. The TRF and SRF of patients who underwent nephrostomy were compared to those who did not. RESULTS: Seven patients were included (rhabdomyosarcoma: 5, ovarian germ cell tumor: 1, malignant rhabdoid tumor: 1). Nephrostomies were placed in four, which were successfully managed without severe infections. Estimated glomerular filtration rate (eGFR) was significantly improved at the end of treatment in patients with nephrostomy. In contrast, eGFR in patients who did not undergo nephrostomy was not improved. Nuclear imaging studies (renograms or renal scintigrams) revealed impaired SRF of the affected kidney compared to the contralateral kidney, even in patients whose eGFR was within normal levels. Notably, SRF showed a trend to improve over time in one patient treated with nephrostomy. CONCLUSION: Nephrostomy for UUTO caused by pelvic tumors may improve renal outcome.

Metal stent for the ureteral stricture after surgery and/or radiation treatment for malignancy.

BACKGROUND: To assess the efficacy and safety of self-expanding metal ureteral stent for the stricture following surgery and/or radiation for malignancy. METHODS: We performed 36 metal ureteral stent insertion procedures (32 patients) between May 2019 and June 2020. The main inclusion criterion was the patients with ureteral stricture due to surgery and/or radiation treatment for malignancy. The diagnosis of stricture was ascertained by history and radiographic imaging. The etiologies underlying the strictures were: surgery and/or radiation therapy for cervical and rectal cancer, surgery for ovarian cancer. The primary outcome was the stent patency rate, and the secondary outcomes were the postoperative complications and glomerular filtration rate (GFR). Stent patency was defined as stent in situ without evident migration, unanticipated stent exchange or recurrent ureteral obstruction. Cost analysis was calculated from stent cost, anesthesia cost and operating room fee. RESULTS: The pre-metallic stent GFR was 22.53 ± 6.55 mL/min/1.73 m2. Eight patients were on double-J stents before insertion of metallic stents. The total annual cost of per patient in our study was $10,600.2 US dollars (range $9394.4-$33,527.4 US dollars). During a median follow-up time of 16 months (range 8-21 months), 27 cases (31 sides, 84%) remained stent patency. Twelve patients died from their primary malignancy carrying a patency stent. Stent migration was observed in 4 patients within 10 months after insertion. Ectopic stents were endoscopically removed and replaced successfully. Three stents were occluded, and no encrustation was seen in our study. Three and four patients had postoperative fever and gross hematuria, respectively. Infection was observed in 2 cases, mandating antibiotics therapy. In addition, postoperative volume of hydronephrosis postoperatively was significantly reduced compared with preoperation (54.18 ± 15.42 vs 23.92 ± 8.3, P = 0.019). However, no statistically significant differences regarding GFR, creatinine levels, blood urea nitrogen and hemoglobin existed between preoperation and last follow-up. CONCLUSIONS: The current study demonstrated that metal ureteral stent is effective and safe in the treatment of stricture following surgery and/or radiation therapy for malignant cancer. Patients hydronephrosis could be improved by the stent placement.

Non-invasive evaluation of obstruction after ureteroscopic stone removal: Role of renal resistive index assessment.

OBJECTIVES: The aim of this study is to evaluate prediction of postoperative ureteral obstruction needing ureteral stent insertion by evaluating the resistive index (RI) values and the grade of hydronephrosis. MATERIAL AND METHODS: A total of 66 adult patients undergoing stentless endoscopic ureteral stone treatment (URS) between January 2018 and January 2019 were included in this prospective study. Preoperative patient and stone characteristics were noted. All patients were evaluated with renal Doppler ultrasonography study to assess degree of hydronephrosis and RI values. A renal Doppler ultrasonography was repeated at postoperative 1st, 3rd and 7th days. Changes in both RI and hydronephrosis levels before and after the procedures were noted. On the postoperative 7th day, patients were divided into two groups including obstructive and non-obstructive cases according to RI values assessed where a RI value of 0.7 was accepted as the cut-off for obstruction. The preoperative and perioperative characteristics of both groups were evaluated in a comparative manner. RESULTS: The mean patient age was 43.6 ± 1.72 years. Significant improvements were noted in RI and grade of hydronephrosis after the operation. The grade of hydronephrosis and RI values were found to improve more significantly on postoperative 3rd day when compared to the postoperative 7th day (p < 0.01 and p < 0.01). A significant correlation was detected between the grade of hydronephrosis (>grade 2) and obstructive RI values (> 0.7) in each postoperative visits (p: 0.001). RI values (> 0.7) at postoperative seventh days were correlated with larger mean stone size, increased ureteral wall thickness, increased diameter of the ureter proximal to the stone, and longer duration of the operation. Preoperative high-grade hydronephrosis indicated obstructive RI values at postoperative seventh day (p = 0.001) Conclusion: Changes in RI values on Doppler sonography and the grade of hydronephrosis may be a guiding parameter in assessing postoperative ureteral obstruction.

In utero myelomeningocele repair: The natural history of patients with incontinent pattern (sphincteric deficiency: leakage below 40 CMH20).

INTRODUCTION: Since 2011 we have been following prospectively myelomeningocele patients treated in utero with particular interest to patients with sphincter weakness/deficiency. We investigated the changes of bladder pattern and upper urinary tract with time in children who underwent in utero repair and had low-pressure incontinence based on urodynamic evaluation (UE). MATERIALS AND METHODS: From the 120 patients in our database, 117 had at least one UE. Of these, 30 were classified as incontinent when leaking at low pressure (<40 cmH20). We reviewed clinical evaluation, urinary tract ultrasound, voiding cystourethrography (VCUG), and other UE parameters at first and last evaluation. RESULTS: We found 30 cases (25.64%). Mean age at initial evaluation was 4.97 months followed by UE done initially at mean age of 5.73 months. Follow-up was 28.4 months. Febrile urinary tract infection has been found in four patients (13.3%), hydronephrosis in four patients, and bladder neck thickening in three (10%). The VCUG showed vesicoureteral reflux in three cases (3/27, 11.1%). A total of 90% of patients had detrusor overactivity with mean maximum detrusor pressure (33.37 cmH20). Only 16.67% of patients showed normal bladder capacity. From the 30 patients, 23 had at least two UE. We noticed a change of bladder pattern as follows: six patients became of high-risk pattern, five normal, and two with underactive bladder pattern. The average interval between the first and last UE was 25.5 months (median: 15 months). CONCLUSION: We concluded that 43.47% of patients with low DLPP have kept the incontinent pattern. If the initial LPP was below 30 cmH20, 70% remained with the incontinet pattern.

An overview of hydronephrosis in adults.

Hydronephrosis is diagnosed more often with the increased availability of computed tomography and ultrasound scanning. Hydronephrosis is an important consideration in patients with abdominal or pelvic pathology as progressive dilation of the upper urinary tract can lead to acute kidney injury and, if not corrected, permanent nephron loss. This article explores how to approach an adult patient with hydronephrosis, encompassing aetiology, clinical presentation, diagnosis and management.

Prognostic value of preoperative hydronephrosis in patients with bladder cancer undergoing radical cystectomy: A meta-analysis.

BACKGROUND: Hydronephrosis is a common finding in patients with bladder cancer. The aim of the study was to appraise the prognostic value of preoperative hydronephrosis in bladder cancer patients undergoing radical cystectomy. METHODS: We conducted a literature search using PubMed and Embase databases in Aug 2018. Summary hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using fixed-effect or random-effects models. The primary endpoint was overall survival (OS). Secondary endpoints were cancer-specific survival (CSS) and recurrence-free survival (RFS). RESULTS: Overall, 13 studies published between 2008 and 2018 including 4,820 patients were selected for the meta-analysis. The age of bladder cancer patients ranged from 27 to 90.4 years, and the overall proportion of males was 72.5%. Preoperative hydronephrosis was reported in 27.4% of patients. The pooled HR was statistically significant for OS (HR, 1.36; 95% CI [1.20-1.55]) and CSS (HR, 1.64; 95% CI [1.33-2.02]), with no heterogeneity among the enrolled studies. Patients with bilateral hydronephrosis showed a poorer CSS compared to those with no hydronephrosis (HR 5.43, 95% CI [3.14-9.40]). However, there was no difference in CSS between no hydronephrosis and unilateral hydronephrosis groups (HR 1.35, 95% CI [0.84-2.14]). Despite a tendency towards poorer RFS (HR, 1.27; 95% CI [0.96-1.96]), the results demonstrated no significant association between presence of preoperative hydronephrosis and RFS after radical cystectomy. CONCLUSION: This meta-analysis indicates that preoperative hydronephrosis is significantly associated with poorer OS and CSS after radical cystectomy for patients with bladder cancer. Preoperative hydronephrosis has a stronger effect on CSS in patients with bilateral hydronephrosis. The presence of preoperative hydronephrosis not only predicts prognosis, but may also help to identify patients who benefit the most from neoadjuvant chemotherapy.

Unusual cause of dysphagia.

In this case, we describe a unique case of large renal hydronephrosis in a 79-year-old Indian male patient who had initially presented with 3 months of progressive dysphagia and loss of weight. His dysphagia was initially thought to be related to the atypical diagnosis of achalasia and was being considered for an elective laparoscopic Heller myotomy. On performing CT of the abdomen, a large renal mass was discovered. However, predicament remained regarding the exact aetiology of this renal mass. This case highlights a tremendously intriguing case of dysphagia with an underlying aetiology that has not been reported elsewhere previously.

Need for urodynamic evaluation as a regular follow-up tool in assessment of long-term urological outcomes in patients with sacrococcygeal teratoma.

AIM: To assess the long-term urologic outcomes in follow-up of patients of sacrococcygeal teratoma (SCT) using urodynamic study (UDS) in addition to clinical and radiologic evaluation. METHODS: A prospective study of clinical, radiological and urodynamic evaluation in patients with SCT who underwent resection between January 2002-June 2015 and were followed up till January 2016 was conducted. RESULTS: Total 57 patients, 42 (73.7%) females and 15 (26.3%) males with 35 (62.4%) following treatment for benign and 22 (38.5%) for malignant disease were included. Twenty-eight of 57 (49.12%) had urological problems. Clinical complaints in 21 (36.8%) patients included stress urinary incontinence-14 (66.7%), enuresis-9 (42.9%), and poor stream or dribbling of urine-6 (28.6%). Eight of 51 patients (15.7%) had abnormal ultrasound findings, which included contracted, trabeculated thick walled bladder (3), bilateral hydronephrosis (3) and significant post void residue (PVR) (6). Seven of 57 underwent micturating cystourethrogram (MCU), 5 had an abnormal report[significant PVR (4), small trabeculated bladder (3), reflux (2) and large capacity bladder (1)]. Urodynamic study was done in 27 patients, 18/27 (66.7%) had abnormalities. Six patients without any clinical or ultrasonographic abnormalities had abnormal UDS. Total 28 (49.12%) had urological comorbidities. Three patients had overactive bladder, five dysfunctional voiding, one underactive bladder and one had giggle incontinence. Children were managed by behaviour therapy and pharmacotherapy. CONCLUSION: Urodynamic evaluation could detect abnormalities in patients who had no urinary complaints or abnormality on ultrasound. The abnormalities have a potential for progressive upper tract damage. Urodynamics should be an integral part of urological surveillance in patients operated for SCT. TYPE OF STUDY: Prognostic study. LEVEL OF EVIDENCE: Level II (Prospective cohort study).

Relation between ureteral telocytes and the hydronephrosis development in children.

INTRODUCTION: Hydronephrosis is an actual pediatric problem, affecting children in the ante- and neonatal periods. Intrinsic stenosis is due to external obstruction and creates a pathophysiological basis of this urological pathology. Co-localization of ureter with a renal vasculature also could not be omitted from this point of view. Mesenchymal cells, partially telocytes, are important for local fibrosis development and hydronephrosis formation as well. In the current study, we focused on identification of telocytes in the human ureters to hypothesize their role in hydronephrosis pathophysiology. MATERIAL AND METHODS: the samples were taken from 18 surgically treated patients with hydronephrosis (due to ureteral obstruction and crossing renal vessel). The control group consisted of 10 patients suffered from a non-obstructive disease of the urinary tract - predominantly renal tumors. Tissue samples from a ureter were stained for c-kit, tryptase, CD34 and PDGFRα to identify telocytes. Routine histology was performed to analyze tissue morphology, collagen deposits and mast cell's profile. RESULTS: Telocytes were detected in the ureteral wall. In patients with hydronephrosis we revealed decreasing density of telocytes, the prevalence of collagen, rise in mast cells amount and the ureteral wall thickening. In ureters with crossing renal vessels as a primary etiologic factor more telocytes have been observed in comparison with the obstructive hydronephrosis. CONCLUSIONS: A declined density of telocytes accompanied hydronephrosis development. Increased number of mast cells in the ureteral wall reflects a local inflammation, while detailed observation of collagen/muscle deposits and density of telocytes reveal a difference depended on etiologic factor (obstruction or crossing vessel) in patients with hydronephrosis.

Changes of arterial pressure following relief of obstruction in adults with hydronephrosis.

BACKGROUND: As much as 20% of all cases of hypertension are associated with kidney malfunctions. We have previously demonstrated in animals and in pediatric patients that hydronephrosis causes hypertension, which was attenuated by surgical relief of the ureteropelvic junction (UPJ) obstruction. This retrospective cohort study aimed to investigate: (1) the proposed link between hydronephrosis, due to UPJ obstruction, and elevated arterial pressure in adults; and (2) if elevated blood pressure in patients with hydronephrosis might be another indication for surgery. MATERIALS AND METHODS: Medical records of 212 patients undergoing surgical management of hydronephrosis, due to UPJ obstruction, between 2000 and 2016 were assessed. After excluding patients with confounding conditions and treatments, paired arterial pressures (i.e. before/after surgery) were compared in 49 patients (35 years old; 95% CI 29-39). Split renal function was evaluated by using mercaptoacetyltriglycine (MAG3) renography before surgical management of the hydronephrotic kidney. RESULTS: Systolic (-11 mmHg; 95% CI 6-15 mmHg), diastolic (-8 mmHg; 95% CI 4-11 mmHg), and mean arterial (-9 mmHg; 95% CI 6-12) pressures were significantly reduced after relief of the obstruction (p < 0.001). Split renal function of the hydronephrotic kidney was 39% (95% CI 37-41). No correlations were found between MAG3 and blood pressure level before surgery or between MAG3 and the reduction of blood pressure after surgical management of the UPJ obstruction. CONCLUSIONS: In adults with hydronephrosis, blood pressure was reduced following relief of the obstruction. Our findings suggest that elevated arterial pressure should be taken into account as an indication to surgically correct hydronephrosis.

Laparoscopic resection of large pelvic lipoma causing obstructive uropathy in a 66 year old female - A case report from Greece.

Lipomas are benign, usually asymptomatic, tumours and pelvic lipomas are extremely rare. We describe the case of a giant pelvic lipoma causing obstructive uropathy to a 66-year-old morbidly obese female treated in the 4th Surgical Department of the Medical School of Aristotle University of Thessaloniki in General Hospital "G. Papanikolaou" in March 2016. The patient presented with a history of nocturia and frequent daytime urination for 1 year. Her medical history included diffuse lipomatosis. Computer tomography revealed a giant pelvic mass which lead to left side hydronephrosis, hydrouterer and a pear-shaped bladder, with the differential diagnosis including pelvic lipoma or liposarcoma. An ultrasound guided biopsy excluded the diagnosis of liposarcoma. The patient was submitted to laparoscopic resection of the pelvic lipoma, with complete remission of urinary symptoms. The key-point is to consider the possibility that the pelvic mass is a well-differentiated liposarcoma and to manage it adequately and thus, we recommend intact excision of the mass through a wound protector, and extreme caution to avoid any rupture of the capsule.

Hydronephrosis After Pyeloplasty: "Will It Go Away?"

OBJECTIVE: To identify attributes of pediatric patients with hydronephrosis due to ureteropelvic junction obstruction and of their surgical encounters which are predictive of resolution of dilatation in order to provide more effective counseling about expected outcomes. This study was inspired by the suggestion in recent literature that greater than 20% improvement in anteroposterior diameter (APD) of the renal pelvis after pyeloplasty is indicative of resolution of obstruction. The remaining dilatation, however, is often distressing to caregivers, and there are no data to guide clinicians in counseling about its likelihood to resolve. METHODS: We retrospectively reviewed children who underwent surgery at our institution for ureteropelvic junction obstruction between 1/01/2010 and 6/30/2017. APD of the pre- (preAPD) and postoperative (postAPD) renal pelves were documented. In children with more than 1 postoperative ultrasound, lastAPD was the measurement on their most recent study. Appropriate statistical tests examined the effects of clinical and surgical variables on hydronephrosis resolution. RESULTS: PostAPD and lastAPD were obtained at medians of 3 months and 1.9 years after surgery, and were 0 cm in 12 of 105 (11.5%) and 9 of 65 (13.8%) patients, respectively. None of the variables analyzed significantly impacted complete resolution at either time point. Of those that did not resolve, 80.6% (75/93) showed greater than 20% improvement in APD; however, 3 of these children required reoperation due to secondary obstruction. In our study, no one with APD reduction greater than 43% required reintervention. CONCLUSION: Complete resolution of hydronephrosis is uncommon and unpredictable. All caregivers should be counseled to expect dilatation to persist after obstruction is corrected.

[Evaluation of upper urinary tract function in patients undergoing autoplastic surgery for hydronphrosis of the intrarenal pelvis].

AIM: To investigate the functional state of the upper urinary tract in patients undergoing autoplastic surgery for a hydronophrosis of the intrarenal pelvis. MATERIAL AND METHODS: The study comprised 78 patients with the intrarenal pelvis and impaired urinary outflow due to stricture of the ureteropelvic junction and vascular conflict (interatrial and arteriovenous narrowing), who underwent pyeloplasty using autologous tunica vaginalis. All patients underwent an incision of ureteropelvic stricture and resection of the parietal layer of the tunica vaginalis which was used to repair the obstruction site and internal stenting of the upper urinary tract. RESULTS: The patients were examined at baseline and during follow-up ranging from 3 months to 3 years. At three months after surgery, there was a decrease in the size of the renal pelvis and calyces with an improvement of all parameters of uro- and hemodynamics. At three years after surgery, the structural and functional parameters of the upper urinary tract were completely restored. CONCLUSION: Obstructive uropathy, resulting from the intrarenal pelvis, leads to persistently impaired urinary outflow from the upper urinary tract. Surgical intervention is the only curative treatment able to restore the urinary flow. In men with the intrarenal pelvis, the autoplastic surgery of the ureteropelvic junction obstruction using a parietal layer of the tunica vaginalis is an effective surgical modality improving renal pelvis capacity and contributing to the recovery of urinary outflow from the upper urinary tract.

[A new method of evaluation of split renal function based on contrast-enhanced multislice spiral computed tomography].

INTRODUCTION: Traditionally, evaluation of the split renal function is performed using nephroscintigraphy. However, as shown in several studies, there might be quite significant inaccuracy in the interpretation of dynamic nephroscintigraphy results. But due to the lack of alternative methods for evaluation of split renal function, nephroscintigraphy remains the method of choice. AIM: To investigate the feasibility of digital analysis of contrast-enhanced MSCT imaging for evaluation of the split renal function. MATERIALS AND METHODS: This is a prospective study conducted at the R.M. Fronshteyn Clinic of Urology from November 2015 to February 2017. The study comprised 31 patients with urolithiasis (n=7), hydronephrosis (n=9), kidney cancer (n=14) and urinary bladder tumor (n=1). During the preoperative period, the patients underwent contrast-enhanced MSCT, 3D-reconstruction, and digital analysis. The obtained data were compared with the results of dynamic nephroscintigraphy. RESULTS: Contrast-enhanced MSCT findings were not inferior to data obtained with dynamic nephroscintigraphy regarding information content (p<0.004). CONCLUSIONS: The new method of digital processing of three-dimensional contrast-enhanced MSCT allows for concomitant assessment of both the anatomical features of the kidney and renal function that may help to improve the accuracy of surgical planning to choose the optimal extension of the intervention.

Hydronephrosis is associated with elevated plasmin in urine in pediatric patients and rats and changes in NCC and γ-ENaC abundance in rat kidney.

Obstruction of urine flow at the level of the pelvo-ureteric junction (UPJO) and subsequent development of hydronephrosis is one of the most common congenital renal malformations. UPJO is associated with development of salt-sensitive hypertension, which is set by the obstructed kidney, and with a stimulated renin-angiotensin-aldosterone system (RAAS) in rodent models. This study aimed at investigating the hypothesis that 1) in pediatric patients with UPJO the RAAS is activated before surgical relief of the obstruction; 2) in rats with UPJO the RAAS activation is reflected by increased abundance of renal aldosterone-stimulated Na transporters; and 3) the injured UPJO kidney allows aberrant filtration of plasminogen, leading to proteolytic activation of the epithelial Na channel γ-subunit (γ-ENaC). Hydronephrosis resulting from UPJO in pediatric patients and rats was associated with increased urinary plasminogen-to-creatinine ratio. In pediatric patients, plasma renin, angiotensin II, urine and plasma aldosterone, and urine soluble prorenin receptor did not differ significantly before or after surgery, or compared with controls. Increased plasmin-to-plasminogen ratio was seen in UPJO rats. Intact γ-ENaC abundance was not changed in UPJO kidney, whereas low-molecular cleavage product abundance increased. The Na-Cl cotransporter displayed significantly lower abundance in the UPJO kidney compared with the nonobstructed contralateral kidney. The Na-K-ATPase α-subunit was unaltered. Treatment with an angiotensin-converting enzyme inhibitor (8 days, captopril) significantly lowered blood pressure in UPJO rats. It is concluded that the RAAS contributes to hypertension following partial obstruction of urine flow at the pelvo-ureteric junction with potential contribution from proteolytic activation of ENaC.

Protein Kinase 2ß Is Expressed in Neural Crest-Derived Urinary Pacemaker Cells and Required for Pyeloureteric Contraction.

Nonobstructive hydronephrosis, defined as dilatation of the renal pelvis with or without dilatation of the ureter, is the most common antenatal abnormality detected by fetal ultrasound. Yet, the etiology of nonobstructive hydronephrosis is poorly defined. We previously demonstrated that defective development of urinary tract pacemaker cells (utPMCs) expressing hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3) and the stem cell marker cKIT causes abnormal ureteric peristalsis and nonobstructive hydronephrosis. However, further investigation of utPMC development and function is limited by lack of knowledge regarding the embryonic derivation, development, and molecular apparatus of these cells. Here, we used lineage tracing in mice to identify cells that give rise to utPMCs. Neural crest cells (NCCs) indelibly labeled with tdTomato expressed HCN3 and cKIT. Furthermore, purified HCN3+ and cKIT+ utPMCs were enriched in Sox10 and Tfap-2α, markers of NCCs. Sequencing of purified RNA from HCN3+ cells revealed enrichment of a small subset of RNAs, including RNA encoding protein kinase 2ß (PTK2ß), a Ca2+-dependent tyrosine kinase that regulates ion channel activity in neurons. Immunofluorescence analysis in situ revealed PTK2ß expression in NCCs as early as embryonic day 12.5 and in HCN3+ and cKIT+ utPMCs as early as embryonic day 15.5, with sustained expression in HCN3+ utPMCs until postnatal week 8. Pharmacologic inhibition of PTK2ß in murine pyeloureteral tissue explants inhibited contraction frequency. Together, these results demonstrate that utPMCs are derived from NCCs, identify new markers of utPMCs, and demonstrate a functional contribution of PTK2ß to utPMC function.

Predictors of Recoverability of Renal Function after Pyeloplasty in Adults with Ureteropelvic Junction Obstruction.

BACKGROUND: This study aimed to identify factors predicting the recoverability of renal function after pyeloplasty in adult patients with ureteropelvic junction obstruction. METHODS: We retrospectively reviewed 138 adults with unilateral renal obstruction-induced hydronephrosis and who underwent Anderson-Hynes dismembered pyeloplasty from January 2013 to January 2016. Hydronephrosis was classified preoperatively according to the Society for Fetal Urology (SFU) grading system. All patients underwent Doppler ultrasonography, excretory urography, computed tomography, and technetium-99m-diethylenetriamine pentaacetic acid radioisotope (99mTc DTPA) renography before and after surgery. Renal resistive index (RRI) and 99mTc DTPA renography were repeated at 1, 3, 6, and 12 months. RESULTS: Multivariate analysis identified age, renal pelvic type, SFU grade, preoperative RRI, decline of RRI, and renal parenchyma to hydronephrosis area ratio (PHAR) as independent predictors of renal function recoverability after pyeloplasty. However, preoperative RRI and RRI decline were not significantly associated with recoverability of renal function in patients aged >35 years. Lower preoperative RRI, greater decline in RRI, higher PHAR, lower SFU grade, and extrarenal pelvis were associated with greater improvements in postoperative renal function. CONCLUSIONS: Preoperative differential renal function cannot independently predict the recoverability of postoperative renal function in adult patients with unilateral renal obstruction-induced hydronephrosis. SFU grade, renal pelvic type, PHAR, preoperative RRI, and decline in RRI were significantly associated with the recoverability of renal function in adult patients aged <35 years, while only SFU grade, renal pelvic type, and PHAR were significantly associated with renal function recoverability in patients aged ≥35 years. Renal function recovery was better in patients younger than 35 years when compared with older patients.

Changes in arterial pressure and markers of nitric oxide homeostasis and oxidative stress following surgical correction of hydronephrosis in children.

OBJECTIVE: Recent clinical studies have suggested an increased risk of elevated arterial pressure in patients with hydronephrosis. Animals with experimentally induced hydronephrosis develop hypertension, which is correlated to the degree of obstruction and increased oxidative stress. In this prospective study we investigated changes in arterial pressure, oxidative stress, and nitric oxide (NO) homeostasis following correction of hydronephrosis. METHODS: Ambulatory arterial pressure (24 h) was monitored in pediatric patients with hydronephrosis (n = 15) before and after surgical correction, and the measurements were compared with arterial pressure measurements in two control groups, i.e. healthy controls (n = 8) and operated controls (n = 8). Markers of oxidative stress and NO homeostasis were analyzed in matched urine and plasma samples. RESULTS: The preoperative mean arterial pressure was significantly higher in hydronephrotic patients [83 mmHg; 95% confidence interval (CI) 80-88 mmHg] than in healthy controls (74 mmHg; 95% CI 68-80 mmHg; p < 0.05), and surgical correction of ureteral obstruction reduced arterial pressure (76 mmHg; 95% CI 74-79 mmHg; p < 0.05). Markers of oxidative stress (i.e., 11-dehydroTXB2, PGF2α, 8-iso-PGF2α, 8,12-iso-iPF2α-VI) were significantly increased (p < 0.05) in patients with hydronephrosis compared with both control groups, and these were reduced following surgery (p < 0.05). Interestingly, there was a trend for increased NO synthase activity and signaling in hydronephrosis, which may indicate compensatory mechanism(s). CONCLUSION: This study demonstrates increased arterial pressure and oxidative stress in children with hydronephrosis compared with healthy controls, which can be restored to normal levels by surgical correction of the obstruction. Once reference data on ambulatory blood pressure in this young age group become available, we hope cut-off values can be defined for deciding whether or not to correct hydronephrosis surgically.