Ureteropelvic junction obstruction causes histologic alterations in contralateral kidney (original) (raw)
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Int J Exp Pathol, 2010
Ureteropelvic junction (UPJ) obstruction is the most frequently observed cause of obstructive nephropathy in children. Neonatal and foetal animal models have been developed that mimic closely what is observed in human disease. The purpose of this review is to discuss how obstructive nephropathy alters kidney histology and function and describe the molecular mechanisms involved in the progression of the lesions, including inflammation, proliferation ⁄ apoptosis, renin-angiotensin system activation and fibrosis, based on both human and animal data. Also we propose that during obstructive nephropathy, hydrodynamic modifications are early inducers of the tubular lesions, which are potentially at the origin of the pathology. Finally, an important observation in animal models is that relief of obstruction during kidney development has important effects on renal function later in adult life. A major shortcoming is the absence of data on the impact of UPJ obstruction on long-term adult renal function to elucidate whether these animal data are also valid in humans.
International Urology and Nephrology, 2015
group underwent Ulm-Miller surgery to create UPJO, whereas the left kidneys of nine rabbits from the second group underwent sham surgery. A pressure flow study (Whitaker's test) was done during postoperative week 6. Based on the Whitaker test, the DU, DRS, and MRU findings were compared. The number of apoptotic renal cells was counted after death. Result The Whitaker test run during postoperative week 6 revealed obstructions in 15 rabbits from group 1; the nine rabbits of the sham group had no obstructions. Sensitivity and specificity of DRS were 93.3 and 88.8 %, respectively, and those of MRU were 93.3 and 88.8 %, respectively. The postoperative mean RI values were significantly higher than the preoperative values, associated with sensitivity of 86.6 % and specificity of 77.5 % for detecting UPJO. DRS, MRU, and RI could not predict UPJO in one (8 %), one (8 %), and two (16 %) kidneys, respectively. Likelihood ratio (LR) was 8.4 for MRU and scintigraphy, while for RI, LR was 3.9. Pathology specimens revealed that all kidneys with UPJO underwent apoptosis, and the number of apoptotic cells was significantly higher on the UPJOcreated side than on the contralateral and in the sham group (p < 0.05). No test predicted all apoptosis related to UPJO. Conclusion The RI, DRS, and DMRU results correlated with the pressure flow results for detecting UPJO. No single radiological technique predicted all initial UPJO-created kidneys that concluded with apoptosis. Further studies are required to seek with better methods for diagnosing an obstruction or to define a combination of radiological techniques aiding in the management decision.
Gazi Medical Journal, 2015
Objective: We aimed to assess the impact of obstructive uropathy and its revision on renal apoptotic and inflammatory activity in an experimental model in rabbits. Methods: Twenty-four rabbits were separated into four different groups. Ureteropelvic junction (UPJ) obstruction model was performed in Group 1 and 2. Ureterovesical junction (UVJ) obstruction model was performed in Group 3 and 4. Thirty days after the operations, bilateral nephrectomy was performed in Group 1 and 3. Thirty days after the initial surgery, the obstruction was revised in Group 2 and 4. Thirty days after the revision surgeries, bilateral nephrectomy was performed in Group 2 and 4. The apoptotic and inflammatory activity was measured at the protein level and nephrectomy specimens were examined histologically. Results: Caspase 3 levels were significantly higher in operated left kidneys than the levels obtained in the right counterparts. The increase in procaspase 9 and caspase 3 activities in the UVJ obstruction group was less than those of the UPJ obstruction group (p<0.05, p<0.01, respectively). After the revision of obstruction, the decrease in procaspase 9 and caspase 3 activities was more significant in Group 4 than in Group 2 (p<0.05, p<0.01, respectively). Cyclooxygenase-2 expression decreased insignificantly in Group 2 and 4 when compared to Group 1 and 3 (p>0.05, p>0.05, respectively). Conclusion: The rabbits with a UVJ obstruction had lower apoptotic indexes as compared to those with a UPJ obstruction. The apoptotic activity decreased to almost normal levels following an adequate revision of the obstruction in both groups, but this improvement was more significant in animals with a UVJ obstruction.
Journal of Urology, 1998
Purpose: There are few reports of pathological kidney findings in ureteropelvic junction obstruction in pediatric patients. The role of hyperfiltration in the genesis and progression of these changes has been a matter of debate. We determine wheiher segmental sclerosis is evidence of hyperfiltration and renal damage in children who underwent surgery for ureteropelvic junction obstruction. Materials and Methods: We retrospectively analyzed the clinical records of 38 children with a mean age of 4.4 years with ureteropelvic junction obstruction. Histological changes in biopsies (39 renal units) and nephrectomy specimens (2 renal units) were compared with clinical history, imaging studies and urinary protein excretion. Results: Renal histology was essentially normal in 75% of the biopsies. Focal dilatation of Bowman's space and occasionally of the collecting tubules was noted in a third of this group. Abnormal changes consistent with renal damage were present in 25% of the biopsies, including variable degrees of interstitial chronic inflammation, eosinophilic acellular material within Bowman's space and focal concentric glomerulosclerosis. Severe changes, chronic interstitial fibrosis and inflammation, and diffuse glomerulosclerosis were only found in nephrectomy specimens, while eosinophilic acellular material and glomerulosclerosis were observed in 7 biopsies. In all of these renal units there was evidence of hyperfiltration with bilateral or unilateral ureteropelvic junction obstruction with a contralateral multicystic dysplastic kidney. Urinary protein excretion in 19 patients was increased in obstructed compared with normal contralateral kidneys (p <0.05). Conclusions: Hyperfiltration should be considered a mechanism involved in the progression of histological changes in kidneys with ureteropelvic junction obstruction. We suggest that early surgical correction be considered in obstructed kidneys at risk for hyperfiltration.
Renal injury in complete ureteric obstruction
Urological Research, 1991
This preliminary study examined reno-vascular injury sustained by the multipapillary porcine kidney in acute and chronic complete ureteric obstruction. In combination with measurement of upper tract pressure, regional function was assessed by [99mTc]-dimercaptosuccinic acid (DMSA) uptake and qualitative renal perfusion, by resin casting of the arterial tree prior to scanning electron microscopy (SEM). In acute obstruction, segmental defects were noted in the renal poles on both [99mTc]-DMSA scanning and casting. On SEM there was a polar afferent arteriolar vasodilatation after 30 min of obstruction and, subsequently, a segmental reduction in cortical perfusion. In kidneys that had been obstructed for 20 days, we observed a marked reduction in outer cortical perfusion coincident with afferent arteriolar vasoconstriction. The pathogenesis and significance of segmental injury to the multipapillary kidney in obstructive uropathy is discussed.
Urinary obstruction is a common cause of acute and chronic renal failure. The symptoms and signs of an obstructed kidney may vary from asymptomatic to severe acute pain. The diagnosis and management of a hydronephrotic kidney is not very difficult with ultrasonography, IVU, and diuretic renography. The approach to manage such patients has been rationalized after the advent of diuretic renography. The obstructed kidney should be decompressed as early as possible because of progressive loss of renal function with prolonged obstruction. Nephrectomy may be required for a non-functioning kidney. Further advancements are being made as the molecular mechanisms involved in the pathophysiology of the obstructed kidney become known to us.
2019
Introduction : Several studies have addressed the unique management challenges in poorly functioning kidneys of patients with ureteropelvic junction obstruction. Trial with percutaneous drainage of such kidneys as a guide to choose the type of surgical management would be a solution to this dilemma. We aimed to evaluate the role of percutaneous nephrostomy in treatment of poorly functioning kidneys in pediatric patients with UPJO. Materials and Methods : A prospective study was performed on patients with poorly functioning kidneys (split renal function<10% on renal dynamic scan) and unilateral ureteropelvic junction obstruction from August 2016 to January 2018. Ultrasound-guided nephrostomy was inserted for these patients. Data regarding the differential renal function and glomerular function rate (GFR) was collected before and after nephrostomy insertion. Decision regarding pyeloplasty or nephrectomy of the involved kidney was made based on changes seen in differential function ...
European Journal of Nuclear Medicine and Molecular Imaging, 2008
Purpose We investigated the functional consequences of relieving ureteric obstruction in young pigs with experimental hydronephrosis (HN) induced by partial unilateral ureteropelvic obstruction. Materials and methods Three groups of animals were followed from the age of 2 weeks to the age of 14 weeks: Eight animals had severe or grades 3-4 HN throughout the study. Six animals had relief of the obstruction after 4 weeks. Six animals received sham operations at both ages. Morphological and functional examinations were performed at age 6 weeks and again at age 14 weeks and consisted of magnetic resonance imaging (MRI), technetiumdiethylenetriaminepentaaceticacid ( 99m Tc-DTPA) renogra-phy, renal technetium-dimercaptosuccinicacid ( 99m Tc-DMSA) scintigraphy, and glomerular filtration rate (GFR) measurement.
Nephro-Urology Monthly, 2015
Background: Pyeloplasty is a widely accepted treatment for ureteropelvic junction obstruction (UPJO). However, the renal function recoverability after pyeloplasty is still a matter of debate. Different parameters have been used to predict renal functional recoverability after corrective surgery, with conflicting results. Objectives: In this study, renal biopsy was carried on a series of cases of UPJO, during pyeloplasty, to study the extent of histological alterations in renal parenchyma, as a result of obstruction, and its predictive value in renal function recoverability after pyeloplasty. Patients and Methods: We retrospectively analyzed the renal biopsy obtained during pyeloplasty in 53 adult patients. Histopathological changes were graded on a scale of 1 to 3, according to their severity, and compared with the differential renal function (DRF) revealed on the preoperative and postoperative follow up diethylene triamine pentaacetic acid (DTPA) renal scan. A Fischer's t test was used to evaluate statistical differences between values. Results: This study showed a linear relationship between the severity of histological changes and renal function recovery, after pyeloplasty. Out of 24 obstructed renal units (ORU), with minimal histopathological changes (grade I), 21 ORU (87.5%), with > 35% DRF preoperatively, showed significant improvement in renal function after 12 months of pyeloplasty (P < 0.05). On the other hand, all kidneys (n = 29) with moderate to severe obstructive changes (grade II and III) had minimal improvement in DRF, after pyeloplasty, which was clinically insignificant (P > 0.05). Renal function deterioration after pyeloplasty was not observed in any of the cases. Conclusions: The severity of pathological changes in renal parenchyma, due to UPJO, is a good predictor of renal function recoverability, after pyeloplasty. The ORUs, with DRF > 35%, usually have normal (grade I) renal biopsy and might be expected to present better functional recoverability after pyeloplasty.
Pediatric Radiology, 2008
Background Improvement in resolution and use of highfrequency transducers in US has enabled visualization of previously unreported changes in medullary pyramid echogenicity in children with obstructive hydronephrosis. Objective To determine whether these unreported changes in echogenicity and morphology of the renal pyramids in ureteropelvic junction (UPJ) obstruction correlate with differential renal function (DRF) of the kidney as determined by technetium-99m mercaptoacetyltriglycine ( 99m Tc-MAG3) scan. Materials and methods Renal sonograms in 60 children with UPJ obstruction were retrospectively reviewed. Children were divided into three groups based on the echogenicity of the pyramids: (1) normal echogenicity of the pyramids, (2) increased echogenicity of the pyramids with maintained corticomedullary differentiation (CMD), and (3) loss of CMD. DRF, as determined by 99m Tc-MAG3 scan, of the obstructed kidney of ≥45% was considered normal and of ≤44% was considered abnormal based on a published study correlating histological changes with DRF.