Focus on Upper Urinary Tract Stones Combined with Parenchymal Infiltrative Renal Pelvis Cancer

INTRODUCTION

Upper urinary tract stones combined with parenchymal infiltrative renal pelvic cancer are challenging to detect on imaging and to evaluate the differential diagnosis.

CASE PRESENTATION

The symptoms and diagnoses in three cases of parenchymal infiltrative renal pelvic cancer and upper urinary tract stones that occurred between June 2019 and June 2022 were reviewed. Primary symptoms of lumbar discomfort and hematuria were evident in all 3 patients. Preoperative computed tomography (CT) abdominal imaging revealed that all three cases had hydronephrosis along with renal stones, while the other two cases only had localized hypoenhancement of the renal parenchyma, which was only thought to be limited inflammatory changes in the renal cortex as a result of the combination of renal pelvis infection. After percutaneous nephrolithotomy or ureteroscopic lithotripsy, a combined renal pelvis tumor was discovered in all of these instances. Radical tumor surgery was later performed. One patient who had several tumor metastases passed away 6 months after surgery. A case with multiple metastases was discovered 15 months after surgery and survived with the help of the current chemotherapy. A case with a bladder tumor recurrence was discovered 16 months after surgery and had transurethral bladder tumor electrosurgery and routine bladder perfusion chemotherapy.

CONCLUSION

Upper urinary tract stones and parenchymal infiltrative pyel carcinoma have atypical imaging, easily confused with infectious diseases. CT or computed tomography urography (CTU) must be considered by urologists. Patients who have a CT with local renal parenchyma density should be suspected of having parenchymal invasive renal pelvis carcinoma; a needle biopsy ought to be performed; and repeat biopsies may be performed if necessary. High-risk individuals need multiple, sufficient biopsies as needed and a comprehensive intraoperative assessment of the renal pelvic mucosa.

Kidney collecting system anatomy applied to endourology - a narrative review

OBJECTIVE

To evaluate the surgical anatomy of the kidney collecting system through a narrative review of the literature, highlighting its importance during diagnosis and its approach during surgical procedures for the treatment of renal stones.

MATERIAL AND METHODS

We carried out a review about the anatomy of the kidney collecting system. We analyzed papers published in the past 40 years in the databases Pubmed, Embase and Scielo, and we included only papers in English and excluded case reports, editorials and opinions of specialists.

RESULTS

Renal collecting system could be divided in four groups: A1 - kidney midzone (KM), drained by minor calyx that are dependent on the superior or the inferior caliceal groups; A2 - KM drained by crossed calyx, one draining into the superior caliceal group and another draining into the inferior caliceal group; B1 - KM drained by a major caliceal group independent of both the superior and inferior groups; and B2 - KM drained by minor calyx entering directly into the renal pelvis. Some details and anatomic variations of the collecting system are related to clinical and radiological aspects, particularly perpendicular calyces, interpyelocalyx space, position of calyces in relation to renal border, classification of the renal collecting system, infundibular diameter and the angle between the lower infundibulum and renal pelvis.

CONCLUSION

The knowledge of intra-renal collecting system divisions and variations as the angle between the renal pelvis and lower infundibula, position of the calices in relationship with renal edge and the diameter and position of the calyces are important for the planning of minimally invasive renal surgeries.

Ureteropelvic junction obstruction with polyps in children: clinical manifestations and supranormal preoperative differential renal function

OBJECTIVE

To describe and analyze the clinical manifestation and pre-DRF of UPJO children with polyps and explore the possible influencing factors of supranormal pre-DRF.

PATIENTS AND METHODS

All patients undergoing primary Anderson-Hynes pyeloplasty for UPJO due to polyp were retrospectively reviewed. Patients' characteristics, parameters of ultrasound and dynamic renograms (DR) were recorded in elaborate. Pre-DRF in groups of different age, weight, gender, pain, grade of hydronephrosis, anterio-posterior pelvic diameter (APD), length of kidney and postoperative ultrasonic parameters were compared.

RESULTS

A total of 18 UPJO children with polyps were included. Five (27.78%) patients had SFU III grade of hydronephrosis. Seven (38.89%) patients were supranormal pre-DRF. All patients had pre-DRF > 40%. Drainage curve was delayed excretion in 12 (66.67%) patients and T1/2 < 20 min was in 4 (22.22%) patients. Among the 16 patients who underwent preoperative IVP examination, 15 (93.75%) patients had concentration of intrarenal pelvis contrast agent within 10 min. No significant difference in post-APD reduction rate and post-minPT increased was found between supranormal pre-DRF and non-supranormal pre-DRF groups. The supranormal pre-DRF was more likely to occur in young and low-weight children.

CONCLUSION

The preoperative renal function of UPJO patients with polyps was well preserved, and 38.89% of them had supranormal pre-DRF. Patients with supranormal pre-DRF can be managed with the same strategies as those with normal renal function.

Risk factors for adverse outcomes after pediatric pyeloplasty: A retrospective cohort study

PURPOSE

To identify the risk factors for adverse outcomes after pediatric pyeloplasty.

METHODS

We conducted a retrospective review of all children under the age of 14 years who underwent primary pyeloplasty for unilateral ureteropelvic junction (UPJ) obstruction at a single teaching hospital in Tunisia between January 1, 2013, and December 31, 2022.

RESULTS

A total of 103 patients were included. Median age of patients at surgery was 27 months (interquartile range [IQR], 13-44). On ultrasound, median renal pelvic anteroposterior diameter was 3.2 cm (IQR, 2.3-4), and the median renal cortex thickness (RCT) was 2.5 mm (IQR, 2-3.5). Median differential renal function (DRF) on preoperative radionuclide renal scan was 40% (IQR, 30-46). Postoperative adverse outcomes occurred in 28 patients (27.2%). These included 19 cases of urinary tract infections (UTIs), 11 cases of UPJ restenosis, four cases of UPJ leakage, two cases of urinoma, and two cases of diversion-related complications. Multivariate logistic regression analysis revealed two factors significantly and independently related to postoperative negative outcomes: RCT <3 mm and DRF > 50%.

CONCLUSION

Our study demonstrated that preoperative RCT on ultrasound of less than 3 mm and preoperative DRF on radionuclide renal scan of more than 50% were independent risk factors for adverse outcomes following pediatric pyeloplasty. These factors could be of interest in identifying, early on, patients who will develop postoperative negative outcomes, giving them more attention and support, and explaining the prognosis to the patient and family.

Supranormal differential renal function on MAG3 scan in children with ureteropelvic junction obstruction - Prevalence and pyeloplasty during follow-up

BACKGROUND

Children with suspected ureteropelvic junction obstruction (UPJO) may present with a paradoxical ipsilateral supranormal differential renal function (snDRF) on 99mTechnetium mercaptoacetyltriglycine scintigraphy (MAG3 scan).

OBJECTIVE

The aim was to investigate the prevalence of snDRF, the risk of pyeloplasty among children with UPJO and snDRF, and to explore the experience of snDRF among international pediatric urologists.

METHODS

A retrospective cohort study of children with suspected unilateral UPJO who underwent MAG3 scan at four hospitals in Sweden between 2005 and 2020. SnDRF was defined as DRF ≥55%. Normal DRF was defined as DRF 45-54%. Primary outcome was risk of pyeloplasty. Indications for pyeloplasty were loss of >10%-points of differential renal function (DRF), ipsilateral DRF <40%, or symptomatic UPJO. Logistic and cox regressions were performed in univariate and multivariable analyses, adjusting for age, gender, year, laterality, antenatal hydronephrosis, anterior-posterior diameter (APD), and kidney size. An international questionnaire regarding the management of snDRF was developed and distributed to pediatric urologists.

RESULTS

The prevalence of snDRF was 19%. SnDRF was more common in boys, children with antenatal hydronephrosis, children undergoing their first MAG3 scan at a younger age, and in the left kidney. After further exclusion of 70 children with DRF <45%, a total of 264 were included for longitudinal follow-up of median 6.6 (IQR 2.5-11.5) years. SnDRF was not associated with increased risk of pyeloplasty (adjusted OR 0.98 (95% CI 0.41-2.33), p = 0.96, and adjusted HR 1.00 (95% CI 0.53-1.91), p = 0.99) or time to pyeloplasty (1.1 years vs. 1.6 years, p = 0.40). Among the 79 surveyed pediatric urologists, a majority would not change clinical UPJO-management based on the presence or absence of ipsilateral snDRF.

DISCUSSION

There are only a few studies considering the need of pyeloplasty based on the presence of snDRF and this is the first survey among pediatric urologists on its management. With more included patients than previous studies, this study showed a snDRF prevalence of 19%, congruent with the findings of others. The underlying cause of snDRF is debated, but it cannot solely be explained as an artifact of hydronephrotic kidneys. Further studies on the clinical implications of snDRF are warranted, since DRF influences the decision to operate.

CONCLUSION

A fifth of all children with suspected UPJO presented with ipsilateral snDRF on initial MAG3 scan, and snDRF was not associated with a greater risk of pyeloplasty. Supported by a large group of international pediatric urology colleagues, this study concludes that the same clinical follow-up and management apply, regardless of presence of snDRF.

Unintended placement of a double-J stent in the contralateral renal pelvis during laparoscopic pyeloplasty for pediatric hydronephrosis: a case report

BACKGROUND

The double-J stent (DJS) is a commonly used ureteral stent in urological surgeries, which provides support and drainage. However, the DJS may result in various complications such as infection, hematuria, stone formation, stent occlusion, and migration. Normally, one end of the DJS is located in the renal pelvis, and the other end in the bladder. In this case report, we describe the rare occurrence of a misplaced DJS during laparoscopic pyeloplasty, which was unintentionally placed in the contralateral renal pelvis.

CASE REPORT

A 4-month-old male infant was diagnosed with left hydronephrosis. After confirmation of the diagnosis, laparoscopic left pyeloplasty was performed with the placement of a DJS. The patient did not experience any discomfort, such as nausea, vomiting, refusal to feed, crying and restlessness, or fever, after the operation, and was discharged on postoperative day 4. The patient returned to the hospital for DJS removal 6 weeks after the operation. However, the kidneys, ureters, and bladder (KUB) X-ray examination showed that the DJS was unintentionally placed in the contralateral ureter and renal pelvis. The stent was confirmed and removed under cystoscopy. Postoperative examination of the DJS showed that there was a hole in the side of the middle of the stent for urine drainage, with no obstruction or contralateral hydronephrosis.

CONCLUSIONS

Misplacement of a DJS in the contralateral renal pelvis during laparoscopic pyeloplasty is a rare but potentially serious complication. Surgeons should be cautious when placing the stent and confirm its placement with imaging studies. Patients should be closely monitored for postoperative complications and prompt intervention should be taken if necessary.

Can we improve the usefulness of the diuretic renogram in the diagnosis of ureteropelvic junction obstruction (UPJO) in children? Introduction of mercaptoacetyltriglycine-suspected obstruction scoring system (MAG-SOS)

INTRODUCTION

Mercaptoacetyltriglycine (MAG-3) renogram is one of the gold standard diagnostic tools of ureteropelvic junction obstruction (UPJO); however, there is no widely agreed indications of pyeloplasty based on MAG-3 findings. In this study, we introduce a renogram scoring system that can help improve the prognostic value of MAG-3 renogram and in the decision making of pyeloplasty.

PATIENTS AND METHODS

We retrospectively reviewed consecutive pyeloplasties for antenatal hydronephrosis from 2010 to 2020. A control group was included of non-operatively managed SFU grade 3 and 4. The initial renal ultrasound and preoperative MAG-3 Lasix renogram were reviewed for differential renal function (DRF), type of renogram curve and tracer washout half-time (T1/2). A ROC curve was used to evaluate the cut-off points that can be associated with obstruction. A multivariate linear regression model was used to assess the best renogram parameter that can predict surgical intervention.

RESULTS

We included 188 patients with 209 renal units. The median age for pyeloplasty was 5.4 months. The mercaptoacetyltriglycine-Suspected Obstruction Scoring System (MAG-SOS) was associated with pyeloplasty (AUC = 0.97, P < 0.001) (Figure A). A score of 5 is 100% specific for obstruction. 78% of units required surgical intervention had a MAG-SOS score of≥5 while all units of the control group had a range of score 0-4. Using the multivariate analysis, the MAG-SOS system showed to the only independent predictor for pyeloplasty (HR = 0.03, p < 0.001).

DISCUSSION

This study has some limitations. Firstly, the retrospective nature of the cohort; however, all patients were reviewed by one investigator who was blinded to the line of management. This is a single institutional study; therefor, this MAG-SOS should be evaluated by other centers to ensure its efficiency. Lastly, the pyeloplasty decision was taken by 3 different urologists; nevertheless, all of them adopt the same indications which are similar to those of the Society for Pediatric Urology and the Canadian Urological Association guidelines.

CONCLUSION

The MAG-SOS system showed to be a useful tool that can predict pyeloplasty. A score of 5 has 100% specificity for patients having a pyeloplasty performed. Prospective studies are required to confirm the usefulness of this novel tool.

Ureteropelvic junction obstruction in children by polar vessels: histological examination result

In children, ureteropelvic junction obstruction (UPJO) is mostly caused by intrinsic factors (IUPJO) such as abnormal amounts of muscle and collagen deposition; extrinsic UPJO are rare and often due to crossing vessels (CVs). What is not clear is whether there is also intrinsic UPJ pathology in patients with CV. The aim of our study was to compare the histology of the two types of obstruction and to determine whether these histologic features are distinguishable enough to enable to identify the cause of obstruction based on histologic appearance alone. We retrospectively reviewed pathology reports of 38 children with UPJO that underwent surgery in our hospital from 2008 to 2022. The intrinsic and extrinsic groups consisted of 18 and 20 patients, respectively. After ematoxylin-eosin and Gomori's trichrome staining the specimens were scored for fibrosis and muscular hypertrophy in histhopatology, and CD117 antibody were used to detect interstitial Cajal-like cells. In our study, histological analyses revealed no differences between the CV and IUPJO specimens in terms of presence and degree of fibrosis and muscular hypertrophy; likewise, for presence of interstitial Cajal-like cells.

Renal Pelvis Immunoglobulin G4-Related Disease Mimicking Malignant Tumor: A Case of 18 F-FDG and 68 Ga-FAPI PET/CT Imaging

ABSTRACT

A space-occupying lesion in the left renal pelvis was found in a 56-year-old man. The patient voluntarily participated in a clinical trial of 68 Ga-FAPI in solid tumors. PET/CT images revealed an intense 18 F-FDG and 68 Ga-FAPI uptake in this lesion. Malignant tumor was suspected. The patient subsequently underwent laparoscopic partial nephrectomy. The postoperative pathological examination established the diagnosis of immunoglobulin G4-related disease.

[Primary melanoma of renal pelvis]

A rare case of primary renal pelvis melanoma in 47-year-old man is presented in the article. Before surgery a patient was considered to have metastatic urothelial carcinoma. A diagnosis of malignant melanoma was based on immunophenotyping and detection of intracellular melanin pigment both in pelvis tumor and lung metastasis. The primary localization in the pelvis was proven by the presence of scattered melanocytes within urothelium.The patient had no previous history ofskin or mucosa melanoma. This is the sixth case of renal pelvis melanoma published in PubMed.

Giant renal parapelvic cyst with pelvi-ureteric junction obstruction in an infant: challenges in diagnosis and laparoscopic management

Renal parapelvic cysts (RPC) have an incidence of approximately 1%-3% in the general population. However, they rarely present in children with only two cases reported in literature. RPC are often misdiagnosed as it is difficult to distinguish them from hydronephrosis on preoperative imaging. We report a case of an infant with a giant RPC with associated pelvi-ureteric junction obstruction, who was managed successfully with laparoscopic complete excision of RPC and dismembered pyeloplasty. In our report, we discuss the challenges faced in the diagnosis and surgical management of this unusual case.

Unique case of IgG4-related disease of the renal pelvis involving the inferior vena cava masquerading as locally advanced urothelial cancer

Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease which can affect any organ or tissue in the body but most commonly affects the pancreas, biliary ducts, salivary glands, ocular system and lymph nodes; renal involvement is relatively uncommon and there are no previous reported cases of inferior vena cava involvement. Herein, a 48-year-old Asian man with an unremarkable medical history was found to have an obstructing right renal pelvis mass extending to and involving the inferior vena cava, highly suspicious for upper tract urothelial carcinoma that could not be ruled out based on ureteroscopy and urine cytology. Open radical nephroureterectomy with enbloc resection of a segment of the inferior vena cava and left renal vein ostium was performed, with reconstruction of the inferior vena cava and left renal vein with polytetrafluoroethylene grafts. Final histopathology confirmed the diagnosis of IgG4-related disease. This case demonstrates that IgG4-related disease can mimic upper tract urothelial cancer and should be considered as a diagnosis in atypical presentations of tumours of the upper urinary tract.

Urothelial Cell Carcinoma of the Renal Pelvis Misdiagnosed as Ureteropelvic Junction Obstruction: A Case Report

Urothelial tumors are typically a disease affecting elderly individuals and are rare in young patients. Moreover, upper urinary tract urothelial carcinoma is extremely rare in the young age group. In this study, we present a case of urothelial cell carcinoma of the renal pelvis and ureter in a young man without risk factors of urothelial carcinoma, which was misdiagnosed as ureteropelvic junction obstruction and treated with a laparoscopic pyeloplasty.

Unusual endophytic non-enhancing tumour in the renal pelvis: a diagnostic dilemma

Renal cell cancer (RCC) is incidentally detected on imaging in 50%-60% of cases. Among the RCCs, clear cell variant is most common and classically seen as heterogenous enhancing lesion on CT imaging. Hypoenhancing mass presents a diagnostic dilemma with differential diagnosis being urothelial carcinoma, fat poor angiomyolipoma, oncocytoma or rarer variants of RCC. Such cases require further evaluation in form of urine cytology or newer molecular diagnostic techniques. Here, we present a case of renal mass with minimal enhancement on CT scan and imaging features suggestive of upper tract urothelial cancer. Final histopathology revealed the mass to be chromophobe variant of renal cell carcinoma.

Transient minimal hydronephrosis on contralateral kidney in infants with unilateral hydronephrosis: Is it an early sign of worsening of the affected kidney?

Background/aim

The criteria for surgical management of ureteropelvic junction obstruction are not well-defined, and there is a risk for loss of renal function before the operation. In this context, certain changes in contralateral kidney had been investigated in order to increase the sensitivity of diagnosis. In this study, we aimed to investigate whether contralateral transient minimal hydronephrosis (CTMH) can be considered as an “early alarm” sign for worsening of the affected kidney in infants with hydronephrosis.

Materials and methods

A total of 182 infants (92 surgically treated and 90 conservatively followed-up) with unilateral hydronephrosis were retrospectively analyzed. Ultrasonography and renal scan findings were evaluated. Correlation between the appearance of CTMH, contralateral compensatory hypertrophy (CCH) on ultrasonography, and prognosis of the affected kidney were evaluated.

Results

Among the surgically treated patients, 18 (19.6%) patients developed CTMH on average 7 months (0–13 months) before surgery. Among these 18 patients with CTMH, 12 patients (66.6%) had loss of renal function preoperatively, while this ratio was 29.7% on their counterparts (p = 0049). CCH was observed in 31 (33.7%) individuals in surgically treated patient group including all 18 patients with CTMH, while none of the conservatively followed-up patients developed CCH and/or CTMH. In the multiple logistic regression analysis, among the variables investigated, CTMH was found as an independent predictor of the deterioration in the affected kidney and of the poor prognosis (p = 0.011 and p = 0.0004, respectively).

Conclusion

In our study, among the variables investigated, CTMH was found as an independent predictor of the deterioration in the affected kidney and poor prognosis in infants followed-up with isolated unilateral hydronephrosis. Additionally, CTMH can be considered as an “early alarm” sign for worsening of the affected kidney and the need for surgical intervention.

Giant neonatal hydronephrosis of the upper pole of a complete duplicated renal system

Ureteropelvic junction obstruction (UPJO) in the upper pole of a complete duplicated renal system is extremely rare. We report a case that was diagnosed prenatally and we review 10 cases published in the literature. Diagnoses of adrenal hematoma and cystic neuroblastoma were suspected on prenatal ultrasound, based on the severity of dilatation and the difficulty of identifying the exact origin of this anomaly. Neonatal magnetic resonance imagery (MRI) was subsequently able to show a normal adrenal gland. Surgical management is similar to that of a single-system pyeloureteral junction obstruction. Since this situation is very rare, we believe cystoscopy can be useful to confirm diagnosis of UPJO associated with complete duplication, especially in the absence of preoperative MRI. Among the 11 surgical cases previously published, seven patients underwent pyeloplasty and four heminephrectomy.

[Comparison of functional magnetic resonance urography and dynamic renal scintigraphy in the functional assessment of ureteropelvic junction obstruction in children]

PURPOSE

In order to determine the role and significance of functional magnetic resonance urography (fMRU) in the diagnosis of ureteropelvic junction obstruction (UPJO), a comparative analysis of the results of fMRU and dynamic renal scintigraphy (DRS) was carried out.

MATERIALS AND METHODS

From January 2017 to December 2019, fMRU and diuretic DRS were performed in 36 patients (mean age 89+/-63 months). Boys - 26 (72.2%), girls - 10 (27.8%). Left-sided hydronephrosis was detected in 23 (63.9%) children, right-sided in 12 (33.3%) patients, and bilateral lesions in 1 (2.8%) patient (2 renal units (RU)). Antenatal hydronephrosis was detected in 9 (25%) patients, and postnatally in 27 (75%) patients. According to ultrasound data, grade II hydronephrosis occurred in 11 (29.8%) RU, grade III - in 21 RU (56.7%), and grade IV - in 5 RU (13.5%) according to the SFU classification. A diuretic test was performed in 26 patients.

RESULTS

Median and quartiles of differential renal function (DRF) according to fMRU data on the affected side were 37% [29; 43], and according to DRS - 46% [40;49]. When performing fMRU, a positive diuretic test was detected in 20 patients, 5 patients - negative and 1 patient - doubtful, and according to the DRS data, 12 patients had a positive test, 10 patients - negative and 4 patients - doubtful. Differences in DRF between fMRU and DRS varied between 0.7-33%. The average value of differences in DRF on the affected side was 11.3+/-8.5%. When comparing the results of DRF on the affected side, a moderate correlation was found on the Cheddock scale (r=0.59, p<0.05) between fMRU and DRS data. In comparison of the DRF using the Wilcoxon test, statistically significant differences were revealed (p<0,05).

SUMMARY

Our experience demonstrates the high potential of fMRU in terms of replacing the classical methods of diagnosis of UPJO in children, taking into account the high correlation coefficients between the results of fMRU and DRS. Standardization of the fMRU protocol will increase the diagnostic relevance of information and in the future will make fMRU the only necessary study to determine management tactics for patients with UPJO.

Significance of sonographically detected bladder debris in children less than 2 years old with febrile urinary tract infection

PURPOSE

To investigate the relationship between bladder debris found on renal and bladder ultrasonography (RBUS) and the first febrile urinary tract infection (UTI) episode in children under 2 years old.

METHODS

We retrospectively reviewed the data of children aged <2 years with the first febrile UTI. We recorded bladder debris on RBUS and other findings (blood test, urinalysis, and urine culture). Other RBUS findings (renal pelvis debris, renal parenchymal change, wall thickening, and renal collecting system [RCS] dilatation) were recorded. Patients were divided into the debris (D) and non-D groups.

RESULTS

Of 128 patients (boys: girls = 81:47, mean age = 5.6 ± 4.2 months), 24 (18.8%) had bladder debris. The mean C-reactive protein (CRP) levels were higher in the D group (6.1 ± 4.0 vs 4.3 ± 3.5, P = .03). Twenty-one patients in the D group (87.5%) had hematuria (odds ratio = 3.706, 95% confidence interval = 1.035-13.267, P = .04). No significant differences were seen in the urine culture results between both groups. Significant associations were seen between bladder debris and other RBUS findings such as debris in renal pelvis, renal parenchymal change, and RCS wall thickening.

CONCLUSION

Bladder debris on RBUS is a common finding in children aged <2 years during the first febrile UTI. Bladder debris was related to higher CRP levels, hematuria and sonographic findings, but not to urine culture results.

Factors affecting success in the treatment of proximal ureteral stones larger than 1 cm with extracorporeal shockwave lithotripsy in adult patients

The aim of the study was to analyze the factors predicting success for the treatment of proximal ureteral stones larger than 1 cm with extracorporeal shockwave lithotripsy (SWL) in adult patients. Between January 2014 and December 2018, 480 adult patients in total underwent SWL and data were retrospectively evaluated. Patients with multiple ureteral stones, solitary kidney, congenital abnormality, skeletal system abnormality, history of previous urinary system surgery and SWL, renal insufficiency, patients who could not tolerate SWL and pediatric patients were excluded from the study. The remaining 415 patients were divided into two groups as success (Group 1, n = 307) and failure (Group 2, n = 108). The overall success rate was 73.9%. The values of stone size, Hounsfield Unit (HU), skin to stone distance (SSD), ureteral wall thickness (UWT), proximal ureter diameter, renal pelvis diameter, hydronephrosis grade, and duration of renal colic were significantly higher in Group 2 compared to Group 1. In binary logistic regression analyses, HU, UWT, and proximal ureter diameter were found to be independent predictors. HU, UWT, and proximal ureter diameter had sensitivity and specificity of 92-92%, 88-23%, and 87-46%, with cutoff values of 740 HU, 2.5 mm and 8.5 mm, respectively. The area under the curve values were 0.96, 0.97, and 0.96 for HU, UWT, and proximal ureter diameter, respectively. The CT-based parameters, including HU, UWT, and proximal ureter diameter are independent predictive factors with excellent accuracy for the treatment of proximal ureteral stones larger than 1 cm with SWL in adult patients. Based on these factors, SWL can be considered for proximal ureteral stones larger than 1 cm.

Delayed Rupture of the Renal Collecting System Secondary to a Traumatic Hemorrhage in the Setting of Suspected Chronic Ureteropelvic Junction Obstruction

Isolated rupture of the renal pelvis secondary to blunt trauma is rare, though there is increased incidence in the setting of a pre-existing renal abnormality that predisposes the kidney to injury. We report a case of post-traumatic hemorrhage into the renal collecting system leading to delayed rupture of the renal pelvis in the setting of suspected chronic ureteropelvic junction obstruction. This case illustrates the difficulty in diagnosis of acute hemorrhage into the renal collecting system. Special attention should be given to a kidney with a pre-existing abnormality in the setting of trauma to prevent complications. A literature review of hemorrhage into the collecting system along with appropriate imaging and management are discussed.

Prenatal imaging features and postnatal outcomes of isolated fetal duplex renal collecting system: A systematic review and meta-analysis

OBJECTIVES

To perform a systematic review of studies reporting the outcome of fetuses with a prenatal diagnosis of isolated duplex collecting system (DCS).

METHODS

Inclusion criteria were studies reporting the outcome of fetuses with a prenatal diagnosis of isolated DCS, defined as DCS not associated with other major structural anomalies at the time of diagnosis. The outcomes observed were: imaging features of DCS on prenatal ultrasound, associated anomalies detected exclusively at prenatal follow-up ultrasound and at birth, abnormal karyotype, symptoms at birth (including vesicoureteral reflux [VUR] and urinary tract infections [UTI]), need for and type of surgical approach, complications after surgery, and accuracy of prenatal ultrasound in correctly identifying this anomaly.

RESULTS

Eleven studies (284 fetuses with a prenatal diagnosis of DCS) were included. On ultrasound, DCS was associated with ureterocele in 70.7% and with megaureter in 36.6% of cases. Worsening of pelvic/ureteric dilatation was reported to occur in 41.3% of fetuses. At birth, 4.3% of fetuses affected by DCS showed associated renal anomalies. After birth, VUR and UTI presented in 51.3% and 21.7% of children respectively, while 33.6% required surgery. Prenatal diagnosis of DCS was confirmed in 90.9% of included cases.

CONCLUSION

DCS diagnosed prenatally is associated with a generally good outcome. Prenatal ultrasound has a good diagnostic accuracy, while detailed postnatal assessment is required in order to identify associated renal anomalies.

[Native kidney ultrasound in obstructive uropathy]

The term "obstructive uropathy" refers to the complex structural and functional changes following the interruption of normal urinary runoff, which can occur at every level of the urinary tract. Depending on its origin, duration and severity, urinary tract obstructions can be acute or chronic, mono or bilateral, partial or complete. The obstruction can be localized or extended to the entire pielo-caliceal system and/or homolateral urethra. The term "hydronephrosis" indicates the dilation of the pelvis detected through imaging techniques. Among these, ultrasound is considered the gold standard in the diagnosis of obstructive uropathy: it allows to distinguish three degrees of urinary tract dilation, depending on the extent of the dilation itself and the thickness of the parenchyma. Nephrologists are confronted daily with patients who experience kidney failure and must be able to quickly distinguish between chronic and acute and, in the latter case, to discern between issues of nephrological or urological competence. This short review aims at helping them deal with this very common scenario, through the use of ultrasound.

Safety of retrograde pyelography for infected ureteral stones

INTRODUCTION

Initial management of obstructing ureteral stones with concomitant urinary tract infection (UTI) includes prompt renal decompression and antibiotics. Some urologists theorize that performing retrograde pyelography (RGP) at the time of ureteral stent placement may cause pyelovenous backflow of bacteria thereby worsening clinical outcomes. We compared outcomes in patients with infected ureteral stones who underwent RGP versus no RGP prior to stent placement.

MATERIALS AND METHODS

A retrospective chart review was conducted involving patients who presented between 2015 and 2017 with an obstructing ureteral stone and associated UTI. Computed tomography scans were evaluated for stone size and location. Operative reports were reviewed to determine whether the patient underwent RGP at time of ureteral stent placement. Demographics, perioperative information, intensive care unit (ICU) admission rate, and length of stay (LOS) were compared.

RESULTS

Seventy-two patients were identified and stratified by severity of condition at presentation, including UTI without sepsis (n = 18), sepsis (n = 32), severe sepsis (n = 11), and septic shock (n = 11). Forty-three patients underwent RGP at the time of stent placement, and 29 did not. Between both patient cohorts, statistical analysis revealed no significant difference in postoperative ICU admission rate (p = 0.35) or LOS for patients with UTI without sepsis (p = 0.17), sepsis (p = 0.45), severe sepsis (p = 0.66), and septic shock (p = 0.25).

CONCLUSION

The use of RGP prior to ureteral stent placement for an obstructing ureteral stone with concomitant UTI was not associated with unfavorable clinical outcomes in our retrospective series. While these findings support the safety of RGP in this setting, prospective trials are warranted.

[Fetal anteroposterior renal pelvic diameter for predicting antenatal hydronephrosis requiring postnatal surgery]

OBJECTIVE

To assess the value of fetal anteroposterior renal pelvic diameter (APD) in predicting antenatal hydronephrosis requiring surgical treatment after birth.

METHODS

A total of 525 cases of antenatal hydronephrosis detected by prenatal ultrasonography (ultrasound index APD ≥ 4 mm in the second trimester and APD ≥ 7 mm in the third trimester) in Zhejiang Prenatal Diagnosis Center from June 2007 to June 2018 were retrospectively analyzed. ROC curve was used to analyze the relationship between these ultrasound indicators and the requirement for surgical treatment after birth.

RESULTS

There were 162 cases (30.9%) diagnosed in the second trimester and 363 cases (69.1%) diagnosed in the third trimester; 131 cases were diagnosed pathologically after birth, of which 121 finally underwent surgical treatment. The area under ROC curve (AUC) of APD in middle pregnancy for prediction of requiring surgery 1-12 years after birth was 0.910; the cut-off value of APD was 8.45 mm with a sensitivity of 97.1%, specificity of 70.9%, positive predictive value (PPV) of 47.9%, and negative predictive value (NPV) of 98.9%. The AUC of APD in late pregnancy for prediction of requiring surgery 1-12 years after birth was 0.800; the cut-off value of APD was 12.25 mm with a sensitivity of 66.7%, specificity of 81.2%, PPV of 51.7%, and NPV of 89.1%.

CONCLUSIONS

APD in pregnancy can be used to predict whether the fetus with hydronephrosis needs surgical treatment after birth, and the prediction value of APD in the middle pregnancy is better.

Mild-to-moderate renal pelvis dilatation identified during pregnancy and hospital admissions in childhood: An electronic birth cohort study in Wales, UK

BACKGROUND

Chronic kidney disease (CKD) is a growing contributor to the global burden of noncommunicable diseases. Early diagnosis and treatment can reduce the severity of kidney damage and the need for dialysis or transplantation. It is not known whether mild-to-moderate renal pelvis dilatation (RPD) identified at 18-20 weeks gestation is an early indicator of renal pathology. The aim of this follow-up to the Welsh Study of Mothers and Babies was to assess the risk of hospital admission in children with mild-to-moderate antenatal RPD compared with children without this finding. We also examined how the natural history of the RPD (whether the dilatation persists in later pregnancy or postpartum) or its characteristics (unilateral versus bilateral) changed the risk of hospital admission.

METHODS/FINDINGS

This population-based cohort study included singleton babies born in Wales between January 1, 2009, and December 31, 2011 (n = 22,045). We linked ultrasound scan data to routinely available data on hospital admissions from the Patient Episode Database for Wales (PEDW). The outcome was a hospital admission for urinary tract causes (defined by an expert study steering group) in the first three years of life. We used Cox regression to model time to first hospital admission, according to whether there was evidence of RPD at the fetal anomaly scan (FAS) and/or evidence of dilatation in later investigations, adjusting for other predictors of admission. We used multiple imputation with chained equations to impute values for missing data. We included 21,239 children in the analysis. The risk of at least one hospital admission was seven times greater in those with RPD (n = 138) compared with those without (n = 21,101, conditional hazard ratio [cHR] 7.23, 95% confidence interval [CI] 4.31-12.15, p < 0.001). The risk of hospital admission was higher in children with RPD at the FAS and later dilatation (cHR 25.13, 95% CI 13.26-47.64, p < 0.001) and in children without RPD at the FAS who had later dilatation (cHR 62.06, 95% CI 41.10-93.71, p < 0.001) than in children without RPD (n = 21,057). Among children with RPD at the FAS but no dilatation in later pregnancy or postpartum, we did not find an association with hospital admissions (cHR 2.16, 95% CI 0.69-6.75, p = 0.185), except when the initial dilatation was bilateral (cHR 4.77, 95% CI 1.17-19.47, p = 0.029). Limitations of the study include small numbers in subgroups (meaning that these results should be interpreted with caution), that less severe outcomes (such as urinary tract infections [UTIs] managed in the community or in outpatients) could not be included in our analysis, and that obtaining records of radiological investigations later in pregnancy and postpartum was challenging. Our conclusions were consistent after conducting sensitivity analyses to account for some of these limitations.

CONCLUSIONS

In this large population-based study, children with RPD at the FAS had higher rates of hospital admissions when there was persistent dilatation in later pregnancy or postpartum. Our results can be used to improve counselling of parents and develop care pathways for antenatal screening programmes, including protocols for reporting and further investigation of RPD.

Multiple variations of collateral branches of the abdominal aorta associated with pyelic duplication: A case report

PURPOSE

We describe a rare case of anatomical variation of the collaterals of the abdominal aorta associated with a duplication of the pyelic.

MATERIAL AND METHOD

A 51-year-old patient in whom an abdominal CT scan was performed as part of the exploration of a cystic left renal mass objectified on ultrasound.

RESULTS

A celiomesenteric trunk with two left renal arteries and a duplication of the left pyelon were found.

CONCLUSION

The reported case is of interest in the rare association of these anatomical variants.

Vanin-1 in Renal Pelvic Urine Reflects Kidney Injury in a Rat Model of Hydronephrosis

Urinary tract obstruction and the subsequent development of hydronephrosis can cause kidney injuries, which results in chronic kidney disease. Although it is important to detect kidney injuries at an early stage, new biomarkers of hydronephrosis have not been identified. In this study, we examined whether vanin-1 could be a potential biomarker for hydronephrosis. Male Sprague-Dawley rats were subjected to unilateral ureteral obstruction (UUO). On day 7 after UUO, when the histopathological renal tubular injuries became obvious, the vanin-1 level in the renal pelvic urine was significantly higher than that in voided urine from sham-operated rats. Furthermore, vanin-1 remained at the same level until day 14. There was no significant difference in the serum vanin-1 level between sham-operated rats and rats with UUO. In the kidney tissue, the mRNA and protein expressions of vanin-1 significantly decreased, whereas there was increased expression of transforming growth factor (TGF)-β1 and Snail-1, which plays a pivotal role in the pathogenesis of renal fibrosis via epithelial-to-mesenchymal transition (EMT). These results suggest that vanin-1 in the renal pelvic urine is released from the renal tubular cells of UUO rats and reflects renal tubular injuries at an early stage. Urinary vanin-1 may serve as a candidate biomarker of renal tubular injury due to hydronephrosis.

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.

Pre-therapy CT scan showing peritoneal thickening from metastatic renal pelvis carcinoma patients

We investigated clinical significance of peritoneal thickening from metastatic renal pelvis based on pretherapy computed tomography (CT) scan findings. The criteria for inclusion were as follows: (1) pathology and CT scan confirmed metastatic renal pelvis carcinoma and (2) peritoneal thickening based on pre-therapy CT scan findings. We investigated the route of spread, gastrointestinal (GI) complications, and response to chemotherapy. A total of 68 cases were enrolled in this study, including seven patients with liver metastases and three with abdominal wall invasion. GI complications included obstruction in ten patients and bleeding in three. Response to chemotherapy demonstrated by reduced peritoneal thickening was noted in 24 patients. In conclusion. peritoneal thickening with clinical suspicion of peritoneal involvement can get indirect evidence from route of spread (liver or abdominal wall), GI complications (obstruction or bleeding) or response to chemotherapy (obvious decrease peritoneal thickening) from metastatic renal pelvis carcinoma patients. Pretherapy CT scan with peritoneal thickening should be alert that tumor has spread to the peritoneum.

[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.

Single-use flexible ureteropyeloscopy: a systematic review

PURPOSE

Data assessing the effectiveness of single-use flexible ureteropyeloscopy (FURS) are limited. This study evaluates and compares single-use FURS with conventional reusable FURS.

METHODS

A systematic search using electronic databases (Pubmed and Embase) was performed for studies evaluating single-use FURS in the setting of urinary tract stone disease. Outcome measures included a comparative evaluation of their mechanical, optical and clinical outcomes.

RESULTS

Eleven studies on 466 patients met inclusion criteria. In vitro comparative data were available on three single-use flexible ureteropyeloscopes (LithoVue™, Polyscope™ and SemiFlex™) and clinical data were available on two (LithoVue™ and Polyscope™). The overall stone-free rate and complication rate associated with single-use FURS was 87 ± 15% and 9.3 ± 9%, respectively. There were no significant differences in procedure duration, stone size, stone clearance and complication rates when single-use FURS and reusable FURS were compared (duration: 73 ± 27 versus 74 ± 13 min, p = 0.99; stone size: 1.36 ± 0.2 versus 1.34 ± 0.18 cm, p = 0.93; stone-free rate: 77.8 ± 18 versus 68.5 ± 33%, p = 0.76; complication rate 15.3 ± 10.6 versus 15 ± 1.6%, p = 0.3).

CONCLUSIONS

Single-use FURS demonstrates comparable efficacy with reusable FURS in treating renal calculi. Further studies on clinical efficacy and cost are needed to determine whether single-use FURS will reliably replace its reusable counterpart.

The value of adding diffusion-weighted images for tumor detection and preoperative staging in renal pelvic carcinoma for the reader's experience

PURPOSE

This retrospective study aimed to assess the value of adding diffusion-weighted magnetic resonance imaging (DWI) or gadolinium-enhanced fat-suppressed T1WI (CEI) to T2-weighted imaging (T2WI) for preoperative T categorization in renal pelvic carcinoma by the reader's experience using surgical specimens as the reference standard.

METHODS

Two radiologists (Reader 1; 3 years, 2; 13 years) reviewed 49 cases with urothelial carcinoma who underwent magnetic resonance imaging examination before surgery, independently, using three image sets: T2WI alone, T2WI plus DWI, and T2WI plus CEI for tumor detection and T categorization. The differences in the apparent diffusion coefficient values between tumors and renal parenchyma, histopathologic grade were analyzed.

RESULTS

T2WI plus CEI or DWI had high detection rates (93.4%) compared to T2WI alone. When discriminating T3a/T3b, for Reader 1, the use of T2WI plus DWI (88.0%) and T2WI plus CEI (92.0%) was significantly more accurate than T2WI alone (73%), with AUCs of 0.86, 0.86 and 0.77, respectively. For Reader 2, the accuracies were high on all image sets, with AUCs of 0.87-0.95, and the mean ADC of the tumors was significantly lower than that of the normal renal parenchyma. In addition, the mean ADC values of high-grade tumors were significantly lower than that of low-grade tumors.

CONCLUSIONS

DWI and CEI could be more helpful than T2WI alone for preoperative T categorization by less-experienced reader and DWI could be used for preoperative T categorization and for predicting the histopathologic grade of renal pelvic carcinoma.

Usefulness of Ultrasonography and Cortical Transit Time to Differentiate Nonobstructive From Obstructive Dilatation in the Management of Prenatally Detected Pelvic Ureteric Junction Like Obstruction

OBJECTIVE

To differentiate a nonobstructive dilatation from an obstructive dilatation in prenatally detected presumed pelvi-ureteric junction obstruction so that intervention can be planned before irreversible damage can occur to the renal unit.

MATERIALS AND METHODS

From January 2012 to December 2016, all patients with prenatally detected or asymptomatic incidentally detected presumed pelvi-ureteric junction obstruction were evaluated by ultrasonography and renogram. The anteroposterior diameter of the renal pelvis was measured in supine and prone position. Presence of calyceal dilatation in prone position was noted. They were categorized into obstructed, nonobstructed, and equivocal groups based on sonography findings. The differential renal function and the cortical transit time (CTT) was calculated and compared with the sonography groups.

RESULTS

Of the 98 patients, 72 were in the obstructed, 18 were in the nonobstructed, and 8 were in the equivocal category. All except 1 in the nonobstructed category had a function of >40% with CTT of <3 minutes. Seventy patients in the obstructed category had a CTT of >3 minutes, whereas 61 had function <40% on initial evaluation. Eleven patients in the obstructed category with an initial function of >40% had CTT of >3 minutes. All of them showed increasing hydronephrosis and deterioration of function during follow-up, necessitating pyeloplasty. All patients in the equivocal group had function >40% and CTT <3 minutes.

CONCLUSION

Ultrasonography along with CTT can help to differentiate nonobstructive from obstructive dilatation.

The Association of a Number of Anatomical Factors with the Success of Retrograde Intrarenal Surgery in Lower Calyceal Stones

PURPOSE

To determine anatomical factors affecting Retrograde Intrarenal Surgery (RIRS) success in the treatment of renal lower calyx stones.

MATERIALS AND METHODS

The results of patients were evaluated retrospectively. The patients who have preoperative intravenous urography (IVU) and computed tomography (CT) were divided into two groups as successful (S)(N=103) and unsuccessful(U) (N=29). The anatomic characteristics such as infundibulopelvic angle (IPA), infundibular length (IL), infundibular width (IW) and pelvicaliceal height (PCH) values were compared among two groups.

RESULTS

Mean patient age was 47±13.6 years in group S and 49.5 ±11.9 years in group U. The mean stone size was 10mm (6-54mm) in group S and 19mm (8-45mm) in group U (P < .001) Mean IPA was 85.8 ±16.9 degree in group S versus 54.7 ± 11.5 degree in group U. The mean PCH was 1.9cm (0.5-4cm) in group S versus 2.3cm (0.7-3.9cm) in group U. The mean IL were 2.7 ± 0.8 cm and 3.2±0.7cm in group S and group U, respectively. The mean IWs were 0.7 cm (0.2-2.3cm) and 0.7cm (0.3-2) in group S and group U, respectively. The differences were statistically significant for IPA, PCH, IL (P < .05) while was not statistically significant for IW (P > .05). After multivariate analyses, PCH, IPA and stone size were statistically significant factors.

CONCLUSION

In our study we found that IPA, PCH and stone size were significant anatomical factors affecting RIRS success in the treatment of renal lower calyx stones. The patients whose IPA, PCH and stone size valuables are unsuitable, may need multiple RIRS sessions or additionaltreatment modalities.

A urologic stethoscope? Urologist performed sonography using a pocket-size ultrasound device in the point-of-care setting

PURPOSE

Ultrasound is commonly used in urology. Technical advances with reduced size and cost led to diffusion of small ultrasound devices to many clinical settings. Even so, most ultrasound studies are performed by non-urologists. We aimed to evaluate the utility of a pocket-size ultrasound device (Vscan™ GE Healthcare) and the quality of urologist performed study.

METHODS

Three consecutive studies were performed: (1) a urologist using the pocket ultrasound, (2) a sonographist using the pocket ultrasound, and (3) a sonographist using a standard ultrasound device. Thirty-six patients were evaluated with a basic urologic ultrasound study. An excepted deviation between studies was preset for numeric parameters and t test performed. Ordinal parameters were analyzed using Cohen's kappa coefficient.

RESULTS

Kidney length, renal pelvis length, renal cyst diameter, post-void residual and prostate volume (transabdominal) differences were found to be insignificant when comparing a urologist pocket ultrasound study to a sonographist standard ultrasound study (P = 0.15; P = 0.21; P = 0.81; P = 0.32; P = 0.07, respectively). Hydronpehrosis evaluation (none, mild, moderate and severe) and the presence of ureteral jet signs conferred a high inter-observer agreement when comparing the above studies using the Cohen's kappa coefficient (K = 0.63; K = 0.62, respectively).

CONCLUSIONS

Urologist performed pocket ultrasound study is valid in evaluating the upper and lower urinary tract and is practical in many clinical scenarios. The urologic stethoscope is now becoming a reality within reach.