Utility of ultrasound-based scoring system in post-pyeloplasty recovery.

BACKGROUND/OBJECTIVE: Differentiation of uretero-pelvic junction obstruction (UPJO) from non-obstructive dilatation (NOD) is a major challenge. The aim of this retrospective study is to determine whether pyeloplasty prediction score (PPS) could predict the need for surgery and resolution after surgery. METHODS: Among patients with antenatally diagnosed hydronephrosis, those who were stable during post-natal follow-up were considered NOD. The UPJO group were the ones who worsened and underwent pyeloplasty based on conventional indications. All patients with UPJO underwent laparoscopic dismembered pyeloplasty. PPS was determined based on three ultrasound parameters obtained retrospectively: Society of Fetal Urology (SFU) grade of hydronephrosis, transverse anteroposterior (APD), and the absolute percentage difference of ipsilateral and contralateral renal lengths. RESULTS: Among 137 patients included (R:L = 59:73; M:F 102:35), 96 were conservatively managed (NOD), while 41 patients (29%) needed pyeloplasty (UPJO). Mean PPS was 4.2 (1.2) in the NOD group and it was significantly higher at 10.8 (1.63) in the UPJO group (p = 0.001). All patients with PPS > 8 needed a pyeloplasty, while two patients with PPS of 7 needed pyeloplasty due to drop in renal function. PPS cutoff value of >8 had a sensitivity 95%, specificity 100% and a likelihood ratio of 20. Post-pyeloplasty PPS resolution was proportional to the duration of follow-up. CONCLUSIONS: A PPS cutoff value of 8 or above is associated with the presence of significant UPJO. PPS is also useful in the assessment of hydronephrosis recovery post-pyeloplasty. The limitation of PPS: it can only be applied in the presence of contralateral normal kidney.

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.

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.

Squamous cell carcinoma of the renal pelvis masquerading as xanthogranulomatous pyelonephritis.

We report a rare case of a 56-year-old male with a history of hypertension who initially presented to the emergency department with abdominal pain and was radiologically diagnosed with left xanthogranulomatous pyelonephritis (XGP) in a non-functioning kidney with a staghorn calculus. Pathological evaluation of his kidney revealed squamous cell carcinoma (SCC) of the renal pelvis with invasion into the renal parenchyma. We highlight the presentation, diagnosis, and management of this rare condition.

Medullary pyramid thickness: The optimal cut-off value associated with the need for pyeloplasty in infants.

INTRODUCTION: The medullary pyramid compresses during the early phases of severe hydronephrosis and represents a promising ultrasound metric for the diagnosis and surveillance of PUJ obstruction. The aim of this study was to define the optimal cut-off value and utility of medullary pyramid thickness (MPT) associated with the need for pyeloplasty in infants being followed up for hydronephrosis. METHODS: A retrospective review was performed over a five-year period to identify patients that were under surveillance for hydronephrosis during infancy and underwent a MAG3 to monitor the possible need for pyeloplasty. Ultrasound images were retrospectively reviewed to measure the MPT of the affected kidney in a blinded fashion. The primary outcome measure was subsequent requirement for pyeloplasty before three years of age. The Mann-Whitney U Test was used to determine statistically significant differences in the minimum MPT between the infant group requiring pyeloplasty and the non-operative group. Receiver operating characteristic analysis was performed to determine the optimal cut-off value associated with the requirement for pyeloplasty. RESULTS: A total of 63 patient cases were included, of which 45 underwent pyeloplasty (70%). A significant difference was found in the median MPT measurement between the pyeloplasty and non-operative groups (1.7 mm vs. 3.8 mm, p < 0.001). The optimal cut-off value of MPT associated with pyeloplasty was 3.4 mm. An MPT threshold of ≤3.4 mm conferred a sensitivity of 98%, specificity of 63%, positive predictive value of 86%, and negative predictive value of 92%. CONCLUSION: Thinning of the medullary pyramid is an important ultrasound sign of parenchymal deterioration in high-grade hydronephrosis. An optimal MPT cut-off value of ≤3.4 mm is associated with subsequent pyeloplasty in infants. MPT should be considered in future studies addressing the diagnosis and surveillance of PUJ obstruction.

Ureteropelvic junction obstruction (UPJ) due to congenital crossing of the renal vessels (CRV): Comparison of the pre- and postoperative features of UPJO with and without CRV.

We evaluated the differences in demographic characteristics of patients with and without underlying crossing renal vessels (CRVs) operated for unilateral symptomatic ureteropelvic junction obstruction (UPJO). We identified the features of patients who had undergone open, laparoscopic and robotically assisted laparoscopic pyeloplasty at our institution from July 2000 to January 2021. The ratio of renal parenchymal thickness (RPT; ratio between the kidney with UPJO and the healthy kidney), pelvic diameter and kidney functions were recorded. A total of 641 patients were operated for UPJO; 448 were male (69.8%) and 193 (30.1%) were female; 257 had right-side (40%) and 384 (60%) left-side disease. Fifty-eight patients (9%) were found to have CRV (operated on to treat CRV). The age at diagnosis was 6.51 ± 5.09 years in the CRV (+) group and 1.82 ± 1.37 years in the CRV (-) (p < 0.001). The age at surgery was 8.00 ± 4.71 and 4.27 ± 3.54 years, respectively (p < 0.001). At the time of diagnosis, the RPT measurement was significantly better in CRV (+) compared to CRV (-) group (0.71 ± 0.2 vs. 0.64 ± 0.23, p = 0.043) and initial renal functions were 45.53 ± 8.99% and 42.99 ± 11.65% in CRV (+) and (-) groups respectively. At the time of surgery, the RPTs were 0.60 ± 0.24 and 0.63 ± 0.21 in CRV (+) and (-) groups and these values were also correlated with split renal functions (36.28 ± 15.81% and 41.80 ± 14.26%, respectively). Renal functions were significantly decreased in CRV (+) group (p = 0.027). Significant parenchymal improvements were noted during the first postoperative year. The RPTs were 0.71 ± 0.2 and 0.77 ± 0.19 in the CRV (+) and CRV (-) groups, respectively (p = 0.27) in that time; the improvements continued to increase to postoperative third year (0.74 ± 0.20 and 0.78 ± 0.19 respectively; p = 0.939). In patients with CRVs, renal functions seemed to be preserved in the early stages, however it should be kept in mind that sudden obstruction and loss of kidney function might develop in the follow up period.