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Objective: This retrospective aims to develop a comprehensive predictive model based on CT radiomic features and clinical parameters, facilitating early preoperative diagnosis of pyonephrosis. Methods: Clinical and radiological data from 311 patients treated for upper urinary tract stones with obstructive pyelohydronephrosis, between January 2018 and May 2023, were retrospectively collected. Univariate and multivariate logistic regression analyses were conducted on clinical data to identify independent risk factors for pyonephrosis. A clinical model was developed using logistic regression. The 3D Slicer software was employed to manually delineate the region of interest (ROI) in the preoperative CT images, corresponding to the area of pyelohydronephrosis, for feature extraction. The optimal radiomic features were selected to construct radiomic models and calculate the radiomic score (Radscore). Subsequently, a combined clinical–radiomic model—the nomogram—was established by integrating the Radscore with independent risk factors. Results: Univariate and multivariate logistic regression analyses identified cystatin C, Hounsfield Unit (HU) of pyonephrosis, history of ipsilateral urological surgery, and positive urine culture as independent risk factors for pyonephrosis (P < 0.05). Fourteen optimal radiomic features were selected from CT images to construct four radiomic models, with the Naive Bayes model demonstrating the best predictive performance in both training and validation sets. In the training set, the AUCs for the clinical model, radiomic model, and nomogram were 0.902, 0.939, and 0.991, respectively; in the validation set, they were 0.843, 0.874, and 0.959. Both calibration and decision curves showed good agreement between the predicted probabilities of the nomogram and the actual occurrences. Conclusion: The nomogram, constructed from CT radiomic features and clinical variables, provides an effective non-invasive predictive tool for pyonephrosis, surpassing both clinical and radiomic models. [ABSTRACT FROM AUTHOR]

Abstract Objective This retrospective aims to develop a comprehensive predictive model based on CT radiomic features and clinical parameters, facilitating early preoperative diagnosis of pyonephrosis. Methods Clinical and radiological data from 311 patients treated for upper urinary tract stones with obstructive pyelohydronephrosis, between January 2018 and May 2023, were retrospectively collected. Univariate and multivariate logistic regression analyses were conducted on clinical data to identify independent risk factors for pyonephrosis. A clinical model was developed using logistic regression. The 3D Slicer software was employed to manually delineate the region of interest (ROI) in the preoperative CT images, corresponding to the area of pyelohydronephrosis, for feature extraction. The optimal radiomic features were selected to construct radiomic models and calculate the radiomic score (Radscore). Subsequently, a combined clinical–radiomic model—the nomogram—was established by integrating the Radscore with independent risk factors. Results Univariate and multivariate logistic regression analyses identified cystatin C, Hounsfield Unit (HU) of pyonephrosis, history of ipsilateral urological surgery, and positive urine culture as independent risk factors for pyonephrosis (P

Pyelonephritis is one of the main systemic bacterial infections encountered in emergency departments. We present a case of diabetes woman aged 30 years referred to our urology department of El-Idrissi Hospital, Kenitra (Morocco) for recurrent episodes of urinary tract infection, multiple urolithiasis, chills, unilateral lower back pain, chills and severe hydroureteronephrosis. Abdominal CT showed a non-functioning obstructed kidney with pyelic and ureteral stones. Nephroureterectomy was performed by extraperitoneal nephrectomy for avoiding any more extended nephrectomy incision or second iliac incision, this technic ensures nephroureterectomy with minimal risk of affecting the distal ureter, that sometimes follows nephrectomy.Diabetes and urolithiasis coexistence in a patient may cause severe pyonephrosis leading to nephroureteroctomy.

"Purpose: To determine the non-contrast computer tomography imaging features of pyonephrosis and evaluate the predictive value of Hounsfield units (HUs) in different hydronephrotic region slices. Materials and Methods: We retrospectively reviewed data from patients with hydronephrosis who had renal-ureteral calculi. All patients were categorized into pyonephrosis and simple hydronephrosis groups. Baseline characteristics, the mean HU values in the maximal hydronephrotic region (uHU) slice, and the range of uHU in different slices (ΔuHU) were compared between the two groups. Univariate and multivariate analyses were performed to identify risk factors for pyonephrosis. Results: Among the 181 patients enrolled in the current study, 71 patients (39.2%) were diagnosed with pyonephrosis. The mean dilated pelvis surface areas were comparable between patients with pyonephrosis and simple hydronephrosis (822.61 mm2 vs. 877.23 mm2, p=0.722). Collecting system debris (p=0.022), a higher uHU (p=0.038), and a higher ΔuHU (p

Urgent detection of calculous pyonephrosis is crucial for surgical planning and preventing severe outcomes. This study aims to evaluate the performance of computed tomography (CT)-based radiomics and a three-dimensional convolutional neural network (3D-CNN) model, integrated with independent clinical factors, to identify patients with calculous pyonephrosis. We recruited 182 patients receiving either percutaneous nephrostomy tube placement or percutaneous nephrolithotomy for calculous hydronephrosis or pyonephrosis. The regions of interest were manually delineated on plain CT images and the CT attenuation value (HU) was measured. Radiomics analysis was performed using least absolute shrinkage and selection operator (LASSO). A 3D-CNN model was also developed. The better-performing machine-learning model was combined with independent clinical factors to build a comprehensive clinical machine-learning model. The performance of these models was assessed using receiver operating characteristic analysis and decision curve analysis. Fever, blood neutrophils, and urine leukocytes were independent risk factors for pyonephrosis. The radiomics model showed higher area under the curve (AUC) than the 3D-CNN model and HU (0.876 vs. 0.599, 0.578; p = 0.003, 0.002) in the testing cohort. The clinical machine-learning model surpassed the clinical model in both the training (0.975 vs. 0.904, p = 0.019) and testing (0.967 vs. 0.889, p = 0.045) cohorts. [ABSTRACT FROM AUTHOR]

In order to provide decision-making support for the auxiliary diagnosis and individualized treatment of calculous pyonephrosis, the study aims to analyze the clinical features of the condition, investigate its risk factors, and develop a prediction model of the condition using machine learning techniques. A retrospective analysis was conducted on the clinical data of 268 patients with calculous renal pelvic effusion who underwent ultrasonography-guided percutaneous renal puncture and drainage in our hospital during January 2018 to December 2022. The patients were included into two groups, one for pyonephrosis and the other for hydronephrosis. At a random ratio of 7:3, the research cohort was split into training and testing data sets. Single factor analysis was utilized to examine the 43 characteristics of the hydronephrosis group and the pyonephrosis group using the T test, Spearman rank correlation test and chi-square test. Disparities in the characteristic distributions between the two groups in the training and test sets were noted. The features were filtered using the minimal absolute value shrinkage and selection operator on the training set of data. Auxiliary diagnostic prediction models were established using the following five machine learning (ML) algorithms: random forest (RF), xtreme gradient boosting (XGBoost), support vector machines (SVM), gradient boosting decision trees (GBDT) and logistic regression (LR). The area under the curve (AUC) was used to compare the performance, and the best model was chosen. The decision curve was used to evaluate the clinical practicability of the models. The models with the greatest AUC in the training dataset were RF (1.000), followed by XGBoost (0.999), GBDT (0.977), and SVM (0.971). The lowest AUC was obtained by LR (0.938). With the greatest AUC in the test dataset going to GBDT (0.967), followed by LR (0.957), XGBoost (0.950), SVM (0.939) and RF (0.924). LR, GBDT and RF models had the highest accuracy were 0.873, followed by SVM, and the lowest was XGBoost. Out of the five models, the LR model had the best sensitivity and specificity is 0.923 and 0.887. The GBDT model had the highest AUC among the five models of calculous pyonephrosis developed using the ML, followed by the LR model. The LR model was considered be the best prediction model when combined with clinical operability. As it comes to diagnosing pyonephrosis, the LR model was more credible and had better prediction accuracy than common analysis approaches. Its nomogram can be used as an additional non-invasive diagnostic technique. [ABSTRACT FROM AUTHOR]

Background: To develop a model for the accurate prediction of calculous obstructive pyonephrosis prior to percutaneous nephrolithotomy (PNL), leading to early local anaesthesia microchannel nephrostomy for drainage of pyonephrosis. Methods: By comparing the differences in baseline clinical indicators between the pyonephrosis group and nonpyonephrosis groups, independent risk factors were screened out, and a diagnostic alignment diagram model for predicting calculus obstructive pyonephrosis before PNL was established. Results: Multivariate regression analysis showed that preoperative blood neutrophil count (Neu), serum creatinine level (Scr), serum albumin level (Alb), urine nitrite (UN), hydronephrosis density (HD) and fever history within one month (HFWOM) were independent risk factors for calculous obstructive pyonephrosis. The AUC value of the receiver operating characteristic (ROC) curve was 0.929. The calibration curves showed that the predictive model was well corrected and that the predictive model had strong consistency. Decision analysis curves showed good clinical efficacy of the model. Conclusion: The alignment diagram model accurately predicts patients with preoperative calculous obstructive pyonephrosis in the PNL and provides an evidence-based basis for early renal microchannel nephrostomy.

Urgent detection of calculous pyonephrosis is crucial for surgical planning and preventing severe outcomes. This study aims to evaluate the performance of computed tomography (CT)-based radiomics and a three-dimensional convolutional neural network (3D-CNN) model, integrated with independent clinical factors, to identify patients with calculous pyonephrosis. We recruited 182 patients receiving either percutaneous nephrostomy tube placement or percutaneous nephrolithotomy for calculous hydronephrosis or pyonephrosis. The regions of interest were manually delineated on plain CT images and the CT attenuation value (HU) was measured. Radiomics analysis was performed using least absolute shrinkage and selection operator (LASSO). A 3D-CNN model was also developed. The better-performing machine-learning model was combined with independent clinical factors to build a comprehensive clinical machine-learning model. The performance of these models was assessed using receiver operating characteristic analysis and decision curve analysis. Fever, blood neutrophils, and urine leukocytes were independent risk factors for pyonephrosis. The radiomics model showed higher area under the curve (AUC) than the 3D-CNN model and HU (0.876 vs. 0.599, 0.578; p = 0.003, 0.002) in the testing cohort. The clinical machine-learning model surpassed the clinical model in both the training (0.975 vs. 0.904, p = 0.019) and testing (0.967 vs. 0.889, p = 0.045) cohorts.

Abstract Background Limited information is available regarding the outcome of medical management (MM) of benign ureteral obstruction in cats (BUO). Hypothesis Describe clinical characteristics and outcome of MM of BUO. Animals Seventy‐two client‐owned cats with 103 obstructed kidneys. Methods Medical records of cats diagnosed with BUO between 2010 and 2021 that received >72 hours of MM were retrospectively reviewed. Clinical data, treatment, and outcome were reviewed. Outcome was classified as success, partial success, or failure based on ultrasound findings. Factors associated with outcome were assessed. Results Seventy‐two cats with 103 obstructed kidneys were enrolled. The causes of obstruction were uroliths in 73% (75/103), strictures in 13.5% (14/103), and pyonephrosis in 13.5% (14/103) of affected kidneys. Median serum creatinine concentration at presentation was 4.01 mg/dL (range, 1.30‐21.3 mg/dL). Outcome after MM was considered a success in 30% (31/103), partial success in 13% (13/103), and failure in 57% (59/103) of kidneys. Success was reported in 23% (17/75) of kidneys with uroliths, 50% (7/14) with pyonephrosis, and 50% (7/14) with strictures. Median time to a successful outcome was 16 days (range, 3‐115 days). Distal and smaller uroliths (median length, 1.85 mm) were significantly associated with success (P = .05 and P = .01, respectively). Median survival times were 1188 days (range, 60‐1700 days), 518 days (range, 7‐1812 days), and 234 days (range, 4‐3494 days) for success, partial success, and failure, respectively. Conclusions and Clinical Importance We found a higher success rate for MM of BUO than previously reported. Smaller distal uroliths (

Background: Mucinous neoplasms are tumors arising in the epithelial tissue, characterized by excessive mucin secretion. They mainly emerge in the digestive system and rarely in the urinary system. They also seldom develop in the renal pelvis and the appendix asynchronously or simultaneously. The concurrence of this disease in these two regions has not yet been reported. In this case report, we discuss the diagnosis and treatment of synchronous mucinous neoplasms of the right renal pelvis and the appendix. The mucinous neoplasm of the renal pelvis was preoperatively misdiagnosed as pyonephrosis caused by renal stones, and the patient underwent laparoscopic nephrectomy. Herein, we summarize our experience with this rare case in combination with related literature. Case presentation: In this case, A 64-year-old female was admitted to our hospital with persistent pain in the right lower back for over a year. Computer tomography urography (CTU) showed that the patient was confirmed as right kidney stone with large hydronephrosis or pyonephrosis, and appendiceal mucinous neoplasm (AMN). Subsequently, the patient was transferred to the gastrointestinal surgery department. Simultaneously, electronic colonoscopy with biopsy suggested AMN. Open appendectomy plus abdominal exploration was performed after obtaining informed consent. Postoperative pathology indicated low-grade AMN (LAMN) and the incisal margin of the appendix was negative. The patient was re-admitted to the urology department, and underwent laparoscopic right nephrectomy because she was misdiagnosed with calculi and pyonephrosis of the right kidney according to the indistinctive clinical symptoms, standard examination of the gelatinous material, and imaging findings. Postoperative pathology suggested a high-grade mucinous neoplasm of the renal pelvis and mucin residing partly in the interstitium of the cyst walls. Good follow-up results were obtained for 14 months. Conclusion: Synchronous mucinous neoplasms of the renal pelvis and the appendix are indeed uncommon and have not yet been reported. Primary renal mucinous adenocarcinoma is very rare, metastasis from other organs should be first considered, especially in patients with long-term chronic inflammation, hydronephrosis, pyonephrosis, and renal stones, otherwise, misdiagnosis and treatment delay may occur. Hence, for patients with rare diseases, strict adherence to treatment principles and close follow-up are necessary to achieve favorable outcomes. [ABSTRACT FROM AUTHOR]

Background: Limited information is available regarding the outcome of medical management (MM) of benign ureteral obstruction in cats (BUO). Hypothesis: Describe clinical characteristics and outcome of MM of BUO. Animals: Seventy‐two client‐owned cats with 103 obstructed kidneys. Methods: Medical records of cats diagnosed with BUO between 2010 and 2021 that received >72 hours of MM were retrospectively reviewed. Clinical data, treatment, and outcome were reviewed. Outcome was classified as success, partial success, or failure based on ultrasound findings. Factors associated with outcome were assessed. Results: Seventy‐two cats with 103 obstructed kidneys were enrolled. The causes of obstruction were uroliths in 73% (75/103), strictures in 13.5% (14/103), and pyonephrosis in 13.5% (14/103) of affected kidneys. Median serum creatinine concentration at presentation was 4.01 mg/dL (range, 1.30‐21.3 mg/dL). Outcome after MM was considered a success in 30% (31/103), partial success in 13% (13/103), and failure in 57% (59/103) of kidneys. Success was reported in 23% (17/75) of kidneys with uroliths, 50% (7/14) with pyonephrosis, and 50% (7/14) with strictures. Median time to a successful outcome was 16 days (range, 3‐115 days). Distal and smaller uroliths (median length, 1.85 mm) were significantly associated with success (P =.05 and P =.01, respectively). Median survival times were 1188 days (range, 60‐1700 days), 518 days (range, 7‐1812 days), and 234 days (range, 4‐3494 days) for success, partial success, and failure, respectively. Conclusions and Clinical Importance: We found a higher success rate for MM of BUO than previously reported. Smaller distal uroliths (<1‐2 mm) were more likely to pass. [ABSTRACT FROM AUTHOR]

ABSTRACT: Introduction: Pyonephrosis is hydronephrosis accompanied by a bacterial infection in the kidney, causing suppurative destruction of the renal parenchyma; this condition is an emergency and usually associated with stones or chronic urinary tract infections. Urinalysis is typically inaccurate for establishing the diagnosis, as bacteriuria may not manifest due to ureteral obstruction. Case report: We reported a 55-year-old male patient with flanks pain and an account of stone expulsion. Based on history taking, physical examination, radiology examinations, and percutaneous nephrotomy, we concluded a diagnosis of pyonephrosis causing by Streptococcus agalactiae as known as Group B Streptococcus. Discussion: While both US and CT scan guided the early diagnosis, CT was more accurate as it is able to capture the renal function and the underlying cause of obstruction. Pyonephrosis was described as having a pus collection in the pelvicalyceal system, cortex thinning, and the appearance of stones. Conclusion: Pyonephrosis is a rare emergency, and many clinicians find it challenging to recognize since the presentations are frequently nonspecific. In order to prevent renal failure and the spread of bacteremia that entails life-threatening urosepsis, acquiring imaging knowledge (sonography and CT) and other findings are indispensable in determining this entity.

Background: Xanthogranulomatous pyelonephritis (XGP) is chronic pyelonephritis subtype where in renal parenchymal destruction occurs and therefore results in progressive loss of kidney functions. Although middle age group is the predominant age group affected but it can be seen at any age. There is accumulation of macrophages (lipid-laden) leading to renal parenchymal destruction and fibrosis. In this study, we present our data of 15 patients who had undergone nephrectomy and were biopsy proven XGP. Aims and Objectives: The aim of the study was to describe the clinical and radiological features of XGP in adults. Materials and Methods: XGP constituted 4.31% of the 348 nephrectomies done for infective causes over a period of 7 years. All our patients had undergone unilateral total nephrectomy. Demographic and clinical records were analyzed after consent from all the patients. Results: The age range in our study was 18–65 years with mean 42.93±15.66 years. Nine of our patients, that is, 60% were females. Diabetes was present in 53.3% of our patients. Three patients had imaging suggestive of pyonephrosis, three patients had perinephric collection and 9 patients (60%) had concomitant nephrolithiasis. All the kidneys were grossly enlarged and were non-functional on renal scintigraphy. Conclusion: XGP is a form of chronic pyelonephritis which although being less common but is devastating given the destruction of renal parenchyma it does and associated morbidity. Clinicoradiologic correlation cannot be overemphasized. The definitive diagnosis is established after histopathologic examination.

Abstract Background Acute or chronic obstruction of the urinary tract can be due to a lot of different causes. Patients with pyonephrosis usually complain of a triad of fever, loin pain and elevated white blood cell count in cases of acute obstruction; and they may also have hypotension in severe cases of the disease. These patients have to be treated with appropriate decompression, or they may develop septic shock. The urgency of the need for treatment greatly depends on the differentiation between hydronephrosis and pyonephrosis. There is a lack of reliable clinical prognosticators of pyonephrosis in patients with obstructive hydronephrosis. Hounsfield unit (HU) measurement is considered as an adequate predictor of pyonephrosis and may aid in the diagnosis and management of this disease that may be fatal. The use of HU values in differentiation between pyonephrosis from hydronephrosis depends on the fact that the pyonephrotic fluid contains infected material, urine, cellular particles and microorganisms, which when combined can increase the HU values on a computed tomography (CT) study. This study was done to assess the diagnostic value of the HU measured CT in differentiation between hydronephrosis and pyonephrosis. Results Thirty-nine patients were included in this study. All patients had loin pain and were diagnosed with pelvicalyceal dilatation by ultrasonographic examination. They then underwent non-contrast CT examination. Using CT scan, the degree of PC dilatation was significantly higher among hydronephrosis group as hydronephrosis group had 63.1% severe dilatation of PCs versus 30.8% in pyonephrosis group with p value 0.0001. Pelvic wall thickness > 2 mm was reported in 10 (76.9%) patients of pyonephrosis group versus in three (7.9%) patients among hydronephrosis group with p value 0.0001. The mean Hounsfield units were significantly higher among pyonephrosis group compared to hydronephrosis group (16 ± 5.2 versus 1.7 ± 5.5) with p value 0.0001. Sensitivity analysis showed that Hounsfield units can significantly diagnose pyonephrosis using the cutoff point 6.2 units, with sensitivity 92.3%, specificity 93.3%, area under the curve (AUC) 96.9% and p value 0.0001. Conclusions Measuring HU in a NCECT scan of the kidney might be helpful for differentiating between hydronephrosis and pyonephrosis especially upon considering 6.2 HU as a cutoff point.

Introduction: Pyonephrosis is a severe complication of pyelonephritis leading to rapid progression to sepsis and loss of renal function resulting in nephrectomy. Early identification of pyonephrosis based on clinical or radiological characteristics amongst pyelonephritis is paramount. This study aimed to determine the prevalence of pyonephrosis among patients with pyelonephritis admitted to the Department of Nephrology and Urology of a tertiary care centre. Methods: This descriptive cross-sectional study was done in a tertiary care centre among patients with pyelonephritis from 1 July 2016 to 31 Jan 2021. Ethical approval was obtained from Institution Ethics Committee (Reference number: IEC/56/21). The available clinical, demographic and laboratory parameters were recorded from the hospital records in a predesigned proforma. A convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated. Results: Among 550 pyelonephritis patients, the prevalence of pyonephrosis was 60 (10.9%) (8.3-13.5, 95% Confidence Interval). The mean age was 54.62±12.14 years, and 41 (68.33%) were males. The most common clinical symptom was flank pain with or without fever in 46 (76.66%) patients. Escherichia coli was the most common offending organism in 20 (33.33%). Ultrasonography showed classical echogenic debris with floaters and internal echoes in 44 (73.33%) patients. Double J stenting was successfully done in 44 (73.33%) patients. Percutaneous nephrostomy was done in the remaining 16 (26.66%) patients. Conclusions: The prevalence of pyonephrosis in pyelonephritis is similar to previous studies done in similar settings.

Present study tried to check for effect of PCNL on renal function, predictors for renal function deterioration and share our experience for use of long term DJ stents for patients who are very high risk surgical candidates. Data of patients with renal and upper ureter stone disease along with CKD was collected. The eGFR for them was calculated by MDRD equation. Urinary diversion was considered for patients presenting with hydroureteronephrosis, pyonephrosis, or fever. These patient were discharged once after settlement of sepsis and symptoms for serum creatinine to settle and then called again for definitive management. The nadir level generally reached over 2 to 3 weeks was taken as the baseline creatinine to measure preop eGFR. Patients were then classified into different CKD stages based on preop eGFR. General patient characteristics, comorbidities, stone location and burden, preop diversion, preop dialysis, post op complication were recorded. Complications were graded according to clavien dindo scoring system. Mean preop GFR was 37.95 and 27.95 respectively in PCNL and long term stent group. Mean post op GFR was 38.46 and 28.16 respectively in PCNL and long term stent group.Stone free rates and stone recurrence rates are higher in this group of patients due to several reasons. Meaning by they will be needing further interventions in future also and with its associated complications. Long Term Double J stents with prophylactic antibiotics provide a feasible option for patients who are very high risk for surgery or who refuse for it. [ABSTRACT FROM AUTHOR]

Laparoscopic heminephrectomy was performed in a 64-year-old woman with a chronically obstructed horseshoe kidney moiety. More than 3000 cc of pyonephrosis was drained through two percutaneous nephrostomy tubes for infection control before left moiety laparoscopic resection. This case report attests to the feasibility of laparoscopic resection of a massively obstructed horseshoe kidney when performed in a staged manner after prolonged drainage. Since an incision was required for removal of the large specimen, ligation of the horseshoe isthmus was completed through the same incision after hilar control and laparoscopic mobilization of the moiety were completed.

Extravasation of urine following forniceal rupture of a pelviureteric junction is a rare complication; the existence of pyonephrosis can result to retroperitoneal abscess but its fistulization into peritoneal cavity is exceptional. We report a case of a 22-year-old men who presented a clinical aspects of peritonitis, abdominal CT scan findings suggested retroperitoneal peritonitis by rupture of the fornix.This case emphasizes an unusual presentation of pyonephrosis with peritonitis and pyoperitoneum caused by a ureteropelvic junction syndrome.

Psoas abscess is a rare pathology that usually presents with non-specific signs and rare clinical features. These characteristics can delay the diagnosis leading to complications and death. We report a forensic autopsy case of a 65-year-old male, alcoholic, smoker, with a history of hypertension, and urinary infection, who presented to the emergency room for anorexia and consciousness disorder. On physical examination, the patient was febrile and confused. Laboratory exams revealed leukocytosis and elevated C-reactive protein (CRP). Two days later, he died despite extensive resuscitation. Forensic autopsy revealed a large amount of green pus in the left psoas muscle extending to the muscles of the thigh of the same side with multiple cavities. The pus extended to the left kidney with destructive parenchyma and coralliform lithiasis. Histological examination showed destroyed renal tissue by lesions of chronic and acute pyelonephritis with dilatation of the pyelocaliceal cavities. Bacteriological analysis of the pus showed the presence of Escherichia coli. The psoas abscess was secondary to pyonephrosis favored by the immunodeficiency. Thus, death was attributed to a septic shock secondary to a psoas abscess complicating pyonephrosis. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of our study was to evaluate the ability of ureteral stents with different diameters to drain pus that accumulates in an obstructed kidney using an in vitro model. Methods: We developed an in vitro model of an obstructed kidney filled with pus. The model included a silicon kidney unit based on computed tomography (CT) data, a 3D printed ureteral stone based on a real extracted ureteral stone, a latex ureter model, a bladder vessel, and a fluid with qualities resembling pus. Identical printed stones were inserted into four ureter models containing stents with varying diameters (4.8F, 6F, 7F, 8F), each of which was connected to the kidney unit and the bladder vessel. The kidney unit was filled with artificial pus to pressures of 30 cmH2O to simulate an infected and obstructed kidney. The obstruction was relieved with stents in place, while artificial urine was pumped into the kidney; pressure in the kidney and remaining pus were measured continuously. Results: The rate of pressure drop and the final pressure measured in the kidney were unaffected by the diameter of the stent. For all stent diameters, the pressure reached non-obstructed levels within 30 s, final pressure was reached within 90–120 s, and minimal amounts of pus remained in the kidney after 120 min. Conclusions: In vitro experiments demonstrate that all stent diameters drain pus-filled, obstructed kidneys with the same efficacy. The common perception that larger diameter tubes are more effective under such circumstances should be re-examined. [ABSTRACT FROM AUTHOR]

Xanthogranulomatous pyelonephritis (XGP) is an uncommon chronic condition characterized by destructive granulomatous disease of the kidney with uncertain etiology. Significant risk factors for XGP are represented by the coexistence of history of nephrolithiasis, diabetes mellitus, recurrent urinary tract infections and other immunocompromised conditions. It is also associated with higher risk of malignancy, reported in up to 11% of patients. We report a case of a 76-year-old female who presented to the emergency department with an insidious onset of abdominal and right lower back pain. She had a history of renal stones and diabetes mellitus. On physical examination, a painful fistulous orifice in skin on the right lumbar region was found. CT images showed a nonfunctioning right kidney replaced by multiple necrotic cavities with inflammatory involvement of the right hepatic lobe and a nephron-cutaneous fistula. These CT findings were strongly suggestive of XGP (III state). CT images obtained before and after the administration of intravenous contrast material showed also a hyper-vascularized renal mass with irregularly thickened walls confirmed by a targeted CEUS examination and suspicious for malignancy. Pathologic examination confirmed the chronic pyelonephritis and revealed evidence of a concomitant sarcomatoid lesion. This case underlines the central role of a multimodality imaging approach in the emergency department and how this affects the correct management and treatment of patients. In fact, MDCT is considered the current gold standard for the diagnosis and the staging of XPG but the contrast-enhanced ultrasound (CEUS) in selected patients can increase the diagnostic accuracy in the uncertain small renal masses detected on CT scans., (© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.)

Extravasation of urine due to a forniceal rupture at the pelviureteric junction is a seldom-seen complication. While the presence of pyonephrosis can lead to a retroperitoneal abscess, its fistulization into the peritoneal cavity is exceptionally rare. Here, we present the case of a 50-year-old man exhibiting clinical signs of peritonitis. An abdominal CT scan indicated retroperitoneal peritonitis due to the rupture of the fornix. This case underscores the uncommon manifestation of pyonephrosis with peritonitis and pyoperitoneum, attributed to bladder cancer., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Lifa et al.)

Pleural empyema of extra pulmonary origin is uncommon and empyema secondary to a fistula between the urinary tract and thorax is extremely rare. We report a case of nephropleural fistula causing massive pleural empyema in a 64-year-old woman with a long history of urological problems, including nephrolitiasis and urinary tract infection. She was admitted with sepsis, fever, chills, tachypnea, productive cough and pyuria. At clinical examination, breath sounds were reduced over the left hemithorax. CT revealed a fistulous connection from the upper left calyceal group and the pleural space. Drainage of thoracic and perinephric collection was carried out, but nephrectomy and pleural decortication were required due to haemopurulent urine and decreased hemoglobin levels during the hospitalization. This case demonstrates the unusual and prolonged evolution of an obstructive hydroureteronephrosis complicated by pyonephrosis, culminating in retroperitoneal abscess that fistulized into the pleural space, leading to empyema.

Abstract Background A pyonephrosis caused by an obstructing calculus is typically accompanied by fever, loin pain, and other signs of urinary tract infection. Occasionally, severe thinning of the renal parenchyma in pyonephrosis allows direct forniceal rupture into the retroperitoneum and very rarely into the anterior abdominal wall, misconstruing it as an isolated abdominal wall abscess. Case presentation Diabetes-related 55-year-old diabetic male presented with abscess in his periumbilical region extending into right lumbar region. He did not exhibit any urinary symptoms, and contrast enhanced computed tomography [CECT] abdominal and pelvic examinations revealed right pelvic calculus with pyonephrosis. There is a 7.5 mm defect in the lower pole of the right kidney with 171 cc of collection adjacent to the kidney communicating with 150 cc of superficial abdominal wall collection through a 15 mm defect. Incision and drainage of abdominal and retroperitoneal abscesses were done at first. Right DJ stenting was performed. Right lateral decubitus was placed for dependent drainage. Resolution of residual collections was confirmed by subsequent ultrasonography KUB, and drain was then removed. Right DJ stenting done, and patient was discharged. Two months later, DTPA scan done and revealed GFR of 30 ml/min of right kidney. Patient underwent right percutaneous nephrolithotomy. Conclusion The sudden rupture of pyonephrosis is a rare event. Even rarer is the presentation of pyonephrosis as an abscess on the anterior abdominal wall. The correct diagnosis and search for the source of the abscess must be undertaken before intervention. An aggressive and prompt management is needed to prevent further complications from occurring. This case is being presented to add to the literature with regard to abnormal presentations of ruptured pyonephrosis and its management.

Pyonephrosis is a suppurative infection of the kidney caused by ureteral obstruction. It can lead to kidney failure, septic shock, and death. Thus, it requires prompt assessment and appropriate management. We report a case of a 63-year-old male with giant pyonephrosis contained 10 liters of pus and spontaneously ruptured in the adjacent muscles. This clinical case illustrates the value of computed tomography scan in the diagnosis and management of an uncommon upper urinary tract infection and its complications.

Introduction: Urosepsis is a systemic reaction of the body to a bacterial infection of the urogenital organs with the risk of lifethreatening complications including septic shock. Aim: To assess the profile of patients with urosepsis and to analyse outcomes in patient management at a tertiary care centre. Materials and Methods: A retrospective, single-centre study was conducted between January 2015 and December 2019 including patients of either sex, aged =20 to <80 years, with a confirmed diagnosis of urosepsis. Clinical report forms were reviewed to obtain patient characteristics (including age, sex, co-morbid conditions and clinical data). Blood, pus, urine culture data were evaluated to identify the source of infection. Details of upper and lower urinary tract symptoms and their imaging and urological intervention done were also recorded. Results: A total of 582 patients with urosepsis were included in this study. The majority of patients belonged to the age group of 41 to 60 years (n=315). The most frequent radiological diagnosis was infected hydronephrosis with calculus disease (n=237). The associated co-morbid conditions contributing to the perpetuation of urosepsis were Type II Diabetes Mellitus (T2DM), systemic hypertension, chronic kidney disease, decompensated liver disease, neurological disease, and coronary artery disease. Escherichia coli was the most commonly observed uropathogen (57.90%) in this study. Bilateral Double-J (DJ) stenting was usually preferred in patients with infected hydronephrosis and acute pyelonephritis (n=85, 76.58%). The insertion of a suprapubic catheter was more frequent among patients with obstructive lower urinary tract symptoms. Multivariate analysis showed that urosepsis with emphysematous pyelonephritis, uncontrolled diabetes, and persistent hypotension inspite of inotropic agents had a prolonged intensive care unit and higher mortality rate. Conclusion: Renal salvage is achievable in majority of cases with early surgical intervention, either DJ stenting or percutaneous nephrostomy. Suprapubic catheterisation is indicated in urosepsis patients with predominant lower urinary tract symptoms. An early diagnosis and an appropriate treatment can reduce the costs of hospitalisation, morbidity, mortality and better outcome. [ABSTRACT FROM AUTHOR]

Background: Xanthogranulomatous pyelonephritis (XGP) is chronic pyelonephritis subtype where in renal parenchymal destruction occurs and therefore results in progressive loss of kidney functions. Although middle age group is the predominant age group affected but it can be seen at any age. There is accumulation of macrophages (lipid-laden) leading to renal parenchymal destruction and fibrosis. In this study, we present our data of 15 patients who had undergone nephrectomy and were biopsy proven XGP. Aims and Objectives: The aim of the study was to describe the clinical and radiological features of XGP in adults. Materials and Methods: XGP constituted 4.31% of the 348 nephrectomies done for infective causes over a period of 7 years. All our patients had undergone unilateral total nephrectomy. Demographic and clinical records were analyzed after consent from all the patients. Results: The age range in our study was 18–65 years with mean 42.93±15.66 years. Nine of our patients, that is, 60% were females. Diabetes was present in 53.3% of our patients. Three patients had imaging suggestive of pyonephrosis, three patients had perinephric collection and 9 patients (60%) had concomitant nephrolithiasis. All the kidneys were grossly enlarged and were non-functional on renal scintigraphy. Conclusion: XGP is a form of chronic pyelonephritis which although being less common but is devastating given the destruction of renal parenchyma it does and associated morbidity. Clinicoradiologic correlation cannot be overemphasized. The definitive diagnosis is established after histopathologic examination. [ABSTRACT FROM AUTHOR]

Background: Acute or chronic obstruction of the urinary tract can be due to a lot of different causes. Patients with pyonephrosis usually complain of a triad of fever, loin pain and elevated white blood cell count in cases of acute obstruction; and they may also have hypotension in severe cases of the disease. These patients have to be treated with appropriate decompression, or they may develop septic shock. The urgency of the need for treatment greatly depends on the differentiation between hydronephrosis and pyonephrosis. There is a lack of reliable clinical prognosticators of pyonephrosis in patients with obstructive hydronephrosis. Hounsfield unit (HU) measurement is considered as an adequate predictor of pyonephrosis and may aid in the diagnosis and management of this disease that may be fatal. The use of HU values in differentiation between pyonephrosis from hydronephrosis depends on the fact that the pyonephrotic fluid contains infected material, urine, cellular particles and microorganisms, which when combined can increase the HU values on a computed tomography (CT) study. This study was done to assess the diagnostic value of the HU measured CT in differentiation between hydronephrosis and pyonephrosis. Results: Thirty-nine patients were included in this study. All patients had loin pain and were diagnosed with pelvicalyceal dilatation by ultrasonographic examination. They then underwent non-contrast CT examination. Using CT scan, the degree of PC dilatation was significantly higher among hydronephrosis group as hydronephrosis group had 63.1% severe dilatation of PCs versus 30.8% in pyonephrosis group with p value 0.0001. Pelvic wall thickness > 2 mm was reported in 10 (76.9%) patients of pyonephrosis group versus in three (7.9%) patients among hydronephrosis group with p value 0.0001. The mean Hounsfield units were significantly higher among pyonephrosis group compared to hydronephrosis group (16 ± 5.2 versus 1.7 ± 5.5) with p value 0.0001. Sensitivity analysis showed that Hounsfield units can significantly diagnose pyonephrosis using the cutoff point 6.2 units, with sensitivity 92.3%, specificity 93.3%, area under the curve (AUC) 96.9% and p value 0.0001. Conclusions: Measuring HU in a NCECT scan of the kidney might be helpful for differentiating between hydronephrosis and pyonephrosis especially upon considering 6.2 HU as a cutoff point. [ABSTRACT FROM AUTHOR]

Background: Childhood urolithiasis is previously rare but increasingly recognized nowadays. Presentation varies, and often children, do not present with the classical symptoms commonly seen in adults. Case report: This case was initially presented to the emergency department with atypical symptoms of nephrolithiasis. Therefore, he was treated for acute appendicitis before an ultrasound abdomen revealed there is gross hydronephrosis, which is secondary to pelvic-ureteric junction obstruction. CT abdomen was then proceeded, found right nephrolithiasis and vesicoureteric calculus with right hydroureter and gross hydronephrosis. Retrograde pyelography (RPG), ureteroscopy (URS), and insertion of the stent for right pelvicureteric junction obstruction were performed and subsequently, he developed complications. Conclusion: The initial presentation of this case is common however not a classical presentation of renal stone. Therefore, evaluation of the symptoms and initial investigations should be done properly, so that we will not miss this common disease with the rare presentation, especially in children. [ABSTRACT FROM AUTHOR]

Pyonephrosis is defined as the infection of the dilated renal collector system, with a variety of etiological agents. The accumulation of pus may cause the destruction of renal parenchyma, leading to renal insufficiency. The symptoms may occur early or late in the disease’s progress and can be of a great variability. We present a case report of a 53-year-old female which suffered of low back pain, fever and nausea. The ultrasound and CT examination revealed 4th stage pyonephrosis caused by stone obstruction. It was also observed right encysted pleural empyema and pericardial fluid as pyonephrosis’ complications. The first part of the treatment consisted of inserting a percutaneous nephrostomy (PCN) probe along with the administration of antibiotics for the next two months, followed by radical right nephrectomy in renal insufficiency context. The postoperative evolution was favorable with no repercussions.

Introduction: Urosepsis is a systemic reaction of the body to a bacterial infection of the urogenital organs with the risk of life-threatening complications including septic shock. Aim: To assess the profile of patients with urosepsis and to analyse outcomes in patient management at a tertiary care centre. Materials and Methods: A retrospective cohort, single-centre study was conducted at PSG Institute of Medical Science and Research, Coimbatore, Tamil Nadu, India, between January 2015 and December 2019 including patients of either sex, aged ≥20 to

To explore the diagnostic value of noncontrast computed tomography (NCCT) in differentiating pyonephrosis from nonpyogenic hydronephrosis on the basis of CT values (in Horsfield unit [HU]). Data from patients diagnosed with obstructive uropathy at the First affiliated hospital of University of South China from November 2017 to January 2021 were subjected to retrospective analysis. In accordance with the gold standard—the presence of pus during the operation—all patients were divided into the nonpyogenic hydronephrosis group and the pyonephrosis group. The relationship between CT values and the presence or absence of pyonephrosis was performed using binary logistic regression. A receiver operating characteristic (ROC) curve was constructed to determine threshold values for classification on the basis of mean HU. A total of 207 patients, including 100 males and 107 females, were enrolled. Out of the 207 cases, 124 cases of obstructive uropathy were nonpyogenic hydronephrosis and 83 cases were of pyonephrosis. The CT values of the pyonephrosis group were significantly higher than that of the nonpyogenic hydronephrosis group (t = 9.15, P < 0.05). The CT values were dependent on the presence or absence of pyonephrosis (P < 0.05). A HU threshold value of 9.75 could be applied to diagnose the presence of pyonephrosis. The CT values of hydronephrosis might predict the presence of pyonephrosis in the kidney, and the CT value of 9.75 HU might be the appropriate threshold for its prediction. • Noncontrast computer tomography: A non-invasive method to judge pyonephrosis. • Noncontrast computer tomography may speed up the treatment of pyonephrosis. • Sometimes urine tests are not reliable for pyonephrosis. [ABSTRACT FROM AUTHOR]

Introduction. Renoalimentary fistulas represent infrequent pathology with 27 literature reports. The oldest report is from the year 1953. Nowadays, they usually arise after the cryoablation of renal tumors. In this case, we reported secondary renocolic fistula as an unusual complication of pyonephrosis, as well as the treatment modality, providing a literature review that favors a conservative or minimally invasive approach in most cases of renocolic fistula. Case report. In our case, the patient was a young female with a long course of kidney disease, which eventually led to pyonephrosis with renocolic fistula. Initially, the patient was hospitalized due to life-threatening urosepsis, successfully treated with a conservative approach. Afterward, we decided to proceed with surgical treatment. Regarding the poor right kidney function of the patient and the presence of concurrent sepsis, the right hemicolectomy with primary ileocolic anastomosis and the right nephrectomy were performed. The postoperative course was without complications, and the patient was discharged from the hospital on the 10th day. Follow-up did not reveal any complications. Conclusion. Regarding the available literature, a conservative and minimally invasive approach is most frequently employed in such cases. However, in cases of haemorrhage, sepsis, and impaired kidney function, surgery offers the only chance for cure. In patients with concurrent gastrointestinal pathology, surgery is usually the only option. Kidney preservation should be imperative in all cases, except in the case of impaired kidney function. The laparoscopic approach can be utilized in selected cases.

Introduction. Simultaneous ipsilateral coexistence of renal cell carcinoma (RCC) and upper urinary tract urothelial carcinoma (UTUC) rarely occurs. Balkan endemic nephropathy (BEN) is a chronic degenerative tubulointerstitial renal disease, strongly associated with UTUC. Case outline. А 60-year-old man from the region of BEN was referred to our clinic due to right flank pain, fever, and purulent discharge from the cutaneous fistulous opening in the right lumbar area. Multislice computed tomography urography scan showed right-side pyonephrosis and nephrocutaneous fistulous tract between the kidney and the skin in the right lumbar region. Cystoscopy detected a papillary tumor protruding from the right ureteric orifice. Right-side nephroureterectomy with bladder cuff excision was performed. Histopathological examination revealed rhabdoid RCC of the kidney and multifocal urothelial carcinoma of the ureter. Conclusion. Our case report and literature review indicate that due to rising incidence of multiple primary malignant neoplasms (MPMNs), when treating patients with RCC or UTUC, and especially those from the region of BEN, one should keep in mind the likelihood of synchronous or metachronous occurrence of these tumors.

Abstract Background Calculous pyonephrosis is a disease characterized by infectious hydronephrosis associated with pyogenic destruction of the renal parenchyma, with complete or almost complete loss of renal function. Methods The clinical data of laparoscopic nephrolithotomy performed at Peking University People’s Hospital from May 2017 to June 2020 were analyzed retrospectively. Eight patients (2 men; 6 women) aged 27 to 65 years (average age, 45.8 years) were included. Among them, 7 patients were treated with retroperitoneal approach and 1 patient by transperitoneal approach. All patients had received more than one endoscopic lithotripsy before nephrectomy. Renal dynamic imaging and computed tomography revealed the absence of function in pyonephrosis before nephrectomy. General clinical data and perioperative data were recorded. All nephrectomies were performed by the same physician. Results Laparoscopic surgery was successfully performed in 7 patients; however, 1 patient underwent open surgery because of bleeding. The operation time, average operation time, and blood loss were 1.5–4.5 h, 3.4 h, and 100–1000 ml (average, 300 ml), respectively. The postoperative pathology showed inflammatory renal disease in 6 patients, xanthogranulomatous pyelonephritis in 1 patient, and high-grade urothelial cancer in 1 patient. The average postoperative hospital stay was 5.3 days. One patient had a Clavien–Dindo Grade IIIb complication (severe hematuria), which required laparotomy, and was found that there was bleeding of ureteral stump. None of the patients experienced poor healing of endoscopic wounds. Conclusion For patients with complicated calculous pyonephrosis, renal inflammation could not be effectively controlled, and renal function was seriously damaged. Thus, kidneys should be immediately resected. With laparoscopy, patients may recover quickly, but surgeons require enough experience when performing laparoscopy to achieve safety.

Xanthogranulomatous pyelonephritis (XGP) is a chronic pyelonephritis subtype in which destruction of the renal parenchymal occurs, resulting in progressive loss of kidney functions. Although middle age is the predominant age group affected, but it can be spotted at any age. There is accumulation of macrophages (lipid-laden), leading to renal parenchymal destruction and fibrosis. In this study, we present our data of 15 patients who had undergone nephrectomy and had biopsy-proven XGP. XGP constituted 4.53% of the 331 nephrectomies performed for infective causes over a period of 8 years. All our patients had undergone unilateral total nephrectomy. Demographic and clinical data were analyzed after taking consent from all the patients. The age range of patients in our study was 18–65 years with a mean age of 43.93 ± 13.86 years. Ten (66.6%) of our patients were females. Diabetes was present in 40% of the patients. Three patients had imaging, suggestive of pyonephrosis, 3 had perinephric collection and 9 patients (60%) had concomitant nephrolithiasis. All the kidneys were grossly enlarged and were nonfunctional on renal scintigraphy. XGP is a form of chronic pyelonephritis, which, although less common, is devastating because of destruction of the renal parenchyma and associated morbidity. Clinicoradiologic correlation cannot be overemphasized. Definitive diagnosis is established through histopathologic examination.

Background and Aim: Prenatal hydronephrosis is found in 1%-5% of pregnancies. Without well-timed diagnosis and treatment, it can lead to irreversible outcomes. Because little information is available on the indication of Vesicoureteral Reflux (VUR) regarding the antenatal diameter of the kidney pelvis, the current study aimed to determine the association between prenatal hydronephrosis and the VUR. Methods: This cross-sectional study was conducted from 2011 to 2016 on 200 neonates with hydronephrosis detected in fetal life ultrasounds in the third trimester of pregnancy. We assessed the prenatal and postnatal kidney ultrasonography of 400 kidneys and Voiding Cystourethrogram (VCUG). We employed the Spearman correlation coefficient for determining the association between study variables. The obtained data were analyzed using SPSS 16.0 software at a significance level of less than 0.05. Results: Of 200 infants, 71.5% were males and 28.5% were females. No significant relationship was found between the degree of antenatal hydronephrosis and the VCUG severity (r=0.098, P=0.106). Despite antenatal hydronephrosis, the degree of postnatal hydronephrosis and the VCUG severity was correlated (r= 0.255, P=0.001). Conclusion: There is no correlation between the severity of fetal hydronephrosis and VUR severity or the presence of a greater correlation between postnatal hydronephrosis and degree of VUR. Thus in cases of mild prenatal hydronephrosis, we suggest urinary tract ultrasonography three to seven days after birth and then cystography if postnatal sonography showed moderate or severe or progressive hydronephrosis. [ABSTRACT FROM AUTHOR]

Acute renal infection or acute pyelonephritis (AP) denotes the process of inflammation of the renal parenchyma and its collecting system and the urothelium following infection. Uncomplicated AP commonly affects otherwise healthy, young women without structural or functional urinary tract abnormalities and without relevant comorbidities. More severe and complicated AP occurs in patients with a structurally or functionally abnormal genitourinary tract, or in persons with a predisposing medical condition like immune compromised state and diabetes. Complicated AP is characterized by a broader spectrum of clinical presentations, a wider variety of infecting organisms, and a greater risk of progression to a complication, such as intrarenal or perinephric abscess or emphysematous pyelonephritis and has the capacity to damage the organ and at times maybe life threatening. Role of imaging in renal infection is secondary, and in most situations, imaging is done to confirm the clinical diagnosis, map progression of disease in immune-compromised group of patients, or to evaluate for potential complications and therapeutic interventions. This article attempts to discuss the pathophysiology of AP from the standpoint of medical imaging and also brings out illustrative examples of various manifestations of AP and its complications. It provides imaging insight into various stages of inflammation, development of complication, and a roadmap for understanding AP through cross-sectional imaging.

Pyonephrosis is a rare condition in both adult and pediatric population. Here, the author presents a rare case of pyonephrosis induced by extended-spectrum beta-lactamase-producing Klebsiella pneumoniae in a 12-month-old girl presenting with a picture of urosepsis. The patient presented with febrile urinary tract infection and was unresponsive to intravenous meropenem. Physical examination revealed huge, firm and irregular right renal swelling. Ultrasound and computed tomography imaging revealed severely hydronephrotic right kidney, and laboratory investigations showed elevated C-reactive protein level (22.9 mg/dl). Emergency percutaneous nephrostomy tube was inserted, pus was drained (20 ml) and intravenous vancomycin and amikacin were started. Her general condition improved, and urine culture was negative. Functional assessment with dimercaptosuccinic acid renal scan revealed that the split renal function was 5% on the right and 95% on the left side, and the bladder outline was smooth with no reflux in voiding cystourethrogram. A right nephrectomy was done a week later using the anterior subcostal approach. The postoperative course was smooth. Histopathological examination was diagnostic for xanthogranulomatous pyelonephritis. No adverse events were reported in the follow-up over 12 months. It can be concluded that a high degree of suspicion, rapid initiation of appropriate antibiotics and drainage of pus are crucial in the management of pyonephrosis.

Xanthogranulomatous pyelonephritis (XGP) is a rare form of chronic pyelonephritis, which is challenging to diagnose because its clinical presentation mimics other entities and is commonly associated with a history of urinary tract obstruction. We report a case of XGP in a young adult without nephrolithiasis and urinary tract obstruction. A 23-year-old woman presented with intermittent abdominal pain in the right upper quadrant persisting for the last ten months. The pain was dull, poorly localized, and started spreading to the right back, right shoulder, and right thigh in the last three months. Other complaints included fever, chills, pain during urination, and nausea. The patient had a history of infrequent urination, recurrent urinary tract infections (UTIs), and a low fluid intake. A physical examination revealed that the patient had right upper quadrant abdominal tenderness and right costovertebral angle tenderness. Laboratory findings showed leukocytosis and neutrophilia. The radiological examination revealed a round mass in the superior pole of the right kidney with mixed cystic and solid components, and a well-defined margin. It further enlarged from 4.5 cm to 10.6 cm in diameter in three months. The urologist performed a total right nephrectomy. The histopathological examination showed XGP with renal abscess. Proteus mirabilis was identified from the pus specimen culture. XGP should be considered in the diagnosis of patients having chronic UTI presented with or without the findings of urinary tract obstruction.

Introduction: Xanthogranulomatous pyelonephritis (XGPN) is a rare form of chronic renal inflammation, caused by long-term obstruction of the urinary tract. Pyonephrosis is a severe suppurative complication of acute obstructive pyelonephritis. Although minimally invasive approaches have many advantages, the safe dissection of the kidney may not be always achievable., Materials and Methods: We reviewed 27 cases diagnosed with either XGPN or pyonephrosis, who underwent laparoscopic total nephrectomy between October 2016 and March 2022 in our department. All interventions were performed using the Karl Storz 3D laparoscopic system. The surgical approach was standard transperitoneal nephrectomy for the majority of XGPN, while pyonephrosis cases were carried out in a retroperitoneally. All procedures were performed or supervised by the same surgeon., Results: The mean operative time was 269.85 minutes (range 145-360). The mean hemoglobin drop after surgery was 1.41 g/dl (range 0.3-2.3 g/dl). Difficult dissection was encountered in 13 cases (48.14%). Nine out of 13 interventions were carried out in a complete intracorporeal fashion, while conversion to open surgery was needed in 4 cases. Vascular complications involving the major blood vessels comprised of one case of inferior vena cava (IVC) tear. Digestive tract-related complications comprised two fistulas of the descending colon and one peritoneal breach. Multiorgan resection was performed in 6 cases., Conclusion: Total nephrectomy in cases of XGPN and pyonephrosis is a challenging procedure. The laparoscopic approach is feasible, as most complications are resolved intracorporeally. However, it may remain reserved for large-volume centers with experienced surgeons., (Copyright © 2024 AEU. Published by Elsevier España, S.L.U. All rights reserved.)

Purpose: To determine the non-contrast computer tomography imaging features of pyonephrosis and evaluate the predictive value of Hounsfield units (HUs) in different hydronephrotic region slices., Materials and Methods: We retrospectively reviewed data from patients with hydronephrosis who had renal-ureteral calculi. All patients were categorized into pyonephrosis and simple hydronephrosis groups. Baseline characteristics, the mean HU values in the maximal hydronephrotic region (uHU) slice, and the range of uHU in different slices (ΔuHU) were compared between the two groups. Univariate and multivariate analyses were performed to identify risk factors for pyonephrosis., Results: Among the 181 patients enrolled in the current study, 71 patients (39.2%) were diagnosed with pyonephrosis. The mean dilated pelvis surface areas were comparable between patients with pyonephrosis and simple hydronephrosis (822.61 mm² vs. 877.23 mm², p=0.722). Collecting system debris (p=0.022), a higher uHU (p=0.038), and a higher ΔuHU (p<0.001) were identified as independent risk factors for pyonephrosis based on multivariate analysis. The ΔuHU sensitivity and specificity were 88.7% and 86.4%, respectively, at a cutoff value of 6.56 (p<0.001), whereas the sensitivity and specificity for detecting pyonephrosis at a uHU cutoff value of 7.96 was 50.7% and 70.9%, respectively (p=0.003)., Conclusions: Non-contrast computer tomography was shown to accurately distinguish simple hydronephrosis from pyonephrosis in patients with obstructive uropathy. Evaluation of the ΔuHU in different slices may be more reliable than the uHU acquired from a single slice in predicting pyonephrosis., Competing Interests: The authors have nothing to disclose., (© The Korean Urological Association.)