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.

OBJECTIVE: 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.
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.

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.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

BACKGROUND: 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.
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.
CONCLUSIONS: 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.

Pyonephrosis is a serious condition that can lead to kidney dysfunction, loss of the organ, and even fatal end due to its complications. The underlying etiologic factors include lithiasis, recurrent urinary infections, ureter stricture, ureteropelvic junction obstruction, malignancy, and retroperitoneal fibrosis. One of the rare possible complications of pyonephrosis is a retroperitoneal rupture with spontaneous communication to the abdomen causing secondary peritonitis. We present such a case which is the first video-documented report of the peritoneal rupture site within the abdominal cavity.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: The prevalence of pyonephrosis in pyelonephritis is similar to previous studies done in similar settings.
UNASSIGNED: pyelonephritis; pyonephrosis; kidneys.

BACKGROUND: Limited information is available regarding the outcome of medical management (MM) of benign ureteral obstruction in cats (BUO).
OBJECTIVE: Describe clinical characteristics and outcome of MM of BUO.
METHODS: 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: We found a higher success rate for MM of BUO than previously reported. Smaller distal uroliths (<1-2 mm) were more likely to pass.

UNASSIGNED: Generalized peritonitis following proximal ureteral rupture is a very rare complication. This is about a successfully managed case without open surgical intervention.
METHODS: A lady in her 70s presented with generalized abdominal pain, high spiking fever and low urine output for 3 days. She was haemodynamically unstable on admission and was resuscitated and managed at intensive care unit. CECT abdomen revealed partial anterior ureteral rupture with pyonephrosis. She was managed with percutaneous nephrostomy and subsequent anterograde stenting. Her recovery was uneventful and follow up imaging revealed no features of malignancy.
UNASSIGNED: Generalized peritonitis due to renal pathology is very rare and it can be due to urolithiasis or neoplasm. Retroperitoneal infections may lead to irritation of peritoneum or fistulation into the peritoneum leading to generalized peritonitis. This can be managed by various surgical and non-surgical management modalities.
CONCLUSIONS: There are various pathological causes for acute abdomen. One of the rare causes is spontaneous rupture of ureter in pyonephrotic kidney which can also be managed successfully with minimal intervention.