Machine learning constructs a diagnostic prediction model for calculous pyonephrosis.

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.

The mean Hounsfield unit range acquired from different slices produces superior predictive accuracy for pyonephrosis in obstructive uropathy.

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.

Giant pyonephrosis related to nephrolithiasis in diabetes woman: A case report.

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.

Construction of an alignment diagram model for predicting calculous obstructive pyonephrosis before PNL.

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.

Laparoscopic approach for xanthogranulomatous pyelonephritis and pyonephrosis.

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.

Giant Pyonephrosis in an Ectopic Kidney: A Case Report.

Pyonephrosis is characterized by infective hydronephrosis accompanied by suppurative destruction of the renal parenchyma, resulting in partial or complete impairment of renal function. Patients present with wide range of symptoms, they can be asymptomatic in 15% but most of them present with septic features like fever, chills, and flank pain. Urinary tract infections, functional and anatomic obstruction, and anatomic anomalies such as pelvic and horseshoe kidneys are common etiologic factors. We report a 30 years old female patient with giant pyonephrosis in an ectopic kidney. She presented with acute toxic symptoms after she has been experiencing progressive abdominal swelling and pain for a couple of years. Simple nephrectomy was done four weeks after she has been initially treated with percutaneous drainage of the pus and intravenous antibiotics.

Case report: A rare case of synchronous mucinous neoplasms of the renal pelvis and the appendix.

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.

Minimal invasive management of generalized peritonitis as a result of spontaneous ureteral rupture.

INTRODUCTION AND IMPORTANCE: Generalized peritonitis following proximal ureteral rupture is a very rare complication. This is about a successfully managed case without open surgical intervention. CASE PRESENTATION: 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. CLINICAL DISCUSSION: 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. CONCLUSION: 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.

Benign ureteral obstruction in cats: Outcome with medical management.

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.

Mini-PCNL with a vacuum-assisted access sheath for renal calculi with pyonephrosis in the second stage.

OBJECTIVE: To compare the safety and efficacy of mini-PCNL with vacuum-assisted access sheath in the second-stage treatment of renal calculi with obstructive pyonephrosis. MATERIAL AND METHODS: A prospective, randomized clinical study was performed at our hospital from May 2020 to May 2022. Patients with pyogenic drainage fluid who needed percutaneous nephrolithotomy were randomized to the peel-away assisted mini-PCNL group (group A) and the vacuum-assisted mini-PCNL group (group B). Demographic information, clinical features, and perioperative period data were collected. RESULTS: Fifty mini-PCNLs using a single 16 F access sheath were performed in all patients of our study. All patients underwent second-stage surgical treatment. Demographic information and clinical features were not significantly different between groups A and B. But compared with group A, patients in group B had a short operative time (60.60 ± 7.68 min vs. 82.20 ± 14 min p = 0.018), a lower post-operative fever rate (8% vs. 32% p = 0.034), and a higher stone-free rate 2 d after the operation (88% vs. 64% p = 0.047). There was no significant difference between the two groups in blood transfusion, HB deficit, PCT after the operation, total hospitalization costs, stone-free rate 30 d after the operation, and length of stay or stay post-operative. And no serious complications after the operation occurred in either group. CONCLUSIONS: Mini-PCNL with vacuum-assisted access sheath is a safe and efficient treatment for patients with calculi-related obstructive pyonephrosis in the second stage.

Twenty-Four-Month Efficacy of Ureteroureterostomy Combined With Unilateral Nephrostomy Following Radical Cystectomy.

Introduction The purpose of this study was to evaluate the 24-month outcomes of ureteroureterostomy combined with unilateral nephrostomy following radical cystectomy in patients with muscle-invasive bladder cancer (BC). Materials and methods This single-center study with prospectively collected data with retrospective data analysis was carried out between December 2018 and November 2021 and enrolled 36 patients, who underwent radical cystectomy combined with ureteroureterostomy and unilateral nephrostomy. Regular renal function assessment was carried out using serum creatinine and estimated glomerular filtration rate (eGFR), and postoperative complications, endoscopic, ultrasound, and other radiological study findings were evaluated. The follow-up of the patients was carried out over a period of 24 months. Results After completion of the 24-month follow-up, the renal function proved to be slightly improved (mean serum creatinine and eGFR values of 1.38±0.72 mg/dL and 55.9±21.87 mL/min) compared to the first-year results (1.41±0.54 mg/dL and 52.10±19.64 mL/min). However, this improvement is statistically not significant (p=0.44, p=0.30). The 24-month follow-up imaging findings remained stable in 97.22% of patients compared to the first-year results, with preservation of bilateral ureteric dilatation and grade 1 dilatation of the non-drained kidney. No case of acute pyelonephritis was recorded after the completion of the second year of follow-up, in comparison to the eight patients (22.22%) of the 12-month follow-up, who suffered acute pyelonephritis. After completing of the 24-month follow-up, one patient was excluded from further analysis, due to the placement of a second permanent percutaneous nephrostomy in the non-drained kidney, due to ureteroureterostomy stenosis with consecutive hydronephrosis in the contralateral kidney and acute renal failure. No case of anastomotic leak was observed. Conclusions The function of the ureteroureterostomy combined with unilateral nephrostomy is proven to be a safe method of urinary diversion (UD) at 24 months, with minimal and easily manageable complications. Only one case of stenosis of the ureteroureterostomy with consecutive acute renal failure due to hydronephrosis in the non-drained kidney was observed. The renal function remained stable.

Pyoperitoneum revealing a spontaneous renal forniceal rupture due to ureteropelvic junction syndrome: About a rare case report.

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.

Multiple pyonephrotic compartments with different microorganisms and an infected "calcium milk" in a patient with bilateral obstructive uropathy: A challenging case.

INTRODUCTION AND IMPORTANCE: If the surgeon encounters frank pus, he is advised to limit the procedure to efficient drainage of the infected compartment of the urinary tract either by double J stent insertion or percutaneous nephrostomy and abort and postpone the definitive stone treatment until the infection is treated. CASE PRESENTATION: We present a highly complex case of an elderly female with multiple obstructing stones in the left kidney and ureter, with complete staghorn stones in the right kidney. While this scenario was already complex by virtue of the stone burden alone, which demands the combination of multiple stone treatment techniques, it was further complicated by compartmental infections in various parts of the kidneys with different microbes necessitating repeated abortion of procedures. As often in elderly patients, there was no rise of inflammatory markers, and bladder urine cultures were repeatedly negative. Moreover, a rare form of infection was encountered, namely "calcium milk" in the form of a radio-opaque lower pole abscess on the right. CLINICAL DISCUSSION: We discuss the etiology, treatment, and management of pyonephrosis and remind the need to always take it into account and react accurately when encountering infected space behind obstruction during minimally invasive surgeries in urolithiasis. CONCLUSION: Hidden microorganisms with different entities should be considered during surgical management of urinary stones. Complete drainage and appropriate antibiotic therapy are the cornerstones of treating this condition.

Percutaneous Nephrostomy in Complicated Urinary Tract Infections.

Background The study aimed to determine the various indications for percutaneous nephrostomy (PCN) primarily in patients with a urinary tract infection and to determine the various complications arising in these patients due to the procedure. Materials and methods A retrospective study of five-year data based on registers of the Department of Urology was performed. Among 716 patients, 226 inpatient data were obtained, curated, and analyzed. Indications for PCN, the periprocedural complications, the PCN's duration, details of antibiotics, risk factors for UTI, development of acute kidney injury, and renal replacement therapy were recorded. Results Patients were mostly female (53.1%, n=120/226). Malignancy (n=109, carcinoma cervix=68/109) and nephrolithiasis (n=70) contributed to 79.2%. Infections such as pyelonephritis, renal abscess, perinephric abscess, and genitourinary tuberculosis were identified in 47. Infectious diseases were significantly associated with younger age, female gender, diabetes, and prior pyelonephritis. PCN was placed at a median of two days after admission, and bilateral PCN was placed in 36 (15.2%) patients. Hydroureteronephrosis (probably infected) was an indication for PCN in 164/226 patients. In 33 patients with an infectious disease, PCN was performed for an obstructed urinary system. One major and two minor complications gave a rate of 0.06% for patients with infections, which was less than the accepted threshold of 4%. Conclusions We intended to study the utility and problems with placing a PCN catheter in patients with complicated urinary infections. We conclude that PCN is a safe and effective procedure in urinary tract infections with obstructed drainage.

Imaging of Group B Streptococcus infection in pyonephrosis: a case report.

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.

Drainage of infected kidneys with ureteral stents: does size matter?

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.

One-stage tubeless percutaneous nephrolithotomy for asymptomatic calculous pyonephrosis.

BACKGROUND: In recent years, the safety and effectiveness of one-stage percutaneous nephrolithotomy (PCNL) for the treatment of calculous pyonephrosis have been proven. In order to further reduce postoperative pain and hospital stay, we first proposed and practiced the idea of one-stage tubeless percutaneous nephrolithotomy for calculous pyonephrosis. METHODS: A retrospective analysis was performed of case data of 30 patients with asymptomatic calculous pyonephrosis treated in our center with one-stage PCNL from January 2016 to January 2021. Patients were routinely given 20 mg of furosemide and 10 mg of dexamethasone sodium phosphate injection intravenously at the beginning of anesthesia. Among them, 27 patients successfully underwent one-stage tubeless percutaneous nephrolithotomy, while 3 cases were given indwelling nephrostomy tubes because of proposed second-stage surgery or the number of channels was greater than or equal to 3. All patients were operated on by the same surgeon. RESULTS: Preoperatively, 11 of 30 patients (8 men and 22 women) had positive urine bacterial cultures, and all were given appropriate antibiotics based on drug sensitivity tests. All patients completed the surgery successfully. The mean operative time was 66.6 ± 34.7 min, the mean estimated blood loss was 16.67 ± 14.34 mL and the mean postoperative hospital stay was 5.0 ± 3.1 days. The mean postoperative hospital stay was 4.6 ± 2.5 days among the 27 patients with one-stage tubeless percutaneous nephrolithotomy. Of the 3 patients with postoperative fever, 2 had the tubeless technique applied. One patient with 3 channels was given renal artery interventional embolization for control of postoperative bleeding. None of the 30 patients included in the study developed sepsis. The final stone-free rate was 93.3% (28/30) on repeat computed tomography at 1 month postoperatively. The final stone-free rate was 92.6% in the 27 patients undergoing one-stage tubeless percutaneous nephrolithotomy (25/27). CONCLUSIONS: One-stage tubeless PCNL is an available and safe option in carefully evaluated and selected calculous pyonephrosis patients.

A missed psoas abscess diagnosis: A forensic case report.

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.

Spontaneous rupture of a giant pyonephrosis: A case report.

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.

Value of noncontrast computer tomography in predicting the characteristics of obstructive uropathy.

OBJECTIVE: 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]). METHODS: 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. RESULTS: 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. CONCLUSION: 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.