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.

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.

Xanthogranulomatous Pyelonephritis with Pyonephrosis and Renal Abscess in a Young Adult: A Consequence of Neglected Urinary Tract Infection Leading to Nephrectomy.

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.

A Nautilus kidney.

We report a 71-year-old woman who presented with unilateral flank pain and sepsis. A computed tomographic (CT) scan demonstrated left-sided hydronephrosis. Subsequent percutaneous nephrotomy drainage showed pus-like material, confirming the diagnosis of pyonephrosis. The ureteral stricture was caused by previous radiation injury for cervical cancer in this ESRD patient who was on chronic dialysis for years. In our case, the grade IVB hydronephrosis is a result of an extremely atrophic kidney, pyonephrosis, and ureteral stricture. The CT section of pyonephrosis in an extremely atrophic kidney resembles a sagittal section of a Nautilus shell, as the shell corresponds to the diffusely thinned renal cortex.

Challenges and management of laparoscopic treatment of pyonephrosis caused by calculi.

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.

Minimally invasive management of acute ureteral obstruction and severe infection caused by upper urinary tract calculi.

PURPOSETo evaluate therapeutic efficacy of two minimally invasive surgical methods in managing acute ureteral obstruction and severe infection caused by upper urinary tract calculi (UUTC).PATIENTS AND METHODSData of 47 patients diagnosed with acute upper urinary tract obstruction and severe infection caused by ureteral calculus using X-ray CT between September 2014 and January 2019 were retrospectively analyzed. All patients were treated with immediate renal drainage and, after infection and ureteral obstruction were relieved, UUTC removal. Renal drainage was performed by ultrasound-guided percutaneous nephrostomy and retrograde ureteral catheterization was performed using cystoscopy. Kidney and ureteral stones were removed; renal function and the urinary tract were examined by X-ray during follow-up.RESULTSPercutaneous nephrostomy was performed in 29 patients in a critical condition including intolerance to surgery, high-grade hydronephrosis, or failure of retrograde ureteric stent placement. In other 18 patients diagnosed with small stones (≤10 mm) and low-grade hydronephrosis, indwelling double-J ureteral stents were temporally installed by a cystoscope. Acute infection and ureteral obstruction were relieved; white blood cell counts returned to normal values within 3 to 7 days after drainage in all patients. In the second-stage treatment, percutaneous nephrolithotomy (PCNL), ureteroscopic lithotripsy, extracorporeal shock wave lithotripsy and nephrectomy were performed in 24, 10, 8 and 5 patients, respectively. No patients developed severe complication after stone removal surgery. All patients were followed up for 3 months to 4.5 years. Renal function was significantly recovered; 17/29 (59%) patients with elevated serum creatinine returned to normal and serum creatinine in 12/29 (41%) patients improved significantly after drainage, with a pre-operation level of 285±169µM vs 203±91µM post-operation (P = 0.014). Five patients were lost during follow-up.CONCLUSIONThis study demonstrated an optimal approach for relieving upper urinary tract obstruction and acute infection in which percutaneous nephrostomy drainage is preferred for patients with severe pyonephrosis, large stones (>10 mm) with high-grade hydronephrosis, steinstrasse, or failure in retrograde ureteric stent placement, while retrograde ureteral catheterization using cystoscopy is suitable for patients diagnosed with small stones (≤10 mm) and low-grade hydronephrosis.

Urinary tract infection due to anaerobic bacteria in a two-month-old infant.

The significance of anaerobic bacteria as a pathogen in urinary tract infection (UTI) in children is unclear. A two-month-old infant presenting with poor feeding received a diagnosis of polymicrobial anaerobic UTI by next-generation sequencing and was found to have obstructive uropathy. Anaerobic bacteria may be a cause of UTI in children with urinary tract obstruction.

Risk factors and outcomes of urosepsis in patients with calculous pyonephrosis receiving surgical intervention: a single-center retrospective study.

BACKGROUND: Urosepsis is a catastrophic complication, which can easily develop into septic shock and lead to death if not diagnosed early and effectively treated in time. However, there is a lack of evidence on the risk factors and outcomes in calculous pyonephrosis patients. Therefore, this study was conducted to identify risk factors and outcomes of intra- and postoperative urosepsis in this particular population. METHODS: Clinical data of 287 patients with calculous pyonephrosis were collected. In the univariate and multivariate analysis, all patients were divided into urosepsis group and non-urosepsis group. The diagnosis of urosepsis was mainly on the basis of the criteria of American College of Chest Physicians (ACCP)/Society of Critical Care Medicine (SCCM). Patient characteristics and outcomes data were analyzed, and risk factors were assessed by binary logistic regression analysis. RESULTS: Of 287 patients, 41 (14.3%) acquired urosepsis. Univariate analysis showed that white blood cell (WBC > 10*10^9/L) before surgery (P = 0.027), surgery types (P = 0.009), hypotension during surgery (P < 0.001) and urgent surgery (P < 0.001) were associated with intra- and postoperative urosepsis for calculous pyonephrosis patients. In multivariate analysis, hypotension during surgery and urgent surgery were closely related to intra- and postoperative urosepsis. Outcome analysis suggested that patients developing urosepsis had a longer intensive care unit (ICU) stay and postoperative hospital stay and higher mortality. CONCLUSIONS: Hypotension during surgery and urgent surgery were risk factors of intra- and postoperative urosepsis for calculous pyonephrosis patients, which may lead to a prolonged ICU stay, postoperative hospital stay and higher mortality.

[Clinical analysis of 28 cases of calculous pyonephrosis undergoing B-ultrasound-guided renal puncture and drainage followed by secondary percutaneous nephrolithotomy].

Objective: To investigate the therapeutic effects of first phase renal puncture and drainage guided by B ultrasound and second phase percutaneous nephrolithotomy(PCNL) in the treatment of urinary calculi complicated with pyonephrosis. Methods: From January 2014 to April 2018, 28 patients with upper ureteral segment and kidney calculi complicated with pyonephrosis were collected. All patients received the pyonephrosis puncture under B ultrasound. After the inflammation was controlled and the clinical situation improved, the second phase was treated by PCNL. During the operation, routine in dwelling ureteral stent drainage and renal fistula wereperformed. The outcomes of the operation were observed. Results: A total of 28 cases were successfully punctured, the obstruction was relieved and the inflammation was controlled. Additionally, the second phase of PCNL surgery was successful, and there were no significant stone residues after PCNL. There were no complications such as severe systemic inflammatory response syndrome and severe hemorrhage. After 3 to 12 months of follow-up, renal function was restored to varying degrees, and there were no renal failure patients who needednephrectomy. Conclusions: Early diagnosis of urinary calculi complicated with pyonephrosis is the key to successful treatment. Active and effective B ultrasound-guided renal puncture and drainage, drainage of pus, and removal of urinary obstruction can improve the safety of the second phase of PCNL, and thus it attaches great importance to the treatment of pyonephrosis.

Pyonephrosis as the first symptom of congenital hydronephrosis in a 6-year old girl.

Pyonephrosis in the course of hydronephrosis usually provides to total or near-total loss of renal function. In adults pyonephrosis usually results from urolithiasis. In children usually congenital urinary tract anomalies are present as contributing factors. CASE REPORT: 6-year old girl was admitted to the hospital because of 2-day history of high fever, abdominal pain, progressive deterioration of general condition and ultrasonographically (US) detected left hydronephrosis. US on admission showed grossly dilated left renal collecting system together with extensive echogenic debris and laboratory tests highly elevated inflammatory markers. Once diagnosis of pyonephrosis was established on the basis of clinical picture and US as well as laboratory tests results, nephrostomy tube was placed percutaneously. Pus culture obtained during placement of nephrostomy showed E.Coli ESBL (-) growth. Intensive antibiotic treatment (Meropenem) was continued for 3 weeks, nephrostomy was removed after 12 days after receiving normal urine. Further evaluation of urinary tract (US and computed tomography urography) showed large hydronephrosis due to ureteropelvic junction obstruction, while dynamic scintigraphy obstructive renogram with grossly diminished left kidney function to 20% of differential renal function. The girl was referred for operative treatment on urgent basis. Intraoperatively long distance utreteropelvic junction stenosis was found and dismembered Anderson- Hynes pyeloplasty was performed. During 2-years follow-up postoperatively US showed gradually decrease of dilatation of left renal collecting system, while dynamic scintigraphy revealed permanent improvement of drainage together with almost normal renal function (up to 45%). No urinary tract infections were noted. CONCLUSIONS: Proper management of pyonephrosis in hydronephrotic kidney due to congenital ureteropelvic junction obstruction enables good final result of treatment.

Computerized tomography attenuation values can be used to differentiate hydronephrosis from pyonephrosis.

PURPOSE: To determine the diagnostic value of computerized tomography (CT) in differentiating pyonephrosis from hydronephrosis on the basis of attenuation values (Hounsfield unit-HU). METHODS: Data of the patients with grades 1-3 hydronephrosis on abdominopelvic CT, who underwent nephrostomy tube placement for decompression of the collecting system, were retrospectively analyzed. Patient demographics and CT findings were recorded along with the first access urine culture results. Three physicians calculated the surface areas and the attenuation values of the dilated collecting systems using the system software. Mean HU of pyonephrosis and hydronephrosis cases was compared. RESULTS: A total of 105 patients with the mean age of 47.7 ± 15.5 (range 20-80) were included. The interclass correlation coefficient of three physicians was 0.981 for HU measurement and 0.999 for calculation of collecting system surface area. Of the patients, 47 (44.8 %) had pyonephrosis. Mean surface areas of the collecting system were similar in patients with pyonephrosis and hydronephrosis (1481.13 ± 1562.94 vs. 1612.94 ± 2261.4 mm2, p = 0.735). Urine cultures were positive in all patients with pyonephrosis, whereas 12.7 % of hydronephrosis cases had bacterial in first access urine culture. The HU of the patients with pyonephrosis was significantly higher that that of patients with hydronephrosis (13.51 ± 13.29 vs. 4.67 ± 5.37, p = 0.0001). Having a HU of 9.21 or over diagnosed pyonephrosis accurately with 65.96 % sensitivity and 87.93 % specificity. CONCLUSION: Measuring attenuation values of the collecting system may be useful to differentiate pyonephrosis from hydronephrosis. Diagnosing pyonephrosis accurately may avoid septic complications.

A Randomized Study of Minimally Invasive Percutaneous Nephrolithotomy (MPCNL) with the aid of a patented suctioning sheath in the treatment of renal calculus complicated by pyonephrosis by one surgery.

BACKGROUND: Calculus pyonephrosis is difficult to manage. The aim of this study is to explore the value of a patented suctioning sheath assisted minimally invasive percutaneous nephrolithotomy (MPCNL) in the treatment of calculus pyonephrosis. METHODS: One hundred and eighty two patients with calculus pyonephrosis were randomizely divided into observation group (n = 91) and control group (n = 91). The control group was treated with MPCNL traditionally using peel-away sheath while the observation group was treated with MPCNL using the patented suctioning sheath. RESULTS: All the patients in the observation group underwent one stage surgical treatment, 14 patients in the control group underwent first-stage surgery with the rest of the group underwent one stage surgery. The complication rate was 12.1% in the observation group, significantly lower than the rate in the control group which was 51.6%; One surgery stone clearance in the observation group was 96.7% while it was 73.6% in the control group; operative time in the observation group was (54.5 ± 14.5) min, compared to (70.2 ± 11.7) min in the control group; the bleeding amount in the observation group was (126.4 ± 47.2) ml, compared to (321.6 ± 82.5) ml in the control group; the hospitalization duration for the observation group was (6.4 ± 2.3) days, compared to (10.6 ± 3.7) days in the control group. Comparison of the above indicators, the observation group was better than the control group with significant difference (p < 0.001 each). CONCLUSIONS: Minimally invasive percutaneous nephrolithotomy with the aid of the patented suctioning sheath in the treatment of calculus pyonephrosis in one surgery is economic, practical, and warrants clinical promotion. TRIAL REGISTRATION: This study was registered with Chinese Clinical Trial Registry on May 18, 2016 (retrospective registration) with a trial registration number of ChiCTR-IOR-16008490 .

Acute focal bacterial nephritis, pyonephrosis and renal abscess in children.

BACKGROUND-AIM: Acute focal bacterial nephritis (AFBN), renal abscess and pyonephrosis are uncommon and not fully addressed forms of urinary tract infection (UTI) which may be underdiagnosed without the appropriate imaging studies. Here, we review the characteristics and outcome of these renal entities in children managed at a single medial centre. PATIENTS AND METHODS: The medical files of all children hospitalized for episodes of AFBN, renal abscess and pyonephrosis during a 10-year period (2003-2012) were reviewed. RESULTS: Among the 602 children hospitalized for UTI, 21 presented with AFBN, one with abscess and three with pyonephrosis. All 25 children (13 girls), ranging in age from 0.06 to 13.4 years, were admitted with fever and an impaired clinical condition, and 18 had urological abnormalities. More than one lesion, often of different types, were identified in 11 episodes. Urine cultures from 13 episodes grew non-Escherichia coli pathogens and those from two episodes were negative. Antibiotics were administered for 14-60 days, and emergency surgery was required in three cases. During follow-up, 13 patients underwent corrective surgery. Permanent renal lesions were identified in 16 patients. CONCLUSIONS: AFBN, renal abscess and pyonephrosis should be suspected in children with severe presentation and urological history. Appropriate imaging is crucial for management planning. Prognosis is often guarded despite appropriate treatment. Based on the results of this study we propose a management algorithm.

[Ultrasonographic finding and treatment of a cow with pyelonephrosis]. / Sonographische Befunde und Therapie bei einer Kuh mit Pyonephrose.

Ultrasonography of a six-year-old Simmental cow revealed an abscess like structure, approximately 15 cm in diameter, in place of the right kidney. The cow had a history of colic for 4 days and was referred to our clinic with a tentative diagnosis of caecal dilatation. The cow voided dark opaque urine with white floccules. Laboratory examination yielded increased haematocrit, leukocytosis with left shift, hyperbilirubinaemia and azotaemia. The diagnosis was confirmed, the caecum emptied surgically and the pus-filled structure at the site of the right kidney removed. A diagnosis of pyonephrosis was made after pathological examination of the pus-filled structure.

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.

Identification of Calculous Pyonephrosis by CT-Based Radiomics and Deep Learning.

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.

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.