Perioperative outcomes and risk factors for major complications associated with nephrectomy for Xanthogranulomatous pyelonephritis: a multicenter study.

PURPOSE: To determine the risk factors associated with major complications in patients with histologically confirmed Xanthogranulomatous pyelonephritis (XGP) who underwent nephrectomy. METHODS: A multicenter retrospective study was performed including patients who underwent nephrectomy between 2018 and 2022 with histopathological diagnosis of XGP. Clinical and laboratory parameters at the initial presentation were evaluated. Data on extension of XGP was recorded as per the Malek clinical-radiological classification. Characteristics of nephrectomy and perioperative outcomes were obtained. The primary outcome was major complications, defined as a CD ≥ grade 3 and the need for intensive care unit (ICU) admission. Secondary outcomes included the comparison of complications evaluating the nephrectomy approach (transperitoneal, retroperitoneal, and laparoscopic). A sub-analysis stratifying patients who needed ICU admission and Malek classification was performed. RESULTS: A total of 403 patients from 10 centers were included. Major complications were reported in 98 cases (24.3%), and organ injuries were reported in 58 patients (14.4%), being vascular injuries the most frequent (6.2%). Mortality was reported in 5 cases (1.2%). A quick Sepsis-related Organ Failure Assessment (qSOFA) score ≥ 2, increased creatinine, paranephric extension of disease (Malek stage 3), a positive urine culture, and retroperitoneal approach were independent factors associated with major complications. CONCLUSION: Counseling patients on factors associated with higher surgical complications is quintessential when managing this disease. Clinical-radiological staging, such as the Malek classification may predict the risk of major complications in patients with XGP who will undergo nephrectomy. A transperitoneal open approach may be the next best option when laparoscopic approach is not feasible.

Xanthogranulomatous pyelonephritis in adults: clinical, biological, radiological and therapeutic main findings in diffuse and focal forms. About 42 cases.

INTRODUCTION: Xanthogranulomatous pyelonephritis (XGPN) is a particular form of chronic renal suppuration characterized by the destruction of renal parenchyma and its replacement by a granulomatous tissue containing xanthomatous cells. OBJECTIVE: To report and describe the main clinical, biological, radiological and therapeutic aspects of xanthogranulomatous pyelonephritis in adults in focal and diffuse forms. METHODS: This was a monocentric retrospective study involving 42 cases of XGPN operated and histologically confirmed between 2005 and 2015. We included in our study the patients belonging to any age, of both sexes, with a preoperative CT and whose XGPN diagnosis was confirmed histologically. Clinical, biological, bacteriological, radiological data and surgical procedures were collected and analyzed. RESULTS: The mean age was 50 years (34-79) with a sex ratio of 0.61. The XGPN was diffuse in 88% and focal in 12% of cases. Clinical symptoms were dominated by low back pain (95%), fever (64%) and recurrent urinary tract infections (41%). Urine culture was positive in 67% of cases and Escherichia Coli was the most isolated germ (36%). 64% of patients had inflammatory anemia and 57% of patients had an inflammatory biological syndrome. Ultrasound and CT revealed obstruction of the urinary tract in all cases: a lithiasic cause in 90% of cases and the rest were isolated cases of retroperitoneal fibrosis, abnormal pyelo-ureteral junction, ureteral stenosis and pyelo-ureteric duplicity. A peri-renal abscess and / or psoas was associated in 6 cases (14%). The preoperative diagnosis was often pyonephrosis (50%). Neoplasia was suspected in 4 cases. The treatment consisted in a radical nephrectomy for all patients preceded by drainage of the excretory pathways in 41% of the cases and drainage of a collection in 21% of the cases. CONCLUSION: The XGPN is a rare entity whose diagnosis is difficult. This is suspected on a cluster of clinical and biological arguments and can be evoked on the preoperative CT. The kidney cancer is the main differential diagnosis.

Xanthogranulomatous Pyelonephritis.

INTRODUCTION: Xanthogranulomatous pyelonephritis is a chronic destructive granulomatous inflammation of the kidney. This pathology was firstly described in 1916 and a small number of patient series were reported in the literature. In this study, we aimed to report the patients with xanthogranulomatous pyelonephritis in our nephrectomy cases. METHODS: The patients who underwent nephrectomy and were diagnosed with xanthogranulomatous pyelonephritis in our hospital database were reviewed retrospectively. Preoperative laboratory results, radiological imaging findings, patients' age and history of predisposing diseases were recorded. RESULTS: A total of 13 cases of xanthogranulomatous pyelonephritis treated in our hospital from January 2003 to December 2015 were included in the study, consisting of 7 male and 6 female patients with a mean age of 56 ± 16.09 years. In urine analyse, pyuria was positive in 6 patients (46.15%) and leukocytosis was detected in one patient (7.7%). The disease site was the right kidney in 4 patients (30.7%) and the left kidney in 9 patients (69.23%). Radiological findings of the patients were pyonephrosis, renal ectasia, pyelonephritis, hydronephrosis, renal tumor, xanthogranulomatous pyelonephritis and non-functioning kidney with renal calculi. All patients were treated by open surgical techniques and perioperative and postoperative complications did not occur. Partial and radical nephrectomy was performed in one patient and the other patients were treated with simple nephrectomy. CONCLUSION: Xanthogranulomatous pyelonephritis is an uncommon histologic variant of the kidney for patients who are surgically treated for pyelonephritis. Early diagnosis and treatment is very important for decreasing morbidity and mortality. Although radical surgery is the main treatment of choice for patients with diffuse xanthogranulomatous pyelonephritis, nephron sparing surgery is an alternative for patients who have the focal form, if technically possible.

Xanthogranulomatous pyelonephritis: clinical experience with 21 cases.

In this retrospective study, a review of the features of 21 recent cases of xanthogranulomatous pyelonephritis (XGP) is presented and compared with current published reports to improve the preoperative diagnosis. The clinical, laboratory, and radiological features, preoperative diagnoses, and operative methods of 21 patients with XGP were retrospectively reviewed. Mean age of the patients was 52.1 years; the female:male ratio was 2.5:1. All patients were symptomatic, and most common symptoms were flank pain and fever greater than 38 °C. The laboratory results showed anemia in 71.4% of cases, leukocytosis in 61.9%, and pyuria in 81.0%. In radiologic examinations, renal or ureter stone in 9 patients, hydronephrosis in 12 patients, a renal mass in 2 patients, and kidney enlargement in 9 patients were observed. For the patient who was suspected as having XGP before surgery, partial nephrectomy was performed; for 2 patients who were suspected as renal cell carcinoma, radical nephrectomy was performed; and for the remaining 18 patients, simple nephrectomy was performed. Among patients complaining of flank pain and fever, if the patients have a urinary tract infection and show the signs of anemia or leukocytosis and have staghorn calculi or a urinary tract obstruction and renal mass by radioactive examination, it is believed that the possibility of XGP should be considered.

Xanthogranulomatous pyelonephritis: critical analysis of 30 patients.

INTRODUCTION AND OBJECTIVE: Xanthogranulomatous pyelonephritis (XGP) is a chronic inflammatory condition of the kidneys. Nevertheless, disparities between the pre-operative and pathological diagnoses are frequently encountered. We reviewed all patients with XGP over a 17-year period to identify and characterize the pre-operative and pathological characteristics of the disease in our patients. METHODS: A comprehensive review of all nephrectomy patients with a pre-operative diagnosis of pyelonephritis at National Taiwan University Hospital from 1991 to 2008 with the pathological diagnosis of XGP was conducted to demonstrate the clinical and radiological characteristics of XGP. RESULTS: XGP was diagnosed in 30 (18.6%) of the 160 nephrectomies performed for pyelonephritis. Of the 30 patients with XGP, 25 were women (83.3%) and 20 (66.7%) were overweight (body mass index >23). Their mean age was 55.17 years. The average serum creatinine level was 1.68 mg/dL. The image findings included renal calculi (56.7%), staghorn stones (26.7%), and spread of the disease to the retroperitoneum and psoas muscle (33.3%). Escherichia coli (36.7%) was the most prevalent pathogen. The mortality of the two-stage surgical treatment was zero, and morbidity developed in only 1 patient (4.8%). CONCLUSION: The key to accurate pre-operative diagnosis is to keep risk factors in mind such as age, sex, and renal calculi. Clinicians should maintain a high suspicion of XGP for early recognition and be aware of the care of chronic kidney disease. Finally, the association between XGP and central obesity warrants further research.

[Xanthogranulomatous pyelonephritis: main imaging features]. / La pyélonéphrite xanthogranulomateuse: principaux aspects en imagerie.

Xanthogranulomatous pyelonephritis is a rare form of chronic pyelonephritis, which frequently has a pseudotumoral appearance, as a result of which differential diagnosis with malignant renal neoplasia is difficult, especially as there are no specific signs of this lesion. The aim of this article is to notice the various histological, clinical and radiological characteristics, and the different modalities of diagnostic and treatment of this affection.

Preoperative diagnosis of xanthogranulomatous pyelonephritis.

INTRODUCTION: The aim of this study was to evaluate the possibility of differentiating xanthogranulomatous pyelonephritis (XGPN) preoperatively from chronic pyelonephritis on the basis of demographic data, clinical parameters, and biochemical, microbiological, and radiological workups. MATERIALS AND METHODS: Between 1995 and 2005, a total of 239 patients were diagnosed to have pyelonephritis at our center, of which, 56 underwent nephrectomy. Forty-five (80.4%) of the nephrectomy specimens showed diagnosis of chronic pyelonephritis and 11 (19.6%) showed XGPN. RESULTS: Compared to chronic pyelonephritis, XGPN was more likely to occur in the middle-aged women (90.9%) with diabetes mellitus (63.6%). A positive history of UTI was more frequent in these patients, too. The disease was likely to present with flank pain and tenderness in 100.0% and 90.9% of the patients with XGPN, respectively. Anemia (81.8%), hematuria (81.8%), and bacteriuria (90.9%) were more frequent in these patients than in those with chronic pyelonephritis. The mean blood hemoglobin was 7.0 g/dL in the patients with XGPN. Proteus mirabilis was detected in 6 patients (54.5%) of the XGPN group and only 2 of the chronic pyelonephritis group (P < .001). Renomegaly and kidney calculus were more frequently noted in the patients with XGPN. Finally, XGPN led to a higher rate of postoperative complications. CONCLUSION: Demographic data, comorbidities, predisposing factors, and biochemical as well as roentgenological features are significant but nonspecific indicators of preoperative diagnosis of XGPN.

Xanthogranulomatous pyelonephritis: Analysis of 18 cases.

OBJECTIVE: To review and evaluate patients with a clinicopathological diagnosis of xanthogranulomatous pyelonephritis (XGP) with emphasis on the diagnostic methods and the effect of socioeconomic status on disease severity. METHODS: Data compiled from the previous history of the patients, clinical, laboratory, radioimaging findings, preoperative, operative, histopathological diagnosis and postoperative follow-up period were analysed. On the basis of presentation, XGP was classified as complicated and simple. RESULTS: There were 18 cases of XGP. The clinical characteristics included: calculi or obstruction in the urinary tract, and damage to the kidney, complication of urinary tract infection, anaemia, increased erythrocyte sedimentation rate and liver dysfunction. All patients had diffuse XGP. Associated pathological findings such as psoas abscess, nephrocutaneous fistula, renocolonic fistula and paranephric abscess were found in 33.3% of cases. Eleven of 14 patients (78.6%) who were evaluated by computed tomography (CT) had the correct diagnosis made prior to nephrectomy. Urine culture was positive in 88.9% of patients and Proteus mirabilis was the most common organism. CONCLUSION: Our experience with a small number of patients demonstrates that low socioeconomic status could be a risk factor in the development of complicated cases of XGP. CT is considered to be the best radiological test for correct preoperative diagnosis and evaluation of XGP. Nephrectomy and removal of all surrounding affected tissue proved to be curative for XGP.

[Magnetic resonance tomography of xanthogranulomatous pyelonephritis. Epidemiology, pathogenesis and symptoms]. / Magnetresonanztomographie der xanthogranulomatösen Pyelonephritis. Epidemiologie, Pathogenese und Erscheinungsbild.

Xanthogranulomatous pyelonephritis (XGP) is a rare chronic infection of the kidney. In this overview article we reevaluated the magnetic resonance imaging (MRI) findings of our four patients with histologically proven XGP and correlated them with the CT and ultrasound findings described in the literature. Additionally, we give an overview of the pathogenesis and epidemiology. The following criteria were found in MRI: hydronephrosis and/or urethral stricture, vesicoureteral reflux or neurogenic bladder depletion disorders, and calculus as the origin of urinary obstruction. Moreover, in contrast to normal pyelonephritis, XGP is accompanied by fatty deposits in the peripelvic parenchyma, which demonstrate contrast enhancement and form the typical so-called bear paw sign. As XGP is often accompanied by severe kidney failure, contrast-enhanced CT with nephrotoxic contrast agents should be avoided and MRI should be performed instead. Because of proven reduced nephrotoxicity of gadolinium chelates, MRI seems to be superior to CT in patients with suspected XGP. Essential for the correct diagnosis is consideration of the complete medical history including recurrent pyelonephritis to avoid malpractice.

Xanthogranulomatous pyelonephritis in childhood.

PURPOSE: Demographic data, clinical presentation, associated abnormalities, and radiologic findings were evaluated to outline diagnostic criteria that may lead to the diagnosis of xanthogranulomatous pyelonephritis in children. METHODS: Eleven boys and 8 girls with a mean age of 3.4 +/- 1.7 years were classified into obstructive xanthogranulomatous pyelonephritis (n = 13), which was associated with nephrolithiasis and nonobstructive (n = 6), which mimicked Wilms' tumor. RESULTS: Twelve children with obstructive diffuse involvement of the renal parenchyma, 1 with left-sided obstructive focal involvement in a horseshoe kidney (group 1), and 6 with nonobstructive diffuse xanthogranulomatous pyelonephritis (group 2) showed a male to female ratio of 1.2:1 and 2:1, respectively. Mean age was 4.1 +/- 1.2 years in group 1 versus 1.8 +/- 1.5 years in group 2; P =.001. The common features were renal mass, hematuria, and anemia (100%; P =.07) and leucocytosis (77% v 83%; P =.097). Main differences between the 2 groups were acute inflammatory syndrome (0 v 33%; P =.01), recurrent urinary infection (54% v 17%; P =.05), isolation of Proteus mirabilis as a pathogen (69% v 0; P =.001), and renal stones (100% v 0; P =.001). Preoperative diagnosis was accurate in all 13 (100%) children with obstructive xanthogranulomatous pyelonephritis. Radiologic features that were not consistent with Wilms' tumor in group 2 were absence of sharp definition and encapsulation of the mass, ill-defined margins with inflammatory infiltration of the perinephric fat and focal inflammatory tissue destruction. Nephrectomy was technically difficult because of extensive adhesions to the retroperitoneum, psoas muscle, and surrounding structures in both groups. CONCLUSIONS: Xanthogranulomatous pyelonephritis must be considered in the differential diagnosis of a child presenting with a renal mass, anemia, and elevated inflammatory markers. Treatment by nephrectomy is curative. J Pediatr Surg 36:598-601.

Xanthogranulomatous pyelonephritis in pediatric patients.

We observed xanthogranulomatous pyelonephritis in 5 of 27 nephrectomies (18.5%) performed for end stage pyelonephritis. Two patients were 5 months old or younger, of normal birth weight and the products of uncomplicated full-term pregnancies. In all cases clinical histories and findings were consistent with xanthogranulomatous pyelonephritis yet this diagnosis was suspected prospectively in only 1 case. Our observations, supported by recent literature, suggest that xanthogranulomatous pyelonephritis may occur more commonly than previously reported. In addition, the clinical and pathological expression of this process in the pediatric population appears to be no different from that in adults. The true incidence and presumed chronicity of this process need to be reevaluated in light of recent data.

Xanthogranulomatous pyelonephritis in children and adults--an 8 year study.

20 cases of Xanthogranulomatous Pyelonephritis (XPN) were encountered over an 8 year period, constituting 0.4 percent of the total of 47,370 surgical biopsies, 10 percent of the total of 188 nephrectomy specimens removed for various reasons and 35 percent of the nephrectomy specimens associated with chronic pyelonephritis. This is the largest single series, reported in Indian literature. 16 patients were adults and 4 were children, thus 25 percent of our cases were children, a significantly high proportion. Our youngest patient a 5 1/2 month old male, is to the best of our knowledge, the youngest case reported from India. Males predominated in our series, the M:F ratio being 3:1, this contrasts with western literature in which there is a definite female preponderance. The common presenting symptoms were lumbar pain, fever and palpable non-functioning kidney. 4 cases were complicated by cutaneous sinuses. There was a slight predominance of affectation of the left side over the right side. On gross examination, diffuse lesions were commoner than focal lesions and were seen in children as well. An accurate pre-operative diagnosis was made in only 2 cases, in the rest, the diagnosis was either tuberculosis or pyonephrosis. Thus XPN is quite frequently seen in the adult Indian population and is not as rare in children, as it was once thought to be.

Xanthogranulomatous pyelonephritis associated with renal cell carcinoma. Report on two cases and review of the literature.

Xanthogranulomatous pyelonephritis is a rare and particularly aggressive variant of chronic destructive pyelonephritis. Even when all modern diagnostic possibilities are exhausted, it is often not possible to distinguish xanthogranulomatous pyelonephritis from a renal cell carcinoma preoperatively. In clinical practice false diagnoses are therefore frequent. The coexistence of xanthogranulomatous pyelonephritis and renal cell carcinoma is extremely rare. We report 2 such cases. In 1 case surgery was performed on the kidney affected by xanthogranulomatous pyelonephritis using a renal sparing technique.

Xanthogranulomatous pyelonephritis--(a clinicopathological study of 15 cases)

The clinico-pathological features of 15 patients with xanthogranulomatous pyelonephritis (XGP) are described and the probable histogenesis is discussed. Based on our data and the review of literature, we believe that XGP should be regarded as a destructive and at times tumefactive inflammatory process that may complicate chronic pyelonephritis. The initiation of this process remains obscure, but the features commonly associated with XGP are pelvi-calyceal obstruction, ulceration of the pelvic urothelium with collection of necrotic material and bacterial infection.

Xanthogranulomatous pyelonephritis in children.

We report on a child with xanthogranulomatous pyelonephritis--an uncommon entity in children. A review of the literature revealed that in only 18 per cent was the diagnosis made correctly preoperatively. In children the disease is of a focal nature rather than a diffuse one, suggesting that possibly radical surgery would be less necessary for adequate treatment.