Search

Validation studies are prerequisites for computational fluid dynamics (CFD) simulations to be accepted as part of clinical decision-making. This paper reports on the 2011 edition of the Virtual Intracranial Stenting Challenge. The challenge aimed to assess the reproducibility with which research groups can simulate the velocity field in an intracranial aneurysm, both untreated and treated with five different configurations of high-porosity stents. Particle imaging velocimetry (PIV) measurements were obtained to validate the untreated velocity field. Six participants, totaling three CFD solvers, were provided with surface meshes of the vascular geometry and the deployed stent geometries, and flow rate boundary conditions for all inlets and outlets. As output, they were invited to submit an abstract to the 8th International Interdisciplinary Cerebrovascular Symposium 2011 (ICS'11), outlining their methods and giving their interpretation of the performance of each stent configuration. After the challenge, all CFD solutions were collected and analyzed. To quantitatively analyze the data, we calculated the root-mean-square error (RMSE) over uniformly distributed nodes on a plane slicing the main flow jet along its axis and normalized it with the maximum velocity on the slice of the untreated case (NRMSE). Good agreement was found between CFD and PIV with a NRMSE of 7.28%. Excellent agreement was found between CFD solutions, both untreated and treated. The maximum difference between any two groups (along a line perpendicular to the main flow jet) was 4.0 mm/s, i.e. 4.1% of the maximum velocity of the untreated case, and the average NRMSE was 0.47% (range 0.28-1.03%). In conclusion, given geometry and flow rates, research groups can accurately simulate the velocity field inside an intracranial aneurysm-as assessed by comparison with in vitro measurements-and find excellent agreement on the hemodynamic effect of different stent configurations.

Stimulated by a recent controversy regarding pressure drops predicted in a giant aneurysm with a proximal stenosis, the present study sought to assess variability in the prediction of pressures and flow by a wide variety of research groups. In phase I, lumen geometry, flow rates, and fluid properties were specified, leaving each research group to choose their solver, discretization, and solution strategies. Variability was assessed by having each group interpolate their results onto a standardized mesh and centerline. For phase II, a physical model of the geometry was constructed, from which pressure and flow rates were measured. Groups repeated their simulations using a geometry reconstructed from a micro-computed tomography (CT) scan of the physical model with the measured flow rates and fluid properties. Phase I results from 25 groups demonstrated remarkable consistency in the pressure patterns, with the majority predicting peak systolic pressure drops within 8% of each other. Aneurysm sac flow patterns were more variable with only a few groups reporting peak systolic flow instabilities owing to their use of high temporal resolutions. Variability for phase II was comparable, and the median predicted pressure drops were within a few millimeters of mercury of the measured values but only after accounting for submillimeter errors in the reconstruction of the life-sized flow model from micro-CT. In summary, pressure can be predicted with consistency by CFD across a wide range of solvers and solution strategies, but this may not hold true for specific flow patterns or derived quantities. Future challenges are needed and should focus on hemodynamic quantities thought to be of clinical interest.

Acute renal failure that is associated with macroscopic hematuria (ARF-MH) is a widely known complication of IgA nephropathy (IgAN). Although spontaneous recovery of renal function after cessation of MH has been described, no long-term outcome studies have been performed. The outcome of patients who had biopsy-proven IgAN and presented an ARF-MH episode in the period 1975 through 2005 was studied. Thirty-six episodes of ARF-MH that occurred in 32 patients were identified. A complete recovery of baseline renal function after cessation of MH was observed in 27 (group 1); in the remaining nine episodes (25%; group 2), estimated GFR (eGFR) did not reach the baseline value. Final eGFR was 89 +/- 28 ml/min per 1.73 m(2) in group 1 patients and 38 +/- 12 ml/min per 1.73 m(2) in group 2 patients (P = 0.0005). The duration of MH was significantly longer in group 2 patients: 33.7 +/- 25.3 versus 15.4 +/- 18.4 d (P = 0008). A high proportion of tubules that were filled by red blood cell casts and had signs of acute tubular necrosis were the most striking histologic abnormalities. In conclusion, a significant proportion (25%) of ARF-MH in IgAN did not recover the baseline renal function after the disappearance of MH. Duration of MH longer than 10 d, age >50 yr, decreased baseline eGFR, absence of previous episodes of MH, and the severity of tubular necrosis were significant risk factors for an incomplete recovery of renal function.

Background: The age limit of the cadaver kidney donors is increasing in response to the growing demand for renal transplantation. Simultaneous double kidney transplantation (SDKT) with kidneys obtained from elderly adults has been proposed to increase the transplantation number and improve its results. However, if SDKT is performed when there are no clear indications, a negative effect could be produced on the total number of transplanted patients as both kidneys would be used for only one recipient., Material and Methods: In December 1996 we designed a transplantation protocol to be able to extend the selection of cadaver kidney donors with normal serum creatinine levels without establishing any age limit. A pregraft renal biopsy was always performed to analyze the glomerulosclerosis (GE) percentage whenever the donors were 60 years of age or older. A SDKT was performed in a single recipient when the donor age was 75 years or older or when the donors between 60 and 74 years old had a GE rate of more than 15%. On the contrary, a single kidney transplantation was performed in two different recipients for kidneys from donors between 60 and 74 years of age with a GE rate of less than 15%. Kidneys having GE rates of more than 50% were discarded for transplantation. Donor kidneys from subjects younger than 60 years of age were always used for a single kidney transplantation., Results: Based on the above mentioned protocol, from December 1996 to May 1998, 181 patients received a kidney transplantation in our hospital. These patients were divided into three groups: group I which included the SDKT recipients (n=21), group II or single kidney recipients from 60- to 74-year-old donors (n=40), and group III or recipients from <60-year-old donors (n=120). The mean follow-up time was 15+/-5 months (range 6-24). Mean donor age was 75+/-7 years in group I, this was significantly higher than in group II (67+/-4, P<0.001) and group III (37+/-15, P<0.001). The primary nonfunction rate was low in the three groups, there being no statistically significant differences (5, 5, and 4%, respectively). A significantly greater percentage of patients from group I (76%) presented immediate renal graft function as compared with group II (43%, P<0.01) and III (50%, P<0.05). The acute rejections rate was very low in all three groups (9.5, 7.5, and 22%, respectively) with significant differences between groups II and III (P<0.05). No significant differences between the different groups were observed for one year actuarial patient survival (100, 95, and 98%, respectively) or graft survival rates (95, 90, and 93%, respectively). The 6-month serum creatinine levels were excellent in the three groups, although there were significant differences between groups I and II (1.6+/-0.3 vs. 1.9+/-0.6 mg/dl, P<0.05), II and III (1.9+/-0.6 vs. 1.4+/-0.4 mg/dl, P<0.001), and I and III (P<0.05)., Conclusions: Simultaneous double kidney transplantations make it possible to use kidneys from extremely elderly donors (>75 years) or those whose GE>15%. In addition, kidneys from donor 60-74 years old in which the GE<15% can be used for single kidney transplantations in two different recipients with excellent results.

Background: Hepatitis C virus (HCV) infection has been described in association with various types of glomerular diseases, usually type I membranoproliferative glomerulonephritis and rarely membranous glomerulonephritis (MGN). In this article, we describe the first series of MGN exhibited in renal transplant patients and associated with HCV infection., Methods: From January 1980 to December 1994, 2045 kidney transplantations were performed in our renal transplant units. A retrospective analysis demonstrated an overall 20% prevalence of HCV virus-positive patients; 409 transplanted patients were HCV positive (ELISA and RIBA)., Results: Fifteen patients developed an allograft MGN (3.66%) 24 months after renal transplantation. MGN appeared in the form of significant proteinuria (>1.5 g/24 h) with stable renal function. In all cases, graft biopsy demonstrated a thickening of the capillary wall, subepithelial electron-dense deposits, and IgG and C3 diffuse granular deposits along the basal membrane. Ten cases were considered de novo, two cases were considered recurrent MGN, and three cases were considered undetermined because the primary renal disease was chronic glomerulonephritis. All patients showed negative antinuclear antibodies and cryoglobulins, normal complement, and negative rheumatoid factors. During follow-up (an average of 2 years), 12 patients developed a progressive worsening of renal function, with increased serum creatinine and persistent proteinuria; 8 of the 12 patients returned to dialysis. Of the remaining three cases, two patients showed partial remission of nephrotic syndrome after high doses of steroids, and one patient persisted with stable renal function and proteinuria (<2 g/24 h.)., Conclusions: In summary, HCV is preferentially associated with MGN in renal transplant patients, rather than with membranoproliferative glomerulonephritis as in the normal adult population. MGN associated with HCV infection has a similar clinical picture and outcome to posttransplant idiopathic de novo MGN, with persistent massive proteinuria and progressive deterioration of renal function.

The first well-documented case of recurrent type III membranoproliferative glomerulonephritis after kidney transplantation is reported in this article. A 48-year-old man was admitted to the hospital because of nephrotic syndrome and moderate renal failure. The renal biopsy showed double-contour images at light microscopy. Electron microscopy revealed electron-dense deposits in the mesangium and in both the subepithelial and subendothelial sides of the basement membrane. Subepithelial deposits were sometimes hump-like and produced an irregular disruption of the lamina densa. A diagnosis of type III membranoproliferative glomerulonephritis was suggested. The patient had a rapid decrease in renal function and received dialysis in 3 months. Three years later, he received a cadaveric kidney transplant, and subsequently recovered normal renal function. Proteinuria appeared after 13 months, and a biopsy of the graft demonstrated recurrence of the original disease. Seven years after transplantation, he returned to hemodialysis.

Malacoplakia is a chronic inflammatory disease the etiology of which remains obscure. It has a very low incidence and affects primarily the genitourinary tract, although it has been described in some other organs. This paper presents a historic insight of the clinical cases diagnosed in this centre, and includes a review and update of several issues related to this entity such as pathogenesis, pathological anatomy and treatment. Also, the peculiarities related to the involvement of each separate organ with regard to diagnosis, prognosis and treatment are described.

To analyze the long-term outcome in patients with silent lupus nephritis, we retrospectively studied 20 patients with systemic lupus erythematosus without clinical renal involvement who had renal biopsies in our unit between 1978 and 1986 and reviewed 193 cases reported between 1957 and 1995. Two patients of the current series were lost to follow-up. Mean follow-up in the other 18 was 13 +/- 3 years (range, 2 to 17). On kidney biopsy, nine had class I, six class II, one class IV, and two class V disease (WHO classification). Three patients with prior normal renal function died of nonrenal causes. During the study, the remaining 15 patients had normal renal function and urinalysis. Most patients from the literature had "mild" histologic lesions, but 30 had diffuse proliferative glomerulonephritis. Over an average of 46 months of follow-up from biopsy, renal survival rate and patient survival rate were 98% and 91%, respectively. Three patients died of end-stage renal failure. In conclusion, end-stage renal failure in patients with silent lupus nephritis is rare regardless of the histopathological renal lesions. Patients survival depends on nonrenal causes.

Granulomatous prostatitis is an inflammatory condition of the prostate which presents rarely in the urological practice. It is caused by several specific and unspecific infectious agents, and can also be secondary to prostate surgery or a local reflection of a systemic granulomatous disease. With regard to clinical manifestations and treatment, it is an unspecific entity which has a characteristic histopathology. Its major interest consists on the possibility of it being mistaken for a prostate cancer during physical examination. This paper reviews a series of 7 granulomatous prostatitis, with special emphasis on their histology and ultrasound findings.

Renal cell carcinoma (RCC) is an uncommon tumour with high mortality mainly due to late diagnosis. The various morphological variables and the clinico-pathological stage, however, induce highly different evolutions. Awareness of these characteristics would be a significant part of deciding the most appropriate therapy for each case. The pathological anatomy of 130 renal cell carcinomas obtained through nephrectomy was reviewed. A follow-up of at least 5 years was done in 121 patients. Also, a survival study related to the various clinical and pathological parameters was carried out. A significantly lower survival rate was observed for solid tumours with spindle or giant cells and nuclear degrees superior to 2, over 10 mitosis in 10 fields and staging higher than II. A significant correlation was also found between number of mitosis and staging, presence of metastatic disease, survival interval, degree of tumoral necrosis, histological type, cell type and nuclear grade. Our results indicate that staging, histological type, cell type, microscopic vascular infiltration, nuclear grade and number of mitosis can be highly predictive of the evolution and prognosis of RCC patients.

From a series of 333 renal biopsies examined by immunofluorescence microscopy, 231 specimens corresponded to primary glomerulonephritis unassociated with systemic diseases. Of those 231 biopsies, 39 had diffuse mesangial deposits of IgA (16.8%). Thirty cases of IgA nephropathy had one to several glomeruli in the Epon-embedded tissue. All cases showed mild to moderate increase of mesangial cells and matrix. Mesangial deposits were present in all cases; subendothelial (5/30), intramembranous (3/30), and subepithelial (10/30) deposits wee also found. Occasional dense granular deposits involved the basement membrane of the capsule of Bowman (1/30) and the subendothelial region of some extraglomerular arterioles (2/30). Thinning (6/30) and splitting (4/30) of the glomerular lamina densa appeared focally in some cases.

Idiopathic mesangial glomerulonephritis with IgA deposits was observed in two relatives, father and son, in a family of 5 members. In the father the disease started at age 43 with relapsing macroscopic hematuria, proteinuria, renal failure and hypertension, with a progressive course in the ensuing four years. The affected son, the oldest of three brothers, developed relapsing macroscopic hematuria at age 16; two years later renal function was normal and there was no hypertension, but microhematuria persisted without proteinuria. The mother and the other two brothers had no clinical or biological signs of renal disease. Serum immunoglobulins (IgG, IgA, and IgM) and complement (C3, C4, C3 proactivator) were normal in the patients and their relatives. Histocompatibility typing demonstrated the presence of HLA-Bw35 in the father and the two unaffected sons, being negative in the mother and the affected son. The analysis of HLA-Bw35 in 23 patients with IgA mesangial glomerulonephritis gave positive results in 30% of them, while the control group had a positivity of 15% (p non significant with the X2 test). The present observations suggest that IgA mesangial glomerulonephritis is a potentially familial and hereditary renal disease. HLA-Bw35 antigen appears not to be a genetic marker of the disease in our geographical area.

Three episodes of acute renal failure, all of them requiring hemodialysis, were observed in two patients. The renal biopsy specimens showed a massive periglomerular granulomatosis with crescentic glomerulonephritis. With cyclophosphamide therapy, a dramatic improvement in renal function was observed in both patients. Although the histologic findings and the response to cyclophosphamide therapy were characteristic of Wegener's granulomatosis, there was no evidence of respiratory involvement or extrarenal manifestations throughout the patients' clinical course. We think that these cases could represent limited forms of Wegener's granulomatosis with exclusive renal involvement.

In May 1981, a massive intoxication of people who had ingested adulterated cooking oil took place in Madrid and nearby provinces. Although the patients presented, in the first phase of the disease, with acute respiratory illness, later on thromboembolic complications, severe neuromuscular involvement, and scleroderma-like cutaneous lesions appeared. Kidneys were apparently spared; however, 4 out of 842 admitted patients developed glomerulonephritis; kidney biopsies revealed glomerular, vascular, tubular, and interstitial changes. Cases 1 and 3 had diffuse proliferative endocapillary glomerulonephritis; case 2 had diffuse membranoproliferative glomerulonephritis; and case 4 had diffuse extracapillary glomerulonephritis. Three cases had vascular lesions characterized by degenerative and proliferative endothelial changes, intimal foamy macrophages, and partial or complete obliteration of the vascular lumen by concentric myxoid fibrosis. There were signs of necrosis of tubular epithelium along with edema and lymphocytic and eosinophilic interstitial infiltration. Two out of 22 autopsies had segmentary glomerulonephritis, and 17 out of 22 autopsies showed renal vascular lesions.

We have studied ten normotensive patients (nine male and one female, aged between 28 and 51 years) who each had a solitary functioning kidney and proteinuria. Six had undergone unilateral nephrectomy, and four unilateral renal agenesis. In each case, intravenous pyelography revealed only one functioning kidney with compensating hypertrophy. Mild to moderate chronic renal failure was present in six, and microhematuria in two. Proteinuria ranged from 1.10 to 4.10 g/24 hr, being in the nephrotic range in three patients. In seven patients, a renal biopsy showed focal glomerulosclerosis. Immunofluorescence studies demonstrated granular deposits of IgM in three and C3 in six cases, over the sclerotic areas. We suggest that the appearance of proteinuria and focal glomerulosclerosis in a patient with a solitary kidney could be due to chronic glomerular hyperfiltration.

We report the twentieth case in the world literature of testicular malacoplakia. This lesion occurs mainly in middle-aged men, appearing clinically as epididymo-orchitis or enlargement of the testicle with fibrous consistency and some soft areas. Malacoplakia is now considered a nonspecific inflammatory granulomatous lesion subsequent to an infection by gram-negative bacteria. In our case Escherichia coli was cultured in the urine and testicular tissue. The ultrastructural study shows the histiocytic nature of the cellular infiltrate as well as the morphology of Michaelis-Gutmann bodies. Bacilliform structures were not found. The cellular and humoral immunological studies did not show alterations.