An update on sickle cell nephropathy.

Sickle cell disease (SCD) is a major health problem in many countries. Sickle cell nephropathy (SCN) is now a well-characterized entity with specific manifestations, risk factors and prognosis. The presence of sickled erythrocytes in the renal medullary vessels is the hallmark of the disease with a variety of renal complications. Renal manifestations of SCD include renal ischemia, microinfarcts, renal papillary necrosis and renal tubular abnormalities with variable clinical presentations. Proximal tubule dysfunction generally impairs urinary concentration, while more distal tubule dysfunction may impair potassium excretion, leading to hyperkalemia. Glomerular disease with proteinuria may develop due to ischemia and results in a compensatory increase in the renal blood flow and glomerular filtration rate; such hyperfiltration, combined with glomerular hypertrophy, probably contributes to glomerulosclerosis. Acute and chronic kidney disease are the expected outcomes of the disease. Both dialysis and kidney transplantation are effective renal replacement therapies for end-stage renal disease due to SCN, with a higher advantage for transplantation. Whether bone marrow transplantation in the early stage of the disease can halt the progression of SCN is unknown and awaits clinical studies.

Acute renal papillary necrosis with complete bilateral ureteral obstruction in a child.

A 9-year-old girl presented with apparent meningococcal septicemia and developed acute renal failure after 48 hours of treatment with antibiotics and analgesics. Early ultrasound scanning demonstrated mild bilateral hydronephrosis and hydroureter. Intravenous urography showed slow contrast uptake with delay nephrogram and no contrast entering the bladder. Repeat ultrasonography revealed bilateral papillary irregularity and echogenic debris in the distal ureters. Bilateral double-J stents were inserted cystoscopically, resulting in prompt polyuria and a return of normal renal function. Although rare, recognition of sloughed papilla in papillary necrosis causing ureteral obstruction can lead to early management with no long-term sequelae.

Renal papillary necrosis: review and comparison of findings at multi-detector row CT and intravenous urography.

Renal papillary necrosis is not a pathologic entity but rather a descriptive term for a condition--necrosis of the renal papillae--that has various possible causes. The renal medulla and papillae are vulnerable to ischemic necrosis because of the peculiar arrangement of their blood supply and the hypertonic environment. The etiology of renal papillary necrosis includes diabetes, analgesic abuse or overuse, sickle cell disease, pyelonephritis, renal vein thrombosis, tuberculosis, and obstructive uropathy. Renal papillary necrosis has been diagnosed with the use of intravenous urography and ultrasonography, but contrast material-enhanced computed tomography (CT) may better depict a full range of typical features, including contrast material-filled clefts in the renal medulla, nonenhanced lesions surrounded by rings of excreted contrast material, and hyperattenuated medullary calcifications. In the presence of papillary sloughing, CT may depict hydronephrosis and filling defects in the renal pelvis or ureter, which also may contain calcifications. During healing, the epithelialized papillary tip appears blunted. Shrinkage of the kidney, a common sequela, also may be detected at CT. Multi-detector row CT depicts these and other features more clearly and directly than single-detector row CT, given the advantages of thinner sections and multiplanar reformation, and it may help identify the condition at an earlier stage, when effective treatment can reverse the ischemic process. Familiarity with the CT features of the condition therefore is useful for its successful diagnosis and management.

[Emphysematous pyelonephritis with favourable outcome after conservative treatment]. / Une pyélonéphrite emphysémateuse d'évolution favorable après traitement conservateur.

Emphysematous pyelonephritis is a necrotizing renal infection characterized by bacterial gas production in the renal and perirenal area. It is a rare infection diagnosed in diabetic patients in most cases. Emphysematous pyelonephritis is responsible for a high mortality rate. We report the case of a woman, unknown diabetic, who presented with emphysematous pyelonephritis. Early diagnosis performed by CT-scan allowed effective and conservative surgical treatment and final positive outcome.

Emphysematous pyelonephritis: clues to rapid diagnosis in the Emergency Department.

Emphysematous pyelonephritis (EPN) is an acute life-threatening bacterial infection. EPN leads to rapid necrotizing destruction of the renal parenchyma and peri-renal tissue, requiring early and aggressive care to reduce morbidity and mortality. Previous studies have described the use of computed tomography scan and radiology-performed ultrasound to make the diagnosis of EPN We report a case of EPN diagnosed by bedside Emergency Department (ED) ultrasound performed by emergency physicians, allowing a more rapid diagnosis and subsequent treatment.

99mTc ethylene dicysteine scintigraphy for diagnosing cortical defects in acute pyelonephritis: a comparative study with 99mTc dimercaptosuccinic acid.

AIM: To evaluate the clinical usefulness of early cortical phase images in the diagnosis of acute pyelonephritis and to compare the measurements of differential renal function obtained by both 99mTc ethylene dicysteine (99mTc-EC) and 99mTc dimercaptosuccinic acid (99mTc-DMSA). METHODS: Forty-three children who had undergone both 99mTc-EC and 99mTc-DMSA studies within 5 days of acute infection were studied. Cortical images of 99mTc-EC were obtained by the sum of the renogram frames achieved between the first 60-120 s of the renogram study. DMSA and EC images were visually interpreted using four points of semiquantitative ratings: 0, normal; 1, mild hypoactivity; 2, moderate hypoactivity with partial loss of margins; 3, marked hypoactivity with loss of cortical margins. Values for the differential renal function were obtained for both studies. RESULTS: DMSA detected a total of 109 lesions in 36 patients and EC detected 90 lesions with a sensitivity of 82.5%. 99mTc-EC successfully detected moderate-to-severe cortical lesions but was less effective with mild lesions (sensitivity 60%). Bland-Altman analysis demonstrated good agreement among the results for differential renal function (95% CI -0.26 to 0.96). CONCLUSION: 99mTc-EC early phase images detected most of the cortical lesions. Its sensitivity depends on the severity of the lesions. EC provided reliable information in the estimation of differential renal function.

Clinics in diagnostic imaging (99). Left emphysematous pyelonephritis.

A 57-year-old woman, known to have diabetes mellitus, presented with a one-week history of fever, dysuria, and left flank pain. Computed tomography showed extensive left renal parenchymal destruction and a large gas collection. Urine culture revealed growth of Escherichia coli. The diagnosis of emphysematous pyelonephritis was confirmed at left nephrectomy. The clinical manifestations of emphysematous pyelonephritis, types of gas-forming renal infection, and their radiological findings are discussed.

Multiphasic helical CT diagnosis of early medullary and papillary necrosis.

PURPOSE: The feasibility of identifying early manifestations of renal papillary necrosis (RPN) and medullary necrosis (RMN) on multiphasic helical CT, leading to prompt treatment for the causative conditions, and its impact on reducing the incidence of late-stage RML and RPN, was investigated. PATIENTS AND METHODS: Sixty-eight patients (35 male, 33 female) aged 19 to 88 years were examined by multiphasic helical CT for complaints of microscopic hematuria (N=49), macroscopic hematuria (N=2), bacteriuria (N=45), pyuria (N=10), fever (N=15), and flank pain (N=27). Preenhancement, arterial corticomedullary, parenchymal, and excretory phase scans generated 1.25 to 7-mm-thick slices. Follow-up CTs were performed at 1 month (N=62) and 3 months (N=58). RESULTS: While the attenuation coefficients of areas suspect for RMN and RPN were similar on preenhancement CT, they differed substantially on the arterial corticomedullary phase (lesions 55 HU mean; normal medulla 120 HU mean) and parenchymal phase (lesions 58 HU mean, normal medulla 210 HU mean). Investigation for predisposing conditions identified diabetes in 18 patients, upper urinary-tract infections in 48, sickle-cell disease or trait in 17, urinary obstruction in 7, and cirrhosis of the liver in 1. On follow-up examinations, enhancement had normalized in 26 compromised areas of 14 patients at 1 month, and 47 areas (23 patients) at 3 months, remained stationary in 28 patients at 1 month and 9 at 3 months, and progressed in 20 at 1 and 26 at 3 months (P<0.001; Fisher's exact test). Patients (N=35) treated for underlying conditions causing ischemia showed reperfusion in 12 cases at 1 month and 20 at 3 months, while of the untreated patients (N=10), none showed reperfusion, and all lesions increased in size. CONCLUSIONS: Multiphasic helical CT is recommended for identification of RMN and RPN at a stage when effective treatment of underlying causative conditions can arrest or reverse the process of devascularization and prevent loss of medullary tissue.

Sonographic features of necrosed renal papillae causing hydronephrosis.

OBJECTIVE: To describe the sonographic appearance of ureteric obstruction due to necrosed papillae. METHODS: In this study, carried out over 3 years 6 months, patients with diabetes mellitus who had renal colic were studied by sonography. RESULTS: In 15 patients with hydronephrosis, there was a soft tissue mass of necrosed papillae filling the ureteric lumen at the site of obstruction. Necrosed papillae were seen in medullary cavities of the ipsilateral kidney in 5 patients. Ureteroscopic removal of necrosed papillae was done in 13 patients. One patient was not fit for an invasive procedure. CONCLUSIONS: When patients predisposed to renal papillary necrosis have renal colic, and sonography fails to show a ureteric calculus, it is best to look for necrosed papillae in the ureter, which may be causing obstruction.

[Renal papillary necrosis managed by transurethral procedures: a case report].

The patient was a 66-year-old female who had been commonly using an analgesic for rheumatism from age 40. She visited our hospital with the complaints of fever up and right flank pain. Right hydronephrosis and renal failure were pointed out, and she was referred to the urologic clinic. Retrograde pyelography showed a clubbed upper calyx and filling defect in the lower ureter. A ureter stent was positioned for drainage in the right ureter. Then her general state improved. Three weeks later, retrograde pyelography was performed again. Two filling defects were detected in the upper ureter. Since the obstruction persisted we observed the ureter by ureteroscopy. Two specimens black-brown in color and 8 mm in diameter were observed through the ureteroscope and were removed with a basket catheter. Histological examination of the specimens revealed necrotic transepithelial tissues. It was assumed that the tissues were derived from necrotic renal papilla. Four months later, a similar episode was observed in the left upper urinary tract. The same procedures were performed to manage the patient. In this case, drainage using a ureter stent was effective and conservative therapy was possible. This is the first reported case of renal papillary necrosis managed by transurethral procedures in Japan.