Viabahn stent for hemodialysis shunt: efficacy, long segment recanalization and prognostic factors for reintervention.

INTRODUCTION: The study evaluated the Heparin Bioactive Surface (HBS) Viabahn Stent (W.L. Gore & Associates, Flagstaff, Arizona) efficacy in the maintenance or re-establishment of hemodialysis. MATERIALS AND METHODS: Fifty HBS Viabahn stents deployed in 37 consecutive patients with hemodialysis dysfunction from January 2008 to May 2016 were evaluated in a single-institution retrospective review. Outcomes were stent patency intended as primary circuit patency (PP), assisted primary patency (APP), target lesion primary patency (TLPP) and secondary patency (SP). Moreover, the risk factor analysis for hemodialysis dysfunction that required reintervention was performed. A subgroup analysis was conducted to assess patency of Viabahn stent to treat peripheral venous long segment obstruction (LSO). RESULTS: Overall Kaplan-Meyer PPs were 60% at 12 months and 42% at 24 months. Overall TLPP estimated rates were 68% and 49% at 12 and 24 months, respectively. The corresponding SP rates were 85% and 78% at the same period. Estimated PP rates at 12 and 24 months for stent placement after peripheral venous long segment recanalization procedure were 53% and 31%, respectively. Corresponding SP rates were 82% and 68%, respectively. The APP rates were 79% at 12 months and 61% at 24 months. Female sex, access age and thrombosis were associated with reduced primary patency. CONCLUSIONS: Considering the high rates of PP, TLPP, APP and SP, Viabahn stents have been proven effective in maintaining or re-establishing the hemodialysis access. Moreover, stent placement after recanalization of LSO of venous out-flow represented a valid approach to rescue a dysfunctional fistula that would otherwise be abandoned.

Pemetrexed-induced acute kidney failure following irreversible renal damage: two case reports and literature review.

BACKGROUND: Pemetrexed (PEM) is a new-generation multitargeted antifolate agent with a demonstrated broad-spectrum activity in several types of human cancers, including non-small cell lung cancer (NSCLC) and mesothelioma. Major side effects include dose-limiting hematologic toxicities. PEM nephrotoxicity is well known; however, its frequency is considered to be low. CASE PRESENTATION: Here we report two cases of acute kidney injury (AKI) related to PEM administration (500 mg/m2) in patients with NSCLC. The first patient required hemodialysis treatment and was submitted to renal biopsy which showed acute tubular damage and interstitial edema without acute tubular necrosis. No other potential nephrotoxic agents were identified. The second patient developed AKI, not proven by biopsy and did not require renal replacement therapy. Both patients, on regular supplementation with folic acid and vitamin B12, concomitantly developed myelosuppression and even several months after PEM withdrawal, showed only a modest improvement of renal function. CONCLUSIONS: PEM is an antifolate antineoplastic agent with a broad-spectrum activity in locally advanced or metastatic NSCLC. It has been shown that PEM allows longer survival. The risk of acute or chronic kidney disease may be one of the prices to be paid for this success.

Rosuvastatin-induced acute interstitial nephritis.

We report a case of acute interstitial nephritis (AIN), most likely induced by rosuvastatin, in an 83-year-old male patient. The patient underwent angioplasty of the left internal carotid artery, after which he began a regimen of rosuvastatin (20 mg/day). After 3 weeks the patient was admitted to our unit for acute renal failure with mild proteinuria with negligible urinary sediment. A left kidney biopsy showed dense interstitial infiltrates, mainly composed of lymphocytes with evident tubulitis. Rosuvastatin withdrawal plus prednisolone (1 mg/kg/day) treatment, which was slowly tapered over a period of 4 weeks, allowed for a complete recovery of renal function. To our knowledge, this is the first case report of rosuvastatin-induced AIN. Acute renal failure is associated with a clear increase in morbidity, length of hospital stay and mortality. Moreover, since statins are among the most widely prescribed drugs in Western countries, we think that the risk of AIN should be taken into account as a possible side effect of rosuvastatin.

Lanthanum carbonate: a postmarketing observational study of efficacy and safety.

BACKGROUND: Hyperphosphatemia is associated with morbidity and mortality in hemodialysis patients. The use of calcium chelators is restricted by the risk of hypercalcemia and vascular calcifications. Sevelamer, a non-calcium chelator, is associated with risks of metabolic acidosis and poor compliance. Lanthanum carbonate is a non-calcium chelator not associated with these issues. However, accumulation in liver and bone has been a reason for concern. METHODS: Adult patients (n=112) from 9 hemodialysis centers, with serum phosphorus >5.5 mg/dL and on hemodialysis for >1 year, were selected to switch to lanthanum carbonate (mean dosage: 2,189 ± 491 mg/day); 103 completed the study. Laboratory assays for serum phosphate, calcium, parathyroid hormone, alkaline phosphatase, gamma-glutamyl transpeptidase (gammaGT), aspartate transaminase, alanine transaminase and plasma bicarbonate were performed monthly. Seven patients underwent a bone biopsy for evaluation of lanthanum bone content. RESULTS: Switching to lanthanum carbonate led to a reduction in mean serum phosphate levels (-18.2%; p<0.001) and calcium × phosphorus product (-17.6%; p<0.0001). There were no important changes in other variables, except for an increase in transaminases in 2 patients with preexisting liver disease, who discontinued therapy. An increase in plasma bicarbonate concentration was observed (p=0.001). Although some lanthanum was detected in bone, its distribution did not follow the mineralization front. CONCLUSIONS: Lanthanum carbonate is effective and well tolerated, provided that recipients do not have preexisting liver disease. After 8 months of treatment, lanthanum was not detected in the mineralization front of bone. In hemodialysis patients, lanthanum carbonate does not seem to be involved in metabolic bone disease.

Efficacy prospective study of different frequencies of Epo administration by i.v. and s.c. routes in renal replacement therapy patients.

BACKGROUND: The problem of pure red cell aplasia (PRCA) prompted nephrologists to revert to a wider intravenous (i.v.) utilization of erythropoeitin (Epo). Once weekly i.v. Epo administration has been suggested to be as effective as the twice/thrice weekly i.v. dose. The aim of the present study was to test whether once weekly i.v. Epo administration is equally as cost-effective as once weekly subcutaneous (s.c.) and 2-3 times weekly i.v. administration. METHODS: We prospectively studied 41 patients (23 males, aged 28-82 years), on renal replacement therapy for 18-286 months, stabilized on twice or thrice weekly s.c. Epo-alpha (basal). The patients were treated for three consecutive 6 month periods with once weekly s.c. (OWSC), once weekly i.v. (OWIV) and twice/thrice weekly i.v. (TWIV) Epo-alpha. The initial dose for each period was equal to the final dose of the previous one; when necessary, the dose was adjusted according to DOQY guidelines. Iron, folic acid and vitamin B(12) supplementations were given throughout all the study periods. At the end of each of the four study periods, the following parameters were evaluated: haemoglobin, haematocrit, hypochromic red blood cells (RBCs), iron, serum ferritin, transferrin, folate, vitamin B(12), C-reactive protein (CRP), Kt/V, parathyroid hormone (PTH) and weekly dose of Epo-alpha. RESULTS: Thirty-three out of 41 enrolled patients completed the study (there were five deaths, two renal transplants and one transfer). No significant changes were observed as regards iron, serum ferritin, transferrin, folate, vitamin B(12), CRP, Kt/V or PTH level. Haemoglobin levels were not different at the end of the basal (11.7+/-1.21), OWSC (11.8+/-0.86) and TWIV (12.1+/-1.04) periods, while significantly lower levels were observed after the OWIV period (11.0+/-0.97, P<0.01). Weekly Epo consumption (Epo U/week/kg body weight/g haemoglobin) was: basal 11.57+/-5.96; OWSC 10.22+/-4.53; OWIV 15.99+/-7.7*(a); and TWIV 11.89+/-6.3*(a) (*P<0.01 vs basal; (a)P<0.01 vs OWSC). CONCLUSIONS: From our results, the OWIV schedule seems to have less efficacy in the control of anaemia of chronic renal failure patients on dialysis treatment than either OWSC or TWIV schedules.