Revascularization versus medical therapy for renal artery stenosis: antihypertensive drugs and renal outcome.

Endovascular procedures may play a role in renal artery stenosis (RAS) treatment in attempt to preserve renal function and improve hypertension control. We determined renal outcome and the incidence of restenosis in patients with RAS treated with renal percutaneous transluminal angioplasty and stenting (RPTAs) and medical therapy versus patients with RAS treated only with medical therapy. We performed an observational study based on 93 patients with RAS. In all, 53 patients underwent RPTAs in association with medical therapy and 40 patients were only treated pharmacologically. In patients receiving RPTAs, a better renal outcome, a decrease of restenosis rate, and systolic-diastolic blood pressure were associated with angiotensin receptor blockers (ARBs) + angiotensin-converting enzyme inhibitors (ACE-is) therapy. In patients treated with medical therapy alone, renal improvement was related to ARBs in association with BBs (ß-blockers; P < .0001). This study suggests that medical therapy may exert beneficial effects in patients with RAS.

Nephroangiosclerosis and its pharmacological approach.

Nephroangiosclerosis (NAS) is a major cause of progressive renal insufficiency. Hypertension is very important in the causation of NAS but other factors such as race, age, metabolic variables, and genetics play a pathogenic and prognostic role. A multifactorial treatment strategy, including antihypertensive, lipid-lowering and anti-platelet agents, could improve cardiovascular and renal outcomes in patients with vascular nephropathy.

[The risk of bleeding associated with low molecular weight heparin in patients with renal failure]. / Rischio emorragico nell'utilizzo di eparina a basso peso molecolare nel paziente nefropatico?

Cardiovascular mortality and morbidity are higher in patients with chronic renal disease than in the general population. Patients with chronic renal disease are in the highest risk group for thromboembolic disease and many clinical trials have demonstrated the greater safety and efficacy of low-molecular-weight heparin (LMWH) versus unfractionated heparin (UFH). LMWH is cleared only by the kidneys while UFH is cleared by the renal and hepatic routes. Furthermore, LMWH has a significant accumulative effect in patients with impaired renal function (creatinine clearance <30 mL/min). The aim of this study was to evaluate the risk of bleeding when LMWH is used as an anticoagulant in hemodialysis or for treatment of acute thromboembolic disease in patients with renal failure. Twenty-one adult patients were enrolled, 13 with end-stage renal disease requiring chronic hemodialysis and 6 with acute thromboembolic disease and severe renal insufficiency (creatinine clearance <30 mL/min). Group A consisted of 13 patients receiving LMWH (enoxaparin 60 IU/kg/day) for preventing thrombosis of the extracorporeal dialysis circuit. Group B consisted of 8 patients with acute thromboembolic disease receiving LMWH (enoxaparin 60 IU/kg/day). In all patients anti-Xa activity was measured by a chromogenic assay (HEMONOX). In the first group 2 blood samples were taken during the dialysis session (2-4 hours) and a third sample after the end of the session up to 48 hours following enoxaparin injection; in the second group a blood sample was taken 4 days after the start of LMWH treatment, 2 hours after its daily administration. In group A, all dialysis sessions were performed with no minor or major bleeding. Anti-Xa activity was highest 2 hours after the start and remained above 100 seconds after the end of the session, while 44 hours after injection, at the start of the next dialysis session, it was low or absent (<100 seconds). In the second group there were 2 major bleeding episodes, 2 minor bleeding episodes, 1 prolonged time to hemostasis after needle removal, and 2 bleeding episodes at the vascular access site (central venous catheter). Anti-Xa activity was consistently higher than 200 seconds (therapeutic target range:100-200 seconds) and showed interindividual variability (in 2 patients the anti-Xa time was more than 900 seconds), indicating a high risk of bleeding. LMWH seems to be as effective and safe as UFH in terms of bleeding complications and in preventing extracorporeal circuit thrombosis in patients on hemodialysis. Our results indicate that it is preferable to avoid invasive procedures for 12 hours following a dialysis session performed with LMWH anticoagulation because the anticoagulant effect lasted at least 4 hours after its injection. These data suggest that in patients with acute thromboembolic events and severe renal insufficiency, standard anticoagulation with LMWH is not recommended because of an increased risk of major and minor bleeding.

Ischemic nephropathy: proteinuria and renal resistance index could suggest if revascularization is recommended.

BACKGROUND: The aim of endovascular therapy in renal artery stenosis (RAS) is to preserve renal function and have a better hypertension control. The purpose of our study was to determine which biochemical and instrumental parameters could predict a better renal outcome in patients with RAS treated with percutaneous transluminal angioplasty and stenting (RPTAS). METHODS: We performed an observational study based on 40 patients with RAS who met the following criteria before revascularization: urinary protein excretion of over 250 mg/24 h, normal renal function, and/or mild-moderate renal insufficiency (I, II, and III levels of classification of chronic kidney disease, K-DOQI). RESULTS: Assessment at 12 months after RPTAS showed in 20 patients (Group A) that proteinuria serum creatinine (Scr) and creatinine clearance (CrCl) significantly worsened from the baseline; whereas in 20 patients (Group B) proteinuria remained unchanged and the renal function improved after the procedure. CONCLUSIONS: In our study, the decline of renal function after RPTAS is associated with an elevated renal resistance index (RI) in both kidneys (0.83 ± 0.2) and preexisting proteinuria.

Antiphospholipid antibodies and renal involvement.

Antiphospholipid antibodies are a heterogeneous group of autoantibodies associated with the hypercoagulable state affecting all vascular districts with thrombosis named antiphospholipid syndrome (APS). APS is an autoimmune disease with multifactorial etiology that includes cellular, molecular, genetic and pathogenic mechanisms. The APS clinical features are a combination of arterial and/or venous thrombosis, hematological events, recurrent fetal losses, neurological disorders and intra-abdominal manifestations. The renal involvement is associated with both primary and secondary APS. Clinical features include hypertension, renal artery stenosis, thrombotic microangiopathy and other histological manifestations of the nephropathy (APSN), venous renal thrombosis, APSN in the course of systemic lupus erythematosus and renal failure. APSN is an independent risk factor that should be included in the classification criteria for definite APS with characteristic clinical and histological features.

In-stent restenosis of the renal artery in a single kidney patient: the role of ACEI in the therapeutic choice.

Renal artery stenosis (RAS) caused by atherosclerotic changes of the renal arteries has become a concern as a cause of end-stage renal failure. Percutaneous balloon angioplasty with or without endovascular stenting is an increasingly accepted procedure at the expense of classical approaches such as aortorenal bypass and other types of surgery. Renal percutaneous transluminal angioplasty and stenting (RPTAS) represent the first therapeutic choice; however, there is doubt regarding the satisfactory long-term outcome for primary RPTAS. Currently, there is no clear evidence whether or not RPTAS prevents further progressive renal function decline because comparisons between interventional randomized studies and medical therapy are still lacking. Despite the fact that the use of angiotensin-converting enzyme inhibitors (ACEIs) may be a potential cause of acute renal failure, clinical data suggest that ACEI therapy is associated with better survival in patient with RAS. In our case, the use of ACEIs has been fundamental for the indirect evaluation of restenosis degree and RPTAS.

Multiple steno-obstructive vascular lesions and femoral superficial artery dissection in a young Caucasian male with antiphospholipid syndrome.

A young Caucasian male was admitted for claudication intermittens, hyposphygmia on the right lower limb, high blood pressure and deterioration of renal function. Instrumental investigations documented right renal artery stenosis, multiple steno-obstructive manifestations of the splanchnic artery system, occlusion of the right external iliac artery and dissection of the left superficial femoral artery. The patient had not been previously diagnosed with antiphospholipid syndrome. Subsequently, the vascular lesions, because of his thrombophilic state, needed endovascular treatment and anticoagulant therapy.