[Cephalic arch stenosis. Case report and literary review].

Dysfunctional AVF represents one of the leading causes of morbidity in the hemodialysis population, with venous stenosis-related dysfunction being the most common underlying problem. Cephalic arch is a well-known site for the development of stenosis, especially in patients with brachiocephalic fistulas. The pathophysiology of cephalic arch stenosis (CAS) is still being investigated and various contributing factors have been suggested. The treatment options for CAS are many and include angioplasty, endovascular stent insertion, access flow reduction and surgical interventions, but none of the current modalities are ideal. Therefore, the treatment of CAS is difficult, as the stenosis in this area tends to recur leading to the need for repeat angioplasty, stents or surgical revision. A 57-year-old woman undergoing hemodialysis (HD) through a right brachiocephalic arteriovenous fistula was found to have high venous pressure during HD and prolonged bleeding after HD. Clinical examination revealed a hyperpulsatile fistula suggestive of outflow obstruction. Doppler ultrasound examination showed cephalic vein thrombosis, severe outflow stenosis and juxta-anastomotic area. A 10 x 40 mm stent (Cordis Smart stent) was positioned appropriately in the cephalic arch and deployed, the stenotic lesion in juxta-anastomotic area was dilated with angioplasty balloon with improvement in flow. After 14 months, the fistula is still working perfectly with adequate flow.

[Acute kidney injury and rhabdomyolysis after cocaine overdose: case report and literature review].

Cocaine, a natural alkaloid derived from the coca plant, is one of the most commonly used illicit drugs. Cocaine abuse causes systemic adverse effects like stroke, myocardic infarction, arterial dissection, vascular thrombosis and rhabdomyolysis. Cocaine use is, also, associated with renal complications such as acute kidney injury, vasculitis, acute interstitial nephritis, chronic kidney disease, malignant hypertension with thrombotic microangiopathy. Acute kidney injury may or may be not associated to rhabdomyolysis. Rhabdomyolysis caused by cocaine abuse is multifactorial, involving tissue ischemia secondary to vasoconstriction and cellular damage caused by the drug. We report a 50-year-old man with history of chronic hepatitis C and substance abuse admitted to our unit with severe rhabdomyolysis and acute kidney failure after nasal insufflation of cocaine overdose. Renal function recovered after several treatments of dialysis. We conclude that cocaine adversely impacts kidney function ; in addition cocaine and rhabdomyolysis are the double danger for acute kidney injury. Medical management of cocaine toxicity requires a multisystem approach, with close monitoring cardiac, neurological and renal function.

Crossed fused renal ectopia: case report and review of the literature.

Crossed fused renal ectopia is a rare congenital anomaly, and is mostly detected incidentally. A 45-year-old man, during investigation for recurrent abdominal pain, was found to have an empty left renal fossa and right crossed renal ectopia with fusion on ultrasonography. In the present case, there were no abnormalities and/or alteration of the renal function. Abdominal tomography scan with contrast medium confirmed the diagnosis. Ectopic kidney is often associated with other abnormal situations such as agenesis, vascular malformation, incontinence, a palpable abdominal mass, urinary tract infection, high incidence of stone formation, and genital anomalies. Through this case report, we emphasize the importance of adequate imaging.

Echo color Doppler ultrasound: a valuable diagnostic tool in the assessment of arteriovenous fistula in hemodialysis patients.

A functioning vascular access is a critical requirement to improve the quality of life in hemodialysis patients, so monitoring and surveillance of vascular access play key roles in identifying all dysfunctions and reducing the huge economic cost as well as adequacy of dialysis.In our five-year experience, a study protocol has been used and improved with the help of ultrasonography.Doppler ultrasound is an excellent and sensitive modality for hemodialysis access evaluation, one of techniques employed for arteriovenous fistulae (AVF) study, not only as a preoperative tool, but also in post-operative monitoring of AVF maturation. In addition, the current guidelines recommend AVF surveillance by access blood flow measurement and the correction of hemodynamic stenosis in order to prolong access survival. Doppler ultrasound is readily available, directly used by nephrologists, non-invasive, safe, inexpensive, reproducible, although it requires more clinical skill and time to perform and proper equipment. Ultrasonography imaging can substantially reduce the number of subsequent invasive angiographic procedures. In our opinion, Doppler ultrasound should have a crucial place in the interdisciplinary cooperation in AVF monitoring and it should be included as part of an integrated vascular access management program.

[Lactic acidosis, acute renal failure and heart failure during treatment with metformin: what do we know?]. / Acidosi lattica, insufficienza renale acuta e insufficienza cardiaca in corso di terapia con metformina: cosa sappiamo?

Metformin is a common medication used for the treatment of type 2 diabetes, especially in obese subjects. Clinical studies show that, in addition to the lowering effect of blood glucose, metformin reduces cardiovascular risk, does not induce weight gain and additionally, provides a unique safety strategy and efficacy in patients with diabetes and heart disease. However, this treatment is not without risks. The most feared metabolic complication is lactic acidosis that often occurs with complex and severe clinical symptoms and is associated with a high mortality risk. We detail our experience, during one year, regarding four patients with diabetes treated with metformin who developed such acute renal failure and lactic acidosis as to require hemodialysis treatment. The patients selected had previous normal renal function but a history of serious cardiovascular disease (hypertensive cardiomiopathy, ischemic revascularized and/or dilated, chronic obstructive arterial disease). We observed in all four of our patients an onset of non-related symptoms (fever, fatigue, vomiting and gastrointestinal disorders), a rapid deterioration in renal function, anuria and very high levels of lactic acid. In two patients we found acute pancreatitis. In addition to rehydration therapy, hemodialysis was started instantly with progressive rebalancing of the biohumoral status, effective recovery of spontaneous diuresis and improvement of the clinical status in three patients. Unfortunately, we had a failure during the initial hours of ward admittance, with an important clinical situation complicated by acute cardiac ischemia, abnormal heart rhythm, ending in death. Our experience provides us with elements to reflect on. Lactic acidosis is a serious metabolic disorder because it is associated with a high mortality risk. So a rapid diagnosis and a complete recognition of all the fundamental elements are important for its management. Starting hemodialysis early and prolonged treatment can solve complicated clinical status, correct acidosis and restore kidney function in patients with serious comorbidity.