The new frontier in endovascular treatment of arteriovenous fistula stenosis: the role of ultrasound-guided percutaneous transluminal angioplasty

Abstract

Native arteriovenous fistula is the preferred vascular access because of it does not usually cause infections and seems to be closely related with prolonged patient survival, compared to prosthetic grafts and central venous catheters; it also is cost effective. Venous stenosis is one of the main causes of AVF failure. It is caused by a number of upstream and downstream events. The former group comprises hemodynamic and surgical stressors, inflammatory stimuli and uraemia, while downstream events involve the proliferation of smooth muscle cells and myofibroblasts and the development of neo-intimal hyperplasia. Percutaneous transluminal angioplasty is the gold standard for arteriovenous fistula stenosis. It allows the visualization of the whole vascular circuit and the immediate use of the vascular access for the next dialysis session. Ultrasound-guided percutaneous endovascular angioplasty is a feasible and safe alternative to conventional fluoroscopic technique: it is equally effective in treating arteriovenous fistula stenosis, but it presents the advantage of not using contrast media or ionizing radiation. The aim of this review is to report the latest evidence on cellular and molecular mechanisms that contribute to the development of neo-intimal hyperplasia, as well as the current and future therapeutic perspectives, especially concerning the use of anti-proliferative drugs, and the efficacy of the ultrasound-guided angioplasty in restoring and maintaining the vascular access patency over time.

Key words: Percutaneous angioplasty, ultrasound, arteriovenous fistula, hemodialysis, stenosis.

Sorry, this entry is only available in Italian.

Retroperitoneal renal hemorrhage: experience of our dialysis center

Abstract

The aging of the uremic population, the increasingly common use of anticoagulants, antiplatelet agents e heparin, during hemodialysis, can expose our patients to a greatest risk of bleeding. Spontaneous retroperitoneal hematomas are a fairly rare and potentially fatal condition.
We describe 5 clinical cases of retroperitoneal hemorrhage that we observed during 10 years in our department, focusing on modalities of symptom onset, clinical-laboratory picture and treatment modalities

Keywords: Retroperitoneal hemorrhage, hemodialysis

Sorry, this entry is only available in Italian.

Microbiological quality of hemodialysis water: what are the risk factors?

Abstract

Background A dialyzed patient weekly gets in touch with a large amount of water (on average 350 liters) through the dialysis bath. It is therefore essential that this solution would have a high quality and purity. The aim of our study was to monitor the microbiological quality of the hemodialysis water in order to identify possible factors that could affect it.

Methods We conducted a cross-sectional study from January 2015 to October 2017 collecting the dialysis water in AOU Careggi. Samples were aseptically collected by specialized technicians and then transported under ice at 4 ° C to the Laboratory of Biological Hazards of USL Toscana Centro for laboratory analyses.

Results 126 water samples were collected. Coliforms, E. coli, Staphylococcus aureus, enterococci were not detected. Pseudomonas aeruginosa was found in only one sample. Both for CFU at 37 ° C and at 22 ° C, the type of device represented the only statistically significant risk factor (OR 15.21 and OR 10.25 respectively): SDS devices had a significantly higher risk of being positive for CFU at 37 ° C and 22 ° C.

Conclusions As our study demonstrated, the system producing dialysis water must be constantly monitored, especially in cases of SDS devices which may be subjected more frequently to a higher contamination, due to their discontinuous use.

 

Keywords: surveillance, hemodialysis, infections

Sorry, this entry is only available in Italian.

Case of sialadenitis by iodinated contrast medium in a dialysis patient

Abstract

Background
Sialadenitis by iodinated contrast medium (i.c.m) or iodine mumps (IM) is a rare and late benign manifestation that occurs independently of intravenous or endoarterial administration modality. If renal function is normal, i.c.m. does not reach salivary glands concentrations able to induce sialadenitis. However, a critical glomerular filtration reduction may lead to salivary ducts edema and glandular swelling after i.c.m. injection. We report a rare case report of IM in a patient on chronic hemodialysis.
 
Methods
A 72-year-old woman affected by chronic kidney disease on chronic hemodialysis, underwent to endoscopic removal of a rectal cancer. For disease staging, a total body TC with i.c.m. was performed. The following morning, patient showed a soft and aching bilateral paroditidis swelling. Salivary glands ultrasound was diagnostic for sialadenitis. The patient was rapidly treated with betamethasone following by a 240 minutes post-dilution online hemodiafiltration session.
 
Results
Within the next 24h, a complete remission of IM was obtained.
Conclusion
In our patient, a compensatory hyperactivity of the sodium / iodine symporter (NIS) on salivary gland cells may have played a crucial role in IM induction. An high efficiency hemodialysis session within the few following hours after i.c.m injection is a fundamental tool in patients on renal replacement treatment to prevent IM that is an epiphenomenon of i.c.m. accumulation.

 

Keywords: Iodine mumps, chronic kidney disease, hemodialysis, iodine contrast medium, corticosteroids.

Sorry, this entry is only available in Italian.

Vascular calcifications in subjects with and without chronic renal failure: types, sites and risk factors

Abstract

Vascular calcifications worse outcomes in the general population and in patients on dialysis

We investigated 146 patients on chronic hemodialysis and 63 healthy controls with normal renal function under 65 years of age. All subjects underwent B-mode ultrasonography of common and internal carotid artery, abdominal aorta, common and superficial femoral artery and posterior tibial artery to assess the presence of intimal and medial calcifications.

Intimal and media calcifications were present at the level of the carotid vessel, the abdominal aorta, the common femoral artery, the superficial femoral artery and the posterior tibial artery, respectively in 45%, 50%, 45%, 50%, 42% of patients on dialysis and in 5%, 15%, 24%, 5%, 2% of controls (p <0,01).

On multivariate logistic analysis of regression, after adjustment for potential confounders,    carotid intimal calcification, abdominal aortic calcification, medial calcification of the superficial femoral artery and posterior tibial artery calcification were associated with dialysis and with cardiovascular disease. Only intimal arterial calcification were associated with older age and smoking.

Vascular calcifications are extremely common in middle-aged patients on chronic hemodialysis. Ultrasonography currently available in Nephrology, is a sensitive, reproducible, inexpensive imaging technique to identify arterial intimal and medial calcification in high-risk cardiovascular subjects.

Key words: arterial calcifications, arterial intimal calcifications, arterial media calcification, chronic renal failure, hemodialysis, vascular calcifications

Sorry, this entry is only available in Italian.

Digoxin poisoning: new prospects for therapy

Abstract

The digital is a drug  with a narrow therapeutic range, it is used to treat the systolic heart failure. The digitalic intoxication is a fearsome event as potentially fatal for arrhythmias that can lead. We report a case  of digitalis toxicity in a patient treated with  filter “Lixelle S-35”.

The filter has been approved by the Food and Drug Administration for the removal of beta-2 microglobulin in patient undergoing hemodialysis. We used the filter (the patient agrees)  off label, in the course of digitalis intoxication and we have shown that the filter is capable of removing the drug effectively.

Key words: Digoxin poisoning, filter “Lixelle S-35”, hemodialysis

Sorry, this entry is only available in Italian.