Tissue Markers Predictive of Early Stenosis in the Arterovenous Fistula for Hemodialysis

The following study will enroll two cohorts of patients: 75 patients from Population 1 and 75 patients from Population 2, according to the inclusion criteria. Since this is an exploratory study, this number is considered sufficient to observe and compare tissue markers associated with early AVF stenosis.

Patients will be treated according to clinical practice in accordance with the physician's judgment.

The study includes: the recruitment of patients from the two study populations, the obtaining of the surgical specimen from both populations and its sending to the Pathology Department, as part of the normal care pathway, the execution of three tissue samples at the Pathology Department: (i) a sample frozen in liquid nitrogen and stored in an ultrafreezer at -80°C for RT-PCR analysis; (ii) a sample placed in PBS for cell culture; (iii) the remainder of the sample fixed in formalin, embedded in paraffin and processed according to the normal care pathway and histological diagnosis. 2 µm slices will be cut from the paraffin block for histological staining and histochemical and IIC investigations; execution of cell culture investigations and execution of RT-PCR investigations.

• Identification any tissue markers predictive or favoring early stenosis in AVF for haemodialysis. (Biological): Primary objective 1. Identify any predictive or favoring tissue markers of early stenosis in AVF for hemodialysis. Secondary objectives 2. Compare the results on the possible different expression of tissue markers before and during dialysis. 3. Compare the results on the possible different expression of tissue markers between AVFs made with portions of cephalic vein and AVFs made with portions of basilic vein, in order to evaluate whether the different topographic origin of the AVF can influence its duration.

Primary outcomes

• Identify any predictive or favoring tissue markers of early stenosis in AVF for hemodialysis. [From the first patient entrolled, up to the 150th patient, an average of 6 years]: Biomarkers of the treated fistula are histologically examined

Secondary outcomes

• Different expression of tissue markers before and during dialysis. [From the first patient enrolled to the 150th patient, an average of 6 years]: Markers expression of the treated tissue are analysed and compared between the two study group.
• Markers differences between Basilic and cephalic vein [From the first patient enrolled, up to the 150th patient, up to 6 years]: Compare the results on the possible different expression of tissue markers between AVFs made with portions of cephalic vein and AVFs made with portions of basilic vein, in order to evaluate whether the different topographic origin of the AVF can influence its duration.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Age greater than or equal to 18 years;
* Patients candidates for first AVF for hemodialysis or correction of AVF complication, as part of the normal care pathway;
* Obtaining informed consent signed by the patient

Exclusion Criteria:

• Mauro Gargiulo, MD, Principal investigator, IRCCS Azienda Ospedaliero-Universitaria di Bologna