text: [Use of venae comitantes in the creation of arteriovenous fistulas: retrospective evaluation of our experience].
  In order to estimate the outcome of arteriovenous fistula (AVF) for hemodialysis, we reviewed our experience in the construction of AVFs using the venae comitantes in patients without an adequate superficial venous vascular territory. The study included 34 patients affected by end-stage renal disease in whom an AVF was created using the deep venous system. In 26 of them we performed an anastomosis between the brachial artery and its vena comitans. Immediate success, defined by the presence of a thrill at the end of the anastomosis, was obtained in 84%, while primary failure of the AVF (immediate postoperative failure) occurred in 3 patients (12%). Early failure, defined as failure within 6 weeks of AVF placement, occurred in 4% of patients. Of the 22 patients with a functioning AVF, 8 (36%) subsequently requested a second operation to bring the fistula to the surface. Some of these involved the placement of synthetic grafts for better accessibility. The primary patency of the AVFs was equal to 64%, while the patency after a second intervention was 91%. Among the 26 AVFs created with venae comitantes, total patency at 50 weeks was 62%. Our experience with the placement of prosthetic grafts draining into the venae comitantes has not provided encouraging results. We believe that for adequate exploitation of venae comitantes it is important to use native veins that have to meet specific anatomical and functional requirements. The creation of an AVF with a native vein, taking advantage of the deep venous system, is feasible under the right circumstances.