Accumulation of Carbamylation-Derived Products in Aneurysmal Aorta.

INTRODUCTION: Carbamylation is a nonenzymatic post-translational modification of proteins characterized by the binding of isocyanic acid to amino groups of proteins, which leads to the alteration of their properties. An increase in serum carbamylation-derived products, including homocitrulline (HCit), has been shown to be associated with the development of cardiovascular diseases. METHODS: HCit was quantified by LC-MS/MS within extracts of aneurysmal and control human aortas. A mouse model of aortic aneurysm (ApoE-/- mice perfused with angiotensin II and fed with sodium cyanate) was used to evaluate the role of carbamylation in aneurysm development. RESULTS: HCit quantification showed a greater heterogeneity of values in aneurysmal aortas in comparison with control ones. At the maximum diameter of dilation, HCit values were significantly higher (+94%, p < 0.05) compared with less dilated areas. No differences were observed according to aneurysm size or when comparing ruptured and unruptured aneurysms. No significant effect of carbamylation on aneurysm development was observed using the animal model. CONCLUSIONS: These results evidenced the accumulation of HCit within aneurysmal aortas but do not allow concluding about the exact participation of protein carbamylation in the development of human abdominal aortic aneurysms.

Higher patency of transposed brachio-basilic arteriovenous fistulas compared to brachio-axillary grafts for hemodialysis patients.

PURPOSE: We compared outcomes of transposed brachio-basilic arteriovenous fistulas (BBAVF) with brachio-axillary prosthetic grafts (BAPG) for hemodialysis. METHODS: All consecutive patients who underwent creation of a BBAVF or a BAPG, in one of the two institutions, between January 2008 and December 2013 were retrospectively identified. We assessed functional patency and compared complication rates. Patency was also compared between one-stage and two-stage creation procedures for the BBAVF group. RESULTS: Two hundred and thirty-eight patients underwent the creation of a BBAVF (N = 136) or a BAPG (N = 102). Median follow-up was 17 months (range, 1-79). At 6, 12 and 24 months, patients in the BBAVF group had significantly higher primary patency (80%, 69%, 56% vs. 77%, 56%, 37%, respectively; p = 0.005), assisted primary patency (90%, 80%, 71% vs. 80%, 66%, 48%; p<0.0001) and secondary patency (93%, 84%, 72% vs. 94%, 87%, 62%; p = 0.006). Two-stage BBAVF had a significantly higher secondary patency (98%, 92%, 78% vs. 90%, 80%, 68%; p = 0.04) than one-stage BBAVF. The rate of infectious complications was significantly lower in the BBAVF group than in the BAPG group (0.8% vs. 6.9%; p = 0.03). CONCLUSIONS: In this large cohort, BBAVF had a higher functional patency and lower rate of infectious complications than BAPG. After exhaustion of cephalic veins, we suggest creation of a BBAVF instead of BAPG, whenever anatomically feasible. The superiority of one-stage or two-stage BBAVF creation procedure must be further investigated.