Hybrid arteriovenous graft for hemodialysis vascular access in a multicenter registry.

OBJECTIVE: The aim of our study was to identify patients' characteristics that predicted a higher chance of arteriovenous graft patency in patients undergoing Gore Hybrid Vascular Graft (GHVG; W. L. Gore & Associates, Flagstaff, Ariz) implantation for hemodialysis access. The GHVG is a polytetrafluroethylene (PTFE) prosthesis with a nitinol-reinforced section (NRS) at the venous end. METHODS: All consecutive patients undergoing GHVG implantation for hemodialysis access at 10 tertiary referral centers between December 2013 and January 2018 were included in the study and compared with a control group of patients undergoing standard PTFE graft implantation. Selection of patients for hybrid graft implantation was based on the impossibility of autogenous vascular access creation. RESULTS: There were 145 patients included in the GHVG group and 218 in the PTFE group. In the GHVG and the PTFE groups, the mean age was 67 ± 13 years and 65 ± 13 years, and male patients totaled 52% and 46%, respectively. The technical success was 99%. The mean duration of the intervention was 100 minutes (median, 95 minutes; interquartile range, 80-120 minutes). The brachial-axillary configuration was used in the majority of cases (n = 78 [54%]). The 5-cm NRS length was prevalent (n = 108 [75%]). The median NRS oversize was 14% (interquartile range, 0%-21%). Mean follow-up was 13 months (range, 0-55 months). Seventy-one patients (49%) underwent at least one reintervention. Primary, assisted primary, and secondary patency estimates at 12 months were 44% ± 5%, 47% ± 5%, and 65% ± 4% for the GHVG group and 41% ± 4%, 53% ± 4%, and 75% ± 3% for the control group, respectively (P = NS). One-year survival was 90% ± 3%. On multivariable Cox regression analysis, hypotension (P < .001; hazard ratio [HR], 5.8; confidence interval [CI], 2.6-13) and diabetes (P = .024; HR, 1.9; CI, 1.1-3.2) were significant predictors of GHVG loss. A larger graft size was protective against GHVG loss (P = .042; HR, 0.73; CI, 0.54-0.99). The 10-cm-long graft showed a tendency toward improved patency but did not reach statistical significance (P = .074; HR, 0.48; CI, 0.21-1.07). CONCLUSIONS: Diabetes and hypotension were predictors of loss of hybrid arteriovenous access. Smaller diameters of NRS were more prone to thrombosis, whereas the 10-cm length seemed to perform better than the 5-cm one.

Fistula first, graft on arterialized vein second.

OBJECTIVES: Arterovenous grafts (AVGs) present a feasible solution for creating a vascular access in patients who are unsuitable for autogenous fistula (AVF). The aim of this study is to assess the prevention rate of vein stenosis, placing a graft on an arterialized vein (GAV) instead of an anastomized AVG in a native vein (GNV). METHODS: This was a cohort study conducted from January 2009 to November 2012. All consecutive patients who underwent AVG in our institution were included. All patients requiring a secondary intervention were also referred to our centre. Patients underwent ultrasound follow up at first and the every month. A Kaplan-Meier method was used; a Log-rank test was used to identify whether significant difference existed between GAV and GNV (p < 0.05). RESULTS: Forty-six grafts were placed. Twenty patients had arterialized receiving veins (group A), while 26 patients received an AVG immediately because they lacked autogenous veins suitable for fistula (group B).The average follow-up period was 16.1 months (range 0-41). The group A 41 months-patency rate was 84.3%, while group B was 43.7% (p = 0.06). Secondary patency was similar in the two groups. CONCLUSIONS: Vein arterialization seems to prevent venous stenosis improving AVG-patency rate. More data are needed; however, the borderline p value encourages new studies.

High Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios Are Associated with a Higher Risk of Hemodialysis Vascular Access Failure.

Our aim was to determine the predictive role of the preoperative neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in vascular access malfunctioning in patients who had undergone their first native arterio-venous fistula (AVF) for hemodialysis. Methods: This was a single-center retrospective observational study. All patients who underwent the procedure of the creation of a first native AVF for hemodialysis from January 2019 to December 2020 were considered eligible to be part of this study. Reinterventions for AVF malfunctioning were registered and the population was subdivided into two groups with respect to AVF malfunctioning. ROC curves were obtained to find the appropriate cut-off values for the NLR and PLR. A multivariate analysis was used to identify the independent predictors for an AVF malfunction. Kaplan−Meier curves were used to evaluate the AVF patency rates. A total of 178 patients were enrolled in the study, of them 70% (n = 121) were male. The mean age was 67.5 ± 12 years. Reinterventions for AVF malfunctioning were performed on 102 patients (57.3%). An NLR > 4.21 and a PLR > 208.8 was selected as the cut-off for AVF malfunctioning. The study population was divided into two groups depending on the NLR and PLR values of the individual. For the NLR < 4.21 group, the AVF patency rates were 90.7%, 85.3%, and 84% at the 3-, 6-, and 12-month follow-up, respectively, and 77.5%, 65.8%, and 39.3% at 3, 6, and 12 months for the NLR > 4.21 group, respectively (p < 0.0001). For the PLR < 208.8 group, the patency rates were 85.6%, 76.7%, and 67.7% at the 3-, 6-, and 12-month follow-up. For the PLR > 208.28 group, the patency rates were 80.8%, 71.2%, and 50.7% for the 3-, 6-, and 12-month follow-up, respectively (p = 0.014). The multivariate analysis highlighted that diabetes mellitus, the neutrophil count, the lymphocyte count, and the NLR were independent risk factors for an AVF failure. In our experience, the NLR and PLR are useful markers for the stratification of vascular access failure in hemodialysis patients. The inexpensive nature and ready availability of the values of these biomarkers are two points of strength for everyday clinical practice.

Residual dissection of the brachiocephalic arteries: significance, management, and long-term outcome.

OBJECTIVES: Residual dissection of the brachiocephalic arteries after operations for acute type A dissection is considered a benign condition that does not expose patients to late neurologic events. This retrospective study, conducted on an outpatient clinic basis between June 1995 and May 2003, had the objectives of evaluating the consequences of residual dissection of the brachiocephalic arteries, investigating the long-term outcomes of patients with this condition, and illustrating our approach to the condition. METHODS: Forty-two of 137 patients with spontaneous aortic dissection were identified as having residual dissection of the brachiocephalic arteries. There were 30 men and 12 women, with median age of 64.8 years. Patients were followed for a median time of 3.17 years (25th-75th percentile, 1.43-4.40 years; maximum, 7.5 years). The main outcome was the occurrence of cerebral ischemic events (transient ischemic attack or stroke) or death. The functional consequences of brachiocephalic artery dissection were studied by using duplex scanning and transcranial Doppler ultrasonography. RESULTS: Twenty-four focal neurologic complications occurred in 13 of 42 patients (incidence, 30.9%); major strokes occurred in 6 patients, and none were fatal. Minor strokes occurred in 12 patients. In all patients the damaged territory was dependent on a dissected artery. Kaplan-Meier (90-months) freedom from focal neurologic events was 55.7% (95% confidence interval, 33.7%-72.9%). Mean time of freedom from focal neurologic events was 64.5 months (95% confidence interval, 53.1-75.9 months). Positive transcranial Doppler monitoring for microembolic signals was 24.1%, and patients with clinical symptoms had higher microembolic signal counts than did those without symptoms (8.4/h vs 1.9/h, P <.001). Reduced cerebrovascular reactivity to hypercapnia, calculated by using the breath-holding index values, was associated with severely impaired brachiocephalic artery perfusion. The multivariable model for predictors of late stroke (minor and major) included the following variables: microembolic signal count (1 signal/h increase; relative risk, 1.27 [95% CI, 1.12-1.77]), breath-holding index (0.10 increase; relative risk, 0.91 [95% CI, 0.87-0.94]), and the presence of at least one carotid axis with a thrombosed false channel (relative risk, 0.82 [95% CI, 0.64-0.93]). Sixteen operations were performed in 12 patients to relieve residual dissection. CONCLUSIONS: These results suggest an increased risk of ischemic events ipsilateral to the dissected arteries. Strict follow-up and identification of subjects at risk implies the exact knowledge of vessel anatomy and perfusion status. Ultrasonographic transcranial Doppler examination plays an important role in the clinical work-up of these patients.

Lipid composition in atheromatous plaque: evaluation of the lipid three-phase percentage.

There is a renewed interest in the study of plaque lipid composition because it is recognized that it, rather than the luminal narrowing, influences the plaque stability and determines patient symptoms. At this purpose, we quantitatively evaluated in the carotid plaque of different categories of patients the expression of triglycerides, phospholipids, cholesterol, free cholesterol, esters of cholesterol, and the percentages of the three-phases (cholesterol, esters of cholesterol, phospholipids) by using the "Roozeboom triangle". Significant differences in the content of specific lipid and the percentage of the three-phases were detected among the different types of plaque evaluated in this study. The analysis of the three-phases by "Roozeboom triangle" may open a new approach in the study of atheromatous plaque and give new information on development of the disease.