Vascular access clinic results before and after implementing a multidisciplinary approach adding routine Doppler ultrasound. / Consulta de acceso vascular: resultados antes y después de la instauración de un programa multidisciplinar con realización de ecografía doppler de rutina.

BACKGROUND: A multidisciplinary approach and Doppler ultrasound (DU) assessment for the creation and maintenance of arteriovenous fistulas (AVF) for haemodialysis can improve prevalence and patency. The aim of this study was to analyse the impact of a new multidisciplinary vascular access (VA) clinic with routine DU. MATERIAL AND METHODS: We analysed the VA clinic results from 2014 and 2015, before and after the implementation of a multidisciplinary team protocol (vascular surgeon/nephrologist) with routine DU in preoperative mapping and prevalent AVF. RESULTS: We analysed 345 and 364 patients from 2014 and 2015 respectively. The number of surgical interventions was similar in both periods (p=.289), with a trend towards an increase in preventive surgical repair of AVF in 2015 (17 vs. 29, p=.098). 155 vs. 169 new AVF were performed in 2014 and 2015, with a significantly lower primary failure rate in 2015 (26.4 vs. 15.3%, p=.015), and a non-significant increase in radiocephalic AVF, 25.8 vs. 33.2% (n=40 vs. 56), p=.159. The concordance between the indication at the clinic and the surgery performed also increased (81.3 vs. 93.5%, p=.001). Throughout 2015 fewer complementary imaging test were requested from the clinic (78 vs. 35, p <.001), with a corresponding reduction in costs (€87,716 vs. €59,445). CONCLUSIONS: Multidisciplinary approach with routine DU can improve VA results, with a decrease in primary failure rate, higher likelihood of radiocephalic AVF, better management of dis-functioning AVF and lower radiological test costs.

Randomized comparison of 6-mm straight grafts versus 6- to 8-mm tapered grafts for brachial-axillary dialysis access.

OBJECTIVE: This report presents the results of a prospective randomized study that compared 2 grafts of different diameter: 6 mm, and 8 mm tapered to 6 mm at the arterial site, placed in the upper arm for hemodialysis in a selected population of patients younger than 71 years without diabetes. METHODS: Seventy consecutive patients younger than 71 years without diabetes who required an upper arm graft between January 1997 and January 2002 and without previous access in the same limb were randomly allocated to receive either a 6-mm graft or 6- to 8-mm graft. Graft flow was measured every 3 months with the Doppler dilution technique. When access flow was less than 600 mL/min, fistulography was performed, and any stenosis was surgically treated with venous outflow replacement. Thrombectomy and associated stenosis treatment in the same stage was performed in all cases immediately after detection of thrombosis. Complication rate, and primary, assisted primary, and secondary patency rates were compared between the two groups with the Student t test and life table analysis. RESULTS: Mean access flow was 975 mL/min for 6-mm grafts (range, 600-1500 mL/min; 95% confidence interval [CI], 889-1070), and for 6- to 8-mm grafts was 1397 mL/min (range, 1122-2700 mL/min; 95% CI, 1122-1672). This difference was significant (P <.01). Complication rate was 0.45 episodes per graft-year in 6-mm grafts, and 0.19 episodes per graft-year in 6- to 8-mm grafts (P <.01). At 1, 2, and 3 years, primary patency rates were 62%, 58%, and 44%, respectively, for 6-mm grafts, and 85%, 78%, and 73% for 6- to 8-mm grafts; log-rank comparison between curves was P =.0259. At 1, 2, and 3 years, secondary patency rates were 85%, 85%, and 85%, respectively, for 6-mm grafts, and 90%, 90%, and 90% for 6- to 8-mm grafts; log-rank comparison between curves was not significant, at P =.0603. At 1, 2, and 3 years, assisted primary patency rates were 84%, 79%, and 76%, respectively, for 6-mm grafts, and 90% for 6- to 8-mm grafts; log-rank comparison was P =.0414. CONCLUSIONS: The results of this study show an advantage in terms of primary and assisted primary patency rates, and complication rate for upper arm grafts with diameter 6 mm to 8 mm over grafts with 6-mm diameter in a patient population younger than 70 years without diabetes. The finding of a similar secondary patency rate in both groups is probably due to the surveillance program with sequential measurement of access flow and prompt surgical treatment of stenosis. However, we needed twice the number of rescue procedures in 6-mm grafts to achieve a similar patency rate as with large-bore grafts. These study results must be carefully evaluated, taking into consideration the small number of patients and the selected patient population.

Upper arm polytetrafluoroethylene grafts for dialysis access. Analysis of two different graft sizes: 6 mm and 6-8 mm.

The purpose of this retrospective study was to analyze 2 sizes of expanded polytetrafluoroethylene (PTFE) upper arm grafts for dialysis: 8 millimeters, tapered to 6 mm at the arterial side, and 6 millimeters. All upper arm PTFE grafts (Gore-Tex(R)) were performed between January 1981 and April 1997. Patient characteristics, complication rate, and patency rates were compared for both kind of grafts. Five hundred and seven PTFE grafts were analyzed (183 6-mm grafts and 324 6- to 8-mm grafts). Early failure was found in 5 grafts (2.7%) in 6-mm grafts, and in 5 grafts (1.5%) in 8-mm grafts (not significant). Steal syndrome was found in 1 patient (0.5%) of the 6-mm group, and in 11 (3.4%) of the 8-mm grafts (p=0.085). The rate of late complications requiring surgical repair was 0.56 episode per graft-year in the 6-mm grafts group, and 0.33 in the 8-mm grafts (p<0.001). Primary patency rates of 6-mm grafts were 72%, 33%, and 19% at 1, 3, and 5 years; and secondary patency rates were 86%, 68%, 56%, and 44% at 1, 3, 5, and 6 years, respectively. In the 8-mm grafts group, primary patency rates were 77%, 52%, and 39% at 1, 3, and 5 years; and secondary patency rates were 92%, 84%, 73%, and 66% at 1, 3, 5, and 6 years, respectively. Comparison of patency rates of 6-mm and 8-mm grafts were statistically significant (p<0.001) for both primary and secondary curves. However, secondary survival curves were similar for both kind of grafts in a subpopulation of diabetic patients. The authors conclude that the 8-mm graft, tapered to 6 mm at the arterial side, is a dialysis graft with fewer complications and a better patency rate than grafts of 6 mm placed in the same anatomical position, at least in a population of nondiabetic patients. Steal syndrome was observed in some cases of diabetic and older patients with a large-bore graft. Thus, this kind of prosthesis should be avoided in this population. On the other hand, this is not a prospective, randomized study made with any intention for comparison. Therefore, the aforementioned conclusions must be cautiously considered.