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Background: Early cannulation arteriovenous grafts (ecAVG) for dialysis access are limited by reintervention for venous stenosis (VS) despite their good initial patency. Whilst stent-grafts (SG) have shown promise, the optimal sizing is unclear. Therefore, this study aims to determine if outflow vein diameter, SG diameter or these relative to each other (V:Sr) alters outcomes, and if so, which is more important.Methods: Retrospective analysis was performed of Gore®Acuseal®ecAVGs with VS treated with Gore®Viabahn®SG over a 7-year period. Primary patency (PP), time to thrombosis and functional patency were analysed by SG length/diameter, vein diameter and V:Sr.Results: We identified 114 ecAVGs with median follow-up 492 days (IQR 189–770). SG length and diameter did not correlate with PP, however, there was a significant relationship between vein diameter and PP (RR = 0.901 (0.832–0.975), p= 0.01) and between V:Sr and PP (RR = 0.462 (0.255–0.838), x2= 5.866, p= 0.0015). The optimal V:Sr was ⩾1.4 (i.e. vein diameter at least 40% greater than the stent-graft; or ‘free-floating’ stent outflow) (RR = 2.759 (1.670–4.558), p< 0.001), translating to a difference in median PP of 252 versus 496 days (IQR: 188–316; 322–670). On multivariate analysis, absolute vein diameter lost significance, whilst V:Sr remained an independently significant predictor of PP (RR = 3.247 (1.560–6.759), p= 0.02).Conclusions: Placement of the SG outflow into a relatively larger segment of vein was associated with a significant increase in PP independent of the absolute vein diameter. This suggests that larger calibre SG which are apposed to the vein wall are not required for optimal primary patency, and indeed should be actively avoided. Instead, a ‘free-floating’ stent outflow which is undersized relative to the recipient vein (whilst maintaining a minimum anchoring calibre) is recommended where possible. This should be considered during intervention and may require selection of longer devices, where practical, to bring the stent outflow into a larger vein segment.Level of Evidence: Level 3a, Non-randomised controlled cohort/follow-up study

Background: A self-administered 11 item vascular access specific quality of life measure (VASQoL) was previously derived from detailed qualitative interviews with adult patients with kidney failure who have experienced vascular access using the Capabilities Approach as a theoretical base. This study reports the psychometric validation of the VASQoL measure including its reliability, content validity and responsiveness to change.Methods: Cognitive interviews were conducted with 23 adult patients with kidney failure after completion of the VASQoL measure. Focus group discussion with a vascular access professional multidisciplinary team was undertaken (n= 8) and subsequently a further 101 adult kidney failure patients with vascular access (TCVC, AVF or AVG) completed the digital VASQoL measure, EQ-5D and SF-36 questionnaires in a longitudinal study with prospectively recorded vascular access events.Results: Transcript analysis of cognitive interviews after VASQoL completion indicated that the content was comprehensive and well understood by participants. Assessment of Internal reliability for the VASQoL measure was high (Cronbach’s alpha 0.858). Test-retest reliability of the overall VASQoL measure was high (intra class correlation coefficient 0.916). In those patients who experienced a vascular access event, significant differences were observed in paired analysis of the VASQoL physical domain questions and vascular access function domain questions and in the EQ-5D usual activities, pain and anxiety domains. In those with no vascular access event, variation was observed in longitudinal analysis in VASQoL questions relating to worry about VA function and capability domains, whilst no variation was observed in the EQ5D measure.Conclusion: The VASQoL measure has good internal consistency, test-retest reliability, convergent validity and responsiveness to change for clinically relevant vascular access outcomes. This provides a validated, vascular access specific quality of life measure that can be used in future trials of vascular access, evaluation of new technologies and routine use as a patient reported outcome measure (PROM).

Background: Early-cannulation arteriovenous grafts (ecAVG) have good initial patency, but frequent episodes of reintervention for venous stenosis (VS) and thrombosis limit their use. Stent grafts (SG) have shown promise in reducing re-interventions and improving functional patency for dysfunctional ecAVG and recurrent VS. There is little data on the impact of stent grafts as the first elective procedure for VS. The aim of this study was to determine firstly, if treating VS whilst asymptomatic has a better outcome than treating after presentation with thrombosis; and secondly, to determine the best initial treatment for asymptomatic VS: SG or angioplasty.Methods: A retrospective study was performed of 259 ecAVG with a sutured anastomosis. The case-mix and outcomes of 153 who presented with VS was analysed by presentation (elective at surveillance or emergency following thrombosis), and then for only elective patients, by treatment (SG vs angioplasty).Results: There was no significant difference in case-mix and time to presentation by mode of presentation (100 elective and 53 with thrombosis) other than a higher rate of pro-thrombotic disorders in thrombosed ecAVG. Thrombosed ecAVG had poorer outcomes with increased re-intervention rates and thrombosis in the following year, and reduced long-term functional patency. In patients presenting electively, primary SG rather than angioplasty led to significantly reduced thrombosis rates, a longer time to re-intervention in the following year, and superior long-term functional patency. The use of SG was the same in both groups. Both the mode of presentation and the type of intervention performed were independently predictive of a poorer subsequent functional patency.Conclusions: Primary elective stent-grafting may be the optimal strategy to reducing maintenance costs with ecAVG.

Background: It is likely that there will be an increasing role for early-cannulation arteriovenous grafts (ecAVG) with a wider recognition of the need to tailor vascular access to avoid futile procedures and unnecessary TCVC. However, experience of these products is not common and limited to early surgical adopters, with little information on the systemic changes and multi-disciplinary care needed to optimize outcomes. The aim of this study was to report the impact of a multi-disciplinary approach on quantifiable outcomes.Methods: A retrospective analysis of a prospectively maintained database of 295 ecAVG implanted over an 8-year time-period was performed. Indicative outcomes were chosen to reflect nephrology (patient selection), nursing care (cannulation complications of infection and pseudoaneurysm) and radiology (thrombosis) on cumulative impact (functional patency) over three distinct time periods.Results: The incidence of ecAVG increased 10-fold over the three time periods. The use of ecAVG changed significantly from salvage tertiary access to TCVC avoidance and salvage of existing AVF. Nursing complications reduced markedly with significantly fewer over-cannulation episodes and pseudo-aneurysms. With an improved pro-active surveillance programme, the time to first thrombosis doubled and the risk of thrombosis halved. Ultimately this resulted in significantly improved functional patency with a risk of ecAVG loss less than one-third by the last time-period.Conclusions: All aspects of ecAVG use require scrutiny and critical appraisal. Failure or success is not simply achieved by performing good technical surgery with an efficacious product, but by the care taken across a wide range of elements spanning case selection, implantation, use and maintenance.