F NGWENYA1, DC-Y LIN1, TY-T SUN1, E LY1
1Counties Manukau Health, Auckland, New Zealand
Aim: We reviewed arterio-venous fistula(AVF) outcomes in a patient centred vascular access model and identify predictors of primary failure.
Background:A VF primary failure rates may benchmark clinical practice, but are not the sole determinant for evaluating vascular performance. Our model considers premium anatomical choice against patient factors and optimising future fistula options.
Methods: Retrospective analysis of new AVF created at Counties Manukau Health 1stAugust,2016-30thJuly,2017. Follow-up completed 31stMarch 2018. AVF not needled or with planned second stage were excluded. Primary end-points were primary failure (AVF dysfunction resulting in abandonment, requiring intervention prior to first use, used <8/12 dialysis sessions or requiring intervention within first 30 days of needling) and overall AVF patency at six months. Secondary analysis reviewed fistula outcomes against patient characteristics, comorbidities, previous fistula, preoperative vein calibre (<3mm), perioperative surgical and post-operative fistula assessment by clinician.
Results: 85 patients included; 61% radio-cephalic, 38% bracio-cephalic/basilic, 1% other AVF. Major ethnic group Pacific Island(54%), mean age(54years), 55% male, 67% diabetic, 19% atherosclerotic disease, 24% had previous fistula. These factors did not affect AVF outcome. Primary failure was 51%. Overall patency 79% at six months – censored for death, transplant, lost follow-up. On univariate analysis previous functional AVF (odds ratio OR 0.2;p=0.01), perioperative surgical (OR 7.6;p<0.001) and post-operative staff assessment (OR 58.6;p<0.001) were independently associated with AVF outcome. Composite analysis using vein calibre, perioperative surgical and post-operative clinician assessment provided greater accuracy OR 7.1, 33.3 and 129.0; if one, two or three positive respectively p=0.002.
Conclusion: This model produced high primary failure but acceptable overall patency. Increased primary failure may be predicted by combining preoperative imaging, perioperative surgical and post-operative fistula assessments and may guide need for increased monitoring and early intervention.
Fortune Ngwenya is the Counties Manukau Health Vascular Access Co-ordinator. He completed his Nursing Diploma from Mpilo School of Nursing, Zimbabwe and Postgraduate Nursing Diploma through Victoria University, Wellington. He has a thirteen year medical and renal nursing background from Mpilo Hospital and Canterbury District Health Board; and worked at Counties Manukau Health for the last seven years. Fortune has a special interest in improving vascular access outcomes and works closely with Nephrologists, Vascular Surgeons and Interventional Radiologists at Middlemore Hospital, Auckland New Zealand. He is working towards his Master of Nursing degree at Massey University, Auckland.