Steven Rogers ^{a, b}, Katie Simm ^b, Charles McCollum ^a, Sharifah Kiyegga ^b, Adam Haque ^a, Simon Lea ^c, Ramasubramanyan Chandrasekar ^c

^a Academic Surgery Unit, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Wythenshawe Hospital, Southmoor Road, Wythenshawe, Manchester, UK, M23 9LT.

^b Independent Vascular Services Ltd, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Southmoor Road, Wythenshawe, Manchester, UK, M23 9LT.

^c Department of Vascular and Endovascular Surgery, Arrowe Park Hospital, Wirral University Teaching Hospital NHS Foundation Trust, Arrowe Park, Wirral, CH49 5PE.

Background

A well-functioning Arterio-Venous Fistula (AVF) is essential for haemodialysis. Despite regular Duplex-Ultrasound (DUS) a significant number of AVF’s fail. Tomographic 3D ultrasound (tUS) creates a 3D image of the AVF that can be interpreted by the clinician. We compared DUS, tUS and fistulograms for the identification and measurement of flow-limiting stenosis.

Methods

Patients with AVF dysfunction at routine Transonic® surveillance defined as 1) >15% reduction in flow on two consecutive occasions, 2) >30% reduction in flow on one occasion, 3) flow of <600ml/s, 4) presence of recirculation, underwent DUS. tUS imaging of the AVF was performed prior to fistulography. All fistulograms were reported by the same Consultant Radiologist and tUS images by the same vascular scientist blinded to the fistulogram results. Maximum diameter reduction in all stenoses were measured using all three imaging techniques.

Results

In 97 patients with 101 stenoses, the mean (±sd) severity of stenosis was 63.0±13.9%, 65.0±11.6% and 64.8±11.7% for the fistulograms, DUS and tUS respectively. The mean (±sd) time between ultrasound and fistulography imaging was 15.0±14.5 days. Assuming the fistulogram as the “gold standard”, Bland-Altman agreement for DUS was -1.9±15.5% (LOA -32.2-28.4) compared with -1.7±15.4% (LOA -31.9-28.4) for tUS. Mean (±sd) time to complete the investigation was 09:47±03:48 min for DUS and 03:38±01:32 min for tUS (p<0.001).

Conclusions

DUS and tUS were equally accurate at detecting AVF complications but tUS investigation requires less skill and was significantly quicker than DUS.

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