Thermographic assessment of patency in mature hemodialysis arteriovenous fistulas with new flow-related complications.

INTRODUCTION

Arteriovenous fistulas provide reliable vascular access to process high volumes of blood during hemodialysis. Fistula dysfunction can interrupt dialysis treatment and warrants prompt assessment of patency. In this study, we evaluate the diagnostic accuracy of infrared thermography as an accessible point-of-care screening tool to assess mature arteriovenous fistula patency in new flow-related complications that hinder hemodialysis.

METHODS

Thirty adults undergoing hemodialysis were recruited who had been referred to interventional radiology due to new flow-related complications of their mature arteriovenous fistulas, hindering hemodialysis. Assessments of fistulas were first carried out by thermography, then compared with CT angiography for validation.

RESULTS

Thermography demonstrated all instances of stenoses and occlusions in arteriovenous fistulas and their superficial drainage veins, with 100% sensitivity, 94% specificity, 100% negative predictive value, 92% positive predictive value, and 97% accuracy rate. In one case, while thermography suggested superficial stenosis, this could not be demonstrated on CT angiography. Thermography was also able to show superficial venous aneurysmal dilatations. In six cases, fistula dysfunction was secondary to central venous stenoses, and thermography demonstrated consequent superficial venous distensions and collateralizations in the arm.

CONCLUSION

Thermography shows potential to offer an accessible, portable, inexpensive, non-invasive, and radiation-free point-of-care screening tool for the assessment of arteriovenous fistula patency with high accuracy.