Comparison of clinical evaluation with duplex ultrasound parameters in predicting early hemodialysis arteriovenous fistula failure

Abstract

Introduction Early Arteriovenous fistula (AVF) failure is defined as an AVF that never develops adequately to support dialysis or fails with in the first 3 months of its use. Majority of fistulae that have failed to mature adequately can be salvaged by percutaneous interventions and become available for dialysis if identified early. Early intervention regarding identification and salvage of a non-maturing AVF is hence important.

Aims and objectives To compare the diagnostic accuracy of physical evaluation(PE) and duplex ultrasound parameters in predicting early arteriovenous fistula failure in patients undergoing haemodialysis and to find out the risk factors associated with early AVF failure.

Materials and methods This is an observational study done to compare the diagnostic accuracy of clinical evaluation and duplex ultrasound parameters in predicting early arteriovenous fistula failure in patients with chronic kidney disease undergoing hemodialysis conducted in wards and OP of Department of Nephrology, Govt. T D Medical College, Alappuzha. Study variables used in the study includes personal demographic details like age, sex, smoking, antiplatelet use, systolic and diastolic  blood pressure, diabetes mellitus, dyslipidemia, coronary artery disease etc and laboratory variables like hemoglobin, fasting lipid profile,HbA1C, serum calcium, serum phosphorous, intact parathormone(iPTH)  and serum ferritin. Physical examination of AVF and DUS was done at immediate postoperative period and at 2 weeks, 6 weeks and followed up for 3 months. Findings of Physical Examination (PE) of the AVF was validated with gold standard test Doppler ultrasound.

Results Out of the 29 cases which were predicted as successful by PE, 24 of them were finally successful. 5 of those 29 cases (which were predicted as successful by PE) were predicted failure by DUS and final status of them were failed. Out of the 31 cases which were predicted as failure by PE, 25 of them were finally failed. 6 of those 31 cases (which were predicted as failure by PE) were predicted successful by DUS, and final status of them were successful. Physical examination has a sensitivity of 83.3 %, specificity of 83.3 %, positive predictive value of 82.8 %, and negative predictive value of 80.6%. Overall accuracy of the test was 81.6 %.