Session Name: Kidney: Cardiovascular and Metabolic Complications II
Date: Saturday, May 30, 2020
Session Time: 3:15pm-4:45pm
Presentation Time: 3:51pm-4:03pm
*Purpose: Non-contrast MRA can be fraught with artifact and lack of signal both in areas of stenosis as well as normal vessels. Therefore, it is imperative to utilize an MRA sequence that is not dependent on the direction of the underlying artery when scanning transplant renal arteries which often have variable trajectories from their anastomoses and tortuous or kinked segments. The purpose of this study is to determine the accuracy of NATIVE (Non-contrast MRA of the ArTeries and VEins) TrueFISP and NATIVE GRE in the detection, exclusion, and characterization of renal transplant artery stenosis and kinking compared to catheter-based angiography, the gold-standard.
*Methods: Retrospective chart review of all kidney transplant patients that were referred for non-contrast MRA between November 2017 and June 20, 2019. These patients were scanned with the NATIVE sequence with precise 3D reconstruction performed by an expert vascular radiologist. The MRA results were categorized as positive or negative based on the initial interpretation prior to invasive angiography. The positive MRA cases were correlated to CO2 and iodine-based contrast angiography. The negative MRA cases were considered true negatives if a follow-up invasive angiogram documented a patent renal artery, if follow-up Doppler was normal, or if kidney dysfunction was attributed to another cause. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated.
*Results: During the study period, of 908 kidney transplants performed, 89 patients (62 men and 27 women) were referred for MRA with a mean age of 57 years (13 – 79 years); 87 were referred to MRA due to abnormally elevated renal artery velocities (>250 cm/sec) by Doppler ultrasound, while 2 were referred due to clinical suspicion. There were 38 true positive MRA results, while 7 were false positives based on later angiography; 44 were true negative and none were false negative. The sensitivity, specificity, PPV, NPV, and accuracy of MRA were 100%, 86%, 84%, 100%, and 92%, respectively.
*Conclusions: Given the above findings, using this MRA technique with diligent 3D reconstruction, we were able to avoid invasive and costly angiograms with associated risks to the kidney graft in a large number (44) of patients. Our study demonstrates the feasibility of using this non-contrast MRA technique which is highly specific and even more sensitive to reliably triage management of suspected renal artery stenosis. This technique should be further validated in other institutions to ensure reproducibility.
To cite this abstract in AMA style:Infante JC, Mattiazzi A, Morsi M, Guerra G, Defreitas MJ, Chandar J, Chen LJ, Burke GW, Figueiro J, Ciancio G. Time for Change: Assessment of Renal Transplant Artery Stenosis with N.A.T.I.V.E. True-F.I.S.P. and N.A.T.I.V.E. G.R.E [abstract]. Am J Transplant. 2020; 20 (suppl 3). https://atcmeetingabstracts.com/abstract/time-for-change-assessment-of-renal-transplant-artery-stenosis-with-n-a-t-i-v-e-true-f-i-s-p-and-n-a-t-i-v-e-g-r-e/. Accessed May 7, 2021.
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