Carbon Dioxide Angiography in the Treatment of Transplant Renal Artery Stenosis

Background: Transplant renal artery stenosis (TRAS) is a serious complication associated with graft loss. Selective carbon dioxide angiography allows for effective diagnosis and therapy with the use of minimal to no contrast agent. This study sought to evaluate the efficacy of the adjunctive use of carbon dioxide angiography in the treatment of TRAS. Methods: Patients undergoing endovascular therapy (percutaneous transluminal angioplasty with or without stent) for TRAS between the years 2012 and 2017 at a single tertiary care academic medical center were studied. Outcomes of interest included technical success, postoperative glomerular filtration rate, and renal ultrasound hemodynamic parameters. Results: Of the 37 patients who underwent angiography for TRAS during the study period, 34 underwent a therapeutic intervention. Of those, 24 patients (70.6%) underwent adjunctive carbon dioxide angiography versus 10 patients (29.4%) who underwent standard contrast angiography. Baseline characteristics between the carbon dioxide angiography and traditional angiography groups were similar. Patients undergoing carbon dioxide angiography received significantly less contrast agent than patients undergoing traditional angiography [9.5 mL (IQR 2-19.5) versus 19.5 mL (IQR 15-30), P = 0.03)] and maintained equivalent technical success rates (92.2% vs. 91.7%, P = 0.9). Conclusions: The adjunctive use of carbon dioxide angiography allows for significantly less contrast administration compared with standard angiography while achieving an equivalent rate of technical success. Selective carbon dioxide angiography should be considered a first-line modality for patients with TRAS in need of endovascular therapy.