Outcomes and predictors of renal artery stenting after kidney transplant angiography: a retrospective study

Up to 23% of renal transplant recipients may develop transplant renal artery stenosis (TRAS). However, diagnosis requires angiography, and the contrast used may be nephrotoxic. We aimed to identify predictors of TRAS and clarify the safety and outcomes of angiography.

We conducted a retrospective study of renal transplant recipients at a single institution from August 2016 to August 2024 who subsequently underwent transplant renal artery angiography for suspected TRAS. Patient demographics, preprocedure ultrasound findings and creatinine levels, intraoperative findings, and postprocedure creatinine levels were collected and analyzed using SPSS ver. 29.0.

During the study period, 614 patients underwent renal transplantation, and 103 subsequently underwent transplant angiography. The median contrast load was 10 mL (±13.0 mL). No significant change in creatinine levels was observed after the procedure despite contrast exposure (ΔCr 0.02, P=0.904). Overall, 57 patients had confirmed TRAS requiring vascular stent insertion. These patients had higher preangiogram arterial velocities on transplant renal ultrasound (431.5 vs. 388.6 cm/sec, P=0.046). Risk factors for TRAS included deceased donor kidney transplantation, longer cold ischemia time, and shorter anastomosis time. After adjusting for other covariates, a preoperative ultrasound velocity >400 cm/sec was associated with 4-fold higher odds of arterial stenting (P=0.01).

Preprocedure renal ultrasound velocity >400 cm/sec is a strong predictor of TRAS requiring intervention. After angiography and stenting, patients with TRAS exhibit a significant decrease in creatinine. Patients without TRAS display no significant creatine difference, suggesting that the procedure is safe and efficacious and requires a negligible contrast load.