Early Impact on Renal Parenchymal Vascularization of Chimney Grafts Versus Fenestrated Grafts

Objective: The primary objective of this retrospective study was to analyze the early impact of chimney (CG) versus fenestrated grafts (FG) on renal parenchymal vascularization and function.

Methods: All consecutive patients with juxta-renal abdominal aortic aneurysm (JR-AAA) treated by endovascular repair from December 2013 to July 2014 at the vascular unit, Pellegrin University Hospital, Bordeaux, France, were included. Serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) were reported at baseline and at J2 for acute kidney injury (AKI) incidence, and at J7 for AKI staging (KDIGO criteria); renal resistive indices (RRI) were reported for renal parenchymal repercussion at J-1, J0, and J1.

Results: Ten patients were included in the CG group and 25 in the FG group, with 13 and 50 renal target vessels, respectively. Successful target vessel revascularization was achieved in 92.3% and 100.0% of patients. The incidence of AKI (10% and 32%), baseline SCr, and eGFR did not differ significantly. SCr was more elevated in the FG group at J1 (p = .025), J2 (p = .051), and J7 (p = .052), and eGFR was significantly lower from baseline to J1 (p = .015) and J2 (p = .014). RRI did not differ significantly between both groups. RRI augmentation was only noted in the FG group from J-1 to J0 (p = .039) and J-1 to J1 (p = .059). Patients with a KDIGO score <2 versus ≥2 showed significantly different RRI at J0 (p = .038) and J1 (p = .007). ROC curve analysis showed that RRI measures could be a predictive factor for AKI at J0 (cutoff = 0.72, sensitivity [Se] = 50%, specificity [Sp] = 86%) and J1 (cutoff = 0.71, Se = 70%, Sp = 84%).

Conclusions: This study showed no significant difference in terms of RRI, eGFR, and the incidence of AKI or CKD between CG and FG. However, post-operative SCr levels were higher with FG, which was corroborated by comparison between pre- and post-operative RRI. Results are limited by the small sample size, but early repeated measures of RRI could be helpful in alerting the clinician to post-operative renal degradation, allowing better-informed attempts to preserve renal function.