Partial Renal Coverage after Endovascular Aortic Aneurysm Repair with Suprarenal Fixation Seems Not to be Associated with Early Renal Impairment

Background: Efforts to achieve optimal seal during endovascular aortic aneurysm repair (EVAR) may produce partial coverage of the lowest renal artery and in some cases even occlusion. This coverage might alter the renal ostial flow, which could finally affect renal function. We sought to evaluate the incidence of renal ostium coverage and its possible effects on renal function. Methods: All patients undergoing elective EVAR with suprarenal fixation devices between January 2014, and December 2017, at our institution were identified. Patients with preoperative and postoperative computed tomography angiography (CTA), as well as the preoperative, postoperative, and one year postintervention creatinine levels and estimated glomerular filtration rate (eGFR) were included in the present study. Patients in hemodialysis, with a preoperative eGFR <30 mUmin, urgent EVAR, neck adjunctive procedures, excessive aortic thrombus, or procedure-related reintervention were excluded. Results: A total of 127 patients received EVAR for aortoiliac aneurysmatic pathologies between January 2014, and December 2017. Forty-three of them met the inclusion criteria having a median follow-up of 18.8 months (range; 12.0-53.9). Twenty-six (60.5%) patients presented at least one criterion of hostile neck condition and 23 (53.5%) had a preoperative eGFR <60 mUmin. The average distance from the proximal endograft fabric to the lower renal artery was 1.5 mm (range, 0.0-6.0) while a total of 15 renal ostia (34.9%) suffered unintended partial coverage (range, 20 to 75% of the renal ostium) in the postoperative CTA. Nine of these patients (60%) had a hostile neck condition. Eight patients (18.6%) suffered significant deterioration (>20% of the eGFR), 27 patients (62.8%) maintained their renal function and 8 (18.6%) presented an improvement of the eGFR in the latest available blood sample. Renal function impairment showed no significant association with renal ostium coverage (P = 0.561), hostile neck condition (P = 0.973), or the diameter of the renal artery (P = 0.835). In the subgroup analysis, patients with the eGFR <60 mUmin did not show significantly greater renal function deterioration (P = 0.568). Conclusions: Partial renal coverage is not an uncommon phenomenon occurring in one-third of the treated patients. However, it was not associated with renal function impairment in the early term. Further studies with longer follow-up are needed to confirm our results in the long haul.