BACKGROUND: Management of juxta-renal abdominal aortic aneurysms (JRAAA) remains challenging. Both open surgical and endovascular options are feasible, however, there is lack of level 1 evidence to support one modality over the other. Operative interventions frequently necessitate either open repair with a suprarenal clamp positioning (ORSRC) or complex endovascular repair (EVAR) with fenestrated (fEVAR) or parallel stent grafts (chEVAR). AIM: The aim of this study was to compare the renal function deterioration and mortality between ORSRC and fEVAR in patients who were operated on for unruptured JRAAA at a tertiary centre. DESIGN: This was a retrospective observational study of patients. SETTING: Tertiary vascular unit in the United Kingdom. POPULATION: Patients with unruptured juxta-renal AAA. METHODS: A retrospective review of prospectively collected data was performed on patients who underwent repair for unruptured JRAAA between March 2008 and October 2019. Analysis of short and mid-term outcomes after ORSRC (occlusion of the aorta above at least one of the main renal arteries) and fEVAR was conducted. Patients who underwent open repair of JRAAA with an infrarenal clamp were excluded. Procedural data as well as data regarding complications was noted. Acute kidney injury (AKI) and chronic kidney disease were defined using the KDIGO criteria (Kidney Disease: Improving Global Outcomes). Renal impairment data up to 1 year and mortality up to 5 years was recorded. RESULTS: During the study period, 162 patients who underwent JRAAA repair met the inclusion criteria (60.5% of them having ORSRC). Approximately, 85.8% of the population were males (80.6% in the open group compared to 93.7% in the endovascular group; p=0.019). The mean age for patients in the open group was 74.0 (SD=±5.5) years compared to 76.1 (SD=±7.2) years in the fEVAR group (p=0.035). More patients in the ORSRC group were symptomatic (18.4% versus 6.3% in the fEVAR group; p=0.028) and they also had larger aneurysms compared to the fEVAR group (66.9 (±12.7) mm versus 62.6 (±8.6) mm, respectively; p=0.021). In the ORSRC group, all patients required suprarenal clamping, with clamping above only one of the main renal arteries carried out in 43 patients (44.3%) of cases. At baseline, 37.0% and 44.5% of patients had CKD stage 3 or worse in ORSRC and fEVAR groups, respectively (p=0.759). Approximately 47.6% of patients having ORSRC had evidence of acute renal impairment on post-operative day 3 compared to 12.7% of those in the endovascular group (p<0.05). By 9-12 months, 54.6% of patients in the OR group had a CKD stage of 3 or worse, compared to 62.1% of patients in the fEVAR group (Pearson χ2, p=0.713). The median total length of stay (LOS) was 10 days for OR versus 6 days for fEVAR (p<0.05). Patients having fEVAR were more likely to require re-intervention (26.6% v/s 10.2%; p=0.006). Mortality at 30 days was 8.2% for ORSRC against 7.8% for complex EVAR (p=0.936). The corresponding figures at 1 and 5 years were 10.2% and 25.5% for ORSRC compared to 14.1% and 32.8% (p=0.456 and p=0.314, respectively). CONCLUSIONS: In the context of JRAAA, patients receiving fEVAR procedures tended to be older, with a smaller diameter aneurysm. Postoperatively, fEVAR was associated with shorter hospitalisation and less risk of AKI in the immediate post-operative course, but had a greater likelihood of requiring re-intervention over time. Both interventions had similar rate of renal function deterioration at 1 year and the five year mortality rate was comparable.