ObjectiveTo report outcomes of urgent juxta/para-renal aneurysms (J/P-AAAs) managed by off-the-shelf multibranched thoracoabdominal endografts (Cook, T-branch). MethodsIn this observational, multicenter, retrospective study, patients with J/P-AAAs treated by urgent endovascular repair by T-branch in 23 European aortic centers, from 2013 to 2023, were analyzed. Contained J/P-AAAs rupture, presence of related symptoms, and aneurysm diameter >70mm were considered as indication for urgent repair. Technical success (TS), spinal cord ischemia (SCI) and 30-day/hospital mortality were assessed as early outcomes. Survival, freedom from (FF) reinterventions and target arteries instability (TAI) were evaluated during follow-up. ResultsOverall, 197 patients [J-AAAs:64(33%), P-AAAs:95(48%), previous failed-EVAR 38(19%)] were analyzed. The mean age and aneurysm diameter was 75+8 years and 76+4 mm, respectively. The ASA score was 3 and 4 in 118(60%) and 79(40%) patients. Rupture, symptoms and diameter >70mm were present in 51(26%), 110(56%) and 53(27%) patients, respectively. An adjunctive proximal thoracic endograft was used in 28(14%) cases. The mean aortic coverage between the upper portion of the endograft and the lowest renal artery was 154+49mm. Single-stage repair and cerebral-spinal-fluid drainage were reported in 144(73%) and 53(27%) cases, respectively. TS was achieved in 182(92%) cases (rupture:84% vs no rupture:95%; P:.02). Failures consist of target artery loss (11-6%: renal artery - 9; celiac trunk - 2), type I-III endoleak (2-1%) and 24-h mortality (2-1%). Rupture was a risk-factor for technical failure (P:.02;OR:3.8;95%CI:1.1-12.1). Overall, 15(8%) patients had persistent SCI (rupture:14% vs no rupture:5%) with 11(6%) cases of paraplegia (rupture:10% vs no rupture:5%; P:.001). Rupture (P:.04;OR:3.1;95%CI:1.1-8.9) and adjunctive proximal thoracic endograft (P:.01;OR:4.1;95%CI:1.3-12.9) were risk-factors for SCI. Twenty-two (11%) patients died within 30-day or during a prolonged hospitalization. Previous failed-EVAR (P:.04;OR:3.6;95%CI:1.1-12.3), paraplegia (P:<.001;OR:9.9;95%CI:1.6-62.2), postoperative mesenteric complications (P:.03;OR:10.4;95%CI:1.2-93.3) as well as cardiac (P:.03;OR:8.2;95%CI:2.0-33.0) and respiratory (P:<.001;OR:10.1;95%CI:2.9-35.2) morbidities were associated with 30-day/hospital mortality. The mean follow-up was 19+5months. Estimated 3-year survival and FF-reinterventions was 58% and 77%, respectively. TAI occurred in 27(14%) patients (occlusion:15, endoleak:14) with an estimated 3-year FF-TAI of 72%. ConclusionsUrgent repair of J/P-AAAs by T-branchis feasible and effective with satisfactory TS and 30-day/hospital mortality in high-risk patients. However, extensive aortic coverage is necessary, leading to a not negligible SCI rate, especially in case of aortic rupture or when adjunctive thoracic endografts are necessary. Previous failed-EVAR, postoperative mesenteric complications as well as cardiac and respiratory morbidities were associated with 30-day/hospital mortality and they should be subjected to more research for the purpose of improving outcomes.