Background: Surgical management of type B aortic dissections (TBAD) remains significantly technically challenging to obtaine an adequate proximal landing zone in the descending thoracic aorta. With increasingly more options to manage TBAD to seal in zone 2 with a thoracic endovascular aortic repair (TEVAR) the risk profile needs to be identified. Methods: Data was collected by centralised centres in Sweden, New Zealand, Hungary, USA, Serbia and Switzerland using a standardised database template. These were then passed through a turn-key R script that allowed for data federation without identifiable data leaving the local region. Analysis included patient characteristics, case mix analysis, peri-operative outcomes for acute and subacute/chronic TEVAR, predictors of outcomes with multivariate analysis for per-operative mortality and neurological events as well as a sensitivity analysis. Results: A total of 3666 (68%) men and 1720 (32%) women are included in the total analysis. There was a statistically significant decrease in zone 3 TEVAR from 2014 to 2025 (p = 0.0083). Acute TEVAR had a pooled mortality of 10.0%, while occluding the LSA for zone 2 TEVAR was 12.4% and zone 3 TEVAR alone was 11.6%. Acute TEVAR had an acute kidney injury rate of 19.6% with a stroke rate of 7.2%. However subacute/chronic TEVAR had an acute kidney injury rate of 6.9% and a stroke rate of 2.1%. Occlusion of the LSA in zone 2 TEVAR carried higher mortality in subacute/chronic (7.2%) and higher stroke rates in acute treatment (10.1%). Older patients had worse outcomes in open LSA zone 2 treatment and in pooled analysis, but no difference in zone 3 treatments. Conclusions: This is the largest dataset comparing zone 2 and zone 3 TEVAR using a first-of-its-kind turnkey R analysis for true data federation while protecting data residence. Acute TEVAR carries significant additional risks, while coverage and occlusion of the LSA does not increase stroke rates but has elevated mortality rates in TEVAR of any chronicity.