Transatlantic Delphi Consensus on the Common Iliac Artery Sealing Zone in Endovascular Aorto-Iliac Aneurysm Repair (the DECIDE Study)

objective: Knowledge of hostile factors and their influence on long-term seal in the iliac landing zone is limited. currently endorsed clinical practice guidelines lack structural evidence on how the iliac landing zone should be assessed in the pre-, intra-, and postoperative phases. the goal of this study was to obtain an international, expert-based consensus on the definition of a hostile iliac landing zone, on how to size and plan stent-grafts to optimize sustainable distal seal, and on the postprocedural follow-up protocol. methods: delphi consensus methodology was used, involving a panel of international vascular surgeons experienced in endovascular aneurysm repair (EVAR). the first round consisted of open-ended and multiple-choice questions to explore current practices, with subsequent rounds refining statements through a 4-point likert scale. consensus was defined as >75% agreement or disagreement, and the analysis included stability testing and strength of consensus. results: the study engaged 77 international vascular surgeons, reflecting diverse geographic locations and hospital affiliations. consensus was achieved on critical preoperative planning elements for EVAR, including a clear definition for a hostile iliac landing zone. the importance of computed tomography angiography for postoperative follow-up imaging was emphasized, including evaluating distal seal length and recommending specific timing for follow-up computed tomography scans and intervention strategies for diminishing iliac seal. conclusions: this international expert-based delphi consensus establishes a comprehensive set of consensus-driven recommendations focused on the definition and management of hostile iliac landing zones in EVAR. the key recommendation of this study is the definition of a hostile iliac landing zone as short (<15 mm), wide (>24 mm), or conical (>10% diameter difference along the landing zone). although consensus was achieved on several critical aspects, the study also reveals ongoing debates and considerations that warrant further exploration, including how to tackle diminishing seal without a type IB endoleak. clinical Impact: this delphi consensus introduces a standardized definition of a hostile iliac landing zone as short (<15 mm), wide (>24 mm), or conical (>10% diameter difference), clinicians now have a clearer framework for assessing complex anatomies. this study provides a comprehensive set of consensus-driven recommendations focused on the definition and management of hostile iliac landing zones in EVAR which gives guidance where current guidelines lack specificity, particularly for distal iliac sealing. the study also reveals ongoing debates and considerations that warrant further exploration, including how to tackle diminishing seal without a type IB endoleak.