Review Article A systematic review of treatment modalities and outcomes of type Ib endoleak after endovascular abdominal aneurysm repair Claudio Bianchini Massoni, Paolo Perini, Tiziano Tecchio, Matteo Azzarone, Alessandro de Troia and Antonio Freyrie Abstract Objectives: To collect specific literature on type Ib endoleak after aorto-iliac endografting for abdominal aortic aneu- rysm, reporting data on diagnosis, treatment, and follow-up results. Methods: Publications about type Ib endoleak after aorto-iliac endografting for abdominal aortic or iliac aneurysm were searched in PubMed, Web of Science, and Scopus. Considered studies were in English and published until 3 November 2016. Research methods and reporting were performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Inclusion criteria were: (1) reporting on abdominal aortic or iliac aneurysm as primary diagnosis; (2) reporting on distal endoleak after aorto-iliac endografting. Patient data, data on endovascular treatment, endoleak, reintervention, and follow-up were collected by two independent authors. Results: Included studies were 11 (five original articles, six case reports), corresponding to 29 patients and 30 type Ib endoleak. Excluding missing data (2/30, 6.7%), type Ib endoleak was treated intra-operatively, within six months and after six months in six cases (21.4%), eight cases (28.6%), and fourteen cases (50%), respectively. Treatment of type Ib endoleak was endovascular in 27 cases (90%) (7 embolizations þ extender cuffs, 10 extender cuffs, 8 embolizations without extender cuff, 1 Palmaz stenting and 1 iliac branched endograft), hybrid in 1 case (3.3%) and surgical in 2 cases (6.6%). Buttock claudication occurred in two cases (6.7%). One-month mortality was 3.4% (2/29) without events due to type Ib endoleak. In 14 cases (46.7%), median follow-up was six months (interquartile range: 2.75–14; range: 0.75–53). Type Ib endoleak persisted or reappeared in three cases (10%), all after endovascular treatment. Two of these (2/3, 66.7%) needed endovascular reintervention. No death during follow-up was reported. Conclusions: Few specific data are available in literature about type Ib endoleak after aorto-iliac endografting for abdominal aortic aneurysm. About 50% of type Ib endoleak occurred after six months from the endovascular abdominal aneurysm repair procedure. Treatment is mainly endovascular and distal endograft extension is the main and effective treatment. Buttock claudication is the most frequent complication in case of exclusion of internal iliac artery. Persistent type Ib endoleak is possible, and adjunctive endovascular procedures are necessary. Keywords Endoleak, aortic aneurysm, abdominal, endovascular procedures, type I endoleak, type Ib endoleak, endovascular abdominal aneurysm repair Introduction Type I endoleak is defined as the persistent perfusion of the aneurysm sac from the proximal (type Ia) or distal (type Ib) edge of the endograft, following endovascular abdominal aneurysm repair (EVAR). 1 According to the guidelines of the Society for Vascular Surgery, 2 a type I endoleak is “linked to a continued risk of rupture.” In fact, the type I endoleak represents the leading cause of late rupture after EVAR in a recent meta-analysis by Antoniou et al. 3 Type Ib endoleak (IbELs) is associated with large common iliac arteries (16–22 mm in diameter) 4 or Department of Medicine and Surgery, University Hospital of Parma, Parma, Italy Corresponding author: Claudio Bianchini Massoni, Section of Vascular Surgery, Department of Medicine and Surgery, University Hospital of Parma, Via Gramsci 14, Parma 43126, Italy. Email: claudiobianchinim@gmail.com Vascular 2018, Vol. 26(1) 90–98 ! The Author(s) 2017 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/1708538117726468 journals.sagepub.com/home/vas