"Over-SIRIX": A New Method for Sizing Aortic Endografts in Combination with the Chimney Grafts: Early Experience with...

Large gutters after chimney procedures are one of the main causes of type I endoleak (EL-I). This study aims to evaluate a new tailored planning named "Over-SIRIX," based on Osirix Imaging Software, to choose the correct main graft oversizing in order to minimize EL-I incidence.

From 2008 to 2015, 34 patients were treated with parallel grafts for aortic arch diseases at our institution. The study included 22 patients with single stent and antegrade flow configuration; they were divided into 2 groups (PRE- and POST-"Over-SIRIX"). "Over-SIRIX" was carried out in the retrospective group (PRE-"Over-SIRIX"), and it was used to plan the endovascular procedure in the prospective group (POST-"Over-SIRIX"). Through the multiplanar reconstruction (MPR) of the preoperative computed tomography angiography (CTA), the proximal neck of the chimney grafts was studied. Stent and endograft configurations were drawn in order to minimize the "gutters." To obtain the ideal main graft sizing (I-Size), a formula was used by adding the custom sizing (C-Size) to the disease oversizing (D-Over). The same MPR imaging was evaluated on postoperative CTA to study gutters area and presence of EL-I.

The mean I-Size was 41.67 mm that was equivalent to an ideal oversizing of 19.3% (range 10-28%). The gutters area decreased from 7.3 to 1.7 mm² (PRE/POST) and EL-I rate from 28.5% to 0% (PRE/POST). Gutters area bigger than 7.5 mm² and planning made without "Over-SIRIX" were significantly associated (P < 0.05) to EL-I.

"Over-SIRIX" appears to be a feasible method to customize planning during chimney technique, reducing the risk of EL-I which is significantly related to the presence and size of the gutters.