Endograft apposition and infrarenal neck enlargement after endovascular aortic aneurysm repair

Abstract

BACKGROUND: Sufficient apposition and oversizing of the endograft in the aortic neck are both essential for durable endovascular aneurysm repair (EVAR). These measures are however not regularly stated on post-EVAR computed tomography angiography (CTA) scan reports. In this study endograft apposition and neck enlargement (NE) after EVAR with an Endurant II(s) endograft were analyzed and associated with supra-and infrarenal aortic neck morphology. METHODS:In 97 consecutive elective patients, the aortic neck morphology was measured on the pre-EVAR CTA scan on a 3mensio vascular workstation. The distance between the lowest renal artery and the proximal edge of the fabric (shortest fabric distance, SFD), and the shortest length of circumferential apposition between endograft and aortic wall (shortest apposition length, SAL) was determined on the early post-EVAR CTA scan. NE, defined as the aortic diameter change between pre-and post-EVAR CTA scan, was determined at eight levels: +40, +30, +20, +15, +10, 0, -5 and -10 mm relative to the lowest renal artery baseline.The aortic neck diameter and preoperative oversizing were correlated to NE with the Pearson correlation coefficient. The effective post-EVAR endograft oversizing is calculated from the nominal endograft diameter and the post-EVAR neck diameter where the endograft is circumferentially apposed. RESULTS:The median time (interquartile range, IQR) between the EVAR procedure and the pre-and post-EVAR CTA scan was 40 (25, 71) days and 36 (30, 46) days, respectively. The Endurant II(s) endograft was deployed with a median (IQR) SFD of 1.0 (0.0, 3.0) mm. The SAL was <10 mm in 9% of patients and significantly influenced by the pre-EVAR aortic neck length (p=0.001), hostile neck shape (p=0.017), and maximum curvature at the suprarenal aorta (p=0.039). The median (interquartile range) SAL was 21.0 (15.0, 27.0) mm with a median (IQR) pre-EVAR infrarenal neck length of 23.5 (13.0, 34.8) mm. The median (IQR) 3 difference between the SAL and neck length was -5.0 (-12.0, 2.8) mm. Significant (p<.001) NE of 1.7 (0.9, 2.5) mm was observed 5 mm below the renal artery baseline, which resulted in an effective post-EVAR endograft oversizing <10% in 43% of the patients. No correlation was found between NE and aortic neck diameter or preoperative oversizing. CONCLUSIONS:Circumferential apposition between an endograft and the infrarenal aortic neck, SAL, and NE can be derived from standard postoperative CT scans. These variables provide essential information about the post-procedural endograft and aortic neck morphology regardless of the preoperative measurements. Patients with SAL <10 mm or effective oversizing <10% due to NE may benefit from intensified follow-up, but clinical consequences of SAL and NE should be evaluated in future longitudinal studies with longer term follow-up.

Supra- and Infra-Renal Aortic Neck Diameter Increase after Endovascular Repair of a Ruptured Abdominal Aortic Aneurysm

“…The 2.7 ± 1.9 mm infra-renal neck diameter increase in patients with rAAA was substantially more than the 0.9 ± 3.6 mm to 1.6 (1.0, 2.7) mm diameter increase reported for elective EVAR patients at the first postoperative CTA scan [ 11 , 16 ]. The neck diameter increase found in this study is comparable with >3 years of gradual aortic neck diameter increase in elective EVAR patients [ 17 ].…”

“…The endograft main body nominal diameter was obtained from the patient records. There were two endograft oversizing parameters defined: the planned pre-EVAR endograft oversizing and the effective post-EVAR endograft oversizing [ 11 ]. The planned pre- and the effective post-EVAR endograft oversizing were calculated from the nominal endograft diameter and the pre- and post-EVAR neck diameter at the lowest renal artery baseline, respectively, as shown in Formulas (1) and (2): …”

A Statistical Shape Model of Infrarenal Aortic Necks in Patients With and Without Late Type Ia Endoleak After Endovascular Aneurysm Repair

“…This group has also been described in a previous study. 21 Follow-up scans, either CTA or duplex ultrasound, were evaluated in July 2021 to assess the absence of EVAR-related complications. Patients with the longest duration of CTA or duplex ultrasound follow-up were selected, to match the number of patients in the T1aEL group.…”

Pre-operative Aortic Neck Characteristics and Post-operative Sealing Zone as Predictors of Type 1a Endoleak and Migration After Endovascular Aneurysm Repair: A Systematic Review and Meta-Analysis

“…nominal endograft diameter postÀEVAR neck diameter À 1 Â 100% 65 For post-EVAR outcomes, it is absolutely undesirable to pool different types of endoleak. Types 1a, 1b, 2, and 3 endoleak have different origins with different consequences, and the re-intervention strategy is different.…”

“…nominal endograft diameter postÀEVAR neck diameter À 1 Â 100% 65 Type of endoleak: documented as present or absent (including 1a, 1b, 2, 3). 62 Clinically relevant migration: migration resulting in a decrease in the real achieved sealing zone < 10 mm, documented as present or absent.…”