A Statistical Shape Model of the Morphological Variation of the Infrarenal Abdominal Aortic Aneurysm Neck

Hostile aortic neck characteristics, such as short length and large diameter, have been associated with type Ia endoleaks and reintervention after endovascular aneurysm repair (EVAR). However, such characteristics partially describe the complex aortic neck morphology. A more comprehensive quantitative description of 3D neck shape might lead to new insights into the relationship between aortic neck morphology and EVAR outcomes in individual patients. This study identifies the 3D morphological shape components that describe the infrarenal aortic neck through a statistical shape model (SSM). Pre-EVAR CT scans of 97 patients were used to develop the SSM. Parameterization of the morphology was based on the center lumen line reconstruction, a triangular surface mesh of the aortic lumen, 3D coordinates of the renal arteries, and the distal end of the aortic neck. A principal component analysis of the parametrization of the aortic neck coordinates was used as input for the SSM. The SSM consisted of 96 principal components (PCs) that each described a unique shape feature. The first five PCs represented 95% of the total morphological variation in the dataset. The SSM is an objective model that provides a quantitative description of the neck morphology of an individual patient

Type 2 Endoleak With or Without Intervention and Survival After Endovascular Aneurysm Repair

Objective: The aims of the present study were to examine the impact of type 2 endoleaks (T2EL) on overall survival and to determine the need for secondary intervention after endovascular aneurysm repair (EVAR). Methods: A multicentre retrospective cohort study in the Netherlands was conducted among patients with an infrarenal abdominal aortic aneurysm (AAA) who underwent EVAR between 2007 and 2012. The primary endpoint was overall survival for patients with (T2EL+) or without (T2EL-) a T2EL. Secondary endpoints were sac growth, AAA rupture, and secondary intervention. Kaplan–Meier survival and multivariable Cox regression analysis were used. Results: A total of 2 018 patients were included. The median follow up was 62.1 (range 0.1 – 146.2) months. No difference in overall survival was found between T2EL+ (n = 388) and T2EL- patients (n = 1630) (p =.54). The overall survival estimates at five and 10 years were 73.3%/69.4% and 45.9%/44.1% for T2EL+/T2EL- patients, respectively. Eighty-five of 388 (21.9%) T2EL+ patients underwent a secondary intervention. There was no difference in overall survival between T2EL+ patients who underwent a secondary intervention and those who were treated conservatively (p =.081). Sac growth was observed in 89 T2EL+ patients and 44/89 patients (49.4%) underwent a secondary intervention. In 41/44 cases (93.1%), sac growth was still observed after the intervention, but was left untreated. Aneurysm rupture occurred in 4/388 T2EL patients. In Cox regression analysis, higher age, ASA classification, and maximum iliac diameter were significantly associated with worse overall survival. Conclusion: No difference in overall survival was found between T2EL+ and T2EL- patients. Also, patients who underwent a secondary intervention did not have better survival compared with those who did not undergo a secondary intervention. This study reinforces the need for conservative treatment of an isolated T2EL and the importance of a prospective study to determine possible advantages of the intervention

Midterm changes in iliac limb apposition after endovascular aortic aneurysm repair

BACKGROUND: Literature is scarce on the course of iliac endograft limb apposition after endovascular aortic aneurysm repair (EVAR), which is why this study was conducted. METHODS: A retrospective observational imaging study was performed to measure iliac apposition of endograft limbs on the first post-EVAR computed tomography angiography (CTA) scan and on the latest available follow-up CTA scan. With center lumen line reconstructions and CT-applied dedicated software, the shortest apposition length (SAL) of the endograft limbs was assessed as well as the distance between the end of the fabric and the proximal border of the internal iliac artery or the endograft-internal artery distance (EID). RESULTS: Ninety-two iliac endograft limbs were eligible for measurements, with a median follow-up of 3.3 years. At the first post-EVAR CTA, the mean SAL was 31.9±15.6 mm, and the mean EID was 19.5±11.8. At the last follow-up CTA, there was a significant decrease in apposition of 10.5±14.1 mm (P&lt;0.001) and a significant increase in EID of 5.3±9.5 mm (P&lt;0.001). A type Ib endoleak developed in three patients due to a reduced SAL. The apposition was &lt;10 mm in 24% of limbs at the last follow-up vs. 3% at the first post-EVAR CTA. CONCLUSIONS: This retrospective study documented a significant decrease in post-EVAR iliac apposition over time, partly due to retraction of iliac endograft limbs at mid-term CTA follow-up. Further research is required to identify whether regular determination of iliac apposition may predict and prevent type IB endoleaks.</p