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

Abstract

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.

Evaluation of Deep Neural Network Models for Instance Segmentation of Lumbar Spine MRI

“…By sampling from the SSM, different lumbar spine shapes can be generated, and each generated lumbar spine shape could be considered from a virtual patient. We note that the SSM technique has been used to generate virtual but realistic patient geometries in many applications, such as generating aortic aneurysm geometries (Liang et al, 2017; van Veldhuizen et al, 2022; Wiputra et al, 2023). Given a lumbar spine shape, if a lumbar spine MR image can be generated and consistent with the shape, then we will have a new sample with ground-truth.…”

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

“…The data were preprocessed for a PCA of the infrarenal AAA neck by means of a parametrization method, including rigid registration, as described in more detail in a previous publication by our study group. 16 For each patient, 360 contour points along 10 center lumen line points were created, ensuring anatomical point-to-point correspondence. All infrarenal aortic necks in the dataset were aligned at the lowest renal artery baseline, based on these contour points.…”

“…The quality of the SSM was quantitatively evaluated by calculating the generalization ability, by means of a leave-one-out cross-validation method. 16…”

“…15 Recently, we introduced an SSM for the aortic neck of infrarenal abdominal aortic aneurysm (AAA) patients who were treated with EVAR and who did not suffer from neck-related complications. 16 This study investigates the mid-term discriminative ability of an SSM of the infrarenal aortic neck compared with or in combination with conventional measurements in patients who developed T1aEL post-EVAR.…”

Selective aneurysmal sac neck-targeted embolization during endovascular aneurysm repair of abdominal aortic aneurysm with hostile neck anatomy

“…1,2 The shape of the aortic neck is the most important morphological characteristic of Infrarenal AAA for determining the success of endograft repair. 3,4 To achieve great long-term outcomes, aortic endograft manufacturers have de ned precise anatomic parameters of the proximal aneurysm neck, such as the length, diameter, and infrarenal angulation, as instructions for use (IFU) of the endograft. The aortic neck anatomy that exceeds their IFU is referred to be hostile neck anatomy.…”