Morphology-Related Limitations of Endovascular Aneurysm Repair Applicability in the Treatment of Abdominal Aortic Aneurysm in West-Central Poland

Abstract

Morphology is one of the most important factors influencing the long-term durability of endovascular repair of an infrarenal abdominal aortic aneurysm (AAA). The knowledge of morphological characteristics of AAA that may differ in various populations seems to be important for further development of a technology of endovascular repair as well as for planning of treatment strategies. To analyze the current applicability of endovascular aneurysm repair (EVAR) in patients with an infrarenal AAA with an indication for elective treatment in west-central Poland. Computed tomography angiograms of 100 consecutive patients with infrarenal AAA deemed to require treatment were analyzed with an OsiriX DICOM viewer in 3D-multiplanar reconstruction mode. Proximal neck diameter, length, angulation, shape, the presence of thrombus and calcification, distal neck diameter, and morphology of the iliac arteries were determined. Three sets of morphological criteria were established. The optimal criteria consisted of a nonconical proximal neck without moderate or severe calcification or thrombus, with a diameter of 18-28mm, length of ≥15mm, and β angulation of <60%; a distal neck with a diameter of ≥20mm; a landing zone in the common iliac arteries (CIAs) with a length of ≥10mm and diameter of ≤20mm; and external iliac arteries with diameters of ≥7mm. The suboptimal criteria included proximal neck diameters of 18-32mm, neck lengths ≥10mm, infrarenal neck angulations of up to 75°, and CIA diameters of up to 25mm. Finally, the extended suboptimal criteria included proximal neck diameters of 16-34mm and infrarenal neck angulations ≤90°, without limits in the maximal diameter of the CIAs. The median maximum aneurysm diameter was 61mm. The optimal, suboptimal, and extended suboptimal criteria were met by 23%, 32%, and 53% of patients, respectively. The most common deviations were wide, conical, and angulated proximal necks and aneurysmal iliac arteries. The majority of patients with AAA deemed to be candidates for elective repair do not meet the most favorable criteria for EVAR. Availability of better endovascular solutions for conical, angulated, and wide necks and aneurysmal iliac arteries would likely expand EVAR applicability. Open repair remains a valid option.