Follow-up on Small Abdominal Aortic Aneurysms Using Three Dimensional Ultrasound: Volume Versus Diameter

Q M Ghulam; K K Bredahl; L Lönn; L Rouet; H H Sillesen; J P Eiberg

doi:10.1016/j.ejvs.2017.06.016

Follow-up on Small Abdominal Aortic Aneurysms Using Three Dimensional Ultrasound: Volume Versus Diameter

Eur J Vasc Endovasc Surg. 2017 Oct;54(4):439-445. doi: 10.1016/j.ejvs.2017.06.016. Epub 2017 Jul 29.

Authors

Q M Ghulam¹, K K Bredahl², L Lönn³, L Rouet⁴, H H Sillesen⁵, J P Eiberg⁶

Affiliations

¹ Department of Vascular Surgery, Rigshospitalet, University of Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Electronic address: http://twitter.com/@Rigshospitalet.
² Department of Vascular Surgery, Rigshospitalet, University of Copenhagen, Denmark.
³ Department of Interventional Radiology, Rigshospitalet, University of Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
⁴ Medisys, Philips Research, Suresnes, France.
⁵ Department of Vascular Surgery, Rigshospitalet, University of Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
⁶ Department of Vascular Surgery, Rigshospitalet, University of Copenhagen, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Denmark; Copenhagen Academy of Medical Education and Simulation, Capital Region of Denmark, Copenhagen, Denmark.

PMID: 28765014
DOI: 10.1016/j.ejvs.2017.06.016

Abstract

Objectives: Rupture risk in abdominal aortic aneurysms (AAAs) is assessed using AAA diameter; yet 10% of ruptures occur in a small aneurysm. This underlines the inadequacy of diameter as a standalone parameter. In this prospective follow-up study, ultrasound determined aneurysm diameter was compared with aneurysm volume determined by three dimensional ultrasound (3D-US) in a group of 179 AAAs.

Design: This was a prospective cohort study with repeated diameter and volume measurements by 3D-US.

Material and methods: In total, 179 patients with small infrarenal AAAs (diameter 30-55 mm) were enrolled consecutively. At enrolment and at 12 month follow-up, maximum diameter, using dual plane technique, and three dimensional volume were measured. Based on a previous accuracy study, significant change in diameter and volume were defined as an increase exceeding the known range of variability (ROV) of each US technique; ±3.7 mm and ±8.8 mL, respectively. Post-hoc Kaplan-Meier analysis was performed to estimate time to conversion to treatment after the conclusion of the follow-up period between two groups.

Results: In total, 125 patients (70%) had an unchanged diameter during follow-up. In this group, 50 patients (40%) had an increasing aortic volume. Forty-five (83%) of the 54 patients with an increasing aortic diameter showed a corresponding volume increase. During a median follow-up of 367 days (364-380 days), a mean increase in diameter of 2.7 mm (±2.6 mm) and a mean increase in volume of 11.6 mL (±9.9 mL) were recorded. In post-hoc analysis, it was found that more AAAs with a stable diameter and a growing volume than AAAs with a stable diameter and volume were undergoing aortic repair during follow-up, based on the maximum diameter.

Conclusion: In this cohort of small AAAs, 40% of patients with a stable diameter had an increasing volume at 12 month follow-up. From this perspective, 3D-US could have a future supplemental role in AAA surveillance programmes.

Keywords: AAA surveillance; Abdominal aortic aneurysm; Aneurysm diameter; Aneurysm volume; Three dimensional ultrasound.

MeSH terms

Aged
Aged, 80 and over
Aortic Aneurysm, Abdominal / diagnostic imaging*
Aortic Aneurysm, Abdominal / surgery
Female
Follow-Up Studies
Humans
Imaging, Three-Dimensional*
Kaplan-Meier Estimate
Male
Middle Aged
Patient Selection
Prospective Studies
Ultrasonography*
Watchful Waiting