Potential Value of Aneurysm Sac Volume Measurements in Addition to Diameter Measurements after Endovascular Aneurysm Repair

• Published in: Journal of endovascular therapy 2009-08, Vol.16 (4), p.506-513
• Main Authors: van Keulen, Jasper W., van Prehn, Joffrey, Prokop, Mathias, Moll, Frans L., van Herwaarden, Joost A.
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Aneurysms; Aortic Aneurysm, Abdominal - diagnostic imaging; Aortic Aneurysm, Abdominal - surgery; Aortography - methods; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation - instrumentation; Changes; Clinical outcomes; Composition; Databases as Topic; Female; Humans; Male; Medical imaging; Middle Aged; Postoperative period; Predictive Value of Tests; Prosthesis Failure; Stents; Time Factors; Tomography, Spiral Computed; Treatment Outcome
• ISSN: 1526-6028; 1545-1550
• DOI: 10.1583/09-2690.1

Purpose: To investigate the value of aneurysm sac volume measurement in addition to diameter measurements based on computed tomographic angiography (CTA) after endovascular aneurysm repair (EVAR). Methods: Interrogation of a vascular database identified 56 patients (51 men; median age 77 years, range 59–92), 28 with an endoleak and 28 without, who had digital CTA data available at baseline (first postoperative scan) and at 1 and 2 years after EVAR. Total aneurysm volume, transverse maximum diameter (TMD), and orthogonal maximum diameter (OMD; perpendicular to the aortic center lumen line) were compared for all patients and between those with and without endoleak. Differences of 5% for volume and 5 mm for diameters were considered a significant change. Kappa statistics were used to compare measurements. Results: Volumetry detected aneurysm growth in 32 (24%) of 131 scans, which was reflected by TMD in 12 (38%) and by OMD in 14 (44%). Eighteen scans with increasing aneurysm volume were measured in patients with endoleaks, which was documented by TMD in 6 (33%) and by OMD in 8 (44%). Fourteen volume increases were measured in patients without endoleak; both TMD and OMD documented only 43%. Volumetry detected aneurysm shrinkage in 71 (54%) of 131 scans [detected by TMD in 38 (54%) and by OMD in 37 (52%)]. Thirty-two volume decreases were measured in patients with an endoleak, noted by TMD in 18 (56%) and OMD in 14 (44%). Thirty-nine scans showed decreasing volumes in patients without endoleaks; the TMD corresponded in 20 (51%) and the OMD in 23 (59%). The kappa agreements for volume increase were 0.42 (TMD) and 0.35 (OMD) and for volume decrease 0.48 (TMD) and 0.47 (OMD); different thresholds of change produced similar moderate-range kappa values (0.3–0.6). Conclusion: Volumetry detects sac size changes that are not reflected in diameter measurements. Vice versa, diameters can increase without a total volume increase, which might indicate a variety of morphological aneurysm changes. The agreement between volume and diameter measurements using different cutoff values is equally moderate. Volume measurements should be performed in addition to diameter measurements.