Patients and Methods
Between January 2018 and March 2020, we organized a follow-up protocol between Department of Radiology and Department of Cardiovascular Surgery. Consecutive 84 patients who experienced elective and standard EVAR procedure for infrarenal abdominal aortic aneurysm, were evaluated in the outpatient clinic. The mean age of the patients was 68.5±7.8 years (61-89 years). Patient demographics are given in table 1. Hybrid operations, complex EVAR procedures (chimney, snorkel) and emergency cases were excluded. Two operators were performing all the CDUS from the Radiology Department. CDUS operators were blind of any CTA reports as CDUS was carried out first. The time between two modalities was 7 days in average. The reporting protocol was organized as the detection of an endoleak and sac measurements. Caliper placements for measurement of aortic diameter were put into a consensus as outer to outer manner. All reports were recorded to patient’s charts.
Commercially available devices were used during the study, including Medtronic Endurant II, Endologix AFX, Gore Excluder, Jotec and Lifetech Ankura. Endoskeletons were nitinol except Endologix AFX (cobalt chromium) and graft material was Dacron or PTFE.
This study follows the Declaration of Helsinki and ethical approval was granted by the local institutional ethical board. In addition, informed consent was obtained from all the patients.
CDUS. All CDUS was performed by using a GE Logiq S7 Expert R3 (General Electric Company, Millwakuee, WI) equipped with C1-6 Mhz curvilinear broadband transducer probe. Aorta was scanned from the diaphragm to the iliac vessels by transverse and longitudinal planes, the aortic diameter was measured outer to outer manner always. Multiple transverse and anteroposterior measurements were obtained, and maximum measurements were recorded. All patients were asked to fast up to 6-8 hours. All patients were scanned in the supine position in a dark out-patient clinic room according to the organized protocol. The endograft and the aneurysm sac were assessed using B-mode, color flow and spectral Doppler to rule out any endoleak. Doppler scan with color flow was confirmed with spectral analysis and mapping of blood flow pattern. Contrast was not used in any patient.
CTA. The CTA protocol consisted of a set of an arterial scan phase followed by a single venous scan phase. All of the CT angiograms were obtained with a 512 - slice CT scanner (Revolution CT, GE Healthcare, Waukesha, Wisconsin, US). Patients were examined in the supine position. After localizer scans were obtained and 90 mL of nonionic iodinated contrast material (Iohexol, Omnipaque 350 mg of iodine per milliliter; GE Healthcare) was injected at a flow rate of 4 mL/sec through an 18-gauge antecubital intravenous line, the CT angiography series was started with bolus-tracking measurement in the abdominal aorta at a threshold of 170 HU. The arterial phase of the series was followed by venous phase scanning that covered the entire abdominal aorta, with a delay of 80 seconds after completion of the first scan