Schmieder 2009.

Clinical features and settings	People with AAAs who underwent elective treatment with EVAR from 11 July 1996 to 31 March 2007. Analysis excluded people with symptomatic or ruptured AAA and isolated iliac aneurysms. Type of stents received: commercially available and investigational devices, including 160 AneuRx (Medtronic, Santa Rosa, CA, USA), 55 Ancure/EVT (Guidant, Indianapolis, IN, USA), 13 Zenith (Cook, Bloomington, IN, USA), 5 Powerlink (Endologix, Irvine, CA, USA), 2 Excluder (WL Gore & Associates, Flagstaff, AZ, USA), and 1 Quantum (Cordis, New Brunswick, NJ, USA). Aneurysm diameter: not reported. Setting: division of vascular surgery.
Participants	236 participants;202 (86%) men; mean age at the time EVAR: 72 years; range: 51‐90 years. Study population: 211 (89%) white, 20 (8%) African‐American, 4 (2%) Asian, and 1 Hispanic. Comorbidities: not reported. Geography: USA.
Study design	Retrospective longitudinal study (from cohort of 496 consecutive participants, 236 participants had paired CDUS and CT scan).
Target condition and reference standard(s)	Target condition: endoleak. Definition of endoleak: not reported ("Endoleaks were categorized as type I, type II, type III or indeterminate.") Endoleak (absolute n):75. Prevalence of endoleak: 15.9% (75/472). Reference standard: contrast CT scan. Image acquisition: 2.5‐mm acquisition slice. Arterial phase acquisition obtained by mean delay of 25 s after injection. Delayed phase obtained at 70 s after completion of first scan. CT scan reconstruction used 0.625‐mm format. Interpretation of CT scan results performed by radiology. Type of scanner: GE Light‐speed plus 16‐slice scanner (GE Healthcare, Waukesha, WI, USA). Use of contrast: yes, Omnipaque 350 contrast (120 mL; GE Healthcare, Milwaukee, WI, USA).
Index and comparator tests	Index test: CDUS. Image production: endograft, proximal and distal fixation points, and AAA sac imaged in B‐mode. Size of AAA sac measured. Type of US: range: 2.5‐5 MHz curved array, phased array, or mechanical sector, and pulsed Doppler scan transducer. Use of contrast: no. Operator: 1 ("The US examinations were performed by vascular doctors dedicated to US imaging.")
Follow‐up	Unclear.
Notes
Table of Methodological Quality
Item	Authors' judgement	Description
Representative spectrum? All tests	No	From cohort of 496 consecutive participants, 236 participants had paired CDUS and CT scan.
Acceptable reference standard? All tests	Yes	Reference standard was CT scan.
Acceptable delay between tests? All tests	No	Mean interval between CDUS and CT scans 18 days; range: 0‐90 days, and 33% of paired studies performed 4 days from each other. CT scan obtained before CDUS scan 69% of time (n = 325), CDUS study obtained before CT scan 15% of time (n = 71), and both studies obtained on the same day 16% of time (n = 76).
Partial verification avoided? All tests	Yes	All study participants accounted for and results of reference standard reported for all.
Differential verification avoided? All tests	Yes	All participants who received index test subjected to same reference standard.
Incorporation avoided? All tests	Yes	Index test not part of reference standard.
Reference standard results blinded? All tests	Yes	US examinations performed by vascular doctors dedicated to US imaging, blinded to results of CTA.
Index test results blinded? All tests	Yes	Interpretation of CT scan results performed by radiology staff, whereas vascular surgery staff interpreted CDUS results.
Relevant clinical information? All tests	Yes	Yes.
Uninterpretable results reported? All tests	Unclear	Uninterpretable data of participants excluded. No specific numbers reported.
Withdrawals explained? All tests	Unclear	No information provided.