Parent 2002.

Clinical features and settings	People of Norfolk Surgical Group who underwent endovascular graft repair of AAA. Type of stents received: EVT‐EGS/Guidant ‐ Ancure product (Menlo Park, CA, USA) used in all cases. Bifurcated endograft: 63 participants, tube endograft: 12 participants, aortoiliac endograft in 8 participants. Aneurysm diameter: not reported. Setting: unclear.
Participants	83 participants; age and gender not reported. Comorbidities: not reported. Geography: USA.
Study design	Retrospective study.
Target condition and reference standard(s)	Target condition: endoleak. Definition of endoleak: absence of perigraft flow from the source vessel identified with prior study results. Endoleak (absolute n): 23. Prevalence of endoleak: 27.7% (23/83). Reference standard: CT scan. Image acquisition: single detector helical scanner; 3 separate imaging examinations performed: precontrast run for the identification of opacities; contrast run beginning 20 s after start of infusion of 120 mL of Omnipaque 350 (Nycomed, Inc, Princeton, NJ, USA) at 4 mL/s; immediate postcontrast run for delayed imaging in search of late branch vessel endoleaks. CT scan was diagnostic for endoleak if contrast visualized exterior to endograft but within aneurysm sac. CT scan studies performed at Sentara Norfolk General Hospital, read by trained radiologists, and reviewed by authors; thickness: 3 mm: precontrast run for the identification of opacities; contrast run beginning 20 s after start of infusion of 120 mL of Omnipaque 350 (Nycomed, Inc, Princeton, NJ, USA) at 4 mL/s; immediate postcontrast run for delayed imaging in search of late branch vessel endoleaks. CT scan was diagnostic for endoleak if contrast visualized exterior to endograft but within aneurysm sac. CT scan studies performed at Sentara Norfolk General Hospital, read by trained radiologists, and reviewed by authors; thickness: 3 mm. Type of CT scanner: not reported. Use of contrast: yes, 120 mL Omnipaque 350 (Nycomed, Inc, Princeton, NJ, USA).
Index and comparator tests	Index test: CDUS. Image production: CDUS scan evidence of endoleak required identification of perigraft Doppler scan signals with colour flow and confirmed with spectral analysis and mapping of blood flow pattern. In addition, characterization of Doppler scan spectral analysis as biphasic, monophasic, or bidirectional (to/fro) obtained from CDUS scan studies. Type of US: not reported. Use of contrast: no. Operator: unclear.
Follow‐up	8 examinations suboptimal because of gassy abdomen or large abdominal girth.
Notes
Table of Methodological Quality
Item	Authors' judgement	Description
Representative spectrum? All tests	Yes	Participants represented average patients who after receiving EVAR are exposed to endoleak surveillance.
Acceptable reference standard? All tests	Yes	Reference standard was CTA.
Acceptable delay between tests? All tests	Unclear	Information reported unclear although authors reported that CDUS and CT scan examinations were scheduled within 30 days and at 3, 6, and 12 months after surgery and then annually thereafter.
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 was part of reference standard.
Reference standard results blinded? All tests	Unclear	No information provided.
Index test results blinded? All tests	Unclear	No information provided.
Relevant clinical information? All tests	Yes	Yes.
Uninterpretable results reported? All tests	Yes	8 examinations suboptimal because of gassy abdomen or large abdominal girth.
Withdrawals explained? All tests	Yes	42 (51%) participants never had an endoleak at any time in follow‐up period with CT and CDUS scan studies. Remaining 41 (49%) participants with endoleaks identified at any time in follow‐up period form basis of this analysis.