Thompson 1998.

Clinical features and settings	20 people who received endovascular grafts for infrarenal aortic aneurysms. Type of stent received: 6 aortic tube endografts (Endovascular Technologies EGS, Menlo Park, CA, USA), 3 bifurcated systems (Stentor; Mintec, Freeport, Bahamas), and 11 tapered aorto‐uni‐iliac graft. Aneurysm diameter: median transverse diameter: 5.2 cm; range: 4.8‐7.3 cm measured by CT. Setting: department of surgery.
Participants	Median age: 72 years; range: 68‐84 years; median aneurysm diameter: 5.2 cm; range: 4.8‐7.3 cm measured by CT; 5.0 cm; range: 4.3‐7.0 cm measured by duplex imaging; median follow‐up: 14 months; range: 6‐31 months. Comorbidities: not reported. Geography: UK.
Study design	All participants who had a technically successful EVAR were entered into a standard prospective surveillance programme at 3, 6, 12, 18, and 24 months following repair.
Target condition and reference standard(s)	Target condition: endoleak. Definition of endoleak: to presence or absence of flow within aneurysm sac. Endoleak (absolute n):75. Prevalence of endoleak: 15.9% (49/494). Reference standard: contrast CT scan. Image acquisition: initial tomogram determined cranial extent of proximal metallic stent. 30 s following IV injection of contrast, serial 10‐mm slices performed from renal arteries to level of femoral head. Endograft imaged to determine presence of thrombus within graft lumen. Type of CT scanner: Siemens HiQ scanner (Munich, Germany). Use of contrast: yes (type unclear).
Index and comparator tests	Index test: CDUS. Image production: "Duplex imaging was performed with the patient supine using a 3.5 MHz curved linear array transducer, HDI Ultramark 9 (ATL, Letchworth, UK). Colour Doppler ultrasonography was utilized to image flow within the graft, and any flow disturbance was noted. Endoleaks were specifically sought with the colour Doppler set to detect low flow." Type of US: 3.5‐MHz curved linear array transducer, HDI Ultramark 9 (ATL, Letchworth, UK). Use of contrast: no. Operator: 2 ("Diagnostic imaging was performed by investigators.")
Follow‐up	Unclear.
Notes
Table of Methodological Quality
Item	Authors' judgement	Description
Representative spectrum? All tests	Yes	Up to December 1996, EVAR was attempted in 48 participants, with primary success in 43. 20 of these participants followed for ≥ 6 months and formed group for study. Median age: 72 years; range: 68‐84 years; median aneurysm diameter: 5.2 cm; range: 4.8‐7.3 cm as measured by CT and 5.0 cm; range: 4.3‐7.0 cm as measured by duplex imaging; median follow‐up: 14; range: 6‐31 months.
Acceptable reference standard? All tests	Yes	Reference standard was CT scan.
Acceptable delay between tests? All tests	Yes	Yes: CT and US examinations performed on same day.
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	"Diagnostic imaging was performed by investigators (G.F. and T.H.) who were blinded of the result from the other imaging technique and previous scans."
Index test results blinded? All tests	Unclear	"Diagnostic imaging was performed by investigators (G.F. and T.H.) who were blinded of the result from the other imaging technique and previous scans."
Relevant clinical information? All tests	Yes	Yes.
Uninterpretable results reported? All tests	Unclear	Unclear.
Withdrawals explained? All tests	Yes	No withdrawals.