Ashoke 2005b.
Clinical features and settings | 30 participants undergoing EVAR recruited consecutively. 1 participant underwent EVAR as treatment for a pseudoaneurysm, and 4 did not have CT and CDUS scans within the required time intervals during follow‐up. Remaining 25 participants had a mean (± SD) original AAA diameter of 6.0 ± 0.6 cm. Type of stents received: AneuRx (n = 3), Zenith Bifurcated (n = 8), Zenith Trifab (n = 5), EVT (n = 1), and Nottingham‐style aortomonoiliac grafts with a femorofemoral crossover (n = 8). Aneurysm diameter: mean (± SD) original AAA diameter was 6.0 ± 0.6 cm. Setting: hospital. |
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Participants | 25 participants; 22 men; mean (± SD) age: 72.4 ± 6.9 years. Comorbidities: not reported. Geography: London, UK. |
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Study design | Cross‐sectional study; participants consecutively enrolled. | |
Target condition and reference standard(s) |
Target condition: endoleak. Definition of endoleak: "Presence or absence of flow within the aneurysm sac. …Endoleaks were defined by the presence of contrast within the aneurysm sac, and an attempt was made to determine the site of any leak" (Thompson 1998). Endoleak (absolute n): 6. Prevalence of endoleak: 9.1% (6/66). Reference standard: contrast‐enhanced CT. Image acquisition:
Type of CT scanner: Siemens HiQ scanner (Munich, Germany). Use of contrast: not reported. |
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Index and comparator tests |
Index test: CDUS. Image production: duplex imaging performed with participant supine. CDU utilized to image flow within graft, and any flow disturbance noted. Endoleaks specifically sought with colour Doppler set to detect low flow. CDUS scan times 35‐55 minutes. Type of US: 3.5‐MHz curved linear array transducer, HDI Ultramark 9 (ATL, Letchworth, UK). Use of contrast: no. Operator: not reported. |
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Follow‐up | "The 30 patients all received follow‐up scans at 1, 3, 12, 18, and 24 months postoperatively and annually thereafter, although not all follow‐up procedures were undertaken at the correct time intervals." | |
Notes |
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Table of Methodological Quality | ||
Item | Authors' judgement | Description |
Representative spectrum? All tests | Yes | Participants consecutively enrolled. |
Acceptable reference standard? All tests | Yes | Reference standard was CT scan. |
Acceptable delay between tests? All tests | Unclear | Interval between the 2 tests not clearly stated: "At each visit, patients had a clinical examination followed by CT and duplex imaging." |
Partial verification avoided? All tests | Yes | Appeared all participants received both tests. |
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 who were blinded of the result from the other imaging technique and previous scans." |
Index test results blinded? All tests | Yes | "Diagnostic imaging was performed by investigators 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 | Yes | "The CT scans were suboptimal in 2 cases due to calcification, but a diagnosis was still made." |
Withdrawals explained? All tests | Yes | "One pair of scans was excluded because the CT scans were not archived or reported, and the films were lost from the hospital." |