Wolf 2000.
Clinical features and settings | People who received endovascular repair of AAA with bifurcated endograft. Type of stent received: AneuRx (Medtronic). Aneurysm diameter: not reported. Setting: vascular surgery department, Stanford University Hospital. |
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Participants | 100 consecutive participants (age and gender not reported). Comorbidities: not reported. Geography: USA. |
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Study design | Prospective cross‐sectional study (consecutively selected participants, all received both tests). | |
Target condition and reference standard(s) |
Target condition: endoleak. Definition of endoleak: no definition reported. Endoleak (absolute n): unclear. Prevalence of endoleak: 38.0% (62/163). Reference standard: CTA. Image acquisition:
Type of CT scanner: CT scanner (both General Electric Medical Systems, Milwaukee, WI, USA). Use of contrast: yes (type not reported). |
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Index and comparator tests |
Index test: CDUS. Image production: "The protocol included transverse and sagittal imaging and peak systolic diameter measurements at the largest region of the proximal, mid, and distal segments of the abdominal aorta. Visible segments of the iliac arteries were also measured. Close attention was given to the stent device in gray scale and in colour Doppler scanning to rule out endoleak and graft compression." Type of US: Sequoia 512 ultrasound scanning system (Acuson, Mountain View, CA, USA) and sector V4 transducer. Use of contrast: no. Operator: 1 ("the vascular technologist was not aware of the CT scan"). |
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Follow‐up | No apparent loss to follow‐up, missing data, or adverse events. | |
Notes |
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Table of Methodological Quality | ||
Item | Authors' judgement | Description |
Representative spectrum? All tests | Yes | Enrolled participants who "underwent endovascular repair for AAA with the AneuRx (Medtronic) bifurcated endograft at Stanford University Hospital from October 1996 to May 1999. Follow‐up protocol included CT angiography before discharge, duplex scan at 1 month, and CT angiography at 6 months, 1 year, and yearly thereafter." |
Acceptable reference standard? All tests | Yes | Reference standard was CT scan. |
Acceptable delay between tests? All tests | Unclear | Delay between 2 tests in 24 participants unclear. "To compare CT and duplex scans, we obtained both studies, whenever possible, within a period of 7 days from each other. CT and duplex scans were obtained concurrently (within 7 days of each other) in 166 instances in 76 patients (1‐6 scan pairs per patient). These concurrent scan pairs form the basis for the comparison between the tests." |
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 | "During the examination and the reading of the duplex scan, the vascular technologist was not aware of the CT scan results." |
Index test results blinded? All tests | Yes | "In addition to a formal reading by a radiologist who was unaware of the duplex scan result, CT angiograms were reviewed by a panel of radiologists and vascular surgeons to confirm the presence or absence of an endoleak." |
Relevant clinical information? All tests | Yes | Yes. |
Uninterpretable results reported? All tests | Yes | "All CT scans were technically satisfactory. Delayed scans, which were obtained routinely after September 1998, were performed in 57% of CT scans. Sixteen (7%) duplex scans in 10 patients were technically inadequate for determination of aneurysm size and presence of endoleak." |
Withdrawals explained? All tests | Unclear | Unclear. |