Peripheral Vascular Ultrasound and Physiological Testing Appropriate Use Criteria (by Indication)
Section 1. Extracranial Cerebrovascular Ultrasound
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Table 1.2.
Evaluation for Cerebrovascular Disease—Asymptomatic With Comorbidities or Risk Factors for Carotid Artery Stenosis
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Table 1.3.
Follow-Up or Surveillance for Carotid Artery Stenosis—Asymptomatic*†
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Table 1.4.
Surveillance After Carotid Artery Intervention
Section 2. Carotid Duplex Screening Ultrasound
Table 2.1
Summary: Extracranial Cerebrovascular and Carotid Duplex Screening Ultrasound There was significant consensus regarding the appropriateness of cerebrovascular duplex ultrasound for evaluation of the patient with signs or clinical symptoms of cerebrovascular disease ( Table 1.1 ) with 7 of 8 clinical indications rated as appropriate and 1 clinical indication rated as uncertain.
Use of cerebrovascular ultrasound was rated as appropriate for evaluation of the patient with suspected vertebrobasilar occlusive disease with posterior circulation symptoms; although a customized cerebrovascular scanning protocol and supplemental use of transcranial Doppler may be needed for complete assessment of such patients. The multisocietal consensus guidelines for the management of patients with extracranial carotid and vertebral artery disease recommend other imaging modalities (i.e., magnetic resonance angiogram or computed tomography angiography) rather than ultrasound as the initial imaging test for suspected vertebral artery stenosis. Though carotid ultrasound was rated as appropriated for evaluation of suspected carotid artery dissection, its use is best suited for evaluation of suspected carotid dissection arising from dissection of the aortic arch and extending into the arch vessels (e.g., common carotid artery). Carotid ultrasound is not recommended to diagnose carotid dissection in the setting of trauma as a distal dissection of the internal carotid artery may not be detected by duplex scanning. In such cases, another other imaging modality (i.e., MRA or CTA) should be used.
Appropriateness of the use of cerebrovascular duplex ultrasound to assess for carotid stenosis in the patient with syncope with no obvious cardiac cause was rated as uncertain by the panel. Cerebrovascular disease is an unlikely cause of syncope but has been reported in cases of severe (especially bilateral) internal carotid artery stenosis or severe vertebrobasilar occlusive disease or subclavian–vertebral artery steal. The yield of cerebrovascular ultrasound in the evaluation of syncope has been low in published case series, but the uncertain rating for this indication reflects the need for additional research, including cost effectiveness data, in this area.
In contrast to the evaluation of the symptomatic patient or patient with signs of cerebrovascular disease, there was uncertainty regarding the use of cerebrovascular duplex for assessment of the asymptomatic patient with risk factors or comorbidities associated with carotid artery stenosis (Table 1.2), with 6 of 7 indications receiving an uncertain rating and only 1 indication receiving an appropriate rating. The technical panel rated as uncertain all clinical scenarios for cerebrovascular duplex examination prior to cardiac surgery, including evaluation of any asymptomatic patient (i.e., no prior hemispheric symptoms, no bruit) prior to CABG and evaluation of an asymptomatic patient prior to valvular heart surgery, including patients with or without risk factors or comorbidities associated with cerebrovascular disease. These findings reflect a need for more research in this arena, particularly cost effectiveness data.
Clinical management of the asymptomatic patient with atherosclerotic carotid disease typically includes periodic ultrasound surveillance for progressive carotid artery stenosis with the objective of referral for surgical (endarterectomy) or interventional (carotid artery stenting) therapy for severe stenosis of the internal carotid artery. The technical panel reviewed the appropriateness of time points for such surveillance studies (Table 1.3) during the first year after initial diagnosis of carotid stenosis and during subsequent follow-up across all severity categories. Any follow-up was deemed inappropriate following a normal baseline carotid examination (i.e., absent plaque or narrowing). For surveillance of the patient with plaque without narrowing noted on initial duplex examination or mild stenosis of <50%, any surveillance during the first year of follow-up was also deemed inappropriate, and surveillance beyond the first year was uncertain. Ratings for time points for surveillance of moderate (50% to 69%) and severe (≥70%) ICA lesions likely reflect the lack of substantial clinical effectiveness data in this arena, with the majority of indications rated as uncertain. For moderate ICA lesions, repeat ultrasound studies within the first year after diagnosis were rated as inappropriate (at 3 to 5 months) or uncertain, with annual studies rated as appropriate. For severe ICA lesions, an ultrasound study at 6 months and then every 6 or 12 months were rated as appropriate, although it should be emphasized that at this severity of stenosis, the risks versus benefits of revascularization (carotid artery endarterectomy or stenting) should be considered.
The panel reviewed indications for cerebrovascular duplex ultrasound after carotid artery revascularization (endarterectomy or stenting). Obtaining a baseline bilateral cerebrovascular duplex examination was highly rated as appropriate by the technical panel. The panel rated indications for follow-up during the first year after revascularization and beyond based upon whether the initial postrevascularization duplex demonstrated normal, expected postprocedural findings, or indicated a postprocedural abnormality (e.g., significantly elevated velocities) in (Table 1.4). Though not included in the rated clinical indications, it is likely that frequency and appropriateness of testing intervals would change in the setting of new abnormalities identified on a surveillance duplex examination, such as significant in-stent restenosis or significant restenosis at a carotid endarterectomy site.
The presence of carotid artery plaque with or without stenosis has been associated with increased cardiovascular risk in epidemiological studies, including increased risk of myocardial infarction. The technical panel reviewed the appropriateness of a carotid duplex screening ultrasound examination to screen plaque and significant narrowing of the proximal internal carotid arteries. However, these ratings do not include the appropriateness of carotid intima-medial thickness (IMT) assessment, a procedure that requires additional technological capabilities and is not widely nor routinely performed in the clinical vascular laboratory setting. The technical panel rated 2 indications as inappropriate for carotid screening ultrasound: assessment of the patient with low Framingham risk score and assessment of the patient with low or intermediate Framingham risk score who has already undergone another imaging risk assessment (e.g., carotid IMT or coronary artery calcium scoring). The technical panel rated assessment of the patient with intermediate or high Framingham risk score and without prior imaging risk assessment study as uncertain indications for carotid ultrasound, reflecting again the need for outcome and clinical effectiveness data for these screening indications.
Section 3. Renal and Mesenteric Artery Duplex
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Table 3.1.
Evaluation for Renal Artery Stenosis—Potential Signs and/or Symptoms
Table 3.2
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Table 3.3.
Evaluation for Mesenteric Artery Stenosis—Potential Signs and/or Symptoms
Table 3.4
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Table 3.5.
Surveillance After Renal or Mesenteric Artery Revascularization
Summary: Renal and Mesenteric Artery Ultrasound In this section, the ratings were found to be appropriate for the hypertension, creatinine, and heart failure indications in evaluating for renal artery stenosis. The only appropriate indication for duplex investigation of mesenteric artery stenosis was for the patients with symptoms of postprandial pain and weight loss and who have undergone a gastrointestinal (GI) evaluation. Surveillance after renal or mesenteric artery revascularization was deemed to be appropriate at 1 month following the procedure to establish a baseline and any time there are new signs or symptoms. Surveillance every 12 months was the only follow-up time frame rated appropriate after endovascular and surgical revascularization. Routine surveillance following surgical renal or mesenteric revascularization is generally not required in the absence of recurrent or worsening symptoms.
Section 4. Aortic and Aortoiliac Duplex
Table 4.1
Table 4.2
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Table 4.3.
Surveillance of Known Abdominal Aortic Aneurysm
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Table 4.4.
Surveillance After Aortic Endograft or Aortoiliac Stenting
Summary: Aortic and Aortoiliac Artery Duplex Signs and symptoms considered as appropriate indications for duplex evaluation of the abdominal aorta and iliac arteries included intermittent claudication, an aneurysmal femoral or popliteal pulse, a pulsatile abdominal mass, a decreased or absent femoral pulse, and an abdominal or femoral bruit. Inappropriate indications included nonspecific lower extremity discomfort, fever of unknown origin, lower extremity swelling, and hypertension. Erectile dysfunction was the only indication rated as uncertain.
Ultrasound screening of asymptomatic individuals for abdominal aortic aneurysms was considered appropriate in men and women over age 60 who were known to have first-degree relatives with an abdominal aortic aneurysm. Screening was also appropriate for men and women between 65 and 75 years of age who were current or former smokers and any current or former smoker over age 75. However, ultrasound screening was inappropriate for individuals under age 65 with no history of smoking. There was uncertainty over the role of screening for those age 65 and older with no history of smoking.
The reviewers concurred with the primary recommendation of the U.S. Preventive Services Task Force (USPSTF) that screening for abdominal aortic aneurysms was appropriate for men aged 65 to 75 years who had ever smoked. However, the reviewers also considered screening appropriate in both men and women who had a first-degree relative with an abdominal aortic aneurysm, a situation that was acknowledged in the USPSTF report by stating that "clinicians must individualize recommendations depending on a patient's risk and likelihood of benefit." Although the reviewers rated aneurysm screening as appropriate in women aged 65 to 75 years who were current or former smokers, the USPSTF recommended against routine screening in women, based on the low prevalence of large abdominal aortic aneurysms and concern that the harms of screening outweighed the benefits. The reviewers also considered screening appropriate for patients over 75 years of age who were current or former smokers, even though the USPSTF set an upper age limit for screening of 75 years, since the increased prevalence of comorbidities would decrease the chances that older patients would benefit from screening. It is important to note that the purpose of the USPSTF recommendations differ from that of this AUC document. The USPSTF provides guidance on whether population-based screening is generally recommended whereas AUC look at how reasonable testing may be for specific patient populations.
The reviewers' ratings were generally consistent with recommendations for aneurysm screening from the Society for Vascular Surgery (SVS) and the American College of Cardiology (ACC)/American Heart Association (AHA) 2005 Practice Guidelines. The SVS recommends 1-time ultrasound screening for all men at age 65 or older, or at age 55 or older for men with a positive family history for abdominal aortic aneurysms. For women, the SVS recommends screening at age 65 or older if they have ever smoked or have a positive family history. The ACC/AHA guidelines recommend aneurysm screening for high-risk populations, defined as men 60 years of age or older with first-degree relatives who have abdominal aortic aneurysms and men 65 to 75 years of age who have ever smoked.
For surveillance of a known abdominal aortic aneurysm of any size, duplex ultrasound was rated as appropriate. When patients who were asymptomatic or had stable symptoms were considered according to aneurysm size and surveillance frequency, follow-up at 9 to 12 months after a baseline study was rated as appropriate for aneurysms 3.0 cm to 3.9 cm in diameter in both men and women. Earlier follow up at 3 to 5 months after a baseline study was inappropriate, and the value of follow-up at 6 to 8 months was uncertain. After the first year, follow-up was rated as appropriate for aneurysms 3.0 cm to 3.9 cm in diameter at either 12-month or 24-month intervals for those patients with no or slow progression during the first year.
For patients with aneurysms of 4.0 cm to 5.4 cm, surveillance at intervals of 6 to 8 months or 9 to 12 months after a baseline study was appropriate. Surveillance for aneurysms of 5.5 cm or more in diameter was appropriate at 3 to 5 months and 6 to 8 months in the first year and intervals of 6 months and 12 months after the first year, assuming no or slow progression. When rapid progression was observed on serial studies, follow-up was appropriate at 6-month and 12-month intervals for aneurysms 3.0 cm to 3.9 cm in diameter and those 4.0 cm to 5.4 cm in diameter. However, for aneurysms of 5.5 cm or more in diameter with rapid progression, follow up was rated as appropriate only at 6-month intervals, whereas the value of follow-up at 12-month intervals was uncertain, and follow-up at 24-month intervals was inappropriate. Since patients with aneurysms of 5.5 cm or more in diameter are usually considered for elective repair, the role of continued surveillance must be individualized. If a patient has reversible or time-limited factors that prevent elective aneurysm repair, then ongoing surveillance may play a role in clinical decision making. However, if a patient declines elective repair, or is not considered a candidate for repair under any circumstances, then the value of surveillance is questionable.
After an aortic endograft or aortoiliac stenting, duplex scanning was appropriate as a baseline study (within 1 month), as well as for any subsequent new or worsening lower extremity symptoms. For aortic endograft patients with stable or decreasing residual aneurysm sac size and without evidence of endoleak during the first year, duplex follow-up was rated as inappropriate at 3 to 5 months and uncertain at both 6 to 8 months and 9 to 12 months. However, in the presence of an endoleak or increasing residual aneurysm sac size during the first year, follow-up was considered appropriate at either at 6 to 8 months or 9 to 12 months. For asymptomatic patients and those with stable symptoms during the first year after aortic or iliac artery stenting, duplex follow-up was rated as inappropriate at 3 to 5 months and uncertain at 6 to 8 months and 9 to 12 months. Similarly, follow-up every 6 months or 12 months was inappropriate and follow-up every 24 months or greater was considered as uncertain for aortic or iliac artery stent patients who were asymptomatic or had stable symptoms after the first year. Follow-up of aortic endografts without evidence of endoleak and stable or decreasing residual aneurysm sac size after the first year was appropriate at 12-month intervals. When there was an endoleak or increasing residual aneurysm sac size after the first year, follow-up was appropriate at either 6-month or 12-month intervals.
Section 5. Lower Extremity Artery Testing Using Multilevel Physiological Testing Alone or Duplex Ultrasound With Single-level ABI and PVR
Table 5.1
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Table 5.2.
Surveillance of Known Lower Extremity PAD
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Table 5.3.
Surveillance of Lower Extremity PAD After Revascularization (Duplex/ABI)
Section 6. Lower Extremity Artery Testing With ABI Only
Table 6.1
Table 6.2
Section 7. Lower Extremity Artery Testing With Duplex Ultrasound Only
Table 7.1
Section 8. Upper Extremity Arterial Testing—Physiological Testing or Duplex Ultrasound Study
Table 8.1
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Table 8.2.
Surveillance of Upper Extremity PAD After Revascularization
Summary: Upper and Lower Extremity Artery Testing The screening of asymptomatic individuals with ABI alone in this document is also addressed by the USPSTF. The rating of "uncertain" in this document is not consistent with that of the USPSTF where this type of evaluation was not deemed appropriate, or level D. There have been published responses to the USPSTF stance pointing out that ABI evaluation of certain populations would identify a high-risk group for heart attack, stroke, and death. The ACC/AHA guidelines and the American Diabetes Association Guidelines advocate ABI testing in certain disease populations such as those age >50 years with diabetes or chronic smoking. The designation of "uncertain" in this document is reflective of a paucity of data regarding ABI evaluation alone in asymptomatic individuals and effect on prevention of claudication and limb loss. The designation of "uncertain" is not meant to address the potential impact of ABI evaluation on heart attack and stroke outcome. The AUC ratings are meant to determine when diagnostic testing may be a reasonable option under certain clinical circumstances. They are not intended to endorse or imply population-wide screening protocols that are the focus of the USPSTF.
The appropriate indications for lower extremity testing using multilevel physiological methods alone or duplex ultrasound with single-level ABI and pulse volume recording (PVR) were clearly delineated by the reviewers with 6 appropriate and 4 inappropriate. None of the indications were deemed uncertain. Nocturnal leg cramps, neuropathy, lower extremity swelling or hair loss in the setting of normal pulses are not clinical scenarios that support ordering lower extremity artery tests.
There are 2 clear appropriate indications for surveillance of known lower extremity arterial disease, patients with either a normal ABI or an abnormal ABI with new or worsening symptoms. A short follow-up interval of every 6 months is not indicated, whereas it was uncertain whether every 12 months or every 24 months or greater was appropriate for follow-up testing. A baseline study after lower extremity revascularization was deemed appropriate, as was testing for new or worsening symptoms after revascularization. A follow-up interval for surveillance after baseline evaluation was thought most appropriate at 12 months if the patient is stable without new or worsening symptoms. The most appropriate time for surveillance after lower extremity prosthetic or vein bypass graft was 6to 8 months after the procedure.
The appropriate indications for lower extremity artery testing with ABI only were diminished pulses, femoral bruit, age >50 years with diabetes or smoking, and age >70 years, which is consistent with ACC/AHA peripheral artery disease (PAD) guidelines. The evaluation with ABI only for those age <50 years with diabetes was uncertain.
The appropriate indications for lower extremity duplex ultrasound evaluation only included a pulsatile groin mass, bruit or thrill, significant hematoma, or groin pain postprocedure. The presence of ecchymosis only was an uncertain indication.
The appropriate indications for upper extremity arterial testing included claudication, ulcer, unilateral cold painful hand, suspected positional arterial obstruction, and trauma with suspicion of vascular injury. The presence of Raynaud's phenomenon was an uncertain indication. A preoperative evaluation for a procedure such as radial artery harvest or suspected complication after an upper extremity arterial intervention was also appropriate indications for testing.
Similar to the lower extremity, a baseline study after revascularization and new or worsening symptoms are appropriate indications for upper extremity arterial testing. The most appropriate initial surveillance time interval after upper extremity revascularization with either vein or prosthetic bypass graft was at 12 months. A surveillance period of every 6 months after initial postoperative evaluation was most inappropriate for asymptomatic patients.