Postgraduate Medicine
ISSN: 0032-5481 (Print) 1941-9260 (Online) Journal homepage: http://www.tandfonline.com/loi/ipgm20
Evaluating peripheral arterial occlusive disease Robert W. Barnes To cite this article: Robert W. Barnes (1976) Evaluating peripheral arterial occlusive disease, Postgraduate Medicine, 59:2, 98-103, DOI: 10.1080/00325481.1976.11714271 To link to this article: http://dx.doi.org/10.1080/00325481.1976.11714271
Published online: 07 Jul 2016.
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Citing articles: 5 View citing articles
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Date: 23 August 2017, At: 19:35
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evaluating peripheral arterial occlusive disease Robert W. Barnes, MD University of Iowa Hospitals and Clinics Iowa City
The clinical history and physical examination remain the cornerstones for detecting peripheral arterial occlusive disease and determining its anatomie and physiologie extent. Qualitative and quantitative hemodynamic assessment wlth the Doppler ultrasonic veloclty detector provides supplementary information. Arteriography should be reserved for preoperative evaluation.
• Detectable peripheral arterial occlusive disease may be more prevalent than coronary artery disease and stroke, but fortunately it does not pose the major threat to life that the latter two conditions do. Nevertheless, peripheral arterial disease may significantly impair a patient's ability to pursue daily activities and occasionally may be sufficiently severe to threaten loss of a limb. While only about 10% to 20% of patients with arterial occlusive disease require reconstructive operation or amputation, accurate diagoosis is imperative, especially since such disease may mirror similar lesions in the coronary or cerebrovascular circulation. The general availability of arteriography and the recent development of noninvasive diagnostic techniques have prompted many cliniciaos to rely on these methods to establish the diagnosis of arterial disease. This article attempts to reassert the appropriate relative roles of clinical evaluation, laboratory investigation, and arteriographie assessment of arterial occlusive disease of the lower extremity. Cllnlcal Evalulltlon
Presenting symptoms-While patients with arterial disease may be asymptomatic, most patients with arterial occlusive disease have one or more of three cardinal presenting manifestations: intermittent claudication, rest pain, and tissue necrosis (gangrene). Intermittent claudication is present only if the muscle pain in the leg is brought on by exercise and is relieved by rest. The extent of walking required to produce such claudication in a specifie patient should not vary much from day to day. Relief of the leg pain should occur after a fairly short interval of rest (within five to ten minutes), even when the patient is standing. The leg pain does not occur when the patient is at rest (standing, sitting, or lying). Occasionally, significant muscle activity associated with standing, such as the muscle contractions necessary to allow the patient to stand on a ladder, may elicit claudication in individuals with advanced arterial disease. Claudication should be differentiated from pseudoclaudication, which is leg pain of nonvascular etiology, most often of neurospinal origin. In patients with pseudoclaudication, the leg pain occurs after varying degrees of activity, often soon after arising or even at rest. These patients require longer periods of
98
POSTGRADUATE MEDICINE • r=etwu.y 1978 • Vol. 5I • No. 2
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time for relief than do patients with claudication, often having to sit or lie down and change position to get comfortable. Rest pain must be differentiated from night cramps. Vascular rest pain occurs in the most distal portion of the limb-especially the toes, forefoot, or heel-which is inadequately perfused at rest in the presence of advanced peripheral arterial occlusive disease. The pain may become unbearable and the patient often bas to keep the leg dependent, even at night, to obtain a measure of relief. A patient with night cramps often cornplains of actual muscle cramping, usually in the arch of the foot or in the calf. These cramps are not due to arterial disease per se, and relief is often obtained by walking about the room for a briefperiod. Diphenhydramine hydrochloride (Benadryl) or quinine at bedtime is useful in treating this benign disorder. Tissue necrosis or gangrene may indicate advanced arterial disease, although occasionally such lesions result from peripheral arterial emboli from more proximal, relatively mild arterial disease. The nonhealing ulcer associated with arterial insufficiency presents with little or no pink granulation tissue. Such ulcers must be differentiated from trophic ulcers on the plantar aspect of the foot, which occur in diabetic or alcoholic neuropathy, and from venous stasis ulcers, which typically appear on the medial aspect of the ankle, with associated hyperpigmentation. Trophic and venous stasis ulcers should heal with appropriate local therapy, rest, and avoidance of trauma or edema. Physical examination-The patient with mild to moderate claudication may have no external manifestations of disease on the limb. More advanced arterial occlusive disease may be associated with trophic changes,
Vol. 59 • No. 2 • February 1976 • POSTQRADUATE MEDICINE
Figure 1. Normal (a) and abnormal (b) analogue tracings of Doppler arterial velocity signais.
including loss of hair on the toes (loss of hair on the lower leg is not diagnostic), thickened opaque nails, and thin atrophie skin. Such advanced disease may also be associated with cadaveric pallor of the feet with leg elevation and marked rubor with subsequent dependency. Coldness of the feet is nonspecific, unless one limb is colder than the other. The most useful physical finding is the presence of1pulse deficits. It is important to evaluate the abdominal aorta and iliac arteries not only for pulsation but also for aneurysmal change. In addition to palpation of the cornmon femoral arteries, the superficial femoral arteries should be palpated in the proximal thigh. The popliteal arteries are best palpated with the fingers of both bands on the posterior surface of the proximal tibia while the knee is flexed about 30°. Palpation of the posterior tibial and dorsalis pedis arteries (also the peroneal more laterally on the dorsum of the foot) should be carried out with the examiner's bands in a comfortable position ....
99
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Figure 2. Technique of measuring ankle systolic bloocl pressure by Doppler ultrasound.
Figure 3. Location of pneumatic cuffs for measurement of segmentai leg blood pressure.
While any grading system may be used, confusion may be avoided by indicating the pulses as normal, reduced, or absent. Vascular bruits should be carefully sought with the stethoscope over the abdominal aorta, the iliac and common femoral arteries, the proximal and distal superficial femoral arteries, and the popliteal artery behind the knee. The character of the bruit resulting from turbulent flow distal to an arterial narrowing (stenosis) may indicate the severity of the
100
obstruction. A soft systolic bruit (over a relatively normal pulse) indicates mild stenosis. A louder, more harsh systolic bruit, which may be accompanied by a palpable thrill, suggests moderately severe stenosis with sufficient distal pressure (perhaps by collateral circulation) to prevent a diastolic bruit. A bruit throughout systole and diastole suggests severe stenosis with reduced distal pressure. Thus, a continuous pressure gradient suffident to maintain turbulent flow is present throughout the cardiac cycle. In the presence of markedly severe stenosis or arterial occlusion, no bruit may be audible. Interpretation of clinical findings-Clinical evaluation permits anatomie and physiologie assessment of arterial occlusive disease. While the anatomie location of obstruction can be implied from the location of claudication, most often the calf is the only symptomatic muscle mass. Claudication from pain in the calf may result from disease in any of the major arteries proximal to the arterial supply. Claudication from pain in the thigh implies disease of the deep femoral artery or, more commonly, the aortoiliac or common femoral arteries. Claudication in the hip or buttock usually connotes common iliac or aortic occlusive disease. Aortoiliac occlusive disease in men may result in inability to achieve an erection; the physician should always inquire about a history of impotence in such patients. More specifie anatomie diagnosis cornes from assessment of the pulse deficit. Absence of pedal pulses in the presence of a popliteal pulse connotes below-knee (tibioperoneal) disease, which is most common in diabetes. Absence of a popliteal pulse in the presence of a common femoral pulse indicates superficial femoral artery occlusion. Absence of ali pulses in the leg indicates aortoiliac occlusive disease. A di mini shed pulse in the presence of a bruit connotes stenosis of the artery proximal to the point of examination. The physiologie extent of the disease can be determined from the se verity of symptoms. If claudication occurs after the patient has walked more than two blocks, a single anatomie level of occlusion (aortoiliac, superficial femoral, or below-knee) is usually present. Claudication occurring after walking less than two blocks usually implies more than one anatomie level of disease (eg, aor-
POSTGRADUATE IIEDICitE • February 1976 • Vol. 59 • No. 2
toiliac and superficial femoral, superficial femoral and below-knee). Patients with rest pain or gangrene always have more than one anatomie level of arterial occlusive disease. Such patients are at risk of limb Joss, and a vascular reconstructive operation is manda tory if feasible. Patients with claudication alone are candidates for operation only if the walking difficulty significantly impairs their daily activity.
Downloaded by [Australian Catholic University] at 19:35 23 August 2017
Doppler Ultrasonlc Evaluation
The Doppler ultrasonic velocity detector employs a piezoelectric crystal in a hand-held probe which causes a bearn ofultrasound (5 to 10 megahertz) to be transmitted into the tissues through an acoustic gel on the skin. Sound reflected from moving blood cells is shifted in frequency by an amount proportional to the velocity of blood flow. The backscattered sound is received by a second crystal, and the frequency shift is electronically detected and amplified as an audible signal or an analogue waveform. In practice, the Doppler detector is used as a sensitive electronic stethoscope not only to detect the characteristics of the arterial velocity signal but also to determine limb blood pressures to identify the location of arterial occlusive disease and to quantitate its severity. Arterial velocity signal-The normal arterial velocity signaP is multiphasic, with a prominent systolic sound and one or more diastolic sounds. In a major artery such as the femoral artery, the first diastolic sound is that associated with temporary flow reversai (figure la). The importance of the diastolic sounds relates to the fact that such sounds are lost distal to an arterial stenosis or obstruction (figure 1b). At the site of stenosis, the arterial velocity is increased, with the Doppler signal becoming higher in pitch. Distal to the obstruction, the arterial signal is attenuated, with a less prominent systolic sound and no audible diastolic sounds. The Doppler probe can thus local ize obstructions in the external iliac, common femoral, superficial femoral, popliteal, posterior tibial, and dorsalis pedis arteries and the perone al artery in the foot. Resting ankle pressure-A useful quaptitative screening technique for peripheral arte-
Vol. 59 • No. 2 • February 1976 • POSTGRADUATE IIEDICitE
Robert W. Barnes Dr. Barnes is associate professor of surgery, division of thoracic and cardiovascular surgery, University of Iowa Hospitals and Clinics, Iowa City, and chief of vascular surgery, Veterans Administration Hospital, Iowa City.
rial occlusive disease is the measurement of resting arm and ankle systolic blood pressure (figure 2). A standard pneumatic cuff is placed on the arm and on each ankle. Arm and ankle pressures are determined with the Doppler probe over the brachial and the posterior tibial or dorsalis pedis arteries, respective} y. The cuff is inflated until the arterial signal disappears. The cuff is then slowly deflated until the arterial velocity signal returns at the systolic pressure. Normally the ankle pressure is equal to or slightly above the arm pressure. In the presence of arterial occlusive disease, however, the ankle pressure is below the arm pressure by an amount proportional to the degree of circulatory impairment. 2 The ankle pressure has been shown to correlate with postexercise blood flow in the calf. 3 Segmentai leg pressure-The location and relative severity of arterial obstructions in the leg can be determined by segmentai pressure measurements high on the thigh, above the knee, below the knee, and at the ankle (figure 3). 4 To measure these four levels of pressure, a cuff smaller than the standard thigh cuff must be used. The technique requires a cuff with a long bladder* or a pneumatic tourniquet such as that used in the operating room. Such cuffs result in an artifactually high blood pressure but are useful in assessing normal and abnormal gradients in the limb. Normally the pressure drop between any two adjacent cuffs on the limb should not exceed 30 mm Hg. If the drop is greater than this, there is significant stenosis or occlusion of the artery at the site. The high-thigh pressure should normally be 30 to 90 mm Hg higher than the arm pressure (artifact); lower pressure indicates aortoiliac occlusive disease. An abnormal gradient ( > 30 mm Hg)
•o.
E. Hokanson, Mercer Island, Wash.
101
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Figure 4. Normal and abnormal (claudicant) ankle pressure response to treadmill exercise (2 mph, 12% grade).
between the high-thigh and above-knee cuff indicates superficial femoral artery occlusion. An abnormal gradient between the above-knee and below-knee cuffs indicates disease ofthe distal superficial femoral or popliteal artery. An abnormal gradient between the belowknee and ankle cuffs indicates tibioperoneal artery disease, usually of ali three vessels. Postexercise leg pressure-A further quantitation of the physiologie extent of arterial disease may be obtained by measuring the response of the ankle pressure to a period of treadmill exercise (figure 4). 5 A standard constant-load test involves a five-minute walk at 2 mph on a 12% grade. If the arterial system is normal, this exercise is usually weil tolerated, even by elderly individuals. Any significant disease, however, will result in claudication, and the patient may be forced to stop before five minutes. The time to onset of claudication (claudication ti me) and the total duration of tolerable exercise (walking time) are indirectly proportional to the severity of arterial occlusive disease. More quantitative indexes than claudication and walking time are the magnitude and duration of postexercise drop in ankle systolic pressures. The patient exercises with the
102
ankle cuffs in place. lmmediately following exercise the patient resumes the supine position and the ankle pressures are serially measured at one- to two-minute intervals for 20 minutes. Normally after such exercise the ankle pressure remains the same or increases, but in the presence of arterial occlusive disease, the ankle pressure falls by an amount proportional to the extent of disease (figure 4). At times the ankle pressure may be unrecordable. Likewise the duration of the fall in ankle pressure is proportional to the extent of the disease; in advanced disease, ankle pressure does not retum to the preexercise levels for 20 to 30 minutes. The ankle pressure response may also be determined after a multistage graded treadmill test, as performed in cardiology laboratories. A modification of this test is currently employed in seree oing for peripheral vascular disease in prevalence and intervention programs of the lipid research clinics funded by the National Institutes of Health throughout the country. At higher treadmill stages (IV, V, VI), the ankle pressure may normally fall as much as 30 to 65 mm Hg. Patients with significant arterial occlusive disease, however, cannot exercise to such advanced treadmill stages. Arteriographie Evaluation
An extensive discussion of arteriography is outside the scope of this article, but two points are worth emphasizing. First, arteriography should not be considered a routine diagnostic procedure to establish the presence of arterial disease. Such information cao be obtained readily from the clinical examination, and physiologie quanti tati on cao be established by non in va si ve tee hniques. Arteriography should be reserved for the patient for whom an operation is planned. The decision for operation should rest on the clinical manifestation of disease. An artei'iogram, however, is helpful in planning operative therapy, especially in terms of the feasibility of reconstruction and the choice of reconstructive therapy. A second critical factor in arteriography is visualization of the arterial segment in question. The exact technique must rest on the preferences and skills of the radiologist. The clinician and the radiologist should maintain close communication, however, to obtain proper visualization of those anatomie seg-
POSTGRADUATE MEDICINE • February 1976 • Vol. 59 • No. 2
ments which are critical to the reconstructive procédure. For example, a patient with a normal femoral pulse and advanced claudication and rest pain probably bas both superficial femoral artery and below-knee occlusive disease. It becomes critical to ascertain whether a suitable below-knee vessel is present to provide satisfactory outflow for a reconstructive procedure. Thus, whether translumbar or transfemoral angiography is employed, it is imperative that below-knee vascular imaging be obtained.
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Summary and Conclusions
The clinical history and physical examination remain the most important factors in determining the presence, anatomie location, and physiologie extent of arterial occlusive disease and the need for operation. The physician should refrain from ordering arteriography to confirm the diagnosis of arterial disease unless operation is warranted.
If peripheral arterial occlusive disease is diagnosed clinically, its anatomie and physiologie extent cao be determined qualitatively and quantitatively by Doppler ultrasonic studies. These studies are also useful in following the natural history of or the influence of therapy on the course of arterial occlusive disease. Ultrasonic studies coupled with careful clinical assessment and with arteriographie evaluation prior to planned operation provide an optimal armamentarium for the diagnosis and management of peripheral arterial occlusive disease. • Presented in part at the Postgraduate Conference in Surgery: Vascular Disease of the Lower Extremity, University of Iowa, Iowa City.
Address reprint requests to Robert W. Barnes, MD, Department of Surgery, University of Iowa Hospitals and Clinics, Iowa City, lA 52242.
References 1. Strandness DE Jr, McCutcheon EP, Rushmer RF: Application of a transcutaneous Doppler flowmeter in evaluation of occlusive arterial disease. Surg Gynecol & Obstet 122:1039, 1966 2. Carter SA: Indirect systolic pressures and pulse waves in arterial occlusive diseases of the lower extremities. Circulation 37:624, 1968 3. Sumner OS, Strandness DE Jr: The relationship between
calf blood flow and ankle blood pressure in patients with intermittent claudication. Surgery 65:763, 1969 4. Strandness DE Jr, Bell JW: Peripheral vascular disease: Diagnosis and objective evaluation using a mercury strain gauge. Ann Surg 161:Suppl:3, 1965 5. Strandness DE Jr: Peripheral Arterial Disease: A Physiologie Approach. Boston, Little, Brown & Co, 1969, p 61
~eadySOUrce EVALUATING PERIPHERAL
1·
AUDIOVISUALS
ARTERIAL DISEASE
00
Perlpheral Vascular Dlsease (9 cassette tapes) (Sylie) Source: ACS/Ciinitapes, 55 E Erie St, Chicago, IL 60611 Cost: $50 Arteriel Embollsm of the Lower Extremltles (4: 25-min tape, catalog #324) Source: Wisconsin Dial Access Tapes, Department of Continuing Medical Education, 610 Walnut St, Madison, Wl 53706 Cost: $4 '14-in audiotape; $10 Echomatic cartridge
0
Iowa City, University of Iowa Audiovisual Center, 1976 Hemodynamlcs for Surgeons (Strandness, Sumner, editors) New York, Grune & Stratton, 1975 Allen-Barker-Hines Perlpheral Vascular Dlseases (Fairbairn et al, editors) Philadelphia, WB Saunders Co, 1972 Vascular Surgery. 1. Perlpheral Arteriel Dlseases (Cranley, editor) New York, Harper & Row, 1972
TEXTBOOKS
Arteriel Surgery (Eastcott, editer) Philadelphia, JB Lippincott Co, 1969
Doppler Ultrasonlc Evaluation of Perlpheral Arteriel Dlsease (Barnes. Wilson, editors)
For deta1ls on hOw to use ReadySource. see page t61
Vol. 59 • No. 2 • February 1976 • POSTGRADUATE MEDICINE
0
103
ISSN: 0032-5481 (Print) 1941-9260 (Online) Journal homepage: http://www.tandfonline.com/loi/ipgm20
Evaluating peripheral arterial occlusive disease Robert W. Barnes To cite this article: Robert W. Barnes (1976) Evaluating peripheral arterial occlusive disease, Postgraduate Medicine, 59:2, 98-103, DOI: 10.1080/00325481.1976.11714271 To link to this article: http://dx.doi.org/10.1080/00325481.1976.11714271
Published online: 07 Jul 2016.
Submit your article to this journal
View related articles
Citing articles: 5 View citing articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ipgm20 Download by: [Australian Catholic University]
Date: 23 August 2017, At: 19:35
Downloaded by [Australian Catholic University] at 19:35 23 August 2017
evaluating peripheral arterial occlusive disease Robert W. Barnes, MD University of Iowa Hospitals and Clinics Iowa City
The clinical history and physical examination remain the cornerstones for detecting peripheral arterial occlusive disease and determining its anatomie and physiologie extent. Qualitative and quantitative hemodynamic assessment wlth the Doppler ultrasonic veloclty detector provides supplementary information. Arteriography should be reserved for preoperative evaluation.
• Detectable peripheral arterial occlusive disease may be more prevalent than coronary artery disease and stroke, but fortunately it does not pose the major threat to life that the latter two conditions do. Nevertheless, peripheral arterial disease may significantly impair a patient's ability to pursue daily activities and occasionally may be sufficiently severe to threaten loss of a limb. While only about 10% to 20% of patients with arterial occlusive disease require reconstructive operation or amputation, accurate diagoosis is imperative, especially since such disease may mirror similar lesions in the coronary or cerebrovascular circulation. The general availability of arteriography and the recent development of noninvasive diagnostic techniques have prompted many cliniciaos to rely on these methods to establish the diagnosis of arterial disease. This article attempts to reassert the appropriate relative roles of clinical evaluation, laboratory investigation, and arteriographie assessment of arterial occlusive disease of the lower extremity. Cllnlcal Evalulltlon
Presenting symptoms-While patients with arterial disease may be asymptomatic, most patients with arterial occlusive disease have one or more of three cardinal presenting manifestations: intermittent claudication, rest pain, and tissue necrosis (gangrene). Intermittent claudication is present only if the muscle pain in the leg is brought on by exercise and is relieved by rest. The extent of walking required to produce such claudication in a specifie patient should not vary much from day to day. Relief of the leg pain should occur after a fairly short interval of rest (within five to ten minutes), even when the patient is standing. The leg pain does not occur when the patient is at rest (standing, sitting, or lying). Occasionally, significant muscle activity associated with standing, such as the muscle contractions necessary to allow the patient to stand on a ladder, may elicit claudication in individuals with advanced arterial disease. Claudication should be differentiated from pseudoclaudication, which is leg pain of nonvascular etiology, most often of neurospinal origin. In patients with pseudoclaudication, the leg pain occurs after varying degrees of activity, often soon after arising or even at rest. These patients require longer periods of
98
POSTGRADUATE MEDICINE • r=etwu.y 1978 • Vol. 5I • No. 2
Downloaded by [Australian Catholic University] at 19:35 23 August 2017
time for relief than do patients with claudication, often having to sit or lie down and change position to get comfortable. Rest pain must be differentiated from night cramps. Vascular rest pain occurs in the most distal portion of the limb-especially the toes, forefoot, or heel-which is inadequately perfused at rest in the presence of advanced peripheral arterial occlusive disease. The pain may become unbearable and the patient often bas to keep the leg dependent, even at night, to obtain a measure of relief. A patient with night cramps often cornplains of actual muscle cramping, usually in the arch of the foot or in the calf. These cramps are not due to arterial disease per se, and relief is often obtained by walking about the room for a briefperiod. Diphenhydramine hydrochloride (Benadryl) or quinine at bedtime is useful in treating this benign disorder. Tissue necrosis or gangrene may indicate advanced arterial disease, although occasionally such lesions result from peripheral arterial emboli from more proximal, relatively mild arterial disease. The nonhealing ulcer associated with arterial insufficiency presents with little or no pink granulation tissue. Such ulcers must be differentiated from trophic ulcers on the plantar aspect of the foot, which occur in diabetic or alcoholic neuropathy, and from venous stasis ulcers, which typically appear on the medial aspect of the ankle, with associated hyperpigmentation. Trophic and venous stasis ulcers should heal with appropriate local therapy, rest, and avoidance of trauma or edema. Physical examination-The patient with mild to moderate claudication may have no external manifestations of disease on the limb. More advanced arterial occlusive disease may be associated with trophic changes,
Vol. 59 • No. 2 • February 1976 • POSTQRADUATE MEDICINE
Figure 1. Normal (a) and abnormal (b) analogue tracings of Doppler arterial velocity signais.
including loss of hair on the toes (loss of hair on the lower leg is not diagnostic), thickened opaque nails, and thin atrophie skin. Such advanced disease may also be associated with cadaveric pallor of the feet with leg elevation and marked rubor with subsequent dependency. Coldness of the feet is nonspecific, unless one limb is colder than the other. The most useful physical finding is the presence of1pulse deficits. It is important to evaluate the abdominal aorta and iliac arteries not only for pulsation but also for aneurysmal change. In addition to palpation of the cornmon femoral arteries, the superficial femoral arteries should be palpated in the proximal thigh. The popliteal arteries are best palpated with the fingers of both bands on the posterior surface of the proximal tibia while the knee is flexed about 30°. Palpation of the posterior tibial and dorsalis pedis arteries (also the peroneal more laterally on the dorsum of the foot) should be carried out with the examiner's bands in a comfortable position ....
99
Downloaded by [Australian Catholic University] at 19:35 23 August 2017
Figure 2. Technique of measuring ankle systolic bloocl pressure by Doppler ultrasound.
Figure 3. Location of pneumatic cuffs for measurement of segmentai leg blood pressure.
While any grading system may be used, confusion may be avoided by indicating the pulses as normal, reduced, or absent. Vascular bruits should be carefully sought with the stethoscope over the abdominal aorta, the iliac and common femoral arteries, the proximal and distal superficial femoral arteries, and the popliteal artery behind the knee. The character of the bruit resulting from turbulent flow distal to an arterial narrowing (stenosis) may indicate the severity of the
100
obstruction. A soft systolic bruit (over a relatively normal pulse) indicates mild stenosis. A louder, more harsh systolic bruit, which may be accompanied by a palpable thrill, suggests moderately severe stenosis with sufficient distal pressure (perhaps by collateral circulation) to prevent a diastolic bruit. A bruit throughout systole and diastole suggests severe stenosis with reduced distal pressure. Thus, a continuous pressure gradient suffident to maintain turbulent flow is present throughout the cardiac cycle. In the presence of markedly severe stenosis or arterial occlusion, no bruit may be audible. Interpretation of clinical findings-Clinical evaluation permits anatomie and physiologie assessment of arterial occlusive disease. While the anatomie location of obstruction can be implied from the location of claudication, most often the calf is the only symptomatic muscle mass. Claudication from pain in the calf may result from disease in any of the major arteries proximal to the arterial supply. Claudication from pain in the thigh implies disease of the deep femoral artery or, more commonly, the aortoiliac or common femoral arteries. Claudication in the hip or buttock usually connotes common iliac or aortic occlusive disease. Aortoiliac occlusive disease in men may result in inability to achieve an erection; the physician should always inquire about a history of impotence in such patients. More specifie anatomie diagnosis cornes from assessment of the pulse deficit. Absence of pedal pulses in the presence of a popliteal pulse connotes below-knee (tibioperoneal) disease, which is most common in diabetes. Absence of a popliteal pulse in the presence of a common femoral pulse indicates superficial femoral artery occlusion. Absence of ali pulses in the leg indicates aortoiliac occlusive disease. A di mini shed pulse in the presence of a bruit connotes stenosis of the artery proximal to the point of examination. The physiologie extent of the disease can be determined from the se verity of symptoms. If claudication occurs after the patient has walked more than two blocks, a single anatomie level of occlusion (aortoiliac, superficial femoral, or below-knee) is usually present. Claudication occurring after walking less than two blocks usually implies more than one anatomie level of disease (eg, aor-
POSTGRADUATE IIEDICitE • February 1976 • Vol. 59 • No. 2
toiliac and superficial femoral, superficial femoral and below-knee). Patients with rest pain or gangrene always have more than one anatomie level of arterial occlusive disease. Such patients are at risk of limb Joss, and a vascular reconstructive operation is manda tory if feasible. Patients with claudication alone are candidates for operation only if the walking difficulty significantly impairs their daily activity.
Downloaded by [Australian Catholic University] at 19:35 23 August 2017
Doppler Ultrasonlc Evaluation
The Doppler ultrasonic velocity detector employs a piezoelectric crystal in a hand-held probe which causes a bearn ofultrasound (5 to 10 megahertz) to be transmitted into the tissues through an acoustic gel on the skin. Sound reflected from moving blood cells is shifted in frequency by an amount proportional to the velocity of blood flow. The backscattered sound is received by a second crystal, and the frequency shift is electronically detected and amplified as an audible signal or an analogue waveform. In practice, the Doppler detector is used as a sensitive electronic stethoscope not only to detect the characteristics of the arterial velocity signal but also to determine limb blood pressures to identify the location of arterial occlusive disease and to quantitate its severity. Arterial velocity signal-The normal arterial velocity signaP is multiphasic, with a prominent systolic sound and one or more diastolic sounds. In a major artery such as the femoral artery, the first diastolic sound is that associated with temporary flow reversai (figure la). The importance of the diastolic sounds relates to the fact that such sounds are lost distal to an arterial stenosis or obstruction (figure 1b). At the site of stenosis, the arterial velocity is increased, with the Doppler signal becoming higher in pitch. Distal to the obstruction, the arterial signal is attenuated, with a less prominent systolic sound and no audible diastolic sounds. The Doppler probe can thus local ize obstructions in the external iliac, common femoral, superficial femoral, popliteal, posterior tibial, and dorsalis pedis arteries and the perone al artery in the foot. Resting ankle pressure-A useful quaptitative screening technique for peripheral arte-
Vol. 59 • No. 2 • February 1976 • POSTGRADUATE IIEDICitE
Robert W. Barnes Dr. Barnes is associate professor of surgery, division of thoracic and cardiovascular surgery, University of Iowa Hospitals and Clinics, Iowa City, and chief of vascular surgery, Veterans Administration Hospital, Iowa City.
rial occlusive disease is the measurement of resting arm and ankle systolic blood pressure (figure 2). A standard pneumatic cuff is placed on the arm and on each ankle. Arm and ankle pressures are determined with the Doppler probe over the brachial and the posterior tibial or dorsalis pedis arteries, respective} y. The cuff is inflated until the arterial signal disappears. The cuff is then slowly deflated until the arterial velocity signal returns at the systolic pressure. Normally the ankle pressure is equal to or slightly above the arm pressure. In the presence of arterial occlusive disease, however, the ankle pressure is below the arm pressure by an amount proportional to the degree of circulatory impairment. 2 The ankle pressure has been shown to correlate with postexercise blood flow in the calf. 3 Segmentai leg pressure-The location and relative severity of arterial obstructions in the leg can be determined by segmentai pressure measurements high on the thigh, above the knee, below the knee, and at the ankle (figure 3). 4 To measure these four levels of pressure, a cuff smaller than the standard thigh cuff must be used. The technique requires a cuff with a long bladder* or a pneumatic tourniquet such as that used in the operating room. Such cuffs result in an artifactually high blood pressure but are useful in assessing normal and abnormal gradients in the limb. Normally the pressure drop between any two adjacent cuffs on the limb should not exceed 30 mm Hg. If the drop is greater than this, there is significant stenosis or occlusion of the artery at the site. The high-thigh pressure should normally be 30 to 90 mm Hg higher than the arm pressure (artifact); lower pressure indicates aortoiliac occlusive disease. An abnormal gradient ( > 30 mm Hg)
•o.
E. Hokanson, Mercer Island, Wash.
101
Downloaded by [Australian Catholic University] at 19:35 23 August 2017
Figure 4. Normal and abnormal (claudicant) ankle pressure response to treadmill exercise (2 mph, 12% grade).
between the high-thigh and above-knee cuff indicates superficial femoral artery occlusion. An abnormal gradient between the above-knee and below-knee cuffs indicates disease ofthe distal superficial femoral or popliteal artery. An abnormal gradient between the belowknee and ankle cuffs indicates tibioperoneal artery disease, usually of ali three vessels. Postexercise leg pressure-A further quantitation of the physiologie extent of arterial disease may be obtained by measuring the response of the ankle pressure to a period of treadmill exercise (figure 4). 5 A standard constant-load test involves a five-minute walk at 2 mph on a 12% grade. If the arterial system is normal, this exercise is usually weil tolerated, even by elderly individuals. Any significant disease, however, will result in claudication, and the patient may be forced to stop before five minutes. The time to onset of claudication (claudication ti me) and the total duration of tolerable exercise (walking time) are indirectly proportional to the severity of arterial occlusive disease. More quantitative indexes than claudication and walking time are the magnitude and duration of postexercise drop in ankle systolic pressures. The patient exercises with the
102
ankle cuffs in place. lmmediately following exercise the patient resumes the supine position and the ankle pressures are serially measured at one- to two-minute intervals for 20 minutes. Normally after such exercise the ankle pressure remains the same or increases, but in the presence of arterial occlusive disease, the ankle pressure falls by an amount proportional to the extent of disease (figure 4). At times the ankle pressure may be unrecordable. Likewise the duration of the fall in ankle pressure is proportional to the extent of the disease; in advanced disease, ankle pressure does not retum to the preexercise levels for 20 to 30 minutes. The ankle pressure response may also be determined after a multistage graded treadmill test, as performed in cardiology laboratories. A modification of this test is currently employed in seree oing for peripheral vascular disease in prevalence and intervention programs of the lipid research clinics funded by the National Institutes of Health throughout the country. At higher treadmill stages (IV, V, VI), the ankle pressure may normally fall as much as 30 to 65 mm Hg. Patients with significant arterial occlusive disease, however, cannot exercise to such advanced treadmill stages. Arteriographie Evaluation
An extensive discussion of arteriography is outside the scope of this article, but two points are worth emphasizing. First, arteriography should not be considered a routine diagnostic procedure to establish the presence of arterial disease. Such information cao be obtained readily from the clinical examination, and physiologie quanti tati on cao be established by non in va si ve tee hniques. Arteriography should be reserved for the patient for whom an operation is planned. The decision for operation should rest on the clinical manifestation of disease. An artei'iogram, however, is helpful in planning operative therapy, especially in terms of the feasibility of reconstruction and the choice of reconstructive therapy. A second critical factor in arteriography is visualization of the arterial segment in question. The exact technique must rest on the preferences and skills of the radiologist. The clinician and the radiologist should maintain close communication, however, to obtain proper visualization of those anatomie seg-
POSTGRADUATE MEDICINE • February 1976 • Vol. 59 • No. 2
ments which are critical to the reconstructive procédure. For example, a patient with a normal femoral pulse and advanced claudication and rest pain probably bas both superficial femoral artery and below-knee occlusive disease. It becomes critical to ascertain whether a suitable below-knee vessel is present to provide satisfactory outflow for a reconstructive procedure. Thus, whether translumbar or transfemoral angiography is employed, it is imperative that below-knee vascular imaging be obtained.
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Summary and Conclusions
The clinical history and physical examination remain the most important factors in determining the presence, anatomie location, and physiologie extent of arterial occlusive disease and the need for operation. The physician should refrain from ordering arteriography to confirm the diagnosis of arterial disease unless operation is warranted.
If peripheral arterial occlusive disease is diagnosed clinically, its anatomie and physiologie extent cao be determined qualitatively and quantitatively by Doppler ultrasonic studies. These studies are also useful in following the natural history of or the influence of therapy on the course of arterial occlusive disease. Ultrasonic studies coupled with careful clinical assessment and with arteriographie evaluation prior to planned operation provide an optimal armamentarium for the diagnosis and management of peripheral arterial occlusive disease. • Presented in part at the Postgraduate Conference in Surgery: Vascular Disease of the Lower Extremity, University of Iowa, Iowa City.
Address reprint requests to Robert W. Barnes, MD, Department of Surgery, University of Iowa Hospitals and Clinics, Iowa City, lA 52242.
References 1. Strandness DE Jr, McCutcheon EP, Rushmer RF: Application of a transcutaneous Doppler flowmeter in evaluation of occlusive arterial disease. Surg Gynecol & Obstet 122:1039, 1966 2. Carter SA: Indirect systolic pressures and pulse waves in arterial occlusive diseases of the lower extremities. Circulation 37:624, 1968 3. Sumner OS, Strandness DE Jr: The relationship between
calf blood flow and ankle blood pressure in patients with intermittent claudication. Surgery 65:763, 1969 4. Strandness DE Jr, Bell JW: Peripheral vascular disease: Diagnosis and objective evaluation using a mercury strain gauge. Ann Surg 161:Suppl:3, 1965 5. Strandness DE Jr: Peripheral Arterial Disease: A Physiologie Approach. Boston, Little, Brown & Co, 1969, p 61
~eadySOUrce EVALUATING PERIPHERAL
1·
AUDIOVISUALS
ARTERIAL DISEASE
00
Perlpheral Vascular Dlsease (9 cassette tapes) (Sylie) Source: ACS/Ciinitapes, 55 E Erie St, Chicago, IL 60611 Cost: $50 Arteriel Embollsm of the Lower Extremltles (4: 25-min tape, catalog #324) Source: Wisconsin Dial Access Tapes, Department of Continuing Medical Education, 610 Walnut St, Madison, Wl 53706 Cost: $4 '14-in audiotape; $10 Echomatic cartridge
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Iowa City, University of Iowa Audiovisual Center, 1976 Hemodynamlcs for Surgeons (Strandness, Sumner, editors) New York, Grune & Stratton, 1975 Allen-Barker-Hines Perlpheral Vascular Dlseases (Fairbairn et al, editors) Philadelphia, WB Saunders Co, 1972 Vascular Surgery. 1. Perlpheral Arteriel Dlseases (Cranley, editor) New York, Harper & Row, 1972
TEXTBOOKS
Arteriel Surgery (Eastcott, editer) Philadelphia, JB Lippincott Co, 1969
Doppler Ultrasonlc Evaluation of Perlpheral Arteriel Dlsease (Barnes. Wilson, editors)
For deta1ls on hOw to use ReadySource. see page t61
Vol. 59 • No. 2 • February 1976 • POSTGRADUATE MEDICINE
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