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2.1 · Pelvic andLeg Arteries
53
2
As the population ages, more people develop atherosclerotic
occlusive disease. Atherosclerosis aects not only the coronary arteries and the arteries supplying the brain but also the
arteries of the extremities. e prevalence of symptomatic
peripheral arterial occlusive disease
women aged 55–75 is over 5% and, when asymptomatic disease is included, over 20%. Atherosclerosis impairs an individual’s quality of life, causing immobility and disability. Life
expectancy is reduced by about 10 years in male PAOD
patients. e main causes of death are coronary heart disease
(55% of patients with PAOD vs. 36% without PAOD) and
cerebral conditions (11% vs. 4%). While PAOD is the manifestation of generalized atherosclerosis and aects all vascular territories, there is a high rate of concomitant involvement
of the coronary and extracranial cerebral vessels, in particular in PAOD of the pelvic arteries. Patients in whom PAOD
has been diagnosed require individual therapeutic management based on the stage of the disease and the suitability of
their vascular system for surgical repair as well as further
prophylactic diagnostic and therapeutic measures (coronary
heart disease, carotid stenosis). e wider range of therapeutic options available today, percutaneous interventions in
particular, can prevent the loss of a limb by reconstruction or
recanalization of occluded arteries. Timely interventions
restore perfusion and improve quality of life in patients with
steno-occlusive disease. Early diagnosis is thus essential for
the initiation of proper treatment, and duplex ultrasonography is a well-suited noninvasive modality for an ecient and
low-risk primary diagnostic workup and treatment planning.
2.1 Pelvic andLeg Arteries
2.1.1 Vascular Anatomy
2.1.1.1 Pelvic Arteries
At the level of the L4–L5 vertebrae, or the umbilical level
when scanning from the anterior approach, the abdominal
aorta divides into the two common iliac arteries. ey
descend into the true pelvis taking an arched course along
which they bifurcate at about the most posterior point (
artery bifurcation
course behind the respective arteries. e internal iliac artery
arises at the level of the sacroiliac joint, coursing in a posterior direction to supply the pelvic organs, pelvic wall, and
buttocks. e external iliac artery is the continuation of the
common iliac artery and arches into the lacuna vasorum
under the inguinal ligament. It runs medial to the iliopsoas
muscle and gives o the inferior epigastric and deep circumex iliac arteries shortly before it reaches the inguinal ligament. ese two arteries can function as collaterals in pelvic
artery occlusion.
Diameters range from 0.6 to 1.4cm in the common iliac
artery, 0.5 to 1.0cm in the external iliac artery, and 0.4 to
0.8cm in the internal iliac artery.
). e common and external iliac veins
(PAOD) in men and
iliac
2.1.1.2 Leg Arteries
e common femoral artery is about 2–4cm long and, below
the inguinal ligament, divides into the profunda femoris
artery, which typically arises from the posterolateral aspect,
and the supercial femoral artery (. Fig.2.1a).
e origin of the profunda femoris artery is variable,
and several branches may arise directly from the common
femoral artery. Typically, one branch arises posteriorly, while
the main branch arises posterolaterally or, in rare cases, posteromedially. Branches of the medial and lateral circumex
arteries arise from the femoral bifurcation or proximal profunda femoris artery and form important collateral pathways
in patients with steno-occlusive disease of the distal pelvic
segment and common femoral artery. e profunda femoris
artery is the main collateral channel in femoropopliteal
occlusion. Somewhat distal to the femoral bifurcation, the
deep femoral veins converge and unite with the supercial
femoral vein. e deep veins cross the bifurcation. e supercial femoral vein runs behind the artery on its course to the
distal thigh. e plexus passes posteriorly through the vasoadductor membrane at the level of the adductor canal
(Hunter canal), and the supercial femoral artery continues
as the popliteal artery.
Interventional radiologists and vascular surgeons subdivide the popliteal artery into three segments with the P1
segment in angiography extending from the origin to the
upper edge of the patella and the P2 segment to the knee joint
cle. e P3 segment extends to the origin of the anterior
tibial artery, which passes anteriorly through the interosseous membrane at the lower edge of the popliteal muscle. It
continues through the extensor compartment anterior to the
interosseous membrane to the upper edge of the ankle joint
with its proximal segment coursing relatively close to the
bula. e popliteal artery continues as the highly variable
tibiobular trunk with a length of about 1–5cm (. Fig.2.1b),
branching into the posterior tibial and bular arteries. e
posterior tibial artery is the main artery of the lower leg and
passes through the deep crural fascia between the supercial
and deep exors. It continues posterior to the medial ankle to
the sole of the foot, where it divides into the larger lateral
plantar artery and the smaller medial plantar artery. e lateral plantar artery extends to the deep plantar arch, which
completes the arch of foot via its collaterals to the dorsalis
pedis artery, establishing a connection to anterior tibial
branches. e bular artery courses posteromedial to the
bula, also at the level of the deep crural fascia. It ends in the
distal lower leg and gives o several arteries supplying the
muscles and serving as collaterals when other calf arteries
become occluded.
e
arteries below the knee vary widely in caliber. In
cases of hypoplasia or, very rarely, aplasia, the other arteries
act as collaterals. e anterior tibial artery is absent or shorter
in 2% of the population, the posterior tibial artery in about
5%. In about 7% of individuals, the bular artery is the main
calf artery, communicating with the distal posterior tibial
artery or dorsalis pedis artery via large collaterals arising at
54
Superior medial
ry
P
recurrent ar
(not consistently
present)
In
membrane of
leg
Pe
of fibular ar
Lateral anterior
malleolar ar
and latera
malleolar rete
(lateral)
c
Chapter 2 · Extremity Arteries
2
Femoral nerve
Lateral femoral circumflex
artery and vein
Medial femoral circumflex
artery
Great saphenous vein
Profunda femoris artery
Deep femoral vein
Descending branch
Superficial femoral artery
Saphenous nerve
Perforating arteries
a
b
Popliteal
vein
Popliteal
artery
Sciatic nerve
genicular arte
Tibial nerve
Fibular nerve
Lymph nodes
Sural arteries
Gastrocnemius,
medial head
Gastrocnemius,
lateral head
Sural nerve
Small saphenous
vein
Popliteal artery
Articular rete
of knee
osterior tibial
tery
terosseous
rforating branch
tery
tery
l
. Fig. 2.1 a Arteries and veins in the groin (From Heberer and van Dongen 1993). b Arteries and veins in the popliteal fossa (From Heberer and
van Dongen 1993). c Anterior and posterior views of the lower leg arteries
Tibial tuberosity
Anterior tibial
recurrent artery
Anterior tibial
artery
Medial anterior
malleolar artery
and medial
malleolar rete
Dorsalis pedis
artery
Inferior medial
genicular artery
Posterior tibial
artery
Communicating
branch
Medial
malleolar branches
Calcaneal branches
(medial)
Calcaneal rete
Inferior lateral
genicular artery
Fibular
circumflex
branch
Anterior tibial
artery
Fibular artery
Perforating
branch
Lateral malleolar
branches
Calcaneal
branches
2.1 · Pelvic andLeg Arteries
the level of the ankle joint. Collateralization through the malleolar network at the ankle joint plays an important role in
atherosclerotic occlusion or hypoplasia.
2.1.2 Examination Protocol andTechnique
2.1.2.1 Pelvic Arteries
e scanning depth required for an examination of the pelvic
arteries makes it necessary to use a convex transducer with a
frequency of 3.5–5 MHz. e proper pulse repetition frequency (PRF) (no aliasing) and gain are selected in a nondiseased arterial segment. e examination is performed with
the patient in the supine position and aer an adequate
period of rest to prevent false-positive results due to reactive
hyperemia. Exercise-induced hyperemia takes longer to
return to normal in patients with atherosclerotic occlusive
lesions.
Hemodynamically signicant
stenosis above the ingui-
nal ligament can be identied quickly by spectral Doppler
interrogation of the common femoral artery. A triphasic
waveform with a peak systolic velocity (PSV) of at least
70 cm/s (comparison with contralateral side) rules out
higher-grade stenosis at the pelvic level with a high degree of
condence.
For a closer evaluation, the aortic bifurcation is identi-
ed in the transverse plane at the umbilicus, and the com-
mon and external iliac arteries
lesions
in longitudinal orientation (. Fig.2.2a). Bowel loops,
are scanned for stenotic
in particular when lled with air, produce marked scattering
and attenuation, impairing continuous evaluation of the
arteries at the pelvic level. e examiner can move the transducer around to avoid interfering bowel gas or exert pressure
with the transducer to displace overlying gas-lled bowel
loops.
e presence of calcied plaques impairs sonographic
evaluation in all vascular territories. Calcication causes
acoustic shadowing, obscuring both vascular structures and
posterior anatomy in B-mode imaging. When long segments of a vessel are aected by calcied lesions, even higher
gain settings may not allow the examiner to obtain an adequate Doppler signal for detecting stenosis. In this situation,
indirect evidence must be obtained by taking spectral
Doppler measurements upstream and downstream of the
suspected stenotic lesion. If these waveforms show a constant PSV and unchanged triphasic pattern, the plaque in
the nondiagnostic segment between the two sites of Doppler
interrogation does not cause higher-grade stenosis (see
. Fig.2.64 (Atlas)).
e arched course of the iliac arteries through the true
pelvis makes it more dicult to achieve a small angle of incidence, especially at the deepest point, the iliac bifurcation
(. Fig.2.2b), where the origin of the external iliac artery is
particularly prone to the development of stenosis. erefore,
it is important to optimize the Doppler angle by moving the
transducer along the course of the artery in either direction
and angling it (see . Figs. 1.40b, c and 2.2b). However, alias-
55
. Fig. 2.2 a Transducer positioning for examination of the pelvic
segment (aortic bifurcation at the umbilical level). b Diagram of the
arched course of the iliac vessels through the true pelvis. The iliac
bifurcation is situated at the most posterior point, where the common iliac artery gives off the internal iliac artery. The common and
external iliac veins run posterior to the arteries of the same name. The
origin of the external iliac artery is a common site of atherosclerotic
stenosis (x). From the normal anterior transducer position, however,
stenosis cannot be graded due to an extremely poor Doppler angle of
approx. 90°. To obtain a better Doppler angle, the transducer must be
moved upward or downward (arrows) and tilted (see . Fig. 1.40c, d)
ing cannot always be avoided, especially when the course of
a deep artery such as the internal iliac artery at its origin
results in a small angle relative to the Doppler beam. Aliasing
means that higher velocity peaks wrap around and appear
on the other side of the baseline (see
. Fig. 1.35).
7 Sect. 1.1.4.3 and
If the examination is technically challenging and an
abnormal Doppler waveform has been obtained in the groin,
an attempt should be made to at least evaluate the preferred
sites of stenotic disease at the pelvic level, namely the origin
of the common iliac artery from the aorta and the external
iliac artery close to the bifurcation and just proximal to the
inguinal ligament. e spectral Doppler waveforms from
these sites are analyzed for direct evidence of stenosis and
compared for indirect evidence of steno-occlusive lesions
between these sites.
2
56
Chapter 2 · Extremity Arteries
2.1.2.2 Leg Arteries
Because of their supercial course, the leg arteries can be
examined with a higher-frequency transducer of 5–7.5MHz,
2
depending on the thickness of the intervening so tissue layer.
ere are some useful rules to follow when performing a
vascular ultrasound examination (from identication of the
target vessel to characterization of pathology) (. Fig. 2.4,
. Table2.1):
5 e examination begins with identication of the target
artery and its course (arteries arising in bifurcations) in
transverse B-mode. Next, the artery is followed in the
longitudinal plane to evaluate the wall and dierentiate
the patent lumen from wall abnormalities such as plaque
(atherosclerotic intimal lesions), medial thickening due
to inammatory vascular disease, or perivascular
essential to obtain Doppler waveforms from representative sites (common femoral artery and popliteal artery;
anterior and posterior tibial arteries in patients with
clinically relevant obstruction below the knee). Analysis
of the waveforms from these sites using indirect stenosis
criteria provides a fairly comprehensive overview,
allowing the examiner to identify hemodynamically
relevant stenosis or occlusion proximal to the respective
sites. e segment is then mapped for conrmation of
the suspected stenosis or occlusion including precise
localization and grading. If a pulsatile, triphasic waveform with normal PSV (compared to the contralateral
side) is obtained (whipping sound), an obstruction of
the upstream segment is unlikely and mapping is not
required.
structures that might compress the vessel.
5 e color mode is optional but helpful in obtaining an
overview and rapidly identifying sites of stenosis
(aliasing) and occlusion as well as collaterals arising
from the main artery.
5 Waveform analysis using pulsed wave (PW) Doppler is
then performed for exact stenosis localization and
grading. e length of an occluded segment is estimated
by spectral analysis supplemented by color ow informa-
tion. For an ecient, levelwise examination, it is
e use of a
of beam steering and careful alignment with the course of the
vessel to achieve an adequate Doppler angle. A
transducer
somewhat poorer detail resolution but has the advantage of
enabling fast Doppler angle correction (<60°) by tilting the
transducer and placing the sample volume at the lateral edge
of the imaging eld. In contrast, beam steering in most ultrasound devices enables a maximum deection of the emitted
linear-array transducer requires the activation
curved- array
with a small radius yields B-mode scans with
. Table 2.1 Duplex ultrasound examination of the pelvic and leg arteries (stepwise, segmental approach; . Figs.2.2, 2.3, 2.4, and 2.12)
Segment (level) Ultrasound technique/steps Purpose, diagnostic information, criteria of pathology
I Groin B-mode: transverse Overview of vascular anatomy including profunda
femoris origin, evaluation of vessel walls
Depending on
ndings:
Continuous
evaluation of iliac
arteries
B-mode: longitudinal (rotate transducer over the
common femoral artery from transverse to longitudinal plane)
Color duplex:
(a) Longitudinal: curved array transducer tilted
cranially or linear transducer with beam steered
cranially; sample volume in distal external iliac
artery/common femoral artery junction
(b) Longitudinal: curved array transducer tilted
caudally or linear transducer with beam steered
caudally
Doppler waveforms from profunda femoris and
supercial femoral artery origins
(c) Longitudinal (suspected common femoral artery
stenosis): possibly continuous examination of the
common femoral artery with continuous spectral
Doppler measurement (sliding the caudally tilted
transducer toward the inguinal ligament)
In case of abnormal common femoral artery Doppler
waveform (monophasic or reduced pulsatility,
reduced PSV compared with contralateral side):
continuous color mapping of iliac artery in longitudinal plane (3.5–5MHz transducer)
(Plaque?), femoral bifurcation
Interpretation
Spectral Doppler waveform
Comparison with contralateral side
Exclusion or signs of pelvic artery stenosis (triphasic/
monophasic)
Indirect criteria
Localization and grading of stenosis in femoral
bifurcation (.
Stenosis of profunda femoris origin? PSV >180cm/s
Evaluation for stenosis/occlusion
Localization of stenosis
Grading of stenosis
Demonstration of common femoral artery stenosis:
PSV>180cm/s or PSV ratio (.
Evaluation for stenosis/occlusion
Localization of stenosis
Grading of stenosis
Color duplex and spectral Doppler:
Stenosis criterion: PSV ratio>2/>4
In bifurcation: PSV >180cm/s (.
Fig.2.19)
Fig.2.17)
Fig.2.12)
2.1 · Pelvic andLeg Arteries
57
. Table 2.1 (continued)
Segment (level) Ultrasound technique/steps Purpose, diagnostic information, criteria of pathology
2
II Popliteal fossa
(popliteal artery)
Depending on
ndings:
Continuous
evaluation of
femoral artery
III Below the knee B-mode: transverse Identication of arteries
If therapeutically
relevant (patients
with stage III/IV
PAOD):
Anterior and
posterior tibial
arteries at the ankle
If clinically relevant:
Mapping of calf
arteries
B-mode: transverse Identication of popliteal artery to evaluate wall and
perivascular structures: nonatherosclerotic vascular
disease/aneurysm?
B-mode: longitudinal Course of the artery, perivascular structures, evaluation
of wall (nonatherosclerotic disease/aneurysm?)
(Color) duplex
(a) Longitudinal: curved array transducer tilted
cranially linear transducer with beam steered
cranially
(b) Longitudinal: curved array transducer tilted
caudally linear transducer with beam steered caudally
(c) Mapping of popliteal artery if waveform from
distal segment is abnormal
If popliteal artery exhibits monophasic ow or
unilaterally reduced PSV: continuous longitudinal
examination of supercial femoral artery with the
tilted transducer (or beam steering) (color duplex as
needed) and continuous spectral Doppler recording
Duplex: longitudinal
Distal anterior and posterior tibial arteries
(Color) duplex:
In case of abnormal Doppler waveform and clinical
relevance: continuous examination of calf arteries
Transverse: localization of arteries
Longitudinal: color duplex and Doppler waveform to
detect stenosis
Interpretation of Doppler waveform: indirect criteria for
stenosis/occlusion of supercial femoral artery
(triphasic/monophasic)
Comparison of Doppler waveforms from proximal
supercial femoral artery and proximal popliteal artery
Popliteal artery stenosis?
Evaluation of Doppler waveform: monophasic, reduced
PSV compared with contralateral side
Evaluation for stenosis/occlusion
Popliteal artery stenosis:
PSV ratio>2: 50% stenosis
PSV ratio>4: 75% stenosis
Stenosis criteria (7
PSV ratio>2: 50% stenosis
PSV ratio>4: 75% stenosis (. Figs.2.14 and2.20)
Possibly measurement of occlusion length (color
duplex) (. Fig.2.25)
Spectral Doppler sampling, indirect criteria
Doppler waveform: postocclusive
Evaluation for stenosis/occlusion
Localization of stenosis
Grading of stenosis
Stenosis criteria: PSV ratio>2/>4, along the vessel
Fig.2.22)
(.
Search for target vessel for crural bypass graft
Sect. 1.2.3):
PSV peak systolic velocity
beam of only 20° either to the right or to the le of the perpendicular beam axis. us, the smallest Doppler angle
achievable with beam steering is 70° when interrogating vessels running parallel to the skin surface. e evaluation of
spectral tracings for indirect signs of occlusive lesions in the
vicinity of the sample volume requires an angle of less than
60°.
e femoral (. Fig.2.3a) and anterior tibial arteries are
examined in the supine position, all other arteries below the
knee and the popliteal artery in the prone position with slight
elevation of the distal calf by a support placed under the
ankles.
In general, vascular evaluation is performed in two
planes
. First, the artery is identied in the transverse plane.
For a rst overview, the transducer must be angled distally or
cranially to achieve a small angle of insonation relative to the
vessel cross section (. Fig.2.4, . Tables 2.1 and 2.2). Initial
evaluation in the transverse plane has the advantage of
enabling rapid identication of aneurysmal dilation, highgrade stenosis (aliasing), and occlusions (including origins of
collaterals) once settings have been optimized. Abnormal
ndings need to be conrmed and quantied in the longitudinal plane. e pulse repetition frequency (PRF) and gain
are set to allow complete color lling of the patent lumen
without aliasing. An adequate angle of insonation and
Doppler angle correction in the B-mode are prerequisites for
accurate stenosis grading. As with gray-scale sonography, the
monitor display of vascular images in the longitudinal plane
depicts the cranial vessel segment on the le and the distal
segment on the right.
58
Chapter 2 · Extremity Arteries
2
4
1c
3
2b
2c
5b
continuous mapping is most
. In this way,
a
b
. Fig. 2.3 a Transducer positioning for examination of the femoral
arteries (transverse plane for identication of the target vessel, longitudinal plane for measuring blood ow velocity). b Transducer positioning for examination of the distal popliteal artery (at the junction of the
P3 segment and tibiobular trunk)
With the patient in the supine position and aer an adequate period of rest (>5min), the common femoral artery is
identied in the transverse plane and followed along its
length to the bifurcation. e transducer is positioned (on
the inner thigh in most patients) to view the bifurcation in
such a way that the profunda femoris artery, which typically
arises from the posterolateral aspect, comes to lie exactly
behind the supercial femoral artery. e transducer is then
turned longitudinally. In this view, the bifurcation appears as
a tuning fork, which facilitates identication of vascular
anatomy in this area and Doppler angle correction for evaluation of profunda femoris origin stenosis. Especially when
occlusions have been identied in the femoropopliteal segment, the profunda femoris artery should be followed to the
level of second-order branches to check for the presence of
more distal stenosis. A step-by-step description of the examination is given in . Table2.1. e supercial femoral artery
1a
1b
2a
5a
. Fig. 2.4 Sonoanatomy of the leg arteries at representative sites
(transverse views on the left for identication of the target arteries; longitudinal views on the right for evaluation and detection/characterization of stenosis with spectral Doppler measurement). Shown are images
of vascular anatomy at the following sites:
1a and 1b– transverse views of femoral bifurcation in the groin;
1c– longitudinal view of femoral bifurcation. 2a– transverse view of popli-
teal fossa; 2b– longitudinal view of popliteal artery; 2c– longitudinal view
of tibiobular trunk. 3– longitudinal view of supercial femoral artery.
4– longitudinal view of iliac bifurcation. 5a– transverse view of bular
and posterior tibial arteries from posterior approach; 5b– longitudinal
view of bular artery and vein from posterior approach
is scanned in longitudinal orientation down the inner thigh.
When the leg arteries (or other vessels that run parallel to the
body surface) are examined,
eciently accomplished by moving the longitudinally oriented transducer along the artery of interest
long arterial segments can be evaluated in the B-mode with
simultaneous Doppler interrogation (optimal PRF and gain)
at an angle of <60°. At the level of the adductor canal, scattering and attenuation due to connective tissue structures may
require adjustment of receive gain for both B-mode and
spectral Doppler imaging.
In the adductor canal, the artery is easier to follow with
the leg turned outward and the knee slightly bent. e popli-
teal artery
and vein are best examined with the patient lying
prone. e vein runs posterior to the artery. Alternatively, the
2.1 · Pelvic andLeg Arteries
59
. Table 2.2 Diagnostic algorithm in peripheral arterial occlusive disease (PAOD) (key points)
Question Criteria
I Is something to be done? Clinical presentation!
Duplex ultrasonography?
Angiogram unnecessary (obsolete)
II What is to be done? (Color) duplex ultrasound (physical therapy, e.g., walking exercises, PTA, or bypass graft surgery)
Angiogram unnecessary (obsolete)
III How is it to be done? Angiography with PTA
MRA/CTA or duplex ultrasound (possibly with echo enhancer) to select a target segment for
crural bypass procedure
Supplementary invasive diagnostic tests (angiogram)
Ad I: Is the patient’s pain even caused by PAOD? Consider clinical presentation, pulses, ankle-brachial index (ABI) (highly valid screening
test for PAOD). The therapeutic strategy in PAOD is solely guided by clinical necessity (i.e., the patient’s symptoms)
Ad II: Color duplex to identify the level of obstruction (pelvis, thigh, calf). Individual treatment approach based on clinical necessity as well
as on therapeutic measures possible in a patient and their prognosis. Length of occlusion determines whether percutaneous transluminal
angioplasty (PTA) can be attempted or bypass graft surgery is necessary. In occlusion of a pelvic or thigh artery, the decision for bypass
graft surgery and the selection of a target segment can be made on the basis of duplex ultrasound
Ad III: Selective angiography with PTA without prior diagnostic angiogram. Selection of the crural target segment in multilevel
obstruction or in combined popliteal/crural obstruction using angiography or magnetic resonance angiography (MRA). A pedal target
artery is identified using color duplex ultrasound combined with angiography or MRA.The stepwise diagnostic approach demands that
no additional diagnostic tests (e.g., more invasive and more expensive) be performed unless the results may affect the therapeutic
decision
2
popliteal artery can be scanned with the patient supine, the
knee at a 30°–60°angle of exion, and the transducer placed
in the popliteal fossa. As the anterior tibial artery arises from
the anterolateral aspect of the popliteal artery, its origin
appears farther away from the transducer (. Figs.2.3b and
2.2). e origin may be relatively high in individuals with a
short P3 segment or very low when P3 is long. In about 4% of
the population, all three lower leg arteries jointly arise in a
trifurcation (Lippert and Pabst 1985). Aer having pierced
the interosseous membrane, the anterior tibial artery is
traced distally along its anterolateral course in longitudinal
orientation.
e tibiobular trunk varies in length from 1 to 6cm,
depending on the level of origin of the anterior tibial artery.
Its division into the posterior tibial and bular arteries is
identied in the transverse plane. In the longitudinal view,
the vessels are continuously scanned for stenosis or occlusion by following their courses distally (. Fig. 2.5). If an
artery disappears from the scanning plane, it can easily be
identied again by rotating the probe into a transverse plane.
e tibia and bia, with their characteristic acoustic shadowing, can be used as landmarks. Further orientation is provided by the hyperechoic band of the deep crural fascia.
Under good insonation conditions, the arteries below the
knee can be visualized down to the ankle region. Time can
be saved by recording two Doppler waveforms, one in the
proximal and the other in the distal segment of the respec-
tive artery, which in general rules out a hemodynamically
signicant obstruction between the two sampling sites when
both show the same ow prole and normal peak systolic
velocity (PSV).
When there is poor color ow, the examiner should rst
try and adjust machine settings. Selection of a venous preset may improve detection of slow arterial ow below the
knee. If the artery of interest is still dicult to identify, due
to calcication, stenosis, or occlusion, the following measures may be helpful:
5 Look for the accompanying veins, which may be easier
to visualize. When the veins are not readily detected in
the color duplex image, ow can be augmented by distal
compression (sole of foot or ankle).
5 Use the bright reection of the tibia and bula as an
anatomic landmark inlocalizing the arteries below the
knee; additional landmarks are the interosseous mem-
brane and the deep crural fascia (. Figs.2.5 and 2.6).
e dorsalis pedis artery and the posterior tibial artery
behind the medial ankle (. Fig. 2.6) are examined in the
supine position using a high-frequency transducer (7.5–
10 MHz). ese arteries are identied in the transverse
plane to then perform spectral Doppler interrogation in the
longitudinal plane. From there, the plantar artery can be
scanned in the transverse plane to the level of the interdigital arteries.
60
s
ab
ab
cd
Chapter 2 · Extremity Arteries
2
. Fig. 2.5 a Transducer position for examination of bular and posterior tibial arteries (courses indicated by thick black line). b Sonoanatomy
of the posterior tibial artery (A.TIB POST) and bular artery (A.FIBULARIS) scanned from a posterior approach. The arteries (A) are displayed in red
between their paired accompanying veins (V, with ow displayed in blue). The posterior tibial artery courses posterior to the tibia, while the bular
artery courses medial to the bula. Both arteries course in a thin, band-like structure of slightly higher echogenicity, the deep crural fascia, anterior
to the soleus muscle. c Origins of the anterior tibial artery (A.TIB ANT) and tibiobular trunk ( T.TF) from the popliteal artery (A.POP); posterior
approach with transducer placed in popliteal fossa. d Posterior tibial artery (A.TIB.POST) and its accompanying paired veins (V) at the mid-calf level
1
Anterior fibular
artery and vein
Extensor
digitorum muscle
Extensor hallucis
longus muscle
Posterior tibial
muscle
Fibular artery
and vein
Anterior tibial
muscle
2
Gastrocnemius
muscle
Flexor digitorum
muscle
Posterior tibial
artery and vein
Soleus muscle
3
Extensor hallucis
longus muscle
Extensor
digitorum
muscle
Small
saphenous
vein
1
Anterior tibial artery
and vein
Tendon
Great saphenou
vein
Posterior tibial
muscle
Flexor digitorum
muscle
Posterior tibial artery
and vein
2
. Fig. 2.6a, b Anatomy of the anterior and posterior tibial arteries at the mid-calf level (a) and at the ankle joint (b). At the mid-calf level, the
arteries can be scanned from an anterior (1), posterior (2), or posteromedial transducer position (3). At the ankle, the transducer positions for scanning the anterior tibial artery (1) and posterior tibial artery (2) are shown
2.1 · Pelvic andLeg Arteries
61
2
. Table 2.3 Diagnostic and therapeutic management of
patients with vascular disease in dierent territories
Vascular disease Purpose of therapeutic management
and diagnostic procedure
PAO D Symptom-oriented
Nonatherosclerotic
peripheral vascular
disease
Carotid artery
stenosis
Aneurysm Prevention-oriented
Diagnostic procedure prior to:
Symptom-oriented
treatment
Prevention-oriented
treatment
PAO D peripheral arterial occlusive disease
2.1.3 Specic Aspects oftheExamination
Prevention-oriented
Prevention-oriented
Levelwise duplex ultrasound
examination informed by therapeutic
options contemplated/stepwise
diagnostic workup
Duplex sonographic vessel mapping
of predilection sites based on clinical
suspicion or in high-risk patients
fromthePerspective oftheAngiologist
andVascular Surgeon
Ultrasound examinations of the lower extremity arteries are
performed for three purposes:
5 Screening
5 Diagnostic workup and treatment planning
5 Follow-up aer surgical and interventional procedures
or medical treatment
Screening ultrasound is performed to identify individuals in
need of treatment either in a group of the population or
among patients presenting with suspected vascular disease.
Vascular screening ultrasound is primarily performed in vascular territories where the ndings serve to select patients for
preventive interventions (. Table2.3). Screening tests should
be inexpensive and not put patients at risk. In addition, they
must have high sensitivity and a low false-negative rate. A
false-positive diagnosis can be corrected by the subsequent
(invasive) vascular examination.
e German Epidemiological Trial on Ankle-Brachial
Index (GetABI; Lange etal. 2007) conrms earlier investigations (Neuerburg-Heusler 1984), showing that a simple Doppler
examination combined with determination of the ankle-brachial index (ABI) is an ideal screening test for peripheral arterial occlusive disease (PAOD). is test has an accuracy of over
90% in dierentiating patients with pain caused by PAOD from
patients with pain of other etiologies when the clinical examination and pulse measurement are inconclusive (except for
pelvic artery obstruction with good collateral circulation).
As the therapeutic management of patients with PAOD is
symptom-oriented (vs. prevention-oriented management of
patients with carotid artery disease), the clinical presentation
determines the extent of the ultrasound examination, and no
comprehensive vascular mapping is done in all cases
(
. Table2.3). A stepwise algorithm is proposed to ensure an
ecient ultrasound examination of the lower extremity
(. Fig. 2.7). Noninvasive duplex ultrasound is performed if
PAOD is suggested by the patient’s history, clinical examination
with full evaluation of peripheral pulses, and ABI measurement.
Sonography provides information on the severity and localization of obstructive vascular lesions as well as on their cause
(embolism, atherosclerosis, vascular compression syndrome)
and is the basis for deciding about the therapeutic strategy
(medical, interventional, surgical). Angiography is performed
only as part of a therapeutic intervention (diagnostic angiogram
plus angiographically guided percutaneous intervention) or to
plan surgery (evaluation of outow tract for bypass graing and
identication of the most suitable vessel segment for distal anastomosis). Alternatively, the distal leg arteries can be examined by
magnetic resonance angiography (MRA) or computed tomography angiography (CTA) as well as color duplex or contrastenhanced ultrasound (CEUS).
Further diagnostic tests, especially invasive ones such as
angiography, are only done if the ndings are expected to
have therapeutic consequences. Hence, angiography has
been abandoned as a routine modality for diagnosing PAOD
or evaluating the vascular status in patients with denitive or
inconclusive symptoms of claudication.
Adequate therapeutic measures in relation to the stage of
disease are initiated on the basis of the clinical presentation
in conjunction with the duplex ultrasound ndings
(. Table2.6, . Fig.2.8). e sonographically diagnosed site
of obstruction and clinical stage allow interventional or surgical procedures to be performed without prior angiography.
Because ultrasound is not a prevention-oriented examination in PAOD, its extent can be restricted– based on clinical manifestations and disease stage. Patients with stage II
PAOD, for instance, do not normally require a full duplex
evaluation of the calf arteries below the tibiobular trunk
since vascular reconstruction for stenosis or occlusion in this
territory is not indicated at this disease stage.
Steno-occlusive disease of the pelvic arteries, femoral
bifurcation, and supercial femoral and popliteal arteries
can be diagnosed and characterized by duplex ultrasound in
a short amount of time and with a high degree of accuracy
(>90–95% in the recent literature). Sonographic assessment
allows reliable planning of bypass surgery with gra patency
rates comparable to those in patients undergoing preoperative invasive angiography. Since the aim of surgical bypass
graing in patients with multilevel occlusive disease is to
improve inow, in stage III and IV PAOD as well, candidates
for surgical recanalization above the popliteal artery do not
require preoperative angiography or duplex mapping of the
infrapopliteal arteries as long as the sonographic examination demonstrates a patent and nonstenotic popliteal segment. Comprehensive preoperative evaluation of the calf
62
Stepwise Diagonostic Management
a
b
Chapter 2 · Extremity Arteries
• History (PAOD II-IV)
• Clinical examination (pulses)
2
• ABI/Oscillography
• Color/Duplex ultrasound
Flow obstruction:
- Pelvic arteries
- Common femoral artery
and bifurcation
- Superficial femoral artery
- Popliteal artery
- Lower leg arteries
• Angiography (optional, depending on duplex findings)
• CT, MRI (optional)
Patient contact
Claudication
Doppler ultrasound as needed
Normal
Evaluation for other
causes (e.g.,
lumbar syndrome,
polyneuropathy)
Pelvic
level
Sur-
PTA
gery
. Fig. 2.7 a Stepwise diagnostic procedure and algorithm for diagnostic and therapeutic management based on the clinical presentation and
localization of ow obstruction demonstrated by duplex ultrasonography. Symptom-oriented therapy → symptom- oriented diagnostic procedure. The key idea of this approach is that no subsequent diagnostic test is performed unless it is therapeutically relevant. b Diagnostic algorithm
in peripheral arterial occlusive disease (PAOD). The examiner can deviate from the proposed algorithm in the following situations:
1. Crural reconstruction is not indicated in stage II PAOD: diagnostic evaluation of iliacofemoropopliteal arteries by color duplex alone is possible with therapeutic decision based on color duplex ndings (plus clinical presentation and ABI)
2. Normal ankle-brachial index (ABI): patient may have pelvic level occlusion/stenosis with good collateralization; duplex scan if steno-occlusive
disease is suggested by clinical symptoms
3. Multilevel occlusion and suboptimal duplex scan: supplementary angiography may be contemplated and should be used more liberally
4. Sonographic demonstration of popliteal aneurysm with occlusion: treatment (surgical repair) according to clinical symptoms; same diagnostic steps as for PAOD III/calf. If ow is detected in popliteal aneurysm: prophylactic surgical repair with bypass; same diagnostic steps as for
PAOD III/calf
5. Diabetics with severe macroangiopathy and medial sclerosis precluding adequate evaluation (acoustic shadowing): more liberal use of diagnostic angiography
6. Patients with PAOD III or IV and multilevel occlusion: patent popliteal artery without hemodynamically relevant stenosis: surgery or intervention above the popliteal artery to improve inow based on duplex ndings (diagnostic angiography not required); additional obstruction
of lower leg arteries does not aect the initial treatment strategy (e.g., bypass graft onto P1 segment). Steno-occlusive disease of popliteal
segment: search for a suitable recipient artery for crural bypass using angiography (usually DSA), magnetic resonance angiography with dedicated coil, or color duplex (time-consuming), possibly contrast-enhanced ultrasound (CEUS)
Femoral
bifurcation
TEA
Duplex ultrasound
Thigh
level
Sur-
PTA
gery
Calf
level
PAOD II
Nonatherosclerotic
Conser-
vative
vascular disease
Conser-
vative
Rest pain
History/pulses
ABI
Duplex if unclear
Abnormal
Sur-
gery
PAOD III PAOD IV
Duplex ultrasound
Pelvic
level
Sur-
PTA
gery
TEA
Toe ulcer/necrosis
Femoral
bifurcation
Sur-
PTA
gery
Thigh
Treatment based
Calf
level
level
Catheter or MR
angiography
on findings