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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5760_Библиотеки_им_академика_М_И_Перельмана.pdf
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2.3 · Atlas: Extremity Arteries
143
. Fig. 2.73a, b (Atlas) Interpretation of Doppler waveforms from within bypass grafts.
a Blood ow velocity within a bypass graft is largely determined by its diameter and that of the distal recipient artery. In the example shown, peak
systolic velocity (PSV) in the dilated venous bypass graft (V.BP; diameter of 11mm) is only 20cm/s although there is no stenosis proximal to the
sampling site. The waveform is pulsatile and exhibits a steep systolic upstroke.
b There is no stenosis at the distal anastomosis with the distal popliteal artery (P3). The focal increase in PSV to 102cm/s is due to the size mismatch between the dilated graft (bp; see a) and the normal-caliber distal popliteal artery. The triphasic and pulsatile waveform recorded in the
popliteal artery distal to the anastomosis is that of a normal peripheral artery. In the follow-up of bypass grafts, the examiner should compare the
pulsatility and ow velocity with the baseline values determined sonographically within the rst 3months of the bypass procedure
2
a
. Fig. 2.74a–g (Atlas) Low-ow bypass– failing bypass.
a Patient presenting 2years after creation of a venous femorocrural bypass onto the posterior tibial artery. A markedly reduced peak systolic
velocity (PSV) of 35cm/s indicates a low-ow bypass at risk for imminent occlusion. In interpreting ow velocities measured in a bypass, however,
the examiner must take into account a possible size mismatch between graft and recipient artery. In the case presented here, the pulsatile character of the waveform with to-and-fro ow suggests an increase in peripheral resistance and hence an outow obstruction.
b In this patient, slow ow and pulsatility in the bypass are due to occlusion of the posterior tibial artery distal to the bypass anastomosis.
c The proximal posterior tibial artery exhibits retrograde ow (red, directed toward the center, PSV of 110cm/s) and rells the bular artery via
collaterals.
d Blood ow in the bular artery is orthograde, and the PSV is 26cm/s.
e More distal spectral Doppler sampling in the bular artery demonstrates a similar ow character, indicating patency of a long stretch of the
artery and absence of high-grade stenosis. These ndings suggest that the bular artery would be a suitable outow tract for revision of the lowow bypass. However, because of good collateralization and the patient’s multimorbidity including a history of stroke, anticoagulation was initiated instead. The bypass has since been followed up for one year with no evidence of occlusion.
f These sonographic ndings (posterior tibial artery patent proximally and occluded downstream of the bypass anastomosis, relling of bular artery
via collaterals) are conrmed by angiography performed 6months later for PTA of a new stenosis at the proximal anastomosis (see . Fig.2.75 (Atlas)).
g Later angiogram shows patency of a long stretch of the bular artery
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Chapter 2 · Extremity Arteries
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. Fig. 2.75a–c (Atlas) Low-ow bypass and new stenosis of proximal anastomosis.
New high-grade stenosis of the proximal anastomosis (a) in the patient with low-ow bypass presented in . Fig.2.74 (Atlas)). The PSV ratio is 4
(intrastenotic PSV of 4m/s and prestenotic PSV of 1m/s (b)). High pulsatility is due to outow obstruction
a
b
c
. Fig. 2.76a–c (Atlas) Saphenous vein bypass graft– stenosis at valve site.
An autologous bypass graft (great saphenous vein) is more dicult to identify, especially when it is occluded, due to the thin venous wall and the
frequent extra-anatomic course. Color duplex helps identify the graft, but spectral Doppler measurement is necessary for quantitative evaluation.
a A postocclusive waveform with a peak systolic velocity (PSV) of 24cm/s and an end-diastolic velocity (EDV) of 4.1cm/s obtained in the main
body of the graft indicates proximal stenosis.
b While stenosis is rare within a synthetic bypass, the entire length of a venous graft must be carefully scrutinized for the presence of stenosis. In
an in situ vein graft, stenosis tends to develop at sites of retained valves. In the example, the color ow image and spectral Doppler measurement
reveal a short, high-grade stenosis with a PSV of 6m/s at the site of a valve leaet, conrming the stenosis suggested by the postocclusive waveform presented in a.
Aneurysmal dilatation of vein graft.
c Aneurysmal dilatation is a late complication of bypass surgery and is often associated with elongation of the graft (VBP). The left color ow image
shows a dilated and partially thrombosed venous graft segment (measuring 2.5×3.8cm) 2cm above the distal anastomosis with the P3 segment of
the popliteal artery (VBPAN). The second color ow image shows the site of anastomosis (A), from which the Doppler waveform was obtained
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2.3 · Atlas: Extremity Arteries
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. Fig. 2.77a–f (Atlas) In situ vein graft– AV stula and stenosis.
a Waveform from an in situ vein graft with a steep systolic upstroke but monophasic ow pattern and large diastolic component. The high ow
volume in the graft with a peak systolic velocity (PSV) of 150cm/s and an end-diastolic velocity (EDV) of 50cm/s is attributable to a distal arteriovenous stula (AVF).
b Distal to the high-ow stula (AVF), the ow velocity in the graft (BP) is much lower. Doppler interrogation shows a PSV of 70cm/s and a monophasic pattern, but with some end-diastolic ow. The waveform is still abnormal, chiey showing the inuence of peripheral vasodilation.
c In addition, there is a stenosis 4cm proximal to the distal anastomosis at the site of a retained valve leaet. Stenosis is suggested by a focal
increase in PSV to 1m/s and the monophasic waveform.
d A PSV ratio> 2 is calculated (prestenotic PSV of 45cm/s), corresponding to approximately 50% stenosis. The color duplex image shows aliasing at
the site of stenosis. The site of the AV stula identied by ultrasound was marked on the skin for ligation, while the 50% stenosis was left untreated.
e Over the next 3months, the patient developed a second, high-grade stenosis at the distal anastomosis (ANAST) with a PSV of >3.5m/s.
f Angiogram showing the anastomotic stenosis and relative luminal narrowing approx. 3cm proximal to the anastomosis; the degree of stenosis is
dicult to estimate
. Fig. 2.78a, b (Atlas) Bypass graft– inow stenosis.
a Inow stenosis is suggested if, as in this example, spectral Doppler examination of the bypass demonstrates the characteristic features of poststenotic ow including a monophasic waveform with a delayed systolic upstroke, reduced peak systolic velocity (PSV), and persistent diastolic
ow. When the waveform from within the graft suggests inow obstruction, the inow artery should be followed cranially to identify the site of
stenosis.
b High-grade external iliac artery stenosis caused by posterior plaque, suggested by aliasing in the color ow image and conrmed by spectral
Doppler interrogation (monophasic ow, PSV of 550cm/s, end-diastolic velocity of 220cm/s)
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Chapter 2 · Extremity Arteries
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. Fig. 2.79a–f (Atlas) Pseudoaneurysm– thrombin injection treatment.
a Transverse view of the thigh reveals a pseudoaneurysm (AN) arising from the supercial femoral artery (A.F.S). With the sample volume placed
in the neck, spectral Doppler interrogation reveals the characteristic to-and-fro ow with high-frequency ow into the aneurysm in systole and
backward ow into the artery throughout diastole.
b For treatment of the aneurysm by thrombin instillation, a needle is advanced into the aneurysm and the tip positioned between the center of
the cavity and the near wall under ultrasound guidance (needle tip identied by bright echo).
c Thrombin is instilled at a dose of 5000IU dissolved in 2mL of saline solution. Complete thrombosis of the aneurysm (AN) has occurred after
instillation of one to two drops, as demonstrated by cessation of ow within the cavity in the color duplex mode; shown in transverse orientation
on the left and in longitudinal orientation on the right (A.F.S=supercial femoral artery; A.P.F=profunda femoris artery; V=femoral vein).
Pseudoaneurysm– challenges for thrombin injection treatment.
d, e Very circulatory and fast ow in a larger aneurysm sac will wash away thrombin from the needle tip and dilute it before a clot can begin to
form. Since both spontaneous contrast and color coding show ow directions, the needle can be sonographically guided to a peripheral area with
little ow (in the leftmost aspect of the aneurysm in d), where a thrombus will begin to form and then enlarge with little risk of thrombin being
washed away (e). The waveform shows that the color-coded ow adjacent to the thrombosed aneurysm sac is blood ow in the great saphenous
vein rather than ow into the aneurysm.
Pseudoaneurysm– dierentiation from hematoma.
f Spectral Doppler analysis allows dierentiation of a postinterventional hematoma with blood ow in small arteries coursing through it, as in this
case, from pseudoaneurysm with to-and-fro ow
. Fig. 2.80a, b (Atlas) Suture aneurysm.
a In patients who have undergone an iliacofemoral bypass procedure, palpation of a mildly pulsatile, protruding mass at one of the anastomoses may
suggest a suture aneurysm. In the case presented, the transverse image shows hypoechoic uid extending laterally from the site of anastomosis. Color
duplex imaging demonstrates ow in a portion of the lesion adjacent to the bypass graft. This appearance is also consistent with vibration artifacts.
The suspected suture aneurysm is conrmed by spectral Doppler demonstration of to-and-fro ow in the communication between the mass and the
anastomosis with a characteristic steam engine sound. This sound is produced by high systolic inow into an aneurysm and pandiastolic ow reversal.
b Seroma at an aortofemoral bypass anastomosis. The color duplex appearance of a seroma is similar to that of a suture aneurysm (as described in a). How-
ever, the Doppler waveform recorded at the site of apparent ow (coded red) does not show to-and-fro ow (as in the suture aneurysm) but a signal generated in the seroma by wall motion of the vessel prosthesis. The example nicely illustrates that spectral Doppler analysis can dierentiate true ow signals
in a pseudoaneurysm from transmitted pulsation (which is also important when examining patients with suspected endoleaks after aortic stenting)
2.3 · Atlas: Extremity Arteries
147
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. Fig. 2.81a–c (Atlas) Pseudoaneurysm– compression therapy/thrombin injection.
a In the color duplex mode, the examiner identies the neck connecting the pseudoaneurysm to the femoral artery and then occludes it by exerting pressure with the transducer. During the procedure, which may take up to half an hour, adequate compression is indicated by the absence of
ow signals in the neck and cavity. Following the procedure, absence of ow in the cavity demonstrated by color duplex indicates that complete
thrombosis has been accomplished. If only partial thrombosis is apparent after the procedure, it is often easier to induce complete thrombosis
in a second session on the next day (compression bandage), or complete thrombosis may occur spontaneously. Alternatively, thrombosis of a
pseudoaneurysm may be induced by thrombin injection. However, thrombin injection often leaves a larger residual hematoma, which may cause
persistent symptoms. Thrombin injection is indicated if the site of the aneurysm precludes compression or in patients with perforated aneurysm
or suture aneurysm (which may be infected).
b A small pseudoaneurysm (A.S) measuring only 2cm but not occluding spontaneously arises somewhat atypically from the profunda femoris
artery (A.P.F) approx. 2cm distal to the femoral bifurcation (left image). With the sample volume placed in the neck, the typical systolic–diastolic
to-and-fro ow is recorded. On the medial side of the neck, the supercial femoral artery (A.F.S) and vein (V) are depicted in cross-section. Compression of the neck with the transducer in a more lateral position brings about complete thrombosis of the aneurysm after 15min (right image).
Large pseudoaneurysm with multiple perforation– thrombin injection.
c A very obese patient developed a large hematoma extending from the left groin to the lower abdomen following angiography with cannula-
tion of the femoral artery (A.F.). Pseudoaneurysm is suggested by the demonstration of ow (AN). The leftmost image shows the sample volume
placed in the neck (arrowhead) with the characteristic to-and-fro ow in the corresponding waveform. There is a second aneurysm with a separate communication with the femoral artery (probably due to repeated puncture). The total length of both aneurysms is over 6cm. The image
obtained after thrombin treatment of the upper aneurysm (A.S.NACH TH– middle section) shows the remaining second aneurysm (A.S.) arising
from the femoral artery (A.F.). The Doppler waveform from the neck of the second aneurysm also shows the typical to-and-fro ow. Blood ow in
the neck is very slow (30cm/s during systole and 16cm/s at end diastole), suggesting a large perforation defect. A total dose of 5000IU thrombin
was required to induce closure of both aneurysms, which is very high. Very slow injection was started in the margin to minimize the risk of thrombin escape into the femoral artery. The rightmost image conrms complete thrombosis of both aneurysms and patency of the femoral artery (A.F.)
posteriorly. The poor color lling of the femoral artery despite a low PRF is due to scatter by the hematoma. Leg perfusion was normal, and foot
pulses were palpable
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Chapter 2 · Extremity Arteries
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. Fig. 2.82a, b (Atlas) Internal iliac artery– pseudoaneurysm, thrombin injection.
a Routine abdominal diagnostic workup prior to gastrectomy for cancer in a 78-year-old patient revealed a large spontaneous pseudoaneurysm
(no trauma, no iatrogenic cause) arising from the internal iliac artery and measuring 6×6cm. Under ultrasound guidance, a thin needle is passed
somewhat below the iliac bifurcation between the internal and external iliac arteries to puncture the aneurysm for instillation of 5000IU of
thrombin dissolved in 3mL saline solution. Only marginal thrombosis is achieved (right image). Much of the lumen still shows eddy ow (color
coding). Instillation of a second dose of 5000IU of thrombin into the aneurysm (A.S) results in complete thrombosis (left image). Even at a low PRF,
no ow signals are detected in the color duplex mode. There is ow in the external iliac (A.l.E) and internal iliac (A.I.I) arteries. The patient has no
clinical symptoms.
b The angiogram obtained prior to thrombin injection (left) shows a large pseudoaneurysm arising from the internal iliac artery (detail with
iliac bifurcation in oblique projection). The right angiogram shows the aortic bifurcation and pelvic circulation (both iliac bifurcations) after
ultrasound-guided thrombin injection (oblique projection similar to preinterventional angiogram). Absence of contrast medium at the site of the
aneurysm conrms that complete thrombosis has occurred
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. Fig. 2.83a–e (Atlas) Arteriovenous stula.
a Patient with stage IV PAOD in whom color duplex ultrasound after puncture in the left groin shows a mosaic pattern of colors at the junction of
the external iliac and common femoral arteries. The distal external iliac artery shows the high-frequency ow typical of an artery feeding a stula
with a peak systolic velocity (PSV) of 160cm/s and an end-diastolic ow (EDV) of 50cm/s (monophasic).
b Just proximal to the mosaic pattern, there is a calcied and stenosing plaque with posterior acoustic shadowing. The high-frequency ow signal
from the site of this color pattern (EDV of 80cm/s and PSV of >400cm/s) may be related to a stenosis or stula. The two entities can be dierentiated by evaluating venous drainage and the femoral artery distal to this site.
c The iliac vein exhibits the venous ow signal typical of an AV stula: high-frequency ow (with an angle- corrected velocity of 90cm/s) with pulsatile variation. Adjustment of the PRF to venous ow leads to aliasing (left side of color ow image).
d The Doppler waveform from the profunda femoris artery distal to the AV stula has a delayed and attened systolic upslope and a monophasic
prole with a fairly large diastolic ow component. This is a typical poststenotic prole, caused by the puncture- induced AV stula and the highgrade stenosis resulting from the plaques shown in a. For dierentiation of the cause of the perivascular vibration artifacts, the downstream circulation must be evaluated (stula: venous; stenosis: arterial). This case illustrates that vessel manipulation by puncture may not only induce stula
formation but also cause stenosis through detachment of a plaque from the vessel wall.
e Angiogram: Contrast medium outow in the iliac vein typical of a stula. Angiography does not allow precise localization of the stula, nor does
it provide denitive evidence for the stenosis in this segment (superimposition). Left arrow indicates the femoral vein, right arrow indicates the
femoral artery
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2.3 · Atlas: Extremity Arteries
149
. Fig. 2.84a, b (Atlas) Popliteal artery occlusion– atherosclerosis versus embolism.
a Atherosclerotic occlusion of the popliteal artery. The longitudinal view on the left and the transverse view on the right display the popliteal vein
(V) in blue close to transducer. Extensive plaque throughout the artery (A) with poor demarcation of the wall contour, in conjunction with the
inhomogeneous and partially very hyperechoic vessel lumen, suggests an atherosclerotic process. Based on these ultrasound ndings, catheter
thrombolysis, possibly with PTA, is not promising. Instead, bypass grafting is indicated, if clinically necessary.
b Embolic occlusion. The lumen of the popliteal artery is lled with a hypoechoic, homogeneous thrombus or embolus. There is good delineation
of the vessel wall without signs of plaque. Anterior to the popliteal artery, the popliteal vein is depicted in blue; posterior to it, a red arterial collateral (KOL) is seen
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. Fig. 2.85a–c (Atlas) Embolic occlusion.
a Emboli grow by thrombotic apposition, extending cranially up to the next branching of a hemodynamically signicant collateral, or become
lodged in a bifurcation. In the case of embolic popliteal artery occlusion presented here (longitudinal view on the left and transverse view on the
right), the artery is patent down to the origin of the sural artery while the distal portion is occluded ( TH). The vessel wall is smoothly delineated
and shows no atherosclerotic lesions.
b When there is spontaneous partial or complete recanalization of a thromboembolic occlusion, the Doppler waveform at follow-up will show
ow signals near the wall. In the example, ow (blue, away from transducer) along the intraluminal thromboembolic material is demonstrated in
the distal popliteal artery. The thrombus (TH) is homogeneous and clearly delineated from the wall, which shows no atherosclerotic lesions.
c Although ow is obstructed by the popliteal artery thrombus, the Doppler tracing (arrhythmia) from the patent arteries below the knee shows
triphasic ow (as illustrated here for the distal posterior tibial artery). With compensation through collateral perfusion, the ow obstruction in the
popliteal artery has only little eect on peripheral perfusion. Complete recanalization of the popliteal artery was observed after another 2days of
heparin therapy
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. Fig. 2.86a, b (Atlas) Arterial occlusion in deep leg vein thrombosis and patent foramen ovale.
a Deep vein thrombosis of the leg and ipsilateral arterial embolism in a patient with a patent foramen ovale presenting with a 1-week history of
calf swelling and acute-onset forefoot ischemia. There is thrombosis of the calf veins and of the popliteal vein with a free-oating thrombus (V.P).
The proximal popliteal artery (P1 segment) is patent with high diastolic ow due to low peripheral resistance; regular heartbeat.
b The popliteal artery is occluded distal to the origins of sural branches with residual ow around the thrombus; no plaque is demonstrated. Suspected patent foramen ovale was conrmed by echocardiography
a
c
. Fig. 2.87a–d (Atlas) Bilateral popliteal artery aneurysm.
a Patient with ischemic rest pain due to occlusion of the left popliteal artery caused by a completely thrombosed aneurysm. Segments of the
compressed vein displayed in blue are seen near the transducer. No ow signals are obtained from the lumen of the popliteal aneurysm (transverse view of the aneurysm on the left (A.POP) and longitudinal view on the right).
b The contralateral popliteal artery aneurysm is partially thrombosed leaving a patent lumen (red ow signals) surrounded by hypoechoic mural
deposits of the partially thrombosed popliteal artery aneurysm. The diameter of the aneurysm is 2.7cm (transverse view on the left, longitudinal
view on the right).
c Angiogram: Popliteal arteries with occlusion on the left and aneurysmal dilatation on the right. An estimate of the length and diameter of the
aneurysms is not possible.
d Medial Baker’s cyst (Z) in atypical location must be dierentiated from popliteal artery aneurysm and also from adventitial cystic disease
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2.3 · Atlas: Extremity Arteries
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d
. Fig. 2.88a–d (Atlas) Small popliteal artery aneurysm with arterioarterial embolism.
a, b Patient with small popliteal aneurysms on both sides. Ultrasonography demonstrates occlusion of the popliteal artery distal to the aneurysm
on the right. The aneurysm is partially thrombosed and has a diameter of 1.5cm. There is reduced ow through the aneurysm via collaterals (arising from the popliteal artery in the distal aneurysm). The collaterals are patent but outow is obstructed. This situation is reected by a thump
pattern in the Doppler waveform and a low peak systolic velocity (PSV) of 22cm/s.
c Images of the left popliteal artery (longitudinal view on the left, transverse view on the right) depict the small aneurysm (diameter of 1.5cm)
with only little thrombosis (clearly seen on the transverse view only) and a patent residual lumen of normal width. The arteries below the knee are
still patent. The control examination performed prior to elective aneurysm resection showed an unchanged conguration of the aneurysm, but
occlusions of below-knee arteries due to arterioarterial embolism.
d Left-sided angiogram showing below-knee occlusions without signicant dilatation of the popliteal artery. Only at the upper margin of the
image does the popliteal artery appear somewhat ectatic (corresponding ultrasound images in c)
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a
. Fig. 2.89a–d (Atlas) Pseudoaneurysm following arthroscopy.
a Iatrogenic damage to the vessels in the popliteal fossa is a rare but serious complication of knee arthroscopy. In the case presented, a large pseudoaneurysm developed after outpatient arthroscopy with partial resection of the medial meniscus. Venography performed for swelling of the calf
showed contrast lling defects in the popliteal vein, which were misdiagnosed as popliteal vein thrombosis.
b Duplex imaging performed after initiation of anticoagulation treatment demonstrates the pseudoaneurysm. In the aneurysm, there is ow toward
and away from the transducer (right section). Black areas without ow signals either indicate stasis in the aneurysm or are due to the failure to obtain
ow signals at an angle of 90° (cos 90°=0). The left section depicts the communication between the popliteal artery (A.POP) and the aneurysm (AN)
in blue, indicating ow from the artery into the aneurysm. The aneurysm is surrounded by hematoma (H). Ultrasound shows the popliteal vein to be
compressed by the aneurysm rather than thrombosed.
c The attempt to induce thrombosis of the aneurysm by compression failed because the neck is too wide and there is no adequate structure against
which to compress it. The right section shows persistent ow after attempted compression. Thrombin injection would have been an alternative in this
case but experience with this therapy was still limited at the time this patient was treated.
d Angiogram: Pseudoaneurysm of the popliteal artery
b
. Fig. 2.90a, b (Atlas) Aneurysm of posterior tibial artery.
a Traumatic aneurysm (13mm in diameter) of the posterior tibial artery just above the ankle joint. There is an abrupt increase in diameter from 2.5
to 13mm (montage of two adjacent scans showing the aneurysm in the center). The posterior tibial artery is patent proximal to the aneurysm and
occluded distal to it (A.TIB.P). A collateral artery arises from the aneurysm.
b The posterior tibial artery has a triphasic ow pattern just proximal to the aneurysm (AN). The distal segment is occluded, and ow is maintained
through a collateral arising from the aneurysm. The resulting higher outow resistance leads to a diastolic to-and-fro ow pattern (normal middiastolic ow with reversed early and end-diastolic ow)