Sonographic Evaluation

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  • Sonographic Evaluation ofVascular Injuries

    Diana Gaitini, MD, Nira Beck Razi, MD, Eduard Ghersin, MD,Amos Ofer, MD, Michalle Soudack, MD

    Objective. The purpose of this presentation is to highlight the color Doppler duplex sonographicfeatures of procedure-related and blunt or penetrating trauma-related vascular injuries. Methods.Different kinds of vascular complications such as pseudoaneurysms, arteriovenous fistulas, dissection,and thrombosis are discussed. Cases of vascular injuries in the extremities, neck, and abdomen are pre-sented to illustrate the spectrum of sonographic appearances. Results. Color Doppler duplex sonog-raphy is valuable in the diagnosis and monitoring of most vessel injuries and in the treatment ofpseudoaneurysms. It is useful for flow analysis and for follow-up after treatment. However, because oflimitations inherent to sonography, such as bones, air, casts, skin burns, and relatively slow perfor-mance of the test, magnetic resonance imaging, computed tomography, and angiography are neces-sary for further evaluation in selected cases. Conclusions. Color Doppler duplex sonography is a widelyavailable, noninvasive, and accurate technique for evaluating vascular injuries and should be the first-line imaging modality in most patients. Key words: arteriovenous fistula; diagnosis; false aneurysm;sonography; vascular injuries.

    Received June 21, 2007, from the Department ofMedical Imaging, Rambam Medical Center, Haifa,Israel. Revision requested July 18, 2007. Revisedmanuscript accepted for publication August 1, 2007.

    Address correspondence to Diana Gaitini, MD,Unit of Ultrasound, Department of Medical Imaging,Rambam Medical Center, Haaliya 8, PO Box 9602,31096 Haifa, Israel.

    E-mail: d_gaitini@rambam.health.gov.il

    AbbreviationsAVF, arteriovenous fistula; CDDS, color Doppler duplexsonography; CTA, computed tomographic angiography;DSA, digital subtraction angiography. MRA, magneticresonance angiography

    he prevalence of vessel injuries is on the risebecause of increasing rates of invasive proceduresand traumatic events. At a level I trauma center,iatrogenic injuries were the causes of one third of

    arterial damage.1 The complication rate in complex coro-nary procedures reaches 6%. Fibrinolytic therapy, antico-agulants, large-diameter vascular sheaths, and poorpuncture or compression techniques increase the rate ofvascular complications.2 Partial or complete thrombosis,intimal flaps, dissection, arteriovenous fistulas (AVFs), andpseudoaneurysms are the main vascular complications.

    The neck, extremities, and abdominal organs areanatomic sites amenable to investigation with colorDoppler duplex sonography (CDDS). Subcutaneous air,large hematomas, casts, and large skin wounds mayimpede CDDS performance. Aberrant vessels andanatomic areas difficult to scan, such as the thoracic inletand the pelvis, lessen the accuracy of CDDS. Further lim-itations are derived from operator dependence andlengthy examinations, which may be inappropriate in theacute care setting.3 Despite these limitations, CDDS is

    2008 by the American Institute of Ultrasound in Medicine J Ultrasound Med 2008; 27:95107 0278-4297/08/$3.50

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    Image Presentation

  • presently considered the first-line examinationfor evaluation of vascular injuries, withreported sensitivity of 95% to 97% and accu-racy of 95% to 98%.35 Magnetic resonanceangiography (MRA) and computed tomo-graphic angiography (CTA) are useful comple-mentary examinations. Digital subtractionangiography (DSA) is shifting to a more thera-peutic role for endovascular management.

    Procedure-Related Vascular Injuries

    Vascular injuries may follow percutaneous pro-cedures. Puncture site vascular injuries includeperivascular hematomas, pseudoaneurysms,and AVFs. A perivascular hematoma is the mostfrequent complication at the puncture site.Clinically, it is a nonpulsatile focal swelling withecchymosed skin. It appears as a complex solidand cystic soft tissue mass adjacent to the injuredvessel, without blood flow on Doppler interroga-tion (Figure 1). A diffuse hematoma, even obvi-ous clinically, may be unrecognizable on CDDSbecause of poorly defined infiltration of bloodinto the soft tissues. An AVF is a false vascularchannel between an artery and the adjacent vein.A palpable thrill and a bruit on auscultation areoften present. Color Doppler duplex sonographyshows a mosaic color pattern due to high turbu-lent flow in the fistula, low-resistance arterial flowin the feeding artery, and a high-velocity, chaotic

    waveform in the draining vein. Extravascularcolor signals represent perivascular tissue vibra-tion due to transmitted pulsation of turbulentcontinuous blood flow between the artery andthe vein (Figure 2). A pseudoaneurysm or falseaneurysm is a pulsatile hematoma that commu-nicates through a channel (neck) with the injuredartery. It follows total disruption in the arterialwall and continuous extravascular flow, con-tained by the surrounding tissues. It complicates0.1% to 0.2% of diagnostic and 3.5% to 5.5% ofinterventional procedures, representing morethan 60% of interventional vascular complica-tions.6 Clinically, a pulsatile mass with a palpablethrill and an audible to-and-fro murmur isdetected. Color Doppler duplex sonography isthe diagnostic imaging modality of choice: it candelineate the cavity, the degree of clotting, thecommunication with the artery, and the bloodflow pattern. The lumen has bidirectional,swirling, or yin-yang color flow and turbulent orpulsatile flow on a spectral display. The neck typi-cally has a to-and-fro waveform due to flow enter-ing during systole and exiting during diastole(Figure 3). Pseudoaneurysms vary in size and mayhave multiple compartments (Figure 4). A fluid-fluid level due to hematocrit layering may be seenin large pseudoaneurysms (Figure 5). They mayinvolve surgical sites, most often bypass graftanastomosis (Figure 6). Sonographically guidedthrombin injection is the treatment of choicefor large pseudoaneurysms that do not clotspontaneously, converting them into thrombosedhematomas within seconds, with a 93% to 100%success rate.7,8 A flow void after injection confirmsthrombosis (Figure 7). The neck width of the pseu-doaneurysm is of prognostic value because a wideand short neck may carry a higher risk of failureand embolic complications during thrombininjection. Hypoechoic hypervascular lymphnodes, dilated varicose veins with slow swirlingflow (Figure 8), and fluid containing femoral oringuinal hernias, with fluid movement due to res-piratory motion, may mimic pseudoaneurysms.

    Procedures such as angioplasty, thrombolysis,and stent placement may be complicated bythrombosis, intimal flaps, aneurysms, arterialruptures, and stent stenosis. Arterial thrombosisis the most frequent complication. Varyingdegrees of thrombus echogenicity may be

    96 J Ultrasound Med 2008; 27:95107

    Sonographic Evaluation of Vascular Injuries

    Figure 1. Image from a 70-year-old man with groin swellingafter femoral catheterization. Color Doppler sonography showsa large hypoechoic heterogeneous mass (arrow) surrounding thefemoral artery (fa) at the proximal thigh, consistent with ahematoma.

  • J Ultrasound Med 2008; 27:95107 97

    Gaitini et al

    Figure 2. Images from a 4-year-old child with lower limbswelling after repeated inguinal punctures. A femoral AVF wasdiagnosed by CDDS. A, On a longitudinal scan, color Dopplersonography shows normal flow in the common femoral artery(CFA) followed by a mosaic flow pattern representing aliasingdue to high-velocity flow in the fistula (arrow) between theartery (FA) and vein (FV). B, A transverse scan of the fistulashows perivascular color Doppler signals in the surrounding softtissue due to tissue vibration. C, A spectral display shows turbu-lent flow in the fistula. D, Spectral Doppler sonography shows alow-resistance, high-velocity waveform in the artery. E, SpectralDoppler sonography shows an arterialized waveform in thedraining vein.

    A B

    C

    E

    D

  • detected depending on the thrombus age. A par-tially occluding thrombus causes alteration inthe color flow pattern, waveform, and velocities(Figure 9). A totally occluding thrombus causesan abrupt cutoff of color flow and retrograde flowin a collateral pathway. A vasospasm and exter-nal compression without evidence of an intrinsic

    vessel injury may be correctly diagnosed byCDDS. Focal dissection resulting from guideinsertion may be seen in a severely atherosclerot-ic artery (Figure 10). Color Doppler duplexsonography, at times in combination with MRAand CTA, can noninvasively show most arterialinjuries.9 Vein thrombosis may complicate

    98 J Ultrasound Med 2008; 27:95107

    Sonographic Evaluation of Vascular Injuries

    Figure 3. Images from a 55-year-old man who had a pulsatilemass at the puncture site after coronary artery stent insertion.Color Doppler duplex sonography showed a femoral arterypseudoaneurysm. A, Color Doppler sonography shows bidirec-tional yin-yang color flow in the lumen of the pseudoaneurysmdue to cyclic inflow and outflow during systole and diastole,respectively. B, Spectral Doppler sonography shows classic to-and-fro flow at the neck, appearing as a double trace on bothsides of the baseline.

    A

    B

    Figure 4. Images from a 62-year-old woman with multiple com-partment pseudoaneurysms after coronary arteriography. A, Grayscale sonography shows a chain of false aneurysms connected tothe artery by a single neck. B, Power Doppler sonography showsthe connecting neck.

    A

    B

  • indwelling catheters, inferior vena cava filters,and venous stents and shunts. Thrombosedveins are typically noncompressible (Figure 11).When a thrombus is suspected in a central veinsuch as the brachiocephalic vein or the superi-or vena cava, both sides should be exa