British Journal of Radiology 75 (2002),884-888 © 2002 The British Institute of Radiology
Colour Doppler and grey scale ultrasound features of HIV-related vascular aneurysms
J D Woolgar, FRCS, FCS(SA)1,
R Ray, BSc2,
K Maharaj, MB, ChB1 and
J V Robbs, ChM, FRCPS1
1 Durban Metropolitan Vascular Service and 2 King Edward VIII Hospital Vascular Laboratory, Department of Surgery, University of Natal, Congella, Durban 4013, South Africa
Correspondence: Prof J V Robbs, Department of Surgery, University of Natal, Private Bag 7, Congella, Durban 4013, South Africa
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Abstract
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Atypical aneurysms of large elastic arteries owing to human immunodeficiency virus (HIV) vasculopathy are a well described complication of acquired immunodeficiency syndrome (AIDS). However, there are no reports describing the ultrasound features of these lesions. We performed a retrospective review of ultrasound images of 12 patients presenting with 39 HIV-related aneurysms over a 2 year period. Of these there were a total of 12 patients with symptomatic lesions comprising the superficial femoral artery (n=5), the origin of the internal carotid artery (n=3), the popliteal artery (n=2), the common femoral artery (n=1) and the common iliac artery (n=1). The remainder were asymptomatic and were demonstrated radiologically. The ultrasound features of large symptomatic HIV-related femoral and carotid aneurysms were typical of pseudoaneurysms with a defect or "blow-out" in the vessel wall and turbulent pulsatile flow. Of note was the presence of marked thickening of the vessel adjacent to the aneurysm and hyperechoic "spotting" of the arterial wall. These ultrasound features described may be unique to HIV vasculopathy.
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Introduction
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Since their first recognition in the early 1980s, the human immunodeficiency virus (HIV) and the acquired immunodeficiency syndrome (AIDS) have continued to present formidable challenges to health workers. Nowhere is this more so than in sub-Saharan Africa, where the death toll has already run into millions [1]. The HIV/AIDS epidemic has brought with it new presentations of old and familiar surgical diseases and also several completely new syndromes [2]. In the field of vascular surgery we are seeing atypical aneurysmal and occlusive arteriopathies that have only recently been described.
The association of atypical aneurysms in patients infected with HIV has been reported infrequently in the literature [3–5]. However, Nair et al [6] have recently characterized these lesions as distinct clinical entities linked to HIV vasculopathy [6]. By contrast, there have been no previous reports detailing the duplex ultrasound features of HIV-related aneurysms. In this paper we present our experience using Doppler ultrasound as a diagnostic tool for assessing HIV-related arterial aneurysms.
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Materials and methods
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The Durban Metropolitan Vascular Service provides two tertiary referral centres (King Edward VIII and Addington Hospitals) for vascular surgery for the whole of the province of Kwa-Zulu Natal. This serves approximately 8–9 million inhabitants.
A retrospective review of the duplex images of 12 patients presenting with HIV-related aneurysms between 1999 and 2001 was performed by a senior vascular ultrasonographer and a consultant vascular surgeon. The Vascular Surgical Unit at King Edward VIII Hospital managed all patients in the series. Initial diagnosis was by clinical examination and patients were confirmed to be HIV antibody positive by serological testing using the enzyme-linked immunosorbent assay (ELISA) technique. All patients were screened for other causes of atypical aneurysms including mycotic, luetic and connective tissue disorders.
Patients with symptomatic aneurysms were initially imaged with duplex ultrasound. This was performed by a dedicated vascular sonographer using a Seimens Quantum 2000 (Seimens Quantum Inc, Issaquah, WA) colour duplex machine. Real-time transverse and longitudinal scanning was performed using a 7.5 MHz linear array transducer. Images were saved using a Sony UP860CE (Sony Corp., Tokyo, Japan) thermal video graphic printer.
Screening for additional aneurysms of the femoral and carotid arteries was also performed because of the known high incidence of asymptomatic lesions in this patient cohort [7]. Standard B-mode ultrasound was used to image the abdominal aorta and, if required, CT utilized to provide further definition. Angiography was used to image all aneurysms, including asymptomatic lesions, only in patients considered possible surgical candidates.
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Results
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Patient data
During the study period from 1999 to 2001, 12 African patients (11 male, 1 female) with a total of 39 aneurysms were managed by the unit. The median age was 30 years (range 23–60 years). The anatomical distribution and proportion of symptomatic and asymptomatic aneurysms is shown in Table 1
. All patients were confirmed to be HIV positive on serological testing and showed clinical signs of advanced HIV/AIDS, including weight loss, oral candidiasis and generalized lympadenopathy. Patients with symptomatic aneurysms usually presented with large, painful, expansile masses, often accompanied by thrills or bruits. However, the majority (n=27, 69.2%) of aneurysms were asymptomatic and detected by ultrasound and angiography during pre-operative work-up. Of the 12 symptomatic patients, 10 underwent operative treatment. Six of these patients had histological examination of specimens taken from the aneurysm wall or adjacent vessel that showed the characteristic features of HIV vasculopathy. In the remaining four patients, specimens had either not been taken or results were not available.
Ultrasound findings
A retrospective review of the images of cases with HIV-related aneurysms of the common or superficial femoral arteries revealed several consistent findings. Seven patients with symptomatic femoral aneurysms all gave the subjective impression of thickening of the arterial wall in the area immediately adjacent to the aneurysm with a defect or "blow-out" in the wall of the vessel (Figure 1). Small hyperechoic areas or "spots" within the wall of the vessel adjacent to the site of the defect were visualized; these were most prominent at the site of the pseudoaneurysm but less so along the proximal and distal extents of the vessel (Figure 2). Duplex ultrasound of the mass adjacent to the femoral vessels revealed a large anechoic cavity containing thrombus with turbulent pulsatile arterial flow consistent with a pseudoaneurysm (Figure 3). At surgery the findings of a small defect in the vessel wall communicating with a large false aneurysm cavity was confirmed in all cases.
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Figure 1. Duplex image of a HIV-related aneurysm of the superficial femoral artery. A defect is noted in the vessel wall (arrow) with a large false aneurysm sac posteriorly (asterisk). Vessel wall thickening and "spotting" are not so apparent in this view.
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Figure 2. Thickening and hyperechoic "spotting" (arrow) of the arterial wall adjacent to a carotid pseudoaneurysm.
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Figure 3. Colour-duplex image of a femoral HIV aneurysm showing turbulent flow within the sac typical of a pseudoaneurysm.
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Of 11 patients undergoing carotid duplex scanning, 7 were noted to have abnormal scans. Of these, three patients had large symptomatic carotid artery aneurysms. Duplex scanning in these patients revealed similar findings in terms of arterial wall thickening with hyperechoic spotting, a localized defect in the vessel and an associated pseudoaneurysm. In all cases the false aneurysm had a predilection for the distal common carotid near to the bifurcation. In the four asymptomatic patients, findings on ultrasound consisted of small (never larger than the diameter of the native vessel), saccular, often multiple, aneurysms affecting the distal common carotid arteries (Figure 4). These signs were confined to the common carotid arteries only, the internal and external carotids appearing normal.
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Figure 4. Duplex image of the common carotid artery in an asymptomatic HIV-positive patient showing thickening of the vessel wall and two small saccular aneurysms (arrows) at an early stage of development.
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Two patients with asymptomatic carotid bifurcation lesions re-presented 7 months and 9 months, repectively, after the conclusion of the study period with large unilateral carotid aneurysms.
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Discussion
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The HIV/AIDS epidemic that is affecting sub-Saharan Africa continues its advance with profound social, political and economic implications. From the data based on HIV screening tests of women attending antenatal clinics, current seroprevalence rates in South Africa have been estimated to be over 30% [1]. With the progression of the pandemic, new surgical pathology is being increasingly recognized, including several distinct arteriopathies. Aneurysm formation, vasculitis and large-vessel occlusive disease appear to be common among HIV infected patients in our population [6–9]. Originally described in 1989 by DuPont et al [3], aneurysms are increasingly being recognized in patients with HIV/AIDS [4, 5]. Although some may be mycotic, secondary to immunosuppression, recent studies from our own institution suggest that the pathological mechanism involves an inflammatory arteritis related to the vasa vasorum [6]. Patients with HIV-related aneurysms are typically young and lack the usual risk factors assosciated with vascular disease. In contrast to the ubiquitous atherosclerotic aneurysm, HIV-related aneurysms are often multiple and occur at unusual sites, particularly in the common carotid and superficial femoral arteries. On angiography they may appear saccular or have the appearance of large pseudoaneurysms [7].
A review of the images of the patients from this series shows that HIV-related aneurysms have the features of pseudoaneurysms on duplex ultrasound. Classically, the B-mode image shows an anechoic or mixed echogenic cavity adjacent to the artery. Many of the aneurysms are large and turbulent blood flow within the aneurysm sac can be visualized. On colour flow imaging this has the "yin/yang" sign that is characteristic of pseudoaneurysms (Figure 3
) and the typical "to and fro" sign on Doppler waveform analysis [10–12]. Subjective intraoperative and ultrasound observations have shown that the defect in the vessel wall is rarely less than approximately 5 mm in diameter and is easily seen on scanning. Hyperechoic spotting in the vessel wall of the affected artery is possibly a unique feature associated with this pathology. It is not seen in normal healthy individuals and has not been reported to be associated with other inflammatory arteriopathies such as Takayasu's arteritis, also a common cause of aneurysmal disease in our population. In contrast to HIV-related aneurysms, where pseudoaneurysms occur adjacent to an area of localized vessel wall thickening, the duplex findings of Takayasu's arteritis are characterized by long segment vessel stenoses and occlusions with homogeneous and circumferential thickening of the vessel wall [13]. Aneurysmal degeneration occurs in Takayasu's arteritis. However, pseudoaneurysms are not a feature of this disease.
Sonographically, hyperechoic spotting resembles calcification or dense plaque within the arterial wall. However, we have not seen evidence of this macroscopically at the time of surgery. Moreover, the vessels are usually pristine both proximal and distal to the site of the aneurysm. Microscopically, the features of HIV-vasculopathy are typical of a leucocytoclastic vasculitis that affects the vasa vasorum [8]. The inflammatory infiltrate is restricted to the adventia, with sparing of the inner layers of the artery. It is plausible that hyperechoic spotting may represent discrete areas of inflammation and oedema within the vessel wall, perhaps confined to the larger vasa vasorae. If this is the case, it might be that pseudoaneurysm formation occurs preferentially in areas of the vessel wall weakened by the vasculitic process in contrast to the fusiform true aneurysms that are characteristic of diffuse degenerative diseases, such as cystic medial degeneration or athersclerosis. Further investigation may clarify this matter.
In conclusion, duplex ultrasound provides a quick and non-invasive method of assessment and screening of patients with HIV-related aneurysms. Features are typical of pseudoaneurysms with a blow-out defect, thickening and hyperechoic spotting of the vessel wall.
Received for publication February 13, 2002.
Revision received July 5, 2002.
Accepted for publication July 19, 2002.
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References
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- World Health Organisation, UNAIDS. Report on the global HIV/AIDS epidemic. WHO, 2001.
- Bayley AC. Surgical pathology of HIV infection: lessons from Africa. Br J Surg 1990;77:863–8.[Medline]
- Du Pont JR, Bonavita JA, Di Giovanni RJ, Spector HB, Nelson SC. Acquired immunodeficiency syndrome and mycotic abdominal aortic aneurysms: a new challenge? Report of a case. J Vasc Surg 1989;10:254–7.[Medline]
- Sinzobahamvya N, Kalangu K, Hamel-Kalinowski W. Arterial aneurysms associated with human immunodeficiency virus (HIV) infection. Acta Chir Belgica 1989;89:185–8.[Medline]
- Marks C, Kuskov S. Patterns of arterial aneurysms in acquired immunodeficiency disease. World J Surg 1995;19:127–32.[Medline]
- Nair R, Abdool-Carrim A, Chetty R, Robbs J. Arterial aneurysms in patients infected with human immunodeficiency virus: a distinct clinicopathology entity? J Vasc Surg 1999;29:600–7.[Medline]
- Nair R, Robbs JV, Naidoo NG, Woolgar J. Clinical profile of HIV related aneurysms. Eur J Vasc Endovasc Surg 2000;20:235–40.[Medline]
- Chetty R, Batitang S, Nair R. Large vessel vasculopathy in HIV positive patients: another vasculitic enigma? Hum Pathol 2000;31:374–9.[Medline]
- Nair R, Robbs JV, Chetty R, Naidoo NG, Woolgar J. Occlusive arterial disease in HIV-infected patients: a preliminary report. Eur J Vasc Endovasc Surg 2000;20:353–7.[Medline]
- Abu-Yousef MM, Wiese JA, Shamma AR. The "to-and-fro" sign: duplex Doppler evidence of femoral artery pseudoaneurysm. AJR 1988;150:632–4.[Free Full Text]
- Polak JF. Peripheral arterial disease. Evaluation with colour flow and duplex sonography. Radiol Clin North Am 1995;33:71–90.[Medline]
- Wilkinson DL, Polak JF, Grassi CJ, et al. Pseudoaneurysm of the vertebral artery; appearance on colour flow Doppler sonography. AJR 1988;151:1051–2.[Free Full Text]
- Bond JR, Charboneau JW, Stanson AW. Takayasu's arteritis. Carotid duplex sonographic appearance, including colour Doppler imaging. J Ultrasound Med 1990;9:625–9.[Abstract]
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Abstract
Introduction
