Carotid Artery Aneurysm in HIV. A Review of Case Reports in Literature

BACKGROUND:

HIV infection may affect cardiovascular system through different physio pathological patterns including viral vasculitis, thrombophilia induction, opportunistic infection, major HIV vasculo-tropic coinfections and secondary effects of antiretroviral therapy. Vessel pathology may manifest as obstructive disease, dissection or aneurysm conditions that may involve major , medium or small vessels, in different arterial branches. Rarely reported in HIV negative patients , aneurysms involving carotid artery have been described for the first time in seropositive patients in 1989. Since then, sporadic case reports and monocentric experiences have been published on the subject until nowadays ; unexpectedly, in some of the cases aneurysms have occurred notwithstanding the efficacy of antiviral treatment in chronic viral suppression and restoration of the immune function. As a potential aetiological cause of stroke, and because a complete understanding of physiopathology in this setting hasn’t been reached, studies are needed, to improve management of patients affected by this highly morbid-high mortality non-AIDS related comorbidity.

AIMS:

in our study we have focused on aneurysm pathology affecting carotid arteries in HIV patients , analysing clinical and surgical presentation, management and outcome, through a review of cases published in literature. The cases retrieved were additionally analysed according to the segment of carotid artery involved (extra cranial or intracranial carotid artery) with regard to anagraphic details, aneurysm type, presentation, treatment and outcome, to analyse potential differences due to the two main different localization of the lesion. Because of the availability in literature of only scattered information on this clinical subject (fragmented in case reports or small monocentric reports), and of the lack of a previously published overview, our work was conceived to fulfil this actual and necessary clinical need.

METHODS:

Medline(www.ncbi.nlm.nih.gov/pubmed) database was reviewed for “carotid artery aneurysm AND HIV OR AIDS OR immunodeficiency. Research was restricted to English language. Only case reports were included. Data on patients age, sex, traditional risk factors, timing from HIV diagnosis, pharmacological details, coinfection (syphilis, HCV HBV), anatomical localization of lesion (intra or extra-cranial), neurological presentation and, when available, details on cerebral imaging findings (such as subarachnoid haemorrhage or cerebral infarction) surgical treatment , surgical outcome and overall mortality were collected and summarised in tables.

RESULTS:

19 articles including a total of 46 case were included in our report. Mean age of patients was 30.6±14.2; 30 patients were male (65.2%). Smoke and hypertension were the most frequently reported traditional cardiovascular risk factors (in 13% and 10.9% of cases). Diagnosis of carotid artery aneurysm may occur in previously undiagnosed HIV patients (56.5%), but also in children with vertically acquired infection or years afters HIV diagnosis. They have been described in patients with a CD4+ leucocyte count < 200, but also in patients with a higher count. Previous infectious conditions reported in patients included tuberculosis (19.6%) and herpes virus (13%). In 17.4% of cases a pathogen agent was isolated from peripheral colture . Aneurysms were localized in intra-cranial carotid artery (41.3%) or in extra-cranial localization (58%); the majority were pseudo aneurysms (44%) while fusiform aneurysms occurred in 23.9%. In 39.1% of cases aneurysms involved additional arterial branches. Presenting features at diagnosis included symptoms due to compression of neck structures, as painful cervical mass ( 52.2%) , dysphonia or dysphagia . Positivity for neurological symptoms occurred in 36.9%: cranial nerve palsies, hemiparesis, hemiplegia , monoplegia , aphasia, headache , impaired consciousness and seizures. Ischemic lesions were reported in 5 cases ( 10.9 %) and subarachnoid haemorrhage in 3 (6.5%). For 19 cases a colture of surgical specimen was available; in 63% of patients no infectious agent was identifiable . Patients were managed surgically in 58.7% of cases, in 26% of cases with a conservative pharmacological treatment, 15.2% of cases ( 7 patients ) no treatment was reported . Of these, 4 cases (8.6%) were left untreated because of exitus at presentation ( subarachnoid haemorrhage, generalized seizures, hydrocephalus, airway obstruction waiting for surgery); in the other 3 cases no details on specific treatment were reported; in these cases exitus occurred at a later stage ( ranging from 25 days to 2 months ) as a final event complicating a pre-existing heart failure in one case, a bacterial pneumonia complicating a major stroke in another case, and for a not-specified reason in the third. Surgical options included open surgery (74%) and endovascular interventions (22.2%). Overall surgical morbidity and mortality were both high, 22.2% and 7.4 % respectively, but when considering separately morbidity and mortality for different surgical approaches, endovascular treatment carried the highest rates : 57.1 morbidity ; 14.7 % mortality vs 10% and 5% for open surgery. Finally, the overall mortality in surgically treated and untreated HIV patients with carotid artery aneurysm was 26.1% . The independent sample t-test carried out for further analysis of cases according to two main different aneurysm locations (extra-cranial and intracranial carotid artery), has shown that the majority of common carotid artery involvement was observed in men (81.5%) while 57.9% of intracranial aneurysms were diagnosed in female patients. In paediatric patients ( <18 years old) only intracranial district involvement was reported. Vertical transmission was concerned preponderantly in patients with intracranial aneurysms; previously unknown HIV infection occurred in 85.2% of patients with common carotid artery involvement ( even though this may occur according to the origin of patients from lower income countries). Intracranial aneurysms presented more frequently central neurological symptoms or signs while in cervical location peripheral nerve impairment was more frequent . Extra-cranial aneurysms appeared to be more frequently saccular in shape, intracranial fusiform. Occasional diagnosis of aneurysm in other arterial districts occurred more frequently in patients with intracranial involvement. According to management of patients, a surgical approach was most frequently reported in common carotid artery aneurysm management (24 of 27 patients, 88.8% vs , 3 of 19 patients, 15.8%) while for intra-cranial lesions a conservative approach ( either pharmacological ( 11 cases) or of no treatment ( 3 cases) or lack of data (2 cases) was mainly observed . In 3 untreated cases, this occurred because of fatal outcome on presentation. As for surgical management , in the majority of cases carried out to treat extra-cranial lesions, a high complication rate was observed for endovascular procedures, including stent occlusion , endo-leak and post-operatory myocardial infarction. Surgical reconstruction was complicated in 1 case by major post-operatory stroke. A higher mortality was reported for patients with intracranial aneurysms ( 42.1% vs 14.8% p< 0.02 ). Follow up was brief in the majority of cases ( 1 to 10 months) , and a long term outcome can’t be assessed from available data.

CONCLUSIONS:

aneurysms may occur in both extra and intracranial carotid artery in patients with HIV at younger age than in non-HIV patients and are linked to a high morbidity and mortality . Because of associated comorbidities (coinfections, thrombophilia, inflammatory burden, immunosuppression) both medical and surgical management have a high morbidity and mortality, even higher for endovascular treatment. Carotid aneurysm may occur as a first manifestation of HIV, and must be suspected whenever this rare vascular condition may occur in the absence of a more likely aetiology. Carotid artery aneurysm must be suspected in HIV patients presenting with compressive symptoms of the neck, neurological impairment or in differential diagnosis for stroke. Two different physiopathology patterns may be suggested for extracranial and intracranial carotid artery aneurysms, suggesting a complex entanglement of factors that may combine differently to lead to lesion formation in both districts. Further studies are needed to better understand physiopathology and to improve treatment and patients outcome.