Internal Carotid Artery Aneurysm Discovered by Palpation of Asymmetric Pulses

Abstract

Extracranial internal carotid artery aneurysms are uncommon.1Schechter D.C. Cervical carotid aneurysms.NY State J Med. 1979; 79: 892-901PubMed Google Scholar It is estimated that only 0.1% to 2% of carotid procedures involve extracranial internal carotid artery aneurysms among all major referral centers.2El-Sabrout R. Cooley D.A. Extracranial carotid artery aneurysms: Texas Heart Institute experience.J Vasc Surg. 2000; 31: 207-212Abstract Full Text Full Text PDF PubMed Scopus (293) Google Scholar A review of the literature conducted by the Vascular Group of the Cleveland Clinic Foundation identified only 12 total reported cases, including 8 at their own facility, over a 17-year period.3Cury M. Greenberg R.K. Morales J.P. et al.Supra-aortic vessels aneurysms: diagnosis and prompt intervention.J Vasc Surg. 2009; 49: 4-10Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar Internal carotid artery aneurysms cause concern because they increase the risk of embolic events that can lead to transient ischemic attack or stroke and necessitate urgent intervention.4Jones W.T. Pratt J. Connaughton J. et al.Management of a nontraumatic extracranial internal carotid aneurysm with external carotid transposition.J Vasc Surg. 2010; 51 (Epub 2009 Sep 26): 465-467Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar Nonoperative treatment is associated with a stroke risk as high as 50%.5Rosset E. Albertini J. Magnan P.E. et al.Surgical treatment of extracranial internal carotid aneurysms.J Vasc Surg. 2000; 31: 713-723Abstract Full Text Full Text PDF PubMed Scopus (153) Google Scholar, 6Zwolak R.M. Whitehouse W.M. Knake J.E. et al.Atherosclerotic extracranial carotid artery aneurysms.J Vasc Surg. 1984; 1: 415-422PubMed Scopus (114) Google Scholar We report a case of a left internal carotid artery aneurysm discovered incidentally after asymmetric pulse and blood pressure measurements were obtained in the bilateral upper extremities on physical examination. A 55-year-old woman presented for evaluation of hypertension. She denied any history of angina, dyspnea on exertion, or syncope. Physical examination was negative for jugular venous distension, and no bruits were appreciated. There was evidence of a loud, early systolic click, ejection in nature, as well as a loud A2, consistent with systemic hypertension. She had diminished left upper-extremity pulses, compared with right upper-extremity pulses, and a blood pressure level of 124/80 mm hg in the left upper extremity and 148/92 mm Hg in the right upper extremity. A negative chest x-ray was obtained. Subsequently, computed tomography angiography was ordered to assess the vasculature of her upper extremities and aortic arch to rule out a thoracic outlet syndrome. Results showed patent vasculature to the upper extremities bilaterally. In the mid-left internal carotid artery a large, tortuous aneurysm was found measuring 15.3×9.4 mm at its widest diameter (Figure 1). To prevent rupture risk, thrombosis, embolization, or stroke symptoms, surgical intervention was deemed appropriate. She consented to proceed, and the aneurysm was resected successfully. Neurologic manifestations are the most common sign of extracranial internal carotid artery aneurysms.5Rosset E. Albertini J. Magnan P.E. et al.Surgical treatment of extracranial internal carotid aneurysms.J Vasc Surg. 2000; 31: 713-723Abstract Full Text Full Text PDF PubMed Scopus (153) Google Scholar However, in this instance, the only presenting sign was the inequality between the upper right- and left-extremity blood pressure levels. These pressure differences normalized after surgery. This could lead one to suspect that the aneurysm may have been a contributing factor. This phenomenon, although not documented in the literature to date, offers one reasonable explanation for the events described. The advanced imaging and surgical techniques used in the treatment of this patient avoided potential negative outcomes. However, these techniques would have never come into play had it not been for a complete and thorough physical examination that aroused clinical suspicion and enabled the patient to be diagnosed. As technology advances and the practice of medicine evolves, it is important to keep the fundamentals in mind and use them to help guide clinical decision making.