• Clinical science

Aneurysm

Abstract

True aneurysms are an abnormal dilation of an artery due to a weakened vessel wall. By contrast, false aneurysms are external hematomas with a persistent communication to a leaking artery. Dissections are a separation of the arterial wall layers caused by blood entering the intima-media space after a tear in the internal layer occurred. Aneurysms are differentiated according to their location. This card discusses the etiology and clinical features of cerebral, external carotid, Ileofemoral, popliteal, and ventricular aneurysms. Symptoms generally depend on the location and size of the aneurysm. There are surgical and endovascular treatment options, the choice of which depends on the specific type of aneurysm and if symptoms or complications are present.

For more specific information on individual types of aneurysms, see the learning cards on thoracic aortic aneurysm, abdominal aortic aneurysm, aortic dissection, dissection of the carotid and the vertebral artery, and subarachnoid hemorrhage.

Overview

Aneurysm vs. dissection

True aneurysm False aneurysm (pseudoaneurysm) Dissection
Definition
  • Abnormal dilation of an artery due to a weakened vessel wall
  • Leaking artery leads to a hematoma between the vessel and the surrounding tissue. A persistent communication between the vessel and the hematoma remains.
  • Separation of the arterial wall layers
Etiology/Risk factors
  • Usually trauma (e.g., deceleration injury, gunshot) or iatrogenic (e.g., after vascular puncture or cardiovascular surgery)
Pathophysiology
  • Perforation of the vascular wall causing bleeding into the surrounding tissue
  • Formation of an extravascular (pulsatile) hematoma
  • → Surrounding structures delimit the expansion of the hematoma
  • → Organization of the hematoma
  • → Formation of a false vascular wall and false aneurysm
  • Typical deceleration injury → contained aortic injury of the thoracic aorta (typical location: distal to the left subclavian artery)
  • Transverse tear in the arterial intima (“entry”)
  • → Blood enters the intima-media space (creates a false lumen)
  • Hematoma forms and propagates longitudinally downwards
  • → Rising pressure within the aortic wall and rupture, occlusion of branching vessels, and ischemia in the affected areas
Clinical features
  • See table of different types of aneurysm according to location below.
  • Painful and pulsatile mass at the site of trauma
  • Buzzing sensation
  • Bruit on auscultation
Treatment
  • Ultrasound-guided thrombin injection (e.g., to treat iatrogenic postcatheterization pseudoaneurysms that are symptomatic)
  • Surgical management

Types of aneurysm according to location

Location Etiology Clinical features
Thoracic aortic aneurysm (TAA)
  • Usually asymptomatic
  • Feeling of pressure in the chest
  • Thoracic back pain
Abdominal aortic aneurysm (AAA)
  • Commonly below the renal arteries, may be above the renal arteries
  • Usually asymptomatic
  • Pulsatile abdominal mass
  • Bruit on auscultation
Cerebral aneurysm
  • Circle of Willis
  • Depends on type of aneurysm (berry, fusiform, mycotic, traumatic, or microaneurysms)
Ventricular aneurysm
Popliteal aneurysm
Ileofemoral aneurysm
Carotid aneurysm

References:[1][2][3][4][5][6][7][8][9]

Cerebral aneurysm

References:[10][4][11][12]

Popliteal aneursym

  • Most common peripheral aneurysm and second most common aneurysm after AAAs
  • Epidemiology
    • >
    • Mean age: 65 years
  • Etiology: multifactorial (i.e., inflammation, immune, genetic, and mechanical factors)
  • Clinical features
  • Diagnosis
  • Complications
    • Rupture
    • Distal embolization: blue toe syndrome (small vessel occlusion caused by an embolus)
    • Chronic thrombosis
  • Treatment
    • Anticoagulation (e.g., heparin)
    • Surgery with venous bypass graft or surgical aneurysmal excision
      • Indication: symptomatic or ≥ 2 cm in diameter

References:[5][13][14][15]

Ileofemoral aneurysm

  • Second most common peripheral aneurysm after popliteal aneurysms
  • Etiology: See risk factors for atherosclerosis.
  • Clinical features
    • May be asymptomatic
    • Acute limb ischemia5 Ps
    • Compression of nearby nerves or veins: sudden pain, weakness, swelling, numbness in the leg
    • Painless, pulsatile swelling with a palpable thrill at the mid-inguinal point
    • Auscultation of the swelling: loud, harsh, continuous murmur
    • Often associated with other aneurysms, esp. AAA and thoracic aortic aneurysm
  • Diagnosis
    • Doppler ultrasonography (best initial test): identifies thrombus and patency of vessel
    • CT angiography: preoperative assessment
  • Complications
    • Rupture: acute groin pain
    • Blue toe syndrome
  • Treatment
    • Procedure: surgery with bypass or surgical excision of aneurysm
    • Indication
      • Symptomatic
      • IAA ≥ 3 cm
      • Rapidly expanding
      • Coexistent AAA
      • Complications are present

References:[16][17][18]

External carotid artery aneurysm

  • Etiology: commonly atherosclerosis, trauma (iatrogenic or penetrating injury), infection (septic emboli)
  • Clinical features
  • Diagnosis
    • Ultrasound (initial): evidence of swirling blood with a thrombus
    • CT or MR angiography: determines the site and size of the aneurysm, excludes rupture or other pathologies
  • Complications
  • Treatment: surgical repair, either in the form of an aneurysm excision and reconstruction or endovascular repair (grafting or stenting)

References:[6][19][20][8]

Ventricular aneurysm

References:[7][21]

  • 1. Webber GW, Jang J, Gustavson S, Olin JW. Contemporary management of postcatheterization pseudoaneurysms. Circulation. 2007; 115(20): pp. 2666–2674. doi: 10.1161/CIRCULATIONAHA.106.681973.
  • 2. Mancini MC. Aortic Dissection. In: Geibel J. Aortic Dissection. New York, NY: WebMD. http://emedicine.medscape.com/article/2062452-overview. Updated December 22, 2016. Accessed February 7, 2017.
  • 3. Kumar V, Abbas AK, Aster JC. Robbins & Cotran Pathologic Basis of Disease. Philadelphia, PA: Elsevier Saunders; 2014.
  • 4. Singer RJ, Ogilvy CS, Rordorf G. Unruptured intracranial aneurysms. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/unruptured-intracranial-aneurysms. Last updated September 26, 2013. Accessed February 7, 2017.
  • 5. Reed AB. Popliteal artery aneurysm. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/popliteal-artery-aneurysm. Last updated December 4, 2015. Accessed February 7, 2017.
  • 6. Kirkwood ML. Extracranial carotid artery aneurysm. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/extracranial-carotid-artery-aneurysm. Last updated January 27, 2017. Accessed February 7, 2017.
  • 7. Shapira OM. Left ventricular aneurysm and pseudoaneurysm following acute myocardial infarction. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. https://www.uptodate.com/contents/left-ventricular-aneurysm-and-pseudoaneurysm-following-acute-myocardial-infarction. Last updated January 6, 2016. Accessed February 7, 2017.
  • 8. Tseng E. Thoracic Aortic Aneurysm. In: Mancini MC. Thoracic Aortic Aneurysm. New York, NY: WebMD. http://emedicine.medscape.com/article/424904. Updated July 20, 2016. Accessed February 6, 2017.
  • 9. Rahimi SA. Abdominal Aortic Aneurysm. In: Rowe VL. Abdominal Aortic Aneurysm. New York, NY: WebMD. http://emedicine.medscape.com/article/1979501. Updated December 19, 2016. Accessed February 6, 2017.
  • 10. Le T, Bhushan V, Sochat M, Petersen M, Micevic G, Kallianos K. First Aid for the USMLE Step 1 2014. McGraw-Hill Medical; 2014.
  • 11. Loh C. Charcot-Bouchard aneurysms. https://radiopaedia.org/articles/charcot-bouchard-aneurysms-1. Updated February 7, 2017. Accessed February 7, 2017.
  • 12. Mcdonald JS, Mcdonald RJ, Fan J, Kallmes DF, Lanzino G, Cloft HJ. Comparative effectiveness of unruptured cerebral aneurysm therapies: propensity score analysis of clipping versus coiling. Stroke. 2013; 44(4): pp. 988–994. doi: 10.1161/STROKEAHA.111.000196.
  • 13. Mousa AY, Beauford RB, Henderson P, et al. Update on the Diagnosis and Management of Popliteal Aneurysm and Literature Review . Vascular . 2016; 14(2): pp. 103 – 108. doi: 10.2310/6670.2006.00021.
  • 14. Dawson I, Sie RB, Van bockel JH. Atherosclerotic popliteal aneurysm. Br J Surg. 1997; 84(3): pp. 293–299. pmid: 9117288.
  • 15. Alonso-coello P, Bellmunt S, Mcgorrian C, et al. Antithrombotic therapy in peripheral artery disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012; 141(2 Suppl): pp. e669S–690S. doi: 10.1378/chest.11-2307.
  • 16. Niino T, Unosawa S, Kimura H. Ruptured Common Femoral Artery Aneurysm or Abdominal Aortic Aneurysm?. Case Rep Surg. 2013. doi: 10.1155/2013/306987.
  • 17. de OliveiraI AF, de Oliveira FilhoII H. Ruptured superficial femoral artery aneurysm: case report and literature review. J vasc bras. 2009; 8(3). doi: 10.1590/S1677-54492009000300019 .
  • 18. Sharma S, Nalachandran S. Isolated common femoral artery aneurysm: a case report. Cases J. 2009; 2. doi: 10.1186/1757-1626-2-7522.
  • 19. clevelandclinic.org. Carotid Artery Disease Aneurysm Surgery. http://my.clevelandclinic.org/health/articles/carotid-artery-aneurysm-surgery. Updated February 7, 2017. Accessed February 7, 2017.
  • 20. Zhang Q, Duan ZQ, Xin SJ, Wang XW, Dong YT. Management of extracranial carotid artery aneurysms: 17 years' experience. Eur J Vasc Endovasc Surg. 1999; 18(2): pp. 162–165. doi: 10.1053/ejvs.1999.0876.
  • 21. Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction. Circulation. 2004; 110(5): pp. 588–636. doi: 10.1161/01.CIR.0000134791.68010.FA.
  • Herold G. Internal Medicine. Cologne, Germany: Herold G; 2014.
last updated 10/11/2018
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