Aortic aneurysm

AORTIC​ ​ANEURYSM

Aneurysm​ ​is​ ​the​ ​ballooning​ ​of​ ​the​ ​arterial​ ​wall​ ​due​ ​to​ ​some​ ​weakness​ ​in​ ​it.​ ​It​ ​can​ ​develop​ ​in​ ​any artery​ ​in​ ​the​ ​body.​ ​When​ ​it​ ​affects​ ​the​ ​aorta,​ ​it​ ​is​ ​known​ ​as​ a ​ ortic​ ​aneurysm.

HOW​ ​IT​ ​HAPPENS? Aortic​ ​wall​ ​has​ ​3​ ​layers​ ​–​ ​Intima​ ​(inner​ ​layer),​ ​media​ ​(middle​ ​layer)​ ​and​ ​the​ ​adventitia​ ​(outer layer).​ ​Some​ ​diseases​ ​affect​ ​the​ ​media​ ​and​ ​cause​ ​weakness​ ​in​ ​the​ ​layer.​ ​The​ ​internal​ ​pressure of​ ​blood​ ​acts​ ​constantly​ ​on​ ​the​ ​aortic​ ​wall.​ ​When​ ​it​ ​acts​ ​on​ ​the​ ​weakened​ ​section​ ​of​ ​the​ ​wall,​ ​it balloons​ ​out.​ ​Gradually​ ​an​ ​aneurysm​ ​forms.​ ​The​ ​commonest​ ​disease​ ​that​ ​weakens​ ​aortic​ ​wall​ ​is Atherosclerosis.

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Some​ ​of​ ​the​ ​connective​ ​tissue​ ​disorders​ ​are​ ​genetic​ ​and​ ​runs​ ​in​ ​families.​ ​(eg.​ ​Marfan’s syndrome​ ​and​ ​Ehler-Danlos​ ​syndrome)​ ​These​ ​conditions​ ​cause​ ​weakness​ ​in​ ​the​ ​aortic​ ​wall.

The​ ​affected​ ​persons​ ​have​ ​the​ ​risk​ ​of​ ​developing​ ​aneurysms​ ​at​ ​a​ ​young​ ​age.

Age​ ​related​ ​degeneration​ ​can​ ​also​ ​lead​ ​to​ ​weakness​ ​in​ ​the​ ​arterial​ ​walls​ ​and​ ​cause​ ​aneurysm.

Hypertension​ ​is​ ​an​ ​aggravating​ ​risk​ ​factor​ ​which​ ​hastens​ ​the​ ​enlargement​ ​of​ ​the​ ​aneurysm.

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SYMPTOMS As discussed in earlier section, symptoms of aortic aneurysm vary depending on the site of the disease. Stretch on the aortic wall can cause pain usually of dull and aching variety. Due to the mass effect, it can exert pressure on the neighboring structures. At the ascending aorta dyspnea and chest pain can occur. At the arch and proximal descending aorta patients can have difficulty in swallowing (dysphagia), difficulty in breathing or change in voice due to compression​ ​on​ ​the​ ​nerve​ ​(recurrent​ ​laryngeal​ ​nerve).

In the abdomen symptoms can be confusing – from mild abdominal pain, colicky pain, burning micturition and low backache to jaundice and bleeding. Some patients notice prominent pulsating​ ​swelling​ ​in​ ​the​ ​abdomen.

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When aneurysm is large and threatening to rupture, pain may be more severe. It may present with​ ​abdominal​ ​or​ ​back​ ​pain.

Rupture is associated with excruciating back or abdominal pain. Deterioration can be rapid due to​ ​blood​ ​loss​ ​into​ ​peritoneum​ ​or​ ​chest​ ​cavity.

Aneurysm close to intestines can erode into them and rupture (Aorto-enteric fistula). This is a very​ ​serious​ ​complication​ ​and​ ​treatment​ ​is​ ​difficult​ ​with​ ​poor​ ​prognosis​ ​in​ ​spite​ ​of​ ​timely​ ​surgery.

DIAGNOSIS An Ultrasound of abdomen or an Echo may detect the aneurysm for the first time. The precise evaluation is done by a CT-Aortogram. This contrast CT would provide accurate information on the​ ​size,​ ​location,​ ​extent​ ​and​ ​branch​ ​involvement​ ​of​ ​the​ ​aneurysm.

TREATMENT In the initial stages the treatment is conservative and revolves around risk factor control.

Hypertension should be treated aggressively. Traditionally treatment is recommended once the aneurysm grows beyond 5 cm in diameter. At this point the statistical chance of rupture starts to increase​ ​rapidly.

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Surgery​ ​is​ ​the​ ​traditional​ ​form​ ​of​ ​treatment.​ ​Depending​ ​on​ ​the​ ​site​ ​the​ ​surgical​ ​options​ ​defer. ●

Aortic​ ​root​ ​–​ ​Aortic​ ​root​ ​replacement

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Ascending​ ​aorta​ ​-​ ​Interposition​ ​graft

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Arch​ ​of​ ​aorta​ ​–​ ​Arch​ ​repair​ ​or​ ​replacement

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Descending or Abdominal aorta – repair with interposition graft with/without branch re-implantation

Endo-Vascular Repair of aortic aneurysm using a stent is a viable option in many situations. It is suitable for straight segments with no branch involvement. There should be clear disease free areas​ ​on​ ​either​ ​side​ ​of​ ​the​ ​disease​ ​for​ ​the​ ​stent​ ​to​ ​be​ ​seated​ ​well​ ​(landing​ ​zones).

Hybrid is a method of combining surgery with stenting. This can reduce the morbidity of the treatment​ ​and​ ​widen​ ​the​ ​scope​ ​of​ ​treatment​ ​as​ ​the​ ​two​ ​methods​ ​complement​ ​each​ ​other.

Copyright​ ​ⓒ​ ​2017​ ​Heart​ ​and​ ​Aorta​.​ ​All​ ​rights​ ​reserved.