View source for Aortic aneurysm

{{Short description|Excessive enlargement of the human aorta}}
{{cs1 config|name-list-style=vanc}}
{{Infobox medical condition (new)
|name          = Aortic aneurysm
|synonyms=
|image         = Aortic aneurysm hariadhi svg.svg
|caption       = Figure A shows a normal aorta. Figure B shows a thoracic aortic aneurysm (which is located behind the heart). Figure C shows an abdominal aortic aneurysm located below the arteries that supply blood to the kidneys.
|pronounce=
|field         =  [[Cardiology]], [[Vascular surgery]]
|symptoms=abdominal pain and back pain 
|complications = [[Hemorrhaging]]
|onset=
|duration=
|types=
|causes=
|risks=
|diagnosis=[[ultrasound]]
|differential=
|prevention=
|treatment=
|medication=
|prognosis=
|frequency=
|deaths=
}}
An '''aortic aneurysm''' is an enlargement (dilatation) of the [[aorta]] to greater than 1.5 times normal size.<ref name="pmid1999868">{{cite journal | vauthors = Johnston KW, Rutherford RB, Tilson MD, Shah DM, Hollier L, Stanley JC | title = Suggested standards for reporting on arterial aneurysms. Subcommittee on Reporting Standards for Arterial Aneurysms, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery and North American Chapter, International Society for Cardiovascular Surgery | journal = Journal of Vascular Surgery | volume = 13 | issue = 3 | pages = 452–458 | date = March 1991 | pmid = 1999868 | doi = 10.1067/mva.1991.26737 | doi-access = free }}</ref> Typically, there are no symptoms except when the [[aneurysm]] [[aortic dissection|dissects]] or [[aortic rupture|ruptures]], which causes sudden, severe pain in the abdomen and lower back.<ref name=Kent2014/><ref name=AFP2006>{{cite journal | vauthors = Upchurch GR, Schaub TA | title = Abdominal aortic aneurysm | journal = American Family Physician | volume = 73 | issue = 7 | pages = 1198–1204 | date = April 2006 | pmid = 16623206 }}</ref>

The cause remains an area of active research. Known causes include trauma, infection, and [[inflammatory disorders]]. Risk factors include [[cigarette smoking]], [[alcohol use disorder|heavy alcohol consumption]], advanced age, [[dyslipidemia|harmful patterns of high cholesterol in the blood]], [[hypertension|high blood pressure]], and [[coronary artery disease]].<ref name=song/> The pathophysiology of the disease is related to an initial arterial insult causing a cascade of inflammation and extracellular matrix protein breakdown by [[Protease|proteinases]] leading to arterial wall weakening.<ref>{{cite journal | vauthors = Anagnostakos J, Lal BK | title = Abdominal aortic aneurysms | journal = Progress in Cardiovascular Diseases | volume = 65 | pages = 34–43 | date = March 2021 | pmid = 33831398 | doi = 10.1016/j.pcad.2021.03.009 | s2cid = 233192017 }}</ref> They are most commonly located in the [[abdominal aorta]], but can also be located in the [[thoracic aorta]].

Aortic aneurysms result from a weakness in the wall of the aorta and increase the risk of [[aortic rupture]]. When rupture occurs, massive internal [[hemorrhage|bleeding]] results and, unless treated immediately, [[hypovolemic shock|shock]] and death can occur. One review stated that up to 81% of people having abdominal aortic aneurysm rupture will die, with 32% dying before reaching a hospital.<ref name="reim">{{cite journal |vauthors=Reimerink JJ, van der Laan MJ, Koelemay MJ, Balm R, Legemate DA |title=Systematic review and meta-analysis of population-based mortality from ruptured abdominal aortic aneurysm |journal=The British Journal of Surgery |volume=100 |issue=11 |pages=1405–13 |date=October 2013 |pmid=24037558 |doi=10.1002/bjs.9235 |url=https://academic.oup.com/bjs/article/100/11/1405/6138323|url-access=subscription }}</ref>

According to a review of global data through 2019, the prevalence of [[abdominal aortic aneurysm]] worldwide was about 0.9% in people under age 79 years, and is about four times higher in men than in women at any age.<ref name="song">{{cite journal|display-authors=3 |vauthors=Song P, He Y, Adeloye D, Zhu Y, Ye X, Yi Q, Rahimi K, Rudan I |title=The Global and Regional Prevalence of Abdominal Aortic Aneurysms: A Systematic Review and Modeling Analysis |journal=Annals of Surgery |volume=277 |issue=6 |pages=912–919 |date=June 2023 |pmid=36177847 |pmc=10174099 |doi=10.1097/SLA.0000000000005716}}</ref> Death occurs in about 55-64% of people having rupture of the AAA.<ref name=song/>

Screening with [[ultrasound]] is indicated in those at high risk. Prevention is by decreasing risk factors, such as [[smoking]], and treatment is either by open or [[endovascular surgery]]. Aortic aneurysms resulted in about 152,000 deaths worldwide in 2013, up from 100,000 in 1990.<ref name="GDB2013">{{cite journal | title = Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013 | journal = Lancet | volume = 385 | issue = 9963 | pages = 117–171 | date = January 2015 | pmid = 25530442 | pmc = 4340604 | doi = 10.1016/S0140-6736(14)61682-2 | vauthors = ((GBD 2013 Mortality Causes of Death Collaborators)) }}</ref>

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==Classification==
Aortic aneurysms are classified by their location on the aorta.
* An aortic root aneurysm, or [[aneurysm of sinus of Valsalva|aneurysm of the sinus of Valsalva]].
* [[Thoracic aortic aneurysm]]s are found within the chest; these are further classified as ascending, aortic arch, or descending aneurysms.
* [[Abdominal aortic aneurysm]]s, "AAA" or "Triple A", the most common form of aortic aneurysm, involve that segment of the aorta within the abdominal cavity. Thoracoabdominal aortic aneurysms involve both the thoracic and abdominal aorta.
* Thoracoabdominal aortic aneurysms comprise some or all of the aorta in both the chest and abdomen, and have components of both thoracic and abdominal aortic aneurysms.<ref name="Aortic aneurysm">{{cite journal | vauthors = Mathur A, Mohan V, Ameta D, Gaurav B, Haranahalli P | title = Aortic aneurysm | journal = Journal of Translational Internal Medicine | volume = 4 | issue = 1 | pages = 35–41 | date = April 2016 | pmid = 28191516 | pmc = 5290913 | doi = 10.1515/jtim-2016-0008 }}</ref>
** The Crawford classification describes five types of thoracoabdominal aortic aneurysms:<ref name="Radiodedia">{{cite web |title=Crawford classification |url=https://radiopaedia.org/articles/crawford-classification?lang=gb |access-date=13 February 2023}}</ref>
*** Type I: spans from the left [[subclavian artery]] to just before the [[Renal artery|renal arteries]].
*** Type II: spans the [[descending aorta]] after the left subclavian artery.
*** Type III: spans the descending aorta after the sixth [[intercostal space]].
*** Type IV: spans the descending aorta after the [[thoracic diaphragm]].
*** Type V: spans the portion of the descending aorta between the sixth intercostal space and just before the renal arteries.

==Signs and symptoms==
Most intact aortic aneurysms do not produce symptoms. As they enlarge, symptoms such as [[abdominal pain]] and [[back pain]] may develop. Compression of nerve roots may cause leg pain or numbness. Untreated, aneurysms tend to become progressively larger, although the rate of enlargement is unpredictable for any individual. Rarely, clotted blood which lines most aortic aneurysms can break off and result in an [[Embolism|embolus]].<ref name="Aortic aneurysm"/>

Aneurysms cannot be found on physical examination. Medical imaging is necessary to confirm the diagnosis and to determine the anatomic extent of the aneurysm. In people presenting with aneurysm of the arch of the aorta, a common sign is a hoarse voice from stretching of the left [[recurrent laryngeal nerve]], a branch of the vagus nerve that winds around the aortic arch to supply the muscles of the [[larynx]].<ref>{{cite journal |last=Yuan |first=Shi-Min |date=2020 |title=Hoarseness Due to Aortic Arch Aneurysms |journal=Brazilian Journal of Cardiovascular Surgery |volume=35 |issue=6 |pages=970–976 |doi=10.21470/1678-9741-2019-0352 |issn=1678-9741 |pmc=7731862 |pmid=33306323}}</ref>

===Abdominal aortic aneurysm===<!-- This section is linked from [[List of medical abbreviations]] -->
{{main|Abdominal aortic aneurysm}}
[[File:Abdominal aortic aneurysm.JPG|thumb|Abdominal aortic aneurysms (3,4&nbsp;cm)]]
Abdominal aortic aneurysms (AAAs) are more common than their thoracic counterpart. One reason for this is that [[elastin]], the principal load-bearing protein present in the wall of the aorta, is reduced in the abdominal aorta as compared to the thoracic aorta. Another is that the abdominal aorta does not possess [[vasa vasorum]], the nutrient-supplying blood vessels within the wall of the aorta. Most AAA are ''[[Aneurysm#True and false|true aneurysms]]'' that involve all three layers ([[tunica intima]], [[tunica media]] and [[tunica adventitia]]). The prevalence of AAAs increases with age, with an average age of 65–70 at the time of diagnosis. AAAs have been attributed to [[atherosclerosis]], though other factors are involved in their formation.<ref name="Aortic aneurysm"/> Risk factors for AAA include the male gender, aging, a history of smoking, [[hypercholesterolemia]], and hypertension.<ref name=song/><ref name="Aortic aneurysm"/><ref name="kraf">{{cite journal|display-authors=3 |vauthors=Krafcik BM, Stone DH, Cai M, Jarmel IA, Eid M, Goodney PP, Columbo JA, Mayo Smith MF |title=Changes in global mortality from aortic aneurysm |journal=Journal of Vascular Surgery |date=February 2024 |volume=80 |issue=1 |pages=81–88.e1 |pmid=38408686 |doi=10.1016/j.jvs.2024.02.025|pmc=11193635 }}</ref> Reviews reported estimates for prevalence rates of AAA were 0.9-9% in men and 1–2% in women, where, generally, the incidence of AAA is four times greater in men compared to women at the same age.<ref name=song/><ref name="Aortic aneurysm"/>

[[File:AneurysmAorta.jpg|left|thumb|[[Computed tomography|CT]] reconstruction image of an abdominal aortic aneurysm]]
The risk of rupture of an AAA is related to its diameter; once the aneurysm reaches about 5&nbsp;cm, the yearly risk of rupture may exceed the risks of surgical repair for an average-risk patient. Rupture risk is also related to shape; so-called "fusiform" (long) aneurysms are considered less rupture-prone than "saccular" (shorter, bulbous) aneurysms, the latter having more wall tension in a particular location in the aneurysm wall.<ref name="Abdominal Aortic Aneurysms">{{cite web |url= https://www.lecturio.com/concepts/abdominal-aortic-aneurysms/ | title= Abdominal Aortic Aneurysms
|website=The Lecturio Medical Concept Library | date= 16 October 2020
|access-date=2021-06-25}}</ref>

The prevalence of AAA worldwide in 2019 was approximately 0.9% in people under age 79 years,<ref name=song/> whereas a 2014 review reported a range of 2-12%, occurring in about 8% of men older than 65 years of age.<ref>{{cite journal |display-authors=3 | vauthors = Stather PW, Sidloff DA, Rhema IA, Choke E, Bown MJ, Sayers RD | title = A review of current reporting of abdominal aortic aneurysm mortality and prevalence in the literature | journal = European Journal of Vascular and Endovascular Surgery | volume = 47 | issue = 3 | pages = 240–242 | date = March 2014 | pmid = 24368205 | doi = 10.1016/j.ejvs.2013.11.007 | doi-access = free }}</ref> Men are about four times more likely to have AA compared to women at any age, with death occurring in about 55-64% of people having AAA rupture.<ref name=song/>

Before rupture, an AAA may present as a large, [[Pulsatile flow|pulsatile]] mass above the [[Navel|belly button]]. A [[bruit]] may be heard from the turbulent flow in the aneurysm. Rupture may be the first sign of AAA. Once an aneurysm has ruptured, it presents with classic symptoms of abdominal pain, which is severe, constant, and radiating to the back.<ref name="Aortic aneurysm"/>

The diagnosis of an abdominal aortic aneurysm can be confirmed by the use of [[medical ultrasonography|ultrasound]]. Rupture may be indicated by the presence of free fluid in the abdomen. A contrast-enhanced abdominal [[computed tomography|CT scan]] is the best test to diagnose an AAA and guide treatment options.<ref>{{cite journal | vauthors = Vu KN, Kaitoukov Y, Morin-Roy F, Kauffmann C, Giroux MF, Thérasse E, Soulez G, Tang A | display-authors = 6 | title = Rupture signs on computed tomography, treatment, and outcome of abdominal aortic aneurysms | journal = Insights into Imaging | volume = 5 | issue = 3 | pages = 281–293 | date = June 2014 | pmid = 24789068 | pmc = 4035490 | doi = 10.1007/s13244-014-0327-3 }}</ref>

In 2019, some 170,000 people worldwide died from AAA rupture, with aging, smoking, and hypertension as principal factors.<ref name=song/><ref name=kraf/> Annual mortality from ruptured aneurysms in the United States is about 15,000.<ref name="x970">{{cite journal | last1=Mell | first1=Matthew | last2=White | first2=Julie J. | last3=Hill | first3=Bradley B. | last4=Hastie | first4=Trevor | last5=Dalman | first5=Ronald L. | title=No Increased Mortality With Early Aortic Aneurysm Disease | journal=Journal of Vascular Surgery | publisher=NIH Public Access | volume=56 | issue=5 | date=2024-03-14 | pages=1246–1251 | pmid=22832264 | doi=10.1016/j.jvs.2012.04.023 | pmc=3478494 }}</ref>

===Aortic rupture===
{{main|Aortic rupture}}
An aortic aneurysm can rupture from wall weakness. Aortic rupture is a surgical emergency and has a high mortality even with prompt treatment. Weekend admission for a ruptured aortic aneurysm is associated with increased mortality compared with admission on a weekday, and this is likely due to several factors, including a delay in prompt surgical intervention.<ref>{{cite journal | vauthors = Groves EM, Khoshchehreh M, Le C, Malik S | title = Effects of weekend admission on the outcomes and management of ruptured aortic aneurysms | journal = Journal of Vascular Surgery | volume = 60 | issue = 2 | pages = 318–324 | date = August 2014 | pmid = 24709439 | pmc = 4121436 | doi = 10.1016/j.jvs.2014.02.052 }}</ref>

==Risk factors==
* [[Coronary artery disease]]
* [[Hypertension|High blood pressure]]
* [[Loeys-Dietz Syndrome]]
* [[Hypercholesterolemia|High levels of cholesterol in the blood]]
* [[Hyperhomocysteinemia|High levels of homocysteine in the blood]]
* Elevated [[C-reactive protein]], a marker of inflammation 
* [[Tobacco]] use
* Heavy [[Alcohol (drug)|alcohol]] use
* [[Peripheral artery disease]]
* [[Marfan syndrome]]
* [[Fluoroquinolone use]]<ref name="Rizk_et_al_2024">{{cite journal|first1=John G. |last1=Rizk |first2=Julia F. |last2=Slejko |first3=Emily L. |last3=Heil |first4=Dominique |last4=Seo |first5=Danya M. |last5=Qato |title=Impact of the US Food and Drug Administration warning regarding increased risk of aortic aneurysms or aortic dissections on fluoroquinolone prescribing trends|journal=BMJ Open Quality|year=2024|volume=13|article-number=e002925 |doi=10.1136/bmjoq-2024-002925|doi-access=free |pmid=39053916 |pmc=11733791 }}</ref>
* [[Ehlers–Danlos syndrome|Ehlers-Danlos]] type IV
* [[Bicuspid aortic valve]]
* [[Syphilis]]
* [[IgG4-related disease]]
* [[Pregnancy]]
* Chronic [[obstructive sleep apnea]]
* [[Psoriasis]]<ref>{{cite journal |last1=Yu |first1=Xinyu |last2=Feng |first2=Xin |last3=Xia |first3=Liangtao |last4=Cao |first4=Shiyi |last5=Wei |first5=Xiang |date=November 2020 |title=Risk of aortic aneurysm in patients with psoriasis: A systematic review and meta-analysis of cohort studies |journal=Clinical Cardiology |language=en |volume=43 |issue=11 |pages=1266–1272 |doi=10.1002/clc.23438 |pmid=32757333 |pmc=7661651 |issn=0160-9289}}</ref>

==Pathophysiology==
[[File:6.5cmAAAwith3cmlumen.png|thumb|A 6.5&nbsp;cm AAA with a 3&nbsp;cm lumen]]
An aortic aneurysm can occur as a result of trauma, infection, or, most commonly, from an intrinsic abnormality in the [[elastin]] and [[collagen]] components of the aortic wall. Aortic aneurysm development and progression have been directly associated with a deficiency of elastin as well as a loss of collagen type 1.<ref name="Yamawaki-Ogata2023">{{cite journal |last1=Yamawaki-Ogata |first1=Aika |last2=Mutsuga |first2=Masato |last3=Narita |first3=Yuji |title=A review of current status of cell-based therapies for aortic aneurysms |journal=Inflammation and Regeneration |date=7 August 2023 |volume=43 |issue=1 |page=40 |doi=10.1186/s41232-023-00280-8 |doi-access=free |pmid=37544997 |pmc=10405412 }}</ref> The elastin-to-collagen ratio is also significantly higher in aneurysmal abdominal aortas compared to healthy abdominal aortas.<ref name="Yamawaki-Ogata2023" /> While definite genetic abnormalities were identified in true genetic syndromes involving connective tissue abnormalities (e.g., [[Marfan syndrome|Marfan]], [[Ehlers-Danlos syndrome|Ehlers-Danlos]], and others) associated with aortic aneurysms, both thoracic and abdominal aortic aneurysms demonstrate a strong genetic component in their aetiology.<ref>{{cite journal | vauthors = Saratzis A, Bown MJ | title = The genetic basis for aortic aneurysmal disease | journal = Heart | volume = 100 | issue = 12 | pages = 916–922 | date = June 2014 | pmid = 24842835 | doi = 10.1136/heartjnl-2013-305130 | s2cid = 12989538 }}</ref>

==Prevention==
The risk of aneurysm enlargement may be diminished with attention to the patient's blood pressure, smoking, and [[cholesterol]] levels. There have been proposals to introduce [[ultrasound scan]]s as a screening tool for those most at risk: men over the age of 65.<ref>Routine screening in the management of AAA, UK Department of Health study [http://www.dh.gov.uk/PolicyAndGuidance/ResearchAndDevelopment/ResearchAndDevelopmentAZ/CardiovascularDiseaseAndStroke/CardiovascularDiseaseAndStrokeArticle/fs/en?CONTENT_ID=4002152&chk=/9i9J2 Report] {{webarchive|url=https://web.archive.org/web/20070205230956/http://www.dh.gov.uk/PolicyAndGuidance/ResearchAndDevelopment/ResearchAndDevelopmentAZ/CardiovascularDiseaseAndStroke/CardiovascularDiseaseAndStrokeArticle/fs/en?CONTENT_ID=4002152&chk=%2F9i9J2 |date=2007-02-05 }}</ref><ref>{{cite journal|title=Abdominal Aortic Aneurysm|journal=Bandolier|volume=27|issue=3|date=May 1996|url=http://www.bandolier.org.uk/band27/b27-3.html |access-date=7 March 2021}}</ref>

In a meta-analysis and systematic review of observational data, [[Statin|statins]] were associated with reduced rates of abdominal aortic aneurysm growth, rupture, and 30 day [[perioperative]] mortality.<ref>{{Cite journal |last1=Salata |first1=Konrad |last2=Syed |first2=Muzammil |last3=Hussain |first3=Mohamad A. |last4=de Mestral |first4=Charles |last5=Greco |first5=Elisa |last6=Mamdani |first6=Muhammad |last7=Tu |first7=Jack V. |last8=Forbes |first8=Thomas L. |last9=Bhatt |first9=Deepak L. |last10=Verma |first10=Subodh |last11=Al Omran |first11=Mohammed |date=2018-10-02 |title=Statins Reduce Abdominal Aortic Aneurysm Growth, Rupture, and Perioperative Mortality: A Systematic Review and Meta-Analysis |journal=Journal of the American Heart Association |volume=7 |issue=19 |article-number=e008657 |doi=10.1161/JAHA.118.008657 |pmc=6404894 |pmid=30371297}}</ref> Randomized controlled trial research is unlikely to be conducted in this population due to ethical concerns when considering many patients who present with abdominal aortic aneurysms already have other proven indications of statin use, along with the lack of financial incentive for pharmaceutical companies in conducting expensive research on generic statins. 

[[Anacetrapib]] is a cholesteryl ester transfer protein inhibitor that raises high-density lipoprotein (HDL) cholesterol and reduces low-density lipoprotein (LDL) cholesterol.
Anacetrapib reduces progression of atherosclerosis, mainly by reducing non-HDL-cholesterol, improves lesion stability and adds to the beneficial effects of atorvastatin<ref>{{cite journal | vauthors = Bloomfield D, Carlson GL, Sapre A, Tribble D, McKenney JM, Littlejohn TW, Sisk CM, Mitchel Y, Pasternak RC | display-authors = 6 | title = Efficacy and safety of the cholesteryl ester transfer protein inhibitor anacetrapib as monotherapy and coadministered with atorvastatin in dyslipidemic patients | journal = American Heart Journal | volume = 157 | issue = 2 | pages = 352–360.e2 | date = February 2009 | pmid = 19185645 | doi = 10.1016/j.ahj.2008.09.022 }}</ref>
Elevating the amount of HDL cholesterol in the abdominal area of the aorta in mice both reduced the size of aneurysms that had already grown and prevented abdominal aortic aneurysms from forming at all. In short, raising HDL cholesterol is beneficial because it induces programmed cell death. The walls of a failing aorta are replaced and strengthened. New lesions should not form at all when using this drug.<ref>{{cite journal | vauthors = Torsney E, Pirianov G, Charolidi N, Shoreim A, Gaze D, Petrova S, Laing K, Meisinger T, Xiong W, Baxter BT, Cockerill GW | display-authors = 6 | title = Elevation of plasma high-density lipoproteins inhibits development of experimental abdominal aortic aneurysms | journal = Arteriosclerosis, Thrombosis, and Vascular Biology | volume = 32 | issue = 11 | pages = 2678–2686 | date = November 2012 | pmid = 23023368 | doi = 10.1161/ATVBAHA.112.00009|doi-access = free}}*{{lay source |template=cite web|url=https://www.sciencedaily.com/releases/2013/03/130306084157.htm|title=Early evidence shows 'good' cholesterol could combat abdominal aortic aneurysm|date=March 6, 2013 |website=Science Daily}}</ref> 

[[ACE inhibitor|ACE inhibitors]] have also been associated with a reduced risk of aortic aneurysm rupture, in contrast with other classes of antihypertensive drugs which did not show a significant protective effect in a population based case control study conducted in Ontario, Canada.<ref>{{Cite journal |last=Walling |first=Anne D. |date=2006-11-15 |title=Can ACE Inhibitors Prevent Aortic Aneurysm Rupture? |url=https://www.aafp.org/pubs/afp/issues/2006/1115/p1780.html |journal=American Family Physician |language=en-US |volume=74 |issue=10 |page= 1780}}</ref> However, a prospective cohort study conducted in the UK revealed conflicting results with increased aortic aneurysm growth rates observed in those taking ACE inhibitors, compared with other classes of antihypertensive drugs.<ref>{{Cite journal |last1=Sweeting |first1=Michael J. |last2=Thompson |first2=Simon G. |last3=Brown |first3=Louise C. |last4=Greenhalgh |first4=Roger M. |last5=Powell |first5=Janet T. |date=2010 |title=Use of angiotensin converting enzyme inhibitors is associated with increased growth rate of abdominal aortic aneurysms |journal=Journal of Vascular Surgery |volume=52 |issue=1 |pages=1–4 |doi=10.1016/j.jvs.2010.02.264 |issn=1097-6809 |pmid=20494541}}</ref> A small placebo controlled RCT conducted later found no significant effect of the ACE inhibitor [[perindopril]] or the [[calcium channel blocker]] [[amlodipine]] after 2 years, although the study had limited power to detect small differences between growth rates and higher powered research was warranted.<ref>{{Cite journal |last1=Kiru |first1=Gaia |last2=Bicknell |first2=Colin |last3=Falaschetti |first3=Emanuela |last4=Powell |first4=Janet |last5=Poulter |first5=Neil |date=2016 |title=An evaluation of the effect of an angiotensin-converting enzyme inhibitor on the growth rate of small abdominal aortic aneurysms: a randomised placebo-controlled trial (AARDVARK) |journal=Health Technology Assessment   |volume=20 |issue=59 |pages=1–180 |doi=10.3310/hta20590 |issn=2046-4924 |pmc=5002899 |pmid=27488944}}</ref>

==Screening==
Screening for an aortic aneurysm so that it may be detected and treated prior to rupture is the best way to reduce the overall mortality of the disease. The most cost-efficient screening test is an abdominal aortic ultrasound study. Noting the results of several large, population-based screening trials, the US [[Centers for Medicare and Medicaid Services]] (CMS) now provides payment for one ultrasound study in all smokers aged 65 years or older ("SAAAVE Act").<ref>{{cite web |title=SAAAVE Act Background {{!}} Society for Vascular Surgery |url=https://vascular.org/news-advocacy/articles-press-releases/saaave-act-background |access-date=2024-01-23 |website=vascular.org}}</ref>

==Management==
Surgery (open or endovascular) is the definitive treatment of an aortic aneurysm. Medical therapy is typically reserved for smaller aneurysms or for elderly, frail patients where the risks of surgical repair exceed the risks of non-operative therapy (observation alone).

[[File:Open infrarenal aortic repair model.jpg|thumb|Open infrarenal aortic repair model, showing a surgical clamp above the aneurysm and below the renal arteries]]

===Medical therapy===
Medical therapy of aortic aneurysms involves strict [[blood pressure]] control. This does not treat the aortic aneurysm per se, but control of [[hypertension]] within tight blood pressure parameters may decrease the rate of expansion of the aneurysm.

The medical management of patients with aortic aneurysms, reserved for smaller aneurysms or frail patients, involves cessation of smoking, blood pressure control, use of [[statin]]s and occasionally [[beta blocker]]s. Ultrasound studies are obtained regularly (i.e., every 6 or 12 months) to follow the size of the aneurysm.

Despite optimal medical therapy, patients with large aneurysms are likely to have continued aneurysm growth and risk of aneurysm rupture without surgical repair.<ref>{{cite journal | vauthors = Aggarwal S, Qamar A, Sharma V, Sharma A | title = Abdominal aortic aneurysm: A comprehensive review | journal = Experimental and Clinical Cardiology | volume = 16 | issue = 1 | pages = 11–15 | date = 2011 | pmid = 21523201 | pmc = 3076160 }}</ref>

===Surgery===
Decisions about repairing an aortic aneurysm are based on the balance between the risk of aneurysm rupture without treatment and the risks of the treatment. For example, a small aneurysm in an elderly patient with severe [[cardiovascular disease]] would not be repaired. The chance of the small aneurysm rupturing is overshadowed by the risk of cardiac complications from the procedure to repair the aneurysm.

The risk of the repair procedure is twofold. First, there is consideration of the risk of problems occurring during and immediately after the procedure itself ("peri-procedural" complications). Second, the effectiveness of the procedure must be taken into account, namely whether the procedure effectively protects the patient from aneurysm rupture over the long term, and whether the procedure is durable so that secondary procedures, with their attendant risks, are not necessary over the life of the patient. A less invasive procedure (such as [[endovascular aneurysm repair]]) may be associated with fewer short-term risks to the patient (fewer peri-procedural complications), but secondary procedures may be necessary over long-term follow-up.

The determination of surgical intervention is made on a per-case basis. The diameter of the aneurysm, its rate of growth, the presence or absence of [[Marfan syndrome]], [[Ehlers–Danlos syndromes]] or similar connective tissue disorders, and other [[co-morbidities]] are all important factors in the overall treatment.

A large, rapidly expanding, or symptomatic aneurysm should be repaired, as it has a greater chance of rupture. Slowly expanding aortic aneurysms may be followed by routine diagnostic testing (i.e., [[CT scan]] or [[ultrasound]] imaging).

For abdominal aneurysms, the current treatment guidelines for abdominal aortic aneurysms suggest elective surgical repair when the diameter of the aneurysm is greater than {{convert|5|cm|0|abbr=on}}. However, recent data on patients aged 60–76 suggest medical management for abdominal aneurysms with a diameter of less than {{convert|5.5|cm|0|abbr=on}}.<ref>{{cite journal | vauthors =  | title = Mortality results for randomised controlled trial of early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. The UK Small Aneurysm Trial Participants | journal = Lancet | volume = 352 | issue = 9141 | pages = 1649–1655 | date = November 1998 | pmid = 9853436 | doi = 10.1016/S0140-6736(98)10137-X | s2cid = 24733279 }}</ref>

====Open surgery====
{{main|Open aortic surgery}}
Open surgery starts with exposure of the dilated portion of the aorta via an incision in the abdomen or abdomen and chest, followed by insertion of a synthetic ([[Dacron]] or [[Gore-Tex]]) graft (tube) to replace the diseased aorta. The graft is sewn in by hand to the non-diseased portions of the aorta, and the aneurysmal sac is closed around the graft.

The aorta and its branching arteries are cross-clamped during open surgery. This can lead to inadequate blood supply to the spinal cord, resulting in [[paraplegia]]. A 2004 systematic review and meta-analysis found that cerebrospinal fluid drainage (CFSD), when performed in experienced centers, reduces the risk of ischemic spinal cord injury by increasing the perfusion pressure to the spinal cord.<ref>{{cite journal | vauthors = Cinà CS, Abouzahr L, Arena GO, Laganà A, Devereaux PJ, Farrokhyar F | title = Cerebrospinal fluid drainage to prevent paraplegia during thoracic and thoracoabdominal aortic aneurysm surgery: a systematic review and meta-analysis | journal = Journal of Vascular Surgery | volume = 40 | issue = 1 | pages = 36–44 | date = July 2004 | pmid = 15218460 | doi = 10.1016/j.jvs.2004.03.017 | doi-access = free }}</ref> A 2012 Cochrane systematic review noted that further research regarding the effectiveness of CFSD for preventing a spinal cord injury is required.<ref>{{cite journal | vauthors = Khan SN, Stansby G | title = Cerebrospinal fluid drainage for thoracic and thoracoabdominal aortic aneurysm surgery | journal = The Cochrane Database of Systematic Reviews | volume = 10 | article-number = CD003635 | date = October 2012 | issue = 10 | pmid = 23076900 | pmc = 7173760 | doi = 10.1002/14651858.CD003635.pub3 }}</ref> A 2023 systematic review suggested that rates of postoperative spinal cord ischaemia can be kept at low levels after open repair of thoracoabdominal aneurysm with adequate precautions and perioperative manoeuvres.<ref name="Perioperative neuromonitoring durin">{{cite journal |last1=Sef |first1= D |last2=Thet |first2=MS |last3=Miskolczi |first3=S |last4=Velissaris |first4=T |last5=De Silva |first5=R |last6=Luthra |first6=S |last7=Turina |first7=MI |title=Perioperative neuromonitoring during thoracoabdominal aortic aneurysm open repair: a systematic review. |journal=European Journal of Cardio-Thoracic Surgery |date=1 June 2023 |volume=63 |issue=6 |doi=10.1093/ejcts/ezad221 |pmid=37233116}}</ref> The majority of the surgeons believe prophylactic lumbar drains are effective in reducing spinal cord ischaemia.<ref>{{cite journal |last1=Chung |first1=JC |last2=Lodewyks |first2=CL |last3=Forbes |first3=TL |last4=Chu |first4=MWA |last5=Peterson |first5=MD |last6=Arora |first6=RC |last7=Ouzounian |first7=M |last8=Canadian Thoracic Aortic Collaborative |last9=Canadian Cardiovascular Critical Care |title=Prevention and management of spinal cord ischemia following aortic surgery: A survey of contemporary practice. |journal=The Journal of Thoracic and Cardiovascular Surgery |date=January 2022 |volume=163 |issue=1 |pages=16–23.e7 |doi=10.1016/j.jtcvs.2020.03.034 |pmid=32334886|s2cid=216361355 |doi-access=free }}</ref> Neuromonitoring with motor-evoked potentials (MEP) can provide the surgeon objective criteria to direct selective intercostal reconstruction or other protective anaesthetic and surgical manoeuvres. Simultaneous monitoring of MEP and somatosensory-evoked potentials (SSEP) seems to be the most reliable method.<ref name="Perioperative neuromonitoring durin"/>

====Endovascular====
{{main|Endovascular aneurysm repair}}
[[Endovascular aneurysm repair|Endovascular treatment of aortic aneurysms]] is a minimally invasive alternative to open surgical repair. It involves the placement of an endovascular [[stent]] through small incisions at the top of each leg into the aorta.

As compared to open surgery, EVAR has a lower risk of death in the short term and a shorter hospital stay, but may not always be an option.<ref name=Kent2014>{{cite journal | vauthors = Kent KC | title = Clinical practice. Abdominal aortic aneurysms | journal = The New England Journal of Medicine | volume = 371 | issue = 22 | pages = 2101–2108 | date = November 2014 | pmid = 25427112 | doi = 10.1056/NEJMcp1401430 }}</ref><ref>{{cite journal | vauthors = Thomas DM, Hulten EA, Ellis ST, Anderson DM, Anderson N, McRae F, Malik JA, Villines TC, Slim AM | display-authors = 6 | title = Open versus Endovascular Repair of Abdominal Aortic Aneurysm in the Elective and Emergent Setting in a Pooled Population of 37,781 Patients: A Systematic Review and Meta-Analysis | journal = ISRN Cardiology | volume = 2014 | article-number = 149243 | year = 2014 | pmid = 25006502 | pmc = 4004021 | doi = 10.1155/2014/149243 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Biancari F, Catania A, D'Andrea V | title = Elective endovascular vs. open repair for abdominal aortic aneurysm in patients aged 80 years and older: systematic review and meta-analysis | journal = European Journal of Vascular and Endovascular Surgery | volume = 42 | issue = 5 | pages = 571–576 | date = November 2011 | pmid = 21820922 | doi = 10.1016/j.ejvs.2011.07.011 | doi-access = free }}</ref> There does not appear to be a difference in longer-term outcomes between the two.<ref>{{cite journal | vauthors = Paravastu SC, Jayarajasingam R, Cottam R, Palfreyman SJ, Michaels JA, Thomas SM | title = Endovascular repair of abdominal aortic aneurysm | journal = The Cochrane Database of Systematic Reviews | issue = 1 | article-number = CD004178 | date = January 2014 | volume = 2014 | pmid = 24453068 | doi = 10.1002/14651858.CD004178.pub2 | pmc = 10749584 }}</ref> After EVAR, repeat procedures are more likely to be needed.<ref>{{cite journal | vauthors = Ilyas S, Shaida N, Thakor AS, Winterbottom A, Cousins C | title = Endovascular aneurysm repair (EVAR) follow-up imaging: the assessment and treatment of common postoperative complications | journal = Clinical Radiology | volume = 70 | issue = 2 | pages = 183–196 | date = February 2015 | pmid = 25443774 | doi = 10.1016/j.crad.2014.09.010 }}</ref>

==Epidemiology==
Globally, aortic aneurysms resulted in about ~170,000 deaths in 2017.<ref name=song/> This figure represents an increase from approximately ~100,000 in 1990.<ref name=GDB2013/>

== See also ==
* [[Aortic valve repair]]
* [[Aortic dissection]]
* [[Cardarelli's sign]]
* [[Oliver's sign]]
* [[Tocilizumab]]

== References ==
{{Reflist}}

== External links ==
{{Commons category|Aortic aneurysms}}

{{Vascular diseases}}
{{Medical resources
| DiseasesDB     = 792
| ICD10          = {{ICD10|I|71||i|70}}
| ICD9           = {{ICD9|441}}
| ICDO           =
| OMIM           = 100070
| MedlinePlus    =
| eMedicineSubj  = emerg
| eMedicineTopic = 942
| eMedicine_mult = {{eMedicine2|med|2783}} {{eMedicine2|emerg|27}} {{eMedicine2|radio|1}} {{eMedicine2|med|3443}}
| MeshID         = D001014
}}
{{Authority control}}

{{DEFAULTSORT:Aortic Aneurysm}}
[[Category:Diseases of the aorta|+]]
[[Category:Vascular surgery]]
[[Category:IgG4-related disease]]