Edgepedia

Aoraki / Mount Cook

Aoraki / Mount Cook, also Aorangi, is New Zealand's highest peak at 3,724 m in the Southern Alps, sacred to Ngāi Tahu, first climbed in 1894, lowered by the 1991 rockfall.

The aorta is the body's largest elastic artery, running from the left ventricle through five segments to the iliac bifurcation; coverage spans normal diameters, Windkessel physiology, aneurysm and dissection thresholds, and endovascular repair.

Aortic aneurysm

Aortic aneurysm: balloon-like bulge in the aorta (thoracic or abdominal AAA), often silent; smoking causes ~75% of AAAs; risks dissection and rupture; treated by medicines, open repair, or EVAR.

Aortic aneurysm or dissection

Aortic aneurysm or dissection (ICD-11 BD50): aortic dilation over 1.5 times normal, or an inner-wall tear separating wall layers. AAA repair at 5.5 cm; type A dissection surgical, type B medical.

Aortic aneurysm repair

Aortic aneurysm repair, also known as abdominal aortic aneurysm repair, treats a permanently dilated aortic segment by open replacement with a synthetic graft or endovascular stent-grafting (EVAR), which excludes the sac from circulation.

Aortic arch

The aortic arch, or arch of the aorta, is the curved segment of the aorta between its ascending and descending portions, supplying blood to the head, neck, and arms.

Aortic arch reconstruction

Aortic arch reconstruction is an open cardiovascular operation that repairs or replaces the aortic arch, most often with a prosthetic graft and hypothermic circulatory arrest, for aneurysm and dissection.

Aortic arch repair

Aortic arch repair is a cardiac operation that reconstructs or replaces the transverse aortic arch, using hypothermic circulatory arrest and reimplanted branch vessels to treat aneurysm and dissection.

Aortic arches

Aortic arches: embryonic pharyngeal arch arteries (six pairs from the aortic sac) and the adult aortic arch; typical branching in ~78-81%, bovine arch 13.6%, ARSA about 1%.

Oct 20, 2026

Aortic bifurcation syndrome

Aortic bifurcation syndrome, or Leriche syndrome, is atherosclerotic occlusion of the distal abdominal aorta and iliac arteries, causing buttock-thigh claudication, absent femoral pulses, and impotence; first described by René Leriche in 1923.

Aortic dissection

Aortic dissection: an intimal tear splits the aortic media, creating a false lumen; Stanford type A (ascending) needs emergency surgery with 1–2% mortality per hour untreated, type B managed medically or by TEVAR.

Aortic dissection surgery

Aortic dissection surgery is the open or endovascular repair of a tear in the aortic wall; type A dissection is a surgical emergency, while uncomplicated type B is managed medically.

Aortic endothelial cell

Aortic endothelial cell (Cell Ontology CL:0002544): endothelial cell lining the aortic lumen. Single-cell studies in mouse and human show multiple subpopulations (EC1–EC5), some enriched for coronary artery disease GWAS variants.

Aortic intramural hematoma

An aortic intramural hematoma (IMH) is bleeding contained within the middle muscular layer of the aortic wall, without an intimal flap, and it can progress to dissection or rupture.

Aortic regurgitation

Aortic regurgitation, also called aortic insufficiency, is the diastolic leakage of blood from the aorta back into the left ventricle through a failing aortic valve.

Aortic rupture

Aortic rupture: full-thickness tear of the aorta, usually from aneurysm rupture (rAAA) or dissection. Pooled rAAA mortality 81%; endovascular repair mortality 24.5% vs 44.4% open; risk rises with aneurysm size.

Aortic smooth muscle cell

Aortic smooth muscle cell: the predominant VSMC of the aortic tunica media, arising from neural crest, somites, and secondary heart field; contractile, plastic, and central to aneurysm and dissection.

Aortic stenosis

Aortic stenosis (AS), narrowing of the aortic valve limiting blood flow from the left ventricle, usually from age-related calcification or a bicuspid valve; severe AS (velocity ≥4 m/s, AVA ≤1.0 cm²) is treated by surgical or transcatheter valve replacement.

Aortic valve

Aortic valve: the three-cusp semilunar valve between the left ventricle and aorta. Covers anatomy, embryology, bicuspid valve, stenosis and regurgitation criteria, and SAVR, TAVI, and repair options.

Aortic valve area calculation

Aortic valve area calculation estimates aortic valve opening (cm²) via the invasive Gorlin formula (1951), the Doppler continuity equation, or planimetry by TEE, CMR, or CT; AVA <1.0 cm² defines severe aortic stenosis.

Aortic valve repair

Aortic valve repair: surgical restoration or preservation of the native aortic valve without a prosthesis, using cusp repair, remodeling (Yacoub), or reimplantation (David); low early mortality, ~10% bicuspid reoperation risk.

Aortic valve replacement

Aortic valve replacement (AVR) replaces a diseased aortic valve, via open-heart SAVR or catheter-based TAVR/TAVI, using mechanical valves needing lifelong warfarin or tissue valves; ESC 2025 prefers SAVR under 70, TAVI at 70+.

Aortic valvuloplasty

Aortic valvuloplasty, also known as balloon aortic valvuloplasty (BAV), is a catheter-based procedure that dilates a narrowed aortic valve with an inflated balloon, relieving aortic stenosis without open surgery.

Aortitis

Aortitis is inflammation of the aortic wall, divided into infectious aortitis (Salmonella, Staphylococcus, streptococci) and noninfectious aortitis (giant cell arteritis, Takayasu arteritis, idiopathic), differing in presentation, imaging, treatment, and mortality.

Aorto-ventricular tunnel

Aorto-ventricular tunnel (aortico-left ventricular tunnel, ALVT): rare congenital extracardiac channel from the ascending aorta above the sinotubular junction to the left (>90%) or right ventricle, treated by surgical patch closure.

Aortobifemoral bypass

Aortobifemoral bypass is an open vascular operation joining the abdominal aorta to both femoral arteries with a Y-shaped graft, used since the 1950s for aortoiliac occlusive disease.

Aortoenteric fistula

Aortoenteric fistula (AEF): abnormal communication between the aorta and GI tract, usually the duodenum; primary (aneurysm erosion) or secondary (graft erosion after aortic surgery). Causes massive GI bleeding or sepsis; treated by open or endovascular repair with high mortality.

Aortography

Aortography is an X-ray imaging technique in which contrast dye injected into the aorta shows blood flow through the aorta and its branches, used to diagnose aortic disease.

Aortoiliac occlusive disease

Aortoiliac occlusive disease (AIOD, Leriche syndrome) is atherosclerotic narrowing or blockage of the distal aorta and iliac arteries, causing claudication, erectile dysfunction, and absent femoral pulses; treated endovascular-first with stenting or aortobifemoral bypass.