Free Pocket Medicine: The Massachusetts General Hospital Handbook of Internal Medicine by Marc Sabatine

vs. false (rupture contained by adventitia) • Location : root (annuloaortic ectasia), thoracic aortic aneurysm (TAA), thoracoabdominal aortic aneurysm (TAAA), abdominal aortic aneurysm (AAA) • Type : fusiform (circumferential dilation) vs. saccular (localized dilation of aortic wall) Epidemiology ( Circ 2010;121:e266; Nat Rev Cardiol 2011;8:92)
• In U.S., 15,000 deaths/y from aortic ruptures; overall 50,000 deaths/y from Ao disease • TAA :: 1.7:1; 60% root/ascending Ao; 40% descending Ao; arch & TAAA rarer
Risk factors: HTN ; atherosclerosis ; congenital ( bicuspid AoV , Turner’s); connective tissue diseases (Marfan, Ehlers-Danlos type IV, Loeys-Dietz); aortitis (Takayasu’s, GCA, spondyloarthritis, IgG4, syphilis); familial syndromes; chronic AoD; trauma
• AAA : ~4–8% prev. in those >65 y; 5–10× more common invs.; mostly infrarenal
Risk factors = similar to atherosclerosis : smoking , HTN, hyperlipidemia, age, FHx
    Pathophysiology ( NEJM 2009;361:1114; Nat Med 2009;15:649)
• LaPlace’s law : tension across a cylinder ∝ [(ΔP × r) / (wall thickness)]
• TAA : medial degeneration = muscle apoptosis, elastin fiber weakening, mucoid infiltration • AAA : atherosclerosis & inflammation → matrix degeneration → medial weakening • Inflammatory and infectious (“mycotic”) aneurysms relatively rare Screening ( Annals 2005;142:203; JAMA 2009;302:2015; Circ 2010;121:e266)
• TAA : no consensus guidelines; ? screen if bicuspid AoV or first-degree relative • AAA : ✓ for pulsatile abd mass; U/S>60 y w/ FHx of AAA &65–75 y w/ prior tobacco Diagnostic studies ( Circ 2005;111:816 & 2010;121:e266)
• Contrast CT : quick, noninvasive, high Se & Sp for all aortic aneurysms • TTE/TEE : TTE most useful for root and proximal Ao; TEE can visualize other sites of TAA • MRI : preferred over CT for aortic root imaging for TAA; also useful in AAA but time-consuming; noncontrast “black blood” MR to assess aortic wall • Abdominal U/S : screening and surveillance test of choice for infrarenal AAA Treatment ( Circ 2006;113:e463; 2008;177:1883; 2010;121:1544 & e266)
• Risk factor modification : smoking cessation, statin to achieve LDL-C <70 mg/dL
• BP control : b B (↓ dP/dt) ↓ aneurysm growth ( NEJM 1994;330:1335); ACEI a/w ↓ risk of rupture ( Lancet 2006;368:659), ARB may ↓ rate of aortic root growth in Marfan ( NEJM 2008;358:2787); no burst activity/exercise requiring Valsalva maneuvers (eg, heavy lifting) • Indications for surgery : individualize based on FHx, body size, gender
TAA : sx; asc Ao ≥5.5 cm (? 5.0 cm Marfan, bicuspid AoV; 4.2–4.4 cm Loeys-Dietz); descending >6 cm; ↑ >0.5 cm/y; aneurysm ≥4.5 cm and planned AoV surgery
AAA : infrarenal ≥5.5 cm ( NEJM 2002;346:1437) but consider ≥5.0 cm in; sx; ↑ >0.5 cm/y; inflam/infxn
• Endovascular aneurysm repair (EVAR) ( NEJM 2008;358:494; Circ 2011;124:2020)
↓ short-term mort., bleeding, LOS; but long-term graft complic. (3–4%/y; endoleak, need for reintervention, rupture) necessitate periodic surveillance, with no proven Δ in overall mortality, except ? in those <70 y ( NEJM 2010;362:1863, 1881 & 2012;367:1988)
Guidelines support open repair or EVAR for infrarenal AAA in good surg candidates
In Pts unfit for surgery or high peri-op risks: ↓ aneurysm-related mortality but no Δ in overall mortality over medical Rx ( NEJM 2010;362:1872). EVAR noninferior (? superior) to open repair in ruptured AAA w/ favorable anatomy ( Ann Surg 2009;250:818).
TEVAR (thoracic EVAR) for descending TAA ≥5.5 cm may ↓ peri-op morbidity, no proven mortality benefit ( Circ 2010;121:2780; JACC 2010;55:986;   J Thorac CV Surg 2010;140:1001)
    Complications ( Circ 2010;121:e266; Nat Rev Cardiol 2011;8:92)
• Pain : gnawing chest, back or abdominal pain; new or worse pain may signal rupture • Rupture : risk ↑ w/ diameter,, current smoking, HTN
TAA : ~2.5%/y if <6 cm vs. 7%/y if >6 cm; AAA : ~1%/y if <5 cm vs. 6.5%/y if 5–5.9 cm
rupture