Page 498 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

368 PART 3: Cardiovascular Disorders

■ MORTALITY KEY REFERENCES

Acute type A dissections have an approximate mortality risk of 20%
with operation (range = 7%-35%). The risk is increased with rupture, • Agricola E, Slavich M, Bertoglio L, et al. The role of contrast
age >80 years old, and associated illnesses, especially CADs and preop- enhanced transesophageal echocardiography in the diagnosis and
erative hemodynamic instability. in the morphological and functional characterization of acute aor-
Patients with type B dissections survive with medical therapy in tic syndromes. Int J Cardiovasc Imaging. 2014;30(1):31-38.
80% of cases. If complications arise, patients receiving endostents have • DeSanctis RW, Doroghazi RM, Austen WG, Buckley MJ. Aortic
a 9% hospital mortality with a 10.4% early reintervention rate and an dissection. N Engl J Med. 1987;317(17):1060-1067.
88% 20-month survival. Those requiring surgery have a significantly • Eggebrecht H, Baumgart D, Herold U, et al. Interventional man-
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higher mortality, reaching 75% if renal and visceral artery occlusion agement of aortic dissection. Herz. 2002;27(6):539-547.
is present.
• Erbel R, Alfonso F, Boileau C, et al. Diagnosis and management
of aortic dissection. Eur Heart J. 2001;22(18):1642-1681.
FOLLOW-UP
• Hagan PG, Nienaber CA, Isselbacher EM, et al. The international
Control of the patient’s blood pressure and close observation for the registry of acute aortic dissection (IRAD): new insights into an old
development of late aneurysm (CT scan at 3 months, then in 6 months disease. JAMA. 2000;283(7):897-903.
and then annually if stable) are the most important variables determin- • Hiratzka LF, Bakris GL, Beckman JA, et al. 2010 ACCF/AHA/AATS/
ing the late complications and survival in type A and B dissections, ACR/ASA/SCA/SCAI/SIR/STS/SVM guidelines for the diagnosis
whether they have undergone surgical repair or not. 75,77 The develop- and management of patients with thoracic aortic disease: a report of
ment and rupture of postdissection aneurysms account for 30% of all the American College of Cardiology Foundation/American Heart
late deaths. In the postoperative period, the systolic blood pressure Association Task Force on Practice Guidelines, American Association
should be maintained at the lowest level capable of sustaining normal for Thoracic Surgery, American College of Radiology, American
organ function, as indicated by sensorium, urine output, and other Stroke Association, Society of Cardiovascular Anesthesiologists,
parameters. When the patient is transferred to the ward and onto oral Society for Cardiovascular Angiography and Interventions, Society
antihypertensives, the type and dose must be modified to prevent of Interventional Radiology, Society of Thoracic Surgeons, and
orthostatic hypotension and syncope. Some form of β-blocker must Society for Vascular Medicine. Circulation. 2010;121(13):e266-e369.
be used (unless contraindicated) to control dP/dT as well as systolic • Nienaber CA, Eagle KA. Aortic dissection: new frontiers in diag-
max
pressure. The blood pressure control must be maintained lifelong so as nosis and management: Part I: from etiology to diagnostic strate-
to minimize the risk of late aneurysmal development or redissection. gies. Circulation. 2003;108(5):628-635.
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New aneurysms form because, in 85% of cases, the false lumen remains
patent and so the wall of the aorta is permanently weakened. DeBakey • Svensson LG, Kouchoukos NT, Miller DC, et al. Expert consensus
study highlights the importance of long-term hypertension control. document on the treatment of descending thoracic aortic disease using
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Five hundred twenty-seven patients were followed for 20 years after endovascular stent-grafts. Ann Thorac Surg. 2008;85(suppl 1): S1-S41.
surgical repair of dissections. If hypertension was not controlled, 45.5% • Tsai TT, Bossone E, Isselbacher EM, et al. Clinical characteristics
developed subsequent aneurysms, compared to 17.4% for those with of hypotension in patients with acute aortic dissection. Am J
proper control. Cardiol. 2005;95(1):48-52.
Patients with known patent false lumens must be watched very • Tsai TT, Trimarchi S, Nienaber CA. Acute aortic dissection: per-
closely as they have an estimated aortic expansion rate of 1 to 4.3 mm/y, spectives from the international registry of acute aortic dissection
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which increases the risk of aortic rupture and other complications. (IRAD). Eur J Vasc Endovasc Surg. 2009;37(2):149-159.
Approximately 50% of dissection-related deaths occur in less than
5 years from the acute event. Once the descending aorta reaches
10
5.5 cm, the risk of rupture is ~30% per year. These patients, and those
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experiencing malperfusion and intractable pain, highlight the need REFERENCES
for close long-term surveillance and should be strongly considered for
endostenting. Complete references available online at www.mhprofessional.com/hall

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