*7.1.1 Acute type A dissection*

Acute type A dissection is a surgical emergency with a mortality of 1–2% per hour, as these patients are at high risk of complications such as aortic regurgitation, tamponade, myocardial infarction due to compression of the coronary ostium, stroke, and aortic rupture [24].

This excludes patients with significant comorbidities including prior debilitating stroke, ischemic heart disease, renal failure, malignancy, advancing age, and hemorrhagic stroke, which are associated with a bad prognosis.

These patients should also be assessed for any underlying coronary artery disease or any aortic valve disease by intraoperative transesophageal ECHO to identify any wall motion abnormality or aortic valvular defect.

In the International Registry of Aortic Dissection (IRAD) review of 547 patients in which 80 percent of type A patients were treated surgically and the remaining 20 percent were treatment medically, inpatient mortality rates were 27 and 56 percent for surgical and medically treated patients. Medically treated patients were those with advanced comorbidities and aged individuals with poor prognosis [25].

Poor prognostic factors predicting increased mortality in type A patients according to the IRAD study included advanced age, tamponade at presentation, prior

#### *Differential Diagnosis of Chest Pain*

myocardial infarction, prior stroke, ischemia involving kidney or other viscera, advance renal or lung disease, and previous aortic valve replacement [25–31].

Open surgical repair for type A patients involves resection of the dissecting aneurysm and removal of intimal tear, closure of false lumen and repair of aorta using synthetic graft, and aortic valve repair/replacement. Repair of the aortic arch may also be needed depending on the extent of the pathology.

Patients with genetic disease like Marfan causing Aortic regurgitation, bicuspid aortic valve or aortitis need aortic valve replacement [32].

An alternative to open surgical repair in type A patients with ischemic complications like renal, mesenteric, and peripheral ischemia is endovascular stent grafting.

A novel approach involves the hybrid repair of type A dissection with "frozen elephant trunk repair technique," which involves open surgical repair of the ascending aorta in the form of a traditional elephant trunk and endoscopic stent grafting to repair the descending aorta.

Studies have compared the total arch replacement using the frozen elephant trunk repair technique (FET) with the hemi-arch replacement (AHR) for the type A ascending aortic dissection in which the survival for the patients after 5 years was 95.3% for the FET group and 69.0% for the AHR group, indicating that FET techniques prevent further operations for the complications because of the false lumen [25, 33–35].

#### *7.1.2 Type B aortic dissection*

Medical management is preferred for uncomplicated cases of type B aortic dissections unless the dissection or aneurysm expands, ischemic complications or aortic rupture occurs, or the patient has persistent uncontrolled hypertension or chest pain, when surgical treatment or endovascular grafting is to be considered.

Conservative treatment for type B patients involves optimal BP control and long-term surveillance with imaging.

In the IRAD study of 384 patients with type B aortic dissection [36], 73 percent of patients were treated medically with mortality rate of 13% within the first week of admission. Factors associated with increased mortality were shock on presentation, widened mediastinum, excessively dilated aorta (≥6 cm), periaortic hematoma, patients with coma or altered consciousness, mesenteric or limb ischemia, acute renal failure, and patients who were treated surgically.

Endovascular stent grafting is done with the stent covering the dissection leading to thrombosis causing closure of false lumen.

Open surgical repair is rarely done in type B patients. It may be needed in those patients with genetic condition like Marfan's syndrome in whom endovascular repair is difficult.

Several trials have compared medical management with endovascular stent grafting in uncomplicated patients with type B aortic dissection demonstrating that at 2 years there is no difference in survival in either of the endovascular versus medical groups (89% versus 96%) [37]; however at 5 years the occurrence of the aortic complications is reduced in the endovascular group improving late outcome [38].

#### **7.2 Long-term management**

Optimal blood pressure control is needed to prevent recurrence or aneurysm formation. This is best achieved by oral combination antihypertensive therapy often including oral beta-blockers. Target blood pressure of less than 120/80 mmHg is preferred.

**75**

*Aortic Dissection*

**8. Prognosis**

*DOI: http://dx.doi.org/10.5772/intechopen.89210*

**8.1 Type a aortic dissection patients**

and 3-year survival of 68.7 + 19.8% [39].

**8.2 Type B aortic dissection**

endovascular approach [40].

Anis Shaikh and Ghulam Naroo\*

Rashid Hospital, Dubai, United Arab Emirates

provided the original work is properly cited.

\*Address all correspondence to: gynaroo@dha.gov.ae

**Author details**

At discharge transesophageal ECHO (TEE), magnetic resonance imaging (MRA), or CT angiography should be performed to detect for any leak, and serial images should be done at 3, 6, and 12 months to look for any recurrence, expansion, aneurysmal formation, or leak. MRA is preferred to TEE as is it noninvasive. In

Untreated patients with type A dissections have a mortality rate of 1–2% per hour because of its association with high risk of complications of aortic rupture, tamponade, aortic regurgitation, ischemic complications of myocardial infarction, and stroke [24]. According to the IRAD follow-up study of 303 patients with type A dissection who were discharged from the hospital, surgically treated patients were 273 (90.1%), and medically treated patients were 30 (9.9%). Surgically treated patients had a 1-year survival of 96.1 ± 2.4% and 3-year survival of 90.5 + 3.9%, whereas the medically treated type A dissection patients had a 1-year survival of 88.6 + 12.2%

Uncomplicated type B patients have an overall survival rate of 90% with imme-

However in type B patients with complications of aortic rupture, expansion of dissection or ischemic complications of organ hypoperfusion the mortality rates were high. According to the IRAD study, the overall inhospital mortality rate was 13% during the first week, for all type B aortic dissection patients. Mortality rate in type B dissection patients with complications, undergoing surgical management, was 32.1%, whereas in those treated with medical management alone, the mortality rate was 9.6% and was 6.5% for those treated with endovascular approach [36]. The 3-year survival rate for type B patients who were discharged from the hospital according to the IRAD registry was 77.6 ± 6.6% for medically treated patients, 82.8 ± 18.9% for surgically treated patients, and 76.2 ± 25.2% for those treated with

diate medical management with effective control of blood pressure [36].

Bina Nasim, Anas Mohammad, Sardar Zafar, Laji Mathew, Ahmed Sajjad,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

patients with renal impairment, MRI can be done without gadolinium.

Screening of first-degree relatives should be performed with transthoracic ECHO (TTE) to look for aortic aneurysm.

#### *Aortic Dissection DOI: http://dx.doi.org/10.5772/intechopen.89210*

At discharge transesophageal ECHO (TEE), magnetic resonance imaging (MRA), or CT angiography should be performed to detect for any leak, and serial images should be done at 3, 6, and 12 months to look for any recurrence, expansion, aneurysmal formation, or leak. MRA is preferred to TEE as is it noninvasive. In patients with renal impairment, MRI can be done without gadolinium.
