Interdisciplinary Expert Consensus Document on Management of Type B Aortic Dissection

Study Questions:

This is an expert consensus document developed by a group of European experts in the field of aortic dissection in an effort to provide state-of-the-science recommendations for treatment of type B aortic dissection.

Methods:

Much of the methodology and format are similar to that of guidelines from the American Heart Association, American College of Cardiology, and other relevant societies; however, this manuscript was not developed in conjunction with the major societies. The methodology involved review of all relevant literature published between 2006 and 2012, dealing with the topic of prognosis and treatment of acute and chronic type B aortic dissection. Data were then extracted regarding procedural success and outcomes, and a series of recommendations was provided.

Results:

A total of 63 studies were included in the final review. Studies included data on 1,548 medically treated patients (1,480 acute; 68 chronic or subacute); 1,706 were patients treated with open surgery (1,529 acute, 177 chronic dissections) and 3,457 patients were treated with thoracic endovascular repair (TEVAR). Type B aortic dissection was considered complicated if associated with a malperfusion syndrome or hemodynamic instability. Severe hypertension (not responding to ≥3 antihypertensive agents if not pre-existing) was considered a sign of hemodynamic instability or renal malperfusion. An increase in periaortic hematoma or hemorrhagic pleural effusion on serial computed tomography (CT) was also considered an indication for surgery. Medical therapy was undertaken in 1,480 acute dissection patients in whom early mortality was 6.4% and the cumulative rate of stroke and spinal cord ischemia was 4.2% and 5.3%. At five years, survival ranged from 70% to 89%. Freedom from aortic adverse events (aortic death, rupture, new dissection, enlargement, or reintervention) ranged from 75% to 88.5% in the surveyed studies. Data on outcomes of TEVAR for treatment of acute type B dissection were available for 2,359 patients from 30 studies. Early mortality was 10.2%, and early stroke and spinal ischemia after treatment were 4.9% and 4.2%. At five years, survival ranged from 56.3% to 89%, and freedom from subsequent aortic events ranged from 45% to 77%. Data were available for 1,529 patients with acute type B dissection who underwent open surgical repair. Total mortality was 17.5%, with early stroke rate of 5.9% and spinal cord ischemia of 3.3%. Five-year survival ranged from 44% to 64.8%, and freedom from subsequent events ranged from 58.7% to 68%.

Conclusions:

Specific panel recommendations for treatment of acute type B dissection include: uncomplicated type B dissection should be treated medically. TEVAR (when feasible) should be first-line treatment for complicated acute type B dissection. Aneurysmal evolution and rupture may occur in the absence of warning symptoms, and regular imaging follow-up is essential with CT or magnetic resonance imaging, and is recommended at admission, 7 days, discharge, 6 weeks, and annually thereafter independent of treatment strategy. Recommendations for treatment and follow-up of chronic type B dissection include: medical management unless complications develop, with tight control of blood pressure. Symptom recurrence, aneurysmal dilation (>55 mm) or annual increase >4 mm should be considered instability, and an indication for TEVAR or open surgery. In uncomplicated chronic type B dissection, annual clinical imaging follow-up is recommended irrespective of initial aortic diameter and initial treatment.

Perspective:

This is a thorough review of the available modern literature regarding management of acute and chronic type B aortic dissection. From this panel’s review, the bottom line remains that type B dissection is initially best handled medically unless complications of aortic instability, hemorrhage, hemodynamic compromise, malperfusion, or progressive expansion occur, at which point TEVAR should be considered the first-line option for treatment. Lifelong annual imaging follow-up of type B dissection is necessary.

Keywords: Stroke, Endovascular Procedures, Follow-Up Studies, Pleural Effusion, Hematoma, Magnetic Resonance Imaging, Consensus, Prognosis, Spinal Cord Ischemia, Tomography, Hypertension


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