What's the treatment for aortic dissection?
The risk of death due to aortic dissection is highest in the first few hours after the dissection begins, and decreases afterwards. Because of this, the therapeutic strategies differ for treatment of an acute dissection compared to a chronic dissection. An acute dissection is one in which the individual presents within the first two weeks. If the individual has
managed to survive this window period without death, his prognosis is improved. About 66% of all dissections present in the acute phase.
In all individuals with aortic dissections, medication should be used to control high blood pressure, if present. In the case of an acute dissection, once diagnosis has been confirmed, urgent surgical consultation is warranted to repair the tear in the aorta. Surgical management is superior to medical management for an acute ascending aortic dissection. In the case of acute distal aortic dissections (abdominal aortic dissections), surgical and medical management are equivalant if there are no complications. Individuals who present 2 weeks after the onset of the dissection are said to have chronic aortic dissections. These individuals have been self-selected as survivors of the acute episode, and can be treated with medical therapy as long as they are stable.
Medical management: Medical management is appropriate in individuals with an uncomplicated distal dissection, a stable dissection isolated to the aortic arch, and stable chronic dissections. Patient selection for medical management is very important. Stable individuals who present with an acute distal dissection (typically treated with medical management) still have an 8 percent 30 day mortality. The prime consideration in the medical management of aortic dissection is strict blood pressure control. The target blood pressure should be a mean arterial pressure (MAP) of 60 to 75 mmHg. Another factor is to reduce the shear-force dP/dt (force of ejection of blood from the left ventricle). To reduce the shear force (dP/dt), sodium nitroprusside should be used with a non-selective beta blocker, such as esmolol, propranolol, or labetalol. The alpha-blocking properties of labetalol make it especially attractive in this situation. Calcium channel blockers can be used in the treatment of aortic dissection, particularly if there is a contraindication to the use of beta blockers. The calcium channel blockers typically used are verapamil and diltiazem, because of their combined vasodilator and negative inotropic effects. If the individual has refractory hypertension (persistent hypertension on the maximum doses of three different classes of antihypertensive agents), involvement of the renal arteries in the aortic dissection plane should be considered.
Endovascular Intervention: This minimally invasive procedure requires small incisions in the groin. Small wire-like, catheter devices called endoluminal stent grafts are threaded to the location of the dissection. These devices have a woven synthetic graft tip, which is deployed at the site of dissection and left in place. This provides a channel for blood to flow freely, repairing arterial leakage, and preventing pressure from rupturing the aorta. This procedure is much less invasive than the traditional open surgery, usually with a hospital stay of about 2-3 days and a recuperation period of a couple of weeks. Please note: This procedure can only be performed on specific patients based on clinical criteria, and no long-term data exists regarding its effectiveness compared to open surgery.
Open Surgical Repair: The traditional treatment technique involves opening the chest and surgical removing the dissected aorta. A synthetic graft is sewn in its place for blood to flow freely to the rest of the arterial system. This procedure often requires a hospital stay of a week or more, and recuperation can take 6-8 weeks. |
