In which type of aortic dissection does the origin typically occur in the descending aorta?

Type B aortic dissection typically originates in the descending aorta. This condition involves a tear in the aortic intima that allows blood to flow between the layers of the aorta, creating a false lumen. In Type B dissections, the dissection starts just beyond the left subclavian artery and extends downwards along the descending aorta.

Understanding the classification of aortic dissections is crucial for identifying appropriate management and surgical interventions, as Type A dissections often involve the ascending aorta and may require surgical repair due to their more critical nature. In contrast, Type B dissections primarily affect the descending aorta and can sometimes be managed medically, depending on the patient's condition and any complications.