The evidence of chimney grafts in treating aortic arch diseases

Steep aortic arch (such as Type III arch) and small angle between the chimney artery and aortic arch are two anatomic conditions suitable for chimney grafts (CGs). The more the number of chimneys, the higher the incidence of endoleak and branch occlusion; thus, the triple-chimney technique should be avoided unless the lesion involves zone 0 and no other better option is available, or a pending rupture is present and requires emergent repair. For the oversize of multiple chimneys, we suggest that the aortic stent and chimney stent should be increased by 5%, respectively, on the basis of single chimney. Moreover, the direction of the chimney stent is decided by the relative position of the proximal tear in patients with dissection. When the tear is located in the anterior segment, the chimney graft should be deployed behind the aortic stent graft, close to the posterior wall of the thoracic aorta, and in front of the aortic stent grafts when the tear is located in the posterior segment. In conclusion, if the endoleak is small and the patient’s condition is stable with no obvious discomfort, for most of the patients, the endoleak will disappear spontaneously in the follow-up. If the endoleak is large, microcoil could be implanted through the narrow and long gap to block the endoleak under the guidance of ultrasound. CGs technique needs to be scrutinized continuously as new data emerge. Special configurations of aortic and chimney endograft need to be developed to better treat aortic pathologies involving supra-arch branches.