The primary risk factors for anastomotic leakage at the aortic root are the vulnerable vascular tissues at the anastomosis site, aortic disease caused by non-specific inflammation, poor vascular anastomosis technology, and infection . Currently, anastomotic leakage is preliminarily divided into three types : type I, where the leakage is located at the anastomosis of the proximal ascending aorta, and the shunt goes into the right atrium from the aortic root while using the Cabrol shunt, resulting in heart failure; type II, where the leakage is located at the anastomosis of the ascending aorta, resulting in blood entering the aneurysm wrap to form a local pseudoaneurysm; and type III, where the leakage orifice is usually located at the anastomosis between the aortic arch and the intraoperative stent.
Cases 1 and 2 were diagnosed with type II and I anastomotic leakage, respectively. Case 1 presented with a sudden-onset chest pain, which is easily misdiagnosed as a new aortic dissection, acute coronary syndrome, or acute pulmonary embolism. It might be related to the following factors: (1) a sudden increase in blood pressure led to a significant incremental shunting into the aortic wrap cyst, then an obvious compression to adjacent tissue operated with a small Cabrol shunt; (2) the large shunting resulted in a decrease in coronary blood flow during diastole. Case 2 presented with severe heart failure associated with a significant increase in the Cabrol shunt due to a large anastomotic leakage.
A routine physical examination revealing a continuous murmur around the aortic valve region can aid in anastomotic leakage diagnosis . Early postoperative echocardiographic and CTA findings of color shunting or high-density contrast of anastomosis and Cabrol shunting were signs of bleeding. If Cabrol shunting is present in the echocardiogram and an anastomotic leakage is not easily detected, the sonographer should carefully look for the leakage to avoid misdiagnosis. Transcatheter closure is the preferred procedure for high-risk patients who cannot tolerate secondary thoracotomy [2, 5]. The selection of the occluder also differs according to the leakage location, shape, and size. Currently, the commonly used devices include the VSD occluder, PDA occluder, and Amplatzer vascular plug (AVP). One of the technical difficulties in applying the occluder is that the scar tissue in the anastomotic leakage area is hard and inelastic; thus, it is difficult for the delivery sheath or guide catheter to pass through the leakage. To provide sufficient supporting force, it is conventional to use a hard guide wire or establish an intra-arterial track to ensure that the delivery system crosses the leakage. AVP or Amplatzer Duct Occluder II (ADO-II) is generally selected for sealing the currently reported case of aortic root anastomotic leakage. The advantages of ADO II are that the delivery sheath is thin, and its trafficability is good. Besides, the delivery sheath is flexible, and it can be guided by an ultra-smooth guidewire; thus, it is easy to pass through the small anastomotic leakage due to a lack of elasticity. The only shortcoming was that the detaining plate was large, and there was a risk of affecting the true lumen and branch blood flow after occlusion. The VSD occluder and domestic PDA occluder had a covered membrane structure, requiring a large-sized delivery system. The anastomotic leakage in our patients was large, and both occluders could pass through the leakage. Case 1 developed an ascending aortic pseudoaneurysm, with a large effective aneurysm cavity and regular shape. The guidewire track could be established to provide adequate support of the sheath tube, without the risk of puncturing the pseudoaneurysm. Therefore, a symmetrical VSD occluder was implanted. In case 2, anastomotic leakage caused shunting between the aortic root and right atrium, and the leakage was located above the left coronary sinus in a tunnel shape. To avoid affecting the left coronary artery opening, a domestic PDA occluder was appropriate.
In conclusion, focusing on the clinical manifestations and imaging diagnosis of patients post-aortic dissection surgery is important for early detection of disease progression. The occluder and interventional approach should be individually selected. The short-term efficacy of transcatheter closure is definite, and further follow-up is needed for long-term clinical outcomes.