Cabrol shunt

The Cabrol shunt or Cabrol fistula, also known as a perigraft-to-right atrial shunt, is a technique used for uncontrolled bleeding following aortic root operations.

Rationale

The Cabrol shunt is applied when bleeding from an aortic root reconstruction cannot be controlled by traditional means (e.g. suturing, hemostatic agents). The principle of this shunt is to return shed arterial blood accumulating in the perigraft space automatically to the right atrium (or other venous site) ^1,2. This technique decompresses the perigraft space, thus reducing tension aton the suture lines, which may result toin pseudoaneurysm formation ³. The shunt usually closes during the first postoperative week ⁴.

Procedure

Early Cabrol shunts were performed to decompress the false lumen of an aortic dissection complicated by excessive haemorrhage ⁵. This was accomplished by draining blood from inside the aneurysm into the right atrium while using the classic Bentall technique to perform aortic root replacement. Nowadays, most surgeons have adopted aortic root replacement with direct coronary artery implantation, which leaves no residual tissue to wrap around the prosthetic graft to create a fistula. A pericardial pouch around the prosthetic graft is usually created. This produces a potential space (perigraft space) between the prosthetic graft and pericardial pouch. Several modifications to the Cabrol shunt, which include the use of autologous pericardium or dacron graft to serve as a shunt between the perigraft space and right atrium or other venous sites (e.g. brachiocephalic vein), have been reported ^1,6-10.  

Complications

The Cabrol shunt rarely stays open and may cause aorto-right atrial fistula (left-to-right shunt) that may result in pulmonary arterial hypertension and heart failure.

History and etymology

C Cabrol and colleagues first presented the concept of a perigraft-to-right atrial shunt in 1978 ^1,3. Since then, there have been several modifications to the procedure.