Perigraft-to-Right Atrial Shunt for Aortic Root Hemostasis

Abstract

We have modified the technique of perigraft-to-right atrial shunt to control hemorrhage after aortic root replacement. We have performed this operation in 2 patients, including one who had acute aortic dissection and another who underwent aortic root replacement and single-vessel coronary artery bypass. Neither patient required re-exploration for bleeding, and both shunts closed spontaneously during the follow-up period without any related complications. With this modification, even in the presence of concomitant coronary artery bypass grafting, hemostasis was achieved with preservation of the proximal vein graft. (Tex Heart Inst J 2003;30:205–7)

Diligent surgical technique with careful attention to technical detail is certainly the most important tool in preventing postoperative hemorrhage; nevertheless, hemorrhage cannot always be prevented. Cabrol and colleagues ¹ first presented the concept of perigraft-to-right atrial shunt in 1978 to decompress the space that resulted from suturing the remaining aneurysmal wall around an ascending aortic graft. Cabrol's group accomplished this by draining blood from inside the aneurysm into the right atrium while using the classic Bentall technique to perform aortic root replacement. ¹ Now, 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. Creating a pericardial pouch around the prosthetic graft to drain into the right atrium and thereby control bleeding has been described. ^2–4

Case Reports and Surgical Technique

Patient 1

In September 2002, a 72-year-old woman had acute type A aortic dissection complicated by cardiac tamponade; she was referred to our institution from another hospital within 12 hours of occurrence. The leaking ascending aorta was replaced with a 26-mm Dacron graft while the patient was under deep hypothermic circulatory arrest. After reperfusion, the patient had persistent inaccessible bleeding from the proximal anastomosis. We obliterated the transverse sinus by approximation of the left atrial roof and the right pulmonary arteries with 5-0 Prolene running suture. Then we sewed a piece of glutaraldehyde-preserved bovine pericardial patch to 1) the pericardial reflection below the brachiocephalic vein superiorly, 2) the main pulmonary trunk medially, 3) the right ventricular outflow tract and the right atrium inferiorly, and 4) the superior vena cava laterally. A small remaining portion of pericardium was sutured over the atriotomy site after discontinuation of cardiopulmonary bypass and decannulation of the right atrium (Fig. 1). Blood in the perigraft pouch was drained into the right atrium from the previous cannulation site. The bleeding was satisfactorily controlled and the operation was completed smoothly. The drainage from the mediastinal drain was 100 mL during the first 24 hours postoperatively. Echocardiographic examination was performed before discharge, 7 days postoperatively, and did not reveal any residual shunt. When last seen in June 2003, the patient was well.

Fig. 1 Photograph shows the perigraft-to-right atrial shunt.

B = brachiocephalic vein; P = pericardial patch; RV = right ventricle

Patient 2

In May 2002, an 81-year-old man underwent total aortic root replacement with use of a Freestyle® stentless aortic root bioprosthesis (Medtronic, Inc.; Minneapolis, Minn) for severe aortic stenosis. At the same time, he underwent coronary artery bypass grafting with a saphenous vein graft to the left anterior descending artery for single-vessel disease. As the cross-clamp was released, uncontrollable bleeding from the aortic root occurred. The aortopulmonary window was approximated and the transverse sinus was closed with 5-0 Prolene sutures as described above. A patch of bovine pericardium was sutured to 1) the pericardial reflection below the brachiocephalic vein, 2) the neoaorta medial to the vein graft, 3) the right atrium, and 4) the superior vena cava (Figs. 2 and 3). The pericardial pouch was connected to the atriotomy site after decannulation. Hemostasis was achieved immediately after protamine administration. The drainage from the mediastinal drain was 150 mL during the first 24 hours after surgery. Computed tomographic (CT) scanning before discharge revealed some contrast material in the pericardial pouch between the aorta and the superior vena cava (Fig. 4). The patient's postoperative course was uneventful. A follow-up CT scan, taken 3 months later, showed no abnormal contrast material in the pericardial pouch. The patient was well when last seen in July 2003.

Fig. 2 The perigraft-to-right atrial shunt was constructed to the medial wall of the neoaorta (N), excluding the vein graft (star).

P = pericardial patch; RV = right ventricle

Fig. 3 The drawing illustrates the relation of the right atrium (RA), the neoaorta (N), the vein graft (star), and the bovine pericardial patch. The small round circle on the right atrium indicates the previous cannulation site.

Fig. 4 A computed tomographic scan shows contrast material (arrow) between the aorta (A) and the superior vena cava (star) in the bovine pericardial pouch.

Discussion

Hemorrhage is a substantial cause of morbidity and mortality in ascending aortic and aortic root surgery, particularly after complex reconstruction or prolonged cardiopulmonary bypass. After aortic root surgery, persistent bleeding from the anastomosis remains a problem despite meticulous surgical technique and the use of pharmacologic hemostatic agents. In the past, the Cabrol shunt was used in the classic Bentall operation by suturing the remaining aneurysmal wall around an ascending aortic graft to drain blood from inside the aneurysm into the right atrium. ¹ However, most surgeons have now adopted aortic root replacement with direct coronary artery implantation to eliminate pseudoaneurysm formation at the coronary and the aortic anastomoses. ⁵ Because the diseased aorta is completely removed, there is no option to wrap the graft with the aneurysmal shell or aortic wall, as is done in the Bentall operation. Several modified techniques have been described to control bleeding. ^2–4

The perigraft-to-right atrial shunt in our 1st patient closed spontaneously during the 1st postoperative week. The shunt in the 2nd patient was patent before discharge, as shown by a CT scan, which revealed some contrast material between the aorta and the superior vena cava. After 3 months, the CT scan detected no abnormal contrast material. Cabrol and colleagues ¹ commented that the periprosthetic-to-right atrial fistulas usually close soon after the operation; however, they can be surgically closed relatively easily if they become hemodynamically problematic. ²

Recently, Posacioglu and co-authors ⁶ reported the use of autologous pericardium for perigraft-to-right atrial shunting in acute dissection. In one of their patients, they performed coronary bypass grafting from the right brachiocephalic trunk to the right coronary artery, along with homograft aortic root replacement. ⁶ This combination was similar to that which we performed in our 2nd patient, as was the basic concept for accomplishing hemostasis with a pericardial patch. However, our patch procedure was slightly different. In both of our patients, we obliterated the aortopulmonary window and the transverse sinus by sewing the main pulmonary trunk to the neoaorta and the right pulmonary artery to the left atrial roof to establish the posterior wall of the pouch. In addition, the pericardial patch was sewn to the wall of the neoaorta medially to exclude the vein graft. This modification enabled us to achieve hemostasis with preservation of the proximal vein graft, even in the presence of a concomitant aortocoronary bypass graft.