Abstract
Postoperative ischemia may complicate cardiac surgery, despite myocardial protection and recent technical developments. Its medical management in the intensive cardiac care unit is usually efficient, although sometimes it requires the revision of the surgical site. In other cases, urgent coronary angiography and subsequent coronary stenting may resolve the situation. Ostial stenosis of coronary anastomoses is a well-known uncommon but dramatic complication after aortic surgery causing myocardial ischemia. Cases of effort angina have been described several months after surgery, but in some cases, acute myocardial infarction may occur days or weeks after intervention. We here describe an anteroseptal ST-elevation myocardial infarction soon after a Bentall aortic root replacement due to compression of the left main ostium by surgical glue, which has been effectively treated by emergency coronary stenting. This case highlights the importance of a joint management of acute myocardial ischemia after cardiac surgery by the cardiac surgeon and the interventional cardiologist.
1
Introduction
Bentall–De Bono surgical intervention is a widespread technique for the treatment of aortic aneurysm (or more rarely, dissection) in association with ectasia of the aortic valve ring with valve insufficiency, consisting of complete replacement of the ascending aorta and implantation of a prosthetic valve. The technique was first described by the two surgeons who gave it their own name . Briefly, it consists in using a composite graft, in which an aortic prosthesis tube is fixed to the aortic prosthetic valve, and then the ostia of the coronary arteries are anastomosed to the side of the aortic prosthesis. The modified procedure, in which coronary artery circulation is maintained by removing a full-thickness “button” of aorta surrounding the coronary ostia and subsequent easier reimplantation of the coronary arteries, is also often used . Coronary artery reimplantation has rarely been associated with hemorrhage, particularly due to arterial leakage. In order to treat this complication, surgical glue is occasionally used. However, extrinsic compression of the coronary arteries has been reported following the use of this surgical glue several weeks or months after the surgical procedure. We report a case of early ST-elevation anterior myocardial infarction after a Bentall aortic root replacement due to compression of the left main (LM) ostium, successfully treated by coronary artery stenting.
2
Case report
A 65-year-old woman, dyslipidemic, was admitted to our cardiac surgery for a planned Bentall–De Bono intervention. She had undergone periodic echocardiographic examination of the ascending aorta since 2000. In June 2008, she underwent a coronary angiography and aortography, which showed normal coronary arteries in a left dominant system ( Fig. 1 A ) with an aneurysmatic dilatation of the ascending aorta with a maximal diameter of 56 mm. Echocardiography showed a left ventricle of normal volumes and contractile function, slightly hypertrophic, with an ascending aorta aneurysm (maximum diameter 53 mm) and dilatation of the aortic arch (41 mm), with slight dilatation of the aortic bulb (40 mm) and of the sinus–tubular junction (41 mm), a calcified bicuspid aortic valve with moderate flow gradient (12 mmHg) and moderate insufficiency.
The intervention was performed in the traditional way, through medial sternotomy access, in total cardiopulmonary bypass between common right femoral artery and right atrium. Myocardial protection was obtained by infusing 1800 mL of crystalloid cardioplegia (Custodiol HTK solution, Essential Pharmaceutics) through the aortic root and coronary sinus and also with topical cooling with ice in the pericardial cavity.
On inspection, a macroscopic dilatation of the aorta was noted, extending from valve level to about 1 cm proximal to the rising of anonymous trunk. After the incision of the aneurysm, inspection of the native aortic valve showed that it was diffusely calcific and bicuspid with a median raphe between noncoronary and right coronary cuspid. The coronary ostia were isolated according to the button technique: the right coronary ostium appeared hypoplastic and fibrotic; thus, it was bound, and a saphenous vein graft (SVG) to the right coronary artery (RCA) was confectioned. The proximal anastomosis between aortic annulus and valved tube was realized during distal aortic clamping. Hole on the prosthesis was performed by electrocautery, and the left coronary button was sutured using polypropylene suture 5/0 (Prolene, Ethicon). No technical problems occurred, such as stretching or kinking of the LM coronary artery. Subsequently, in order to protect the anastomoses, 9 mL of Bioglue surgical glue (Cryolife) was applied to the sutures with empty cardiac cavities. When an esophageal temperature of 24°C was obtained, on cerebral protection in retroperfusion through the superior cava vein, the circle was arrested for 14 min of duration and the terminoterminal anastomosis between the prosthetic tube and the ascending aorta was realized with Prolene 4/0. The weaning from extracorporeal circulation needed inotropic support with dopamine.
Thirty minutes after the end of procedure, as the patient was transferred to the Cardiosurgical Intensive Care Unit (CCU), a new left bundle branch block appeared on electrocardiogram (ECG). Subsequently, ventricular fibrillation with cardiocirculatory arrest occurred. It was promptly treated with cardiac massage and synchronous shock at 200 J and intravenous lidocaine boluses. The ECG showed signs of transmural ischemia in the anteroseptal leads ( Fig. 2 A ). A transesophageal echocardiography was performed, which showed a hyperechogenic mass on the anterolateral wall of the aortic prosthesis with a medium diameter of 11 mm, extended to the interatria septum and mitralic annulus ( Fig. 2 B). The patient was therefore reopened, but there was no visible hematoma at the site. Thus, due to ECG abnormalities and electrical instability, the patient was brought to the hemodynamic unit to perform an emergency angiographic control. Coronary angiography performed through the right femoral artery showed proximal occlusion of the SVG for the RCA and a critical severe stenosis (80%) of the LM body ( Fig. 1 B,C), not present in the preoperative angiogram. Using a JL 4 guide catheter, two 0.014″ guides BMW Universal were inserted in the left anterior descending and circumflex arteries. Predilatation of the LM coronary artery (culprit lesion) was performed using a Falcon Forte balloon (Invatec, Roncadelle, Italy) 4.0×10 mm at 6 atm, and a Skylor bare metal stent (Invatec) 5.0×16 mm at 14 atm was deployed. The final angiographic result on the LM coronary artery was excellent ( Fig. 1 D). It was decided not to percutaneously treat the bypass occlusion; since RCA was not dominant, ECG suggested LM to be the culprit vessel, and the patient did not exhibit any sign of right ventricular failure (final blood pressure was 130/80 mmHg).
