Cardiac allograft vasculopathy is a severe complication after heart transplant, and is the major cause of death in patients surviving 1 year after transplant. We present a 59-year-old patient undergoing off-pump, coronary artery bypass surgery, 8 years after heart transplant. Owing to toxic liver disease, the lipid lowering therapy with statins had to be stopped 6 years after transplant, and coronary artery disease developed rapidly within 2 years. Off-pump, coronary bypass surgery was performed using a new, multisuction cardiac positioner; a disposable stabilizer; and a proximal seal system to avoid clamping of the aorta. The patient received 3 bypass grafts: the left internal thoracic artery; to the left anterior descending coronary artery; 1 saphenous vein graft to the marginal branch of the circumflex artery; and 1 saphenous vein graft to the right coronary artery. His postoperative course was uneventful.
Key words : Cardiac allograft vasculopathy, Heart transplant, Coronary artery disease, Bypass coronary surgery
Cardiac allograft vasculopathy after heart transplant is the most common cause of death in this cohort of patients; it occurs in 50% of heart transplant recipients after 5 years (1). Lesions range from diffuse, intimal thickening of the coronary arteries, to focal stenoses (like in coronary artery disease in nontransplanted patients). As the transplanted heart is denervated, patients usually do not present with chest pain. Treatment strategies include percutaneous transluminal coronary angioplasty, coronary artery bypass grafting, and retransplant. Owing to donor shortage and adverse outcome, retransplant is not the first therapeutic option (2). However, percutaneous transluminal coronary angioplasty presents a high restenosis rate in heart transplant recipients; and coronary artery bypass grafting has a superior, long-term outcome compared to stent grafting (3, 7, 8).
Our hypothesis was that the associated risks of a coronary surgical procedure could be reduced, should it be performed without cardiopulmonary bypass, and without cross-clamping of the aorta. We report a 59-year-old patient with asymptomatic coronary 3-vessel disease who was treated with off-pump, coronary artery bypass grafting 8 years after heart transplant.
Our patient underwent orthotopic heart transplant due to ischemic cardiomyopathy in 1999. He received the heart of a 39-year-old male who died of suicide. In a routine coronary angiogram in 2004, coronary artery disease was not identified. However, at this time, the patient developed ascites (caused by toxic liver disease), so all medication (excepting his immunosuppressive drugs) had to be stopped. A transjugular, intrahepatic, portosystemic, stent shunt and Cooley-shunt operation were performed as palliative means to control portal hypertension caused by liver cirrhosis.
In the following coronary angiogram, in 2007; severe, cardiac, allograft vasculopathy had developed with 90% stenosis in the left anterior descending artery, 95% stenosis in the circumflex artery, and 80% stenosis in the right coronary artery. The ejection fraction was 66%. Echocardiography revealed left ventricular hypertrophy, but good contractility in all myocardial areas.
Off-pump coronary artery bypass grafting was scheduled. The patient’s immunosuppressive therapy was switched from sirolimus/mycophenolate mofetil to tacrolimus/mycophenolate mofetil because sirolimus is related to delayed wound healing.
After median sternotomy pericardial adhesions were dissected, 10 000 units of heparin were injected, and 5-0 GORE-TEX-sutures (W. L. Gore & Associates, Inc., Newark, DE, USA) snared around the left anterior descending artery proximal and distal of the anastomosis area, which was stabilized with an Octopus stabilizer (Medtronic; Minneapolis, MN, USA). The left anterior descending artery was incised, and the left internal thoracic artery was anastomosed with 8-0 Prolene (Ethicon/Johnson & Johnson; Somerville, NJ, USA).
After that, the Tentacles device (Sumimoto Bakelite Co. Ltd; Tokyo, Japan) was used to expose the left side of the heart for the anastomosis of the saphenous vein graft to the marginal branch of the circumflex artery (Figure 1). The tentacles device (4) consists of 3 silicon suction cups that are connected to a suction tube to which a negative pressure of 300 mm Hg is applied (Figure 2). The anastomosis was performed with 7-0 Prolene. After that, a Heartstring II Proximal Seal system (Boston Scientific; Natick, MA, USA) was used for the central anastomosis of the vein to the aorta to avoid partial clamping. A second vein graft was anastomosed to the right coronary artery in the same fashion. The patient was hemodynamically stable during the whole procedure, and did not need any blood transfusions. He was extubated on the next day and discharged home in good condition 10 days later. Laboratory values of creatine-kinase and troponin were only slightly elevated after the surgical procedure and decreased constantly.
After 8 weeks, when wound healing was completed, the patient was reswitched to his normal immunosuppression protocol, consisting of sirolimus and mycophenolate mofetil. This combination might provide superior protection against the progression of cardiac allograft vasculopathy, and is associated with less nephrotoxicity (5, 6).
Our patient developed coronary artery disease primarily due to the presence of transplant vasculopathy. However, this process could be possibly accelerated owing to the absence of ACE-inhibitors and HMG-CoA-reductase-inhibitors in his medication, which had to be stopped after his toxic liver disease. Percutaneous transluminal coronary angioplasty was not a therapeutic option, because of the severity of the coronary artery disease. The restenosis rate when bare metal stents are used is 31%, and 15% when drug eluting stents are used (7, 8). Thus, the best long-term outcome is probably achieved with coronary artery bypass grafting (3). However, the use of cardiopulmonary bypass is a high-risk for transplant patients: tissue fragility due to steroid use can cause bleeding complications, which occurs more often in on-pump than in off-pump cases (9, 10). Furthermore, heart transplanted patients are at risk of infection because of immunosuppression, and should be extubated as soon as possible to avoid pneumonia. It has been documented that pulmonary function recovery is better after off-pump coronary artery bypass grafting (11). Third, these patients often have impaired kidney function as an adverse effect of the use of calcineurin inhibitors, such as cyclosporine or tacrolimus. Cardiopulmonary bypass may be responsible for kidney failure, and renal failure rate is lower when off-pump surgery is performed (12). Finally, cross-clamping of the aorta, which may cause neurologic complications, is avoided totally in off-pump surgery when the heartstring is used.
Recent technical progress has enabled us to perform off-pump coronary artery bypass grafting without great risk in redo-procedures, such as cardiac allograft vasculopathy. Myocardial, renal, neurologic, and bleeding complications caused by cardiopulmonary bypass are avoided. Thus, transplant patients presenting with coronary artery disease may benefit from off-pump coronary surgery.
Volume : 7
Issue : 4
Pages : 261 - 263
From the 1Department of Cardiac Surgery; 2Department of Anaesthesiology;
Grosshadern University Hospital, LM-University, Munich, Germany
Address reprint requests to: Andres Beiras-Fernandez MD, PhD, Department of Cardiac Surgery, Grosshadern University Hospital, LM-University Munich, Marchioninistrasse 15, 81377 Munich, Germany
Phone: +49 89 70975074
Fax: +49 89 70971847
Figure 1. Anastomosis of the saphenous vein graft to the marginal branch of the circumflex artery; the field of the anastomosis is stabilizedwith the octopus stabilizer; the left side of the heart is exposedwith the tentacles device (arrows).
Figure 2. Tentacles. Three suction cup positioning device.