Emergency Cardiac Transplantation After Unsuccessful Coronary Artery Bypass Grafting For Left Main Coronary Artery Occlusion During Percutaneous Transluminal Coronary Angioplasty
J Bonatti, H Antretter, S Watzka, C H?nn, V M?ger, O Dapunt
aneurysm, aorta, bypass surgery, cardiac, cardio-pulmonary, cardiopulmonary bypass, cardiothoracic, carotid, chest, heart, heart-lung machine, medicine, surgery, thoracic, valve, vascular, vessel
J Bonatti, H Antretter, S Watzka, C H?nn, V M?ger, O Dapunt. Emergency Cardiac Transplantation After Unsuccessful Coronary Artery Bypass Grafting For Left Main Coronary Artery Occlusion During Percutaneous Transluminal Coronary Angioplasty. The Internet Journal of Thoracic and Cardiovascular Surgery. 1996 Volume 1 Number 2.
At present acute complications of percutaneous transluminal coronary angioplasty (PTCA) requiring surgical intervention are reported to be in the range of 3-7% . Thrombotic occlusion and/or dissection of a coronary vessel during PTCA is an well accepted indication for acute coronary artery bypass grafting (CABG), if percutaneous interventional techniques fail to restore adequate blood flow. The resuscitation methods most commonly applied during preparation for emergency CABG are inotropic support, intraaortic balloon pumping, or cardiopulmonary resuscitation if necessary. According to a recent trial series, installation of percutaneous cardiopulmonary bypass systems after acute complications in the cardiac catheterization laboratory .seems to be a helpful option. Heart transplantation for acute ischemic cardiac events is still rarely performed  but, if carried out, success rates seem to be promising .
A 37-year-old male patient presented to a private cardiologist with a history of typical angina on exertion which had lasted for 4 weeks. The patient reported a history of hypercholesterolemia and smoking 20 cigarettes per day for 9 years. Physical examination was unremarkable and showed no evidence of congestive heart failure. Exercise test revealed ST-segment depression of 0.5 mV in the anterior wall region at 100 W. Coronary angiography revealed a dominant left coronary artery with an left anterior descending artery (LAD) tandem stenosis (95% proximally and 60% distally). No other significant stenoses could be demonstrated. The anterolateral wall was hypokinetic, ejection fraction was 60%. PTCA was indicated to be performed at our center.
The procedure was carried out on November 23, 1994. At 8:15 a.m. the Departments of Cardiac Surgery and Anesthesia were informed about the procedure. At 8:36 a.m. repeat coronary angiography via the right femoral artery was completed, and the diagnosis was confirmed (Fig. 1). After placement of a Swan-Ganz catheter and a transvenous pacemaker through the right femoral vein, an Atherocath(r) guiding catheter was advanced to the left main coronary artery (LMCA). While further advancing this catheter, dissection of the LMCA occurred at 8:48 a.m.(Fig. 1) .
The patient immediately turned unresponsive and pulseless with respiratory arrest. ECG monitoring showed ventricular fibrillation. Cardiopulmonary resuscitation was started according to standard guidelines, but the patient remained in ventricular fibrillation despite electrical countershocks and additional medical therapy. Together with the cardiac surgeon and the anesthesiologist on call, it was decided to install a percutaneous extracorporal membrane oxygenation (ECMO) device. After insertion of a 19Fr and a 21Fr cannula into the right femoral artery and vein, assisted circulation using a Biomedicus(r) centrifugal pump with a Medtronic Maxima(r) oxygenator and a heparin-coated line could be started 31 minutes after LMCA dissection. ECMO flow was 4.5 l/min.
On ECMO the patient was transported to the next available operating room where sternotomy for acute CABG was carried out at 10:30 a.m. Saphenous vein grafts were harvested from the left leg, and the aorta and right atrium were cannulated for the installation of cardiopulmonary bypass, which was started 126 minutes after the PTCA complication (10:54 a.m.). After aortic cross-clamping, warm retro- and antegrade blood cardioplegia was applied. Saphenous vein grafts to the LAD and circumflex artery were sewn in during intermittent cold retro- and antegrade blood cardioplegia. Controlled reperfusion was carried out using warm substrate-enriched blood cardioplegia retrogradely, antegradely and via the saphenous vein grafts. After completion of the graft to aorta anastomoses at 12:48 a.m., the heart showed totally inadequate rhythm and output which did not improve after 90 minutes of reperfusion on cardiopulmonary bypass. The patient developed coagulopathy and massive bleeding. A left ventricular vent was placed via the right superior pulmonary vein and connected to the Biomedicus pump. After decannulation at 2:18 p.m., percutaneous ECMO was restarted. At 4:12 p.m. the patient was transported to the ICU.
Considerable bleeding during the ICU course required extensive application of blood products. As no improvement of ventricular function was seen in repeated transesophageal echocardiographic examinations, the patient was listed for special urgency cardiac transplantation at 7:00 p.m. Resternotomy to control bleeding was performed at 8:30 p.m. An organ offer was obtained from Eurotransplant at 11:55 p.m., and the next day at 3:17 a.m. the heart was harvested at a distant center from where it was sent to our institution by plane.
Orthotopic cardiac transplantation was carried out using a standard technique. The recipient aorta was declamped at 6:51 a.m., which resulted in a donor heart ischemic time of 3 hours and 34 minutes. Cardiac transplantation was completed uneventfully, and the ECMO cannulas were removed. Gross pathological examination and histology of the excised recipient heart revealed a massive left ventricular myocardial infarction with hemorrhage (Fig. 2). LMCA dissection and thrombosis could be seen clearly (Fig. 3), the saphenous vein grafts showed no abnormalities.
The patient required only mild inotropic support during the immediate postoperative period. He was extubated on the first postoperative day. A pulmonary infiltrate, which was noticed eight days after transplantation, was successfully treated with ceftazidime and vancomycin. On the fifteenth postoperative day, the patient developed atrial fibrillation and cardiac enlargement on chest x-ray. After endomyocardial biopsy, which showed an acute rejection grade IIIA (ISHLT guidelines) , he received methylprednisolone 500 mg iv. for 3 days. The control biopsy was unremarkable. Four days before discharge, acyclovir was started for herpes simplex stomatitis. The patient was discharged in good condition on postoperative day twenty-six.
We describe a case of dissection and occlusion of a dominant left main coronary artery during PTCA. Immediate ventricular fibrillation was treated by CPR and installation of percutaneous arteriovenous ECMO in the cardiac catheterization laboratory. After unsuccessful acute CABG, emergency cardiac transplantation was carried out with a satisfactory outcome.
Prophylactic measures during PTCA
PTCA in patients with a dominant left main coronary artery has to be regarded as a high-risk procedure. One might discuss whether in such high-risk cases surgical backup other than the “next available operating room” system, as used in the case described above, should be aimed at. If in the case of PTCA emergencies percutaneous techniques fail to restore adequate blood flow to the ischemic myocardium, acute CABG should ideally be carried out in the catheterization laboratory. A prerequisite would be an adequately adapted angio suite. At present this is not the case at our institution. Also a more rigorous standby with an operating room (OR) available immediately in a PTCA emergency is no longer feasible at our hospital because of OR capacity problems. To date, the literature seems to provide no definite recommendations concerning surgical standby for percutaneous transluminal coronary angioplasties [7,9,16].
A recently reported method to protect the heart from ischemia during PTCA is synchronized coronary venous retroperfusion[8,13]. Clinical trials seem to justify this prophylactic application in high-risk PTCA patients [8,13]. Whether percutaneous placement of a coronary sinus catheter and retrograde perfusion of the ischemic myocardium would be feasible in emergencies such as that described in our case report needs to be evaluated. As a coronary retroperfusion system is not available at our interventional cardiology department, discussions about the benefit of such a device during preparation for acute CABG are only of speculative value.
ECMO for catheterization laboratory emergencies:
In our case percutaneous arteriovenous ECMO was installed in the catheterization laboratory with the intention of providing optimal cerebral protection. This goal was successfully achieved. The disadvantage of percutaneous ECMO installation seems to be prolonged myocardial ischemic time although in our case the installation required only little additional time. Results of percutaneous cardiopulmonary bypass for cardiac catheterization laboratory emergencies was described by Grambow et al . In his series of 30 patients, survival was 0% in patients who presented with cardiac arrest and 26%, respectively, in patients in whom ECMO was installed for cardiogenic shock. In the case described above, the patient exhibited ventricular fibrillation and was treated with adequate cardiopulmonary resuscitation measures while the percutaneous cardiocirculatory support system was placed. The eventually good outcome speaks for the application of such a device in the case of a severe PTCA emergency.
Centrifugal mechanical support as bridge to transplantation
Morbidity associated with the use of centrifugal pump systems is high . Extensive bleeding was the major problem of the patient discussed here. As no alternative cardiocirculatory supporting device was available at the time of the emergency, the only feasible option was to keep the patient on percutaneous ECMO.
Acute CABG after PTCA complications
One might ask the question whether in cases of acute dissection or thrombotic occlusion of a dominant left main coronary artery with a warm myocardial ischemic time of more than two hours, acute coronary artery bypass grafting would still be a beneficial option. Regarding our case retrospectively, the primary insertion of a left or biventricular assist device [6,14,15] with the possibility of mobilizing the patient and listing him electively for cardiac transplantation might have been an alternative. However, the availability of such devices is limited at our institution. Concerning the prognosis of acute CABG in general, the rate of recruitable collaterals during acute left main coronary artery occlusion seems to be unpredictable. Therefore, to our opinion acute CABG was justified.
Acute cardiac transplantation
Champagnac et al.  described a survival rate of 70% after acute cardiac transplantation for cardiogenic shock. Their series of fifteen patients included two cases of PTCA complications requiring emergency cardiac transplantation. Six patients received mechanical assistance using different devices for a mean duration of 4.5 days. Compared to these data, the period of mechanical assistance in our case was very short. Three case reports in the literature [1,2,11] also describe successful acute cardiac transplantation after ischemic cardiac events including PTCA complications. Emergency heart transplantation therefore seems to be a realistic therapeutic option in cases of severe myocardial ischemic damage during percutaneous coronary interventions.
This case report demonstrates that severe ischemic damage to the left ventricle resulting from left main coronary artery dissection during PTCA can be successfully treated by acute cardiac transplantation, if a bridging device is available in principle and if a donor heart can be obtained within a reasonable time span. To our knowledge, transplantation of the donor heart occurred in our case after one of the shortest waiting periods reported so far.