Case Report:
A 61-year-old woman presenting with dyspnea and acute chest pain on an emergency base rapidly was diagnosed with anterolateral ST-elevation myocardial infarction (Creatinin kinase (CK); 2498 U/l, CK-MB; 173U/l, Troponin T; 5668 ng/l). Coronary angiography revealed long segment severe stenosis of left anterior descending (LAD), severe stenosis in the proximal marginal branch of circumflex artery (RM), and segment 2 of the right coronary artery (Fig 1). Due to CS, Impella CP (by Abiomed) was implanted in the cath lab through the right femoral artery as ”bridge therapy,” and the patient was immediately transferred to undergo CABG. Salvage on-pump CABG was performed with coronary bypasses to the LAD by the left mammary artery, to RM and posterior descending artery by a saphenous vein segment. In order to avoid damage to the Impella during aortic cross clamping and proximal anastomosis of the bypass grafts Impella CP was removed. Due to severe LV dysfunction venous-arterial extracorporeal membrane oxygenation (va-ECMO; Centrimag, by Abbott) via the right femoral vessels was inserted. Myocardial markers showed a satisfactory course 6 hours after CABG with clear drop in CK (1504 U/l) and CK-MB (58U/l).
On 7th postoperative day (POD), however, transthoracic echocardiography (TTE) showed still severely impaired systolic LV function with global hypokinesia and moderate distention (ejection fraction; EF 20%), while respiratory function showed no signs of impairment. Therefore, it was decided to attempt a switch from va-ECMO to isolated temporary left ventricular support and unloading by Impella 5.0 in the intention of downgrading the level of support. In the operation room, a 10mm vascular graft was anastomosed to the right axillary artery. However, under transesophageal echocardiography (TEE) as well as fluoroscopic control the Impella 5.0 could not be introduced beyond the subclavian artery. In this situation, the strategy was changed, and the arterial line of the va-ECMO was first transferred from the femoral artery to the axillary artery via already existing prosthesis. Then a further 10mm silver-coated prostheses was sewn on the right common femoral artery, and Impella 5.0 was successfully implanted.
Nevertheless, the weaning of va-ECMO was impossible with maximum flow rates through Impella 5.0 ranging 2.0-2.5 L/min under P3-4 and additional va-ECMO support of ca. 2.5 L/min (Fig. 2a) . The patient was transferred to the ICU and demonstrated signs of right ventricle (RV) failure with central venous pressure 23 mmHg when va-ECMO weaning below 1.5 l/min was attempted. Therefore, a percutaneous RV assisted device (Tandem-Heart ProtekDuo by LivaNova; run by Centrimag pump) with integrated oxygenator was implanted via the right internal jugular vein on 10th POD, allowing termination of va-ECMO therapy and enabling Impella 5.0 flows reaching a full range of 5.0 L/min for the first time (Fig. 2b) .
On 14th POD, TEE demonstrated an external compression of RA and RV. After hematoma removal via re-sternotomy TEE showed sufficient recovery of LV and Impella could be removed. The oxygenator was withdrawn from the RVAD support on 27th POD. TTE demonstrated LVEF recovered to 50% with hypokinesis at the septal and posterior wall, mild mitral regurgitation, mild to moderately depressed RV function. After pharmacological conditioning with Levosimendan, Tandem-Heart was successfully removed on 31st POD. Due to wound healing disorders a further treatment by plastic and reconstructive surgery became necessary and the patient was finally discharged for rehabilitation on the 160thpostoperative day.