*4.1.2 Elective PCI in high-risk patients and left main procedures*

Other studies described the use of ECMO in elective, high-risk, complex PCI. In their single-center prospective investigation on the use of ECMO in these patients,

Tomasello et al. [21] published their findings. 12 consecutive patients with complicated coronary artery disease who were at high risk for surgical revascularization underwent initiation of femoro-femoral VA ECMO before the indexed PCI. All patients responded favorably to the procedure, and there was only one access site hematoma that did not need to be transfused. At the 6-month follow-up, no deaths or MI were reported. Authors proposed that ECMO might serve as a viable substitute to ensure PCI success in unsuitable surgical candidates.

#### *4.1.3 Complicated PCI needs surgical intervention*

Following percutaneous coronary intervention (PCI), complications are often successfully managed in the catheterization laboratory, but certain complications require emergent surgical intervention. One of the most dreadful, albeit rare, complications is coronary artery perforation, which occurs from 0.1% to 3.0% [22]. Patients who have developed mechanical complications produced iatrogenically during diagnostic coronary angiography (CA) and PCI are usually in critical clinical status and require immediate corrective therapy, including inotropic support and mechanical ventilation. In the worst-case scenario, mechanical assist systems such as IABP or ECMO are required in hemodynamically unstable patients [23].

#### **4.2 High-risk TAVI and ECMO support**

Although transcatheter aortic valve implantation (TAVI) is an excellent alternative procedure for high-risk patients with severe symptomatic aortic stenosis, it is often associated with life-threatening complications. TAVI can cause profound hemodynamic perturbation in the perioperative period. VA-ECMO can be used to provide cardiorespiratory support during this time, either prophylactically or emergently. Michael et al. [24] described the utilization of ECMO for patients who had significantly high mean EuroSCORE and had undergone TAVI procedures. Postoperative outcomes were broadly comparable between TAVI patients who did not require ECMO and ECMO patients who had significantly higher mean EuroSCORE. Elective use of ECMO is usually considered in patients with severe pulmonary hypertension (over 60 mmHg) and/ or markedly decreased left ventricular ejection fraction (LVEF under 20%) [25]. In selected cases, it may be advocated to avoid consequences of intraoperative complications, emergency VA-ECMO associated with higher mortality [24, 26].

#### **4.3 ECMO support for postinfarct VSD**

F. Ramponi et al. reported two cases with successful use of VA-ECMO in two high-risk patients' postinfarction ventricular septal defect (VSD) and CS, with 80 % calculated mortality risk by logistic EuroSCORE. Both cases were in detrimental biventricular failure that was treated successfully with VA ECM surviving to hospital discharge [27].

#### **4.4 ECMO and acute pulmonary embolism**

The prognosis is dismal for patients who present with a massive acute pulmonary embolism (PE) exacerbated by right ventricular (RV) failure and CS [28]. Thrombolysis or embolectomy must be performed immediately, but due to logistical or hemodynamic instability, these therapeutic procedures may be postponed.

*Venoarterial Extracorporeal Membrane Oxygenation in Cardiac Surgery DOI: http://dx.doi.org/10.5772/intechopen.106823*

As a stabilizing measure or stepping stone to additional therapies, the use of MCS in these situations is crucial [29]. In cases of RV failure brought on by pressure overload related to pulmonary obstruction, VA-ECMO is the best course of action. Few reports showed successful use of percutaneous VA-ECMO as an adjunct to thrombolytic therapy for circulatory collapse secondary to massive PE [30]. Indeed, successful rescue therapy with ECMO has been described in several cases of life-threatening PE [31, 32], even in patients with acute cardiopulmonary collapse [33]. In some cases, complete lysis of pulmonary artery clots has been reported after a few days of ECMO and heparin treatment [31, 34, 35].

#### **4.5 ECMO and heart transplantation**

In such cases, ECMO could be used as a bridge to heart transplantation or ventricular assist device (VAD) insertion in INTERMACS class I patients or as a bridge to a decision when the prognosis is uncertain [36–40]. Patients receiving ECMO assistance must stay in the intensive care unit, and since the duration of ECMO support is shorter than that of VADs, making transplantation or switching to a VAD is more urgent [41]. The effectiveness of ECMO as a bridge therapy varies widely and is mostly influenced by the characteristics of the pre-ECMO patient and the availability of organs in situations where transplantation is the eventual goal. Additionally, primary graft failure (PGF) after heart transplantation is also treated with ECMO assistance [42, 43]. Patients with PGF who require ECMO have a poorer overall survival rate than patients without PGF. Patients with ECMO-supported PGF, however, have equivalent long-term survival to non-PGF transplant recipients who live past the immediate post-transplant period [43, 44].

### **5. Intraoperative VA-ECMO**

Advances in ECMO technology have led to a broader application of this technique. One example is the intraoperative use of VA-ECMO instead of classical cardiopulmonary bypass (CBP).

We reported two cases where patients underwent coronary artery bypass grafting (CABG) under the support of VA-ECMO in the setting of CS complicating acute myocardial infarction [45]. One of these is a 57-year-old male with multiple comorbidities. Admitted as a case STEMI complicated by CS while undergoing primary PCI. Eventually, he needed a further support with peripheral VA-ECMO. Keeping target ACT over 180 seconds and the target a (aPTT) between 60 and 80 seconds. Coronary angiography showed left main and three-vessel CAD not amenable for PCI. The patient was kept on ECMO support and CABG was done 24hrs after. Surgery was done as beating heart while on ECMO without conversion to conventional CPB. ACT value was kept as routine above 300 seconds. Intraoperatively, VA-ECMO flow has been optimized by adjusting the inotropic support of dopamine and noradrenaline infusion to keep mean arterial pressure (MAP) above 65 mmHg. Hemostasis was achievable while keeping ACT of 180 seconds. After revascularization, intraoperative transesophageal echocardiography (TEE) showed distended left ventricle (LV) and low-velocity time integral 9 cm (VTI); therefore, we decided to keep the ECMO support after revascularization. Decannulation of VA-ECMO was done on the third postoperative day. IABP was removed on the fourth postoperative day. The patient survived to discharge.

In primary PCI, VA-ECMO is a rescue measure for CS. Cases that require emergency surgical revascularization can be carried out utilizing the ECMO circuit instead of instituting CPB circuit, and by this means, the procedure is carried out with less aortic manipulation, prompter revascularization, and less priming volumes; therefore, it needs less anticoagulation, potentially reducing coagulopathy and attenuating systemic inflammatory response [46].
