**5. ECMO (extra corporeal membrane oxygenation)**

ECMO provides a temporary support for heart and lungs. ECMO maintains gas exchange as well as cardiac support, and is used in patients suffering from respiratory failure, cardiac failure, or both. It is used for patients who have reversible cardiopulmonary failure such as advanced heart failure, acute respiratory distress syndrome (ARDS), pulmonary embolism, septic shock syndrome, and multiple organ system failure.

Blood is drained from the body with an external pump; then blood goes through a membrane gas exchanger for oxygenation and returns to the patient's circulation (**Figure 4**).

ECMO can be applied with three different ways such as veno-arterial, veno-venous, and central way. Veno-arterial (VA) ECMO drains blood from right atrium via a femoral venous or a right internal jugular venous catheter and blood returns to the aorta via femoral arterial catheter. VA-ECMO provides cardiac as well as pulmonary support. Veno-arterial ECMO (VA-ECMO) is considered in patients with cardiopulmonary collapse and is used to support patients in cardiogenic shock [9]. In non-post-cardiotomy failure patients requiring urgent cardiac support, peripheral VA-ECMO through the femoral artery and vein is the most common approach. Peripheral VA-ECMO has limitations, including retrograde blood flow leading to inadequate LV decompression. To solve this problem, some centers utilize concurrent IABP [10] or Impella [11] support to reduce the LV after-load, and hence pulmonary edema. Veno-venous (VV) ECMO drains blood from the right atrium and blood returns to the right atrium through the femoral or jugular venous catheter. VV-ECMO requires good cardiac function and mainly uses in isolated severe respiratory failure. Veno-venous ECMO is reserved for patients in isolated respiratory failure with no significant cardiac dysfunction. Central ECMO can be applied after cardiac surgery if the heart cannot be weaned from the heart-lung machine due to post-cardiotomy syndrome. Cannulas, which are inserted for heart lung machine, can be connected to the ECMO circuit and the sternum leaves open and patient can transfer to the ICU with ECMO support for healing period.

With cardiac failure, VA-ECMO is the preferred method because it provides urgent circulatory support with oxygenation in the event of sudden heart failure, thus preventing organ damage. For this reason, it may help to support a patient who is awaiting a heart transplant.

Among other devices, one advantage of ECMO is providing hemofiltration and dialysis. The connectors have been incorporated between the oxygenator outlet and pump inlet so that a continuous renal replacement therapy (CRRT) device can be attached to the extracorporeal circuit.

In a VA-ECMO setting, when the heart has recovered, but if the lungs are still poorly functioning, the native cardiac output bounces against the pumped blood, usually in the aortic arch region. Accordingly, the coronary arteries, and to a variable degree the supra-aortic vessel as well, are provided with hypoxic blood, heart, and brain are harmed. Upper extremity cyanosis has brought up the term "Harlequin syndrome." Therapeutic options consist of a relocation of the arterial cannula in to right subclavian artery or aorta, or in converting the system into a VA-V-setting.

The healthcare team looking after patients on short-term percutaneous MCS aim to avoid any complications that may occur from being on these devices. Some of the more serious problems that may occur in these patients include: (1) bleeding especially from

**Figure 4.** ECMO.

**5. ECMO (extra corporeal membrane oxygenation)**

**Figure 3.** TandemHeart.

72 Heart Transplantation

septic shock syndrome, and multiple organ system failure.

ECMO provides a temporary support for heart and lungs. ECMO maintains gas exchange as well as cardiac support, and is used in patients suffering from respiratory failure, cardiac failure, or both. It is used for patients who have reversible cardiopulmonary failure such as advanced heart failure, acute respiratory distress syndrome (ARDS), pulmonary embolism,

Blood is drained from the body with an external pump; then blood goes through a membrane

ECMO can be applied with three different ways such as veno-arterial, veno-venous, and central way. Veno-arterial (VA) ECMO drains blood from right atrium via a femoral venous or a right internal jugular venous catheter and blood returns to the aorta via femoral arterial catheter. VA-ECMO provides cardiac as well as pulmonary support. Veno-arterial ECMO (VA-ECMO) is considered in patients with cardiopulmonary collapse and is used to support patients in cardiogenic shock [9]. In non-post-cardiotomy failure patients requiring urgent cardiac support, peripheral VA-ECMO through the femoral artery and vein is the most common approach. Peripheral VA-ECMO has limitations, including retrograde blood flow leading to inadequate LV decompression. To solve this problem, some centers utilize concurrent IABP [10] or Impella [11] support to reduce the LV after-load, and hence pulmonary edema. Veno-venous (VV) ECMO drains blood from the right atrium and blood returns to the right atrium through the femoral or jugular venous catheter. VV-ECMO requires good

gas exchanger for oxygenation and returns to the patient's circulation (**Figure 4**).

gastrointestinal system and brain. This can be a very serious problem if the bleeding happens in their brain, lungs, insertion sites of cannulae, or from gastrointestinal system. The patients should be monitored very carefully by frequent physical examinations and lab tests to make sure there is no bleeding. If there is bleeding, then medications can be given to help the blood to stop. Sometimes, surgery is needed to stop the bleeding. Blood and other blood products (such as platelets) may also need to be given if blood counts drop too low. (2) Acute renal failure may sometimes occur due to inadequate blood flow to their kidneys. With dialysis, the kidney damage may get better. However, in some cases, patients may need dialysis for the rest of their life. (3) Systemic or localized infection is another risk for these patients especiall from the insertion site. Infections in these patients can usually be treated with antibiotics. However, some infections can cause to get sick and more organ damages. (4) Leg ischemia is usually the most common problem in these patients due to insertion of the catheter or cannulas through the femoral vessels. In some cases, blood flow may be affected in lower extremity due to occlusion of the vessels and ischemia may occur. Doctors should always be aware of leg ischemia. If this happens, surgery may be needed to get blood flowing back down the leg. (5) Stroke: in patients on short-term p-MCS, stroke is another life-threating complication because of potential small blood clots. This can cause a stroke, and parts of the brain may be permanently damaged. Percutaneous MCS devices can also cause hemolysis and thrombocytopenia.

function, Impella, TandemHeart, or VA-ECMO can be quickly and easily inserted percutaneously and provide active hemodynamic support. During acutely depressed left-ventricular function, IABP may be the first treatment option for clinician, but if patients need more time for recovery or patients need stronger hemodynamic support IABP can switch to Impella or TandemHeart. If patients have respiratory failure along with cardiogenic shock, VA-ECMO

Role of Short-Term Percutaneous Mechanical Circulatory Support Devices as Bridge-to-Heart…

http://dx.doi.org/10.5772/intechopen.75094

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There are only limited studies available for survival of transplanted patients after percutaneous MCS. Jasseron et al. reported that transplantation was associated with a lower risk of mortality, even if the overall survival rate and 1-year post-transplant survival rate were inferior in patient on VA-ECMO and they suggested that transplantation may be considered to be an

Percutaneous MCS can also be used for the treatment of ventricular failure in the situation of acute allograft cardiac failure or post-transplant RV failure after cardiac transplantation. Although each percutaneous MCS device has different working mechanisms, all of them can serve as a bridge-to-bridge or bridge-to-transplant strategy. Device selection or sequential application of percutaneous MCS should be managed according to the LV function, time for

should be opted first because it provides oxygenation and good cardiac support.

and Ahmet Celik3

1 Balikesir Ataturk State Hospital, Cardiovascular Surgery Clinic, Balikesir, Turkey

3 Mersin University Faculty of Medicine, Cardiology Department, Mersin, Turkey

2 Balikesir University Faculty of Medicine, Cardiology Department, Balikesir, Turkey

[1] Jessup M, Brozena S. Heart failure. The New England Journal of Medicine. 2003;**348**:

[2] Lee MS, Makkar RR. Percutaneous left ventricular support devices. Cardiology Clinics.

[3] Thiele H, Zeymer U, Neumann FJ, et al. Intraaortic balloon support for myocardial infarction with cardiogenic shock. The New England Journal of Medicine. 2012;**367**:1287-1296

[4] Rihal CS, Naidu SS, Givertz MM, Szeto WY, Burke JA, Kapur NK, Kern M, Garratt KN, Goldstein JA, Dimas V, Tu T. 2015 SCAI/ACC/HFSA/STS clinical expert consensus statement on the use of percutaneous mechanical circulatory support devices in cardiovascu-

lar care. Journal of the American College of Cardiology. 2015;**65**:e7-e26

acceptable primary therapy in selected patients on VA-ECMO [14].

recovery, and patient's conditions.

\*, Eyup Avci2

\*Address all correspondence to: ahmetdolapoglu@yahoo.com

**Author details**

Ahmet Dolapoglu1

**References**

2007-2018

2006;**24**:265-275. Vii

Mechanical circulatory support can prevent multi-organ failure and death in patients with advanced heart failure during waiting period. Long-term continuous-flow VAD has played a major role in providing circulatory support during the waiting period prior to transplantation, but long-term LVAD must be inserted through a thoracotomy or sternotomy, which can be hazardous and time consuming. For these reasons, patients in decompensated heart failure are best served by an initial period of stabilization with temporary devices.

Most series have combined a variety of temporary devices, but few long-term devices, and the evaluations have involved all patients with cardiogenic shock regardless of the indication for and the type of mechanical support and widely varying rates of recovery have been reported. There are four commonly used types of MCS available, which is temporary and percutaneous application. But the device choice and the implantation timing are not definitely established. Data regarding percutaneous MCS devices in cardiogenic shock are limited. A meta-analysis of three randomized trials comparing TandemHeart and Impella to IABP, TandemHeart and Impella were associated with higher cardiac index, higher mean arterial pressure, lower pulmonary capillary wedge pressure, but increased bleeding complications and no difference in 30-day mortality [12].

Another trial study showed that the Impella was not associated with decreased 30-day mortality in cardiogenic shock compared to IABP [13]. Each device should be applied according to the patient's condition and time for recovery, bridge-to-long-term devices, or bridge-totransplantation. Another treatment strategy for percutaneous MCS is that we may consider to switch one device with other one depending on the indication. IABP can be opted for first option in patient with cardiogenic shock due to easy availability and rapid insertion. An IABP is simple and safe to insert, but provides little active hemodynamic support and depends on residual left ventricular function to be effective. If patients have worse left ventricular function, Impella, TandemHeart, or VA-ECMO can be quickly and easily inserted percutaneously and provide active hemodynamic support. During acutely depressed left-ventricular function, IABP may be the first treatment option for clinician, but if patients need more time for recovery or patients need stronger hemodynamic support IABP can switch to Impella or TandemHeart. If patients have respiratory failure along with cardiogenic shock, VA-ECMO should be opted first because it provides oxygenation and good cardiac support.

There are only limited studies available for survival of transplanted patients after percutaneous MCS. Jasseron et al. reported that transplantation was associated with a lower risk of mortality, even if the overall survival rate and 1-year post-transplant survival rate were inferior in patient on VA-ECMO and they suggested that transplantation may be considered to be an acceptable primary therapy in selected patients on VA-ECMO [14].

Percutaneous MCS can also be used for the treatment of ventricular failure in the situation of acute allograft cardiac failure or post-transplant RV failure after cardiac transplantation.

Although each percutaneous MCS device has different working mechanisms, all of them can serve as a bridge-to-bridge or bridge-to-transplant strategy. Device selection or sequential application of percutaneous MCS should be managed according to the LV function, time for recovery, and patient's conditions.
