Minimally Invasive Ventricular Assist Device Surgery

*Marina Comisso, Andrea Montalto, Francesca Nicolò, Romina Pantanella and Francesco Musumeci*

### **Abstract**

Heart failure is a growing disease that affects millions of people around the world. Heart transplantation is currently the therapy of choice for these patients. However, the lack of donors has forced the physician to evolve another kind of therapy such as ventricular assist device (VAD) as a bridge to transplant to compensate the lack of organs. Ventricular assist devices are today a successful therapy for the treatment of heart failure; the evolution of these devices and their progressive miniaturization have allowed an evolution of their implantation technique. To date, therefore, in addition to the traditional implant through sternotomy, there are more mini-invasive implant techniques. The purpose of the treaty is to describe these techniques, the implantation sites, and the benefits they can bring to patients.

**Keywords:** LVAD, minimally invasive, heart failure, ventricular assist device

#### **1. Introduction**

Heart failure is a chronic progressive disease characterized by decreased pump function. This may lead to venous congestion and also to hypoperfusion due to low cardiac output with severe organ comorbidities. Modern conservative therapies for heart failure have improved outcomes in adult patients [1]. Despite medical advances in treating this condition, the disease itself remains a progressive condition. For treating end-stage heart failure, cardiac transplantation remains the gold standard. Despite this evidence, cardiac transplantation as a therapeutic option is limited by donor organ shortage and is therefore limited to patients younger than 65 years [2]. However a promising alternative to cardiac transplantation is ventricular assist device (VAD) implantation. In consideration of these problems, the number of VAD implantations has exceeded the number of cardiac transplantations [3]. This therapeutic trend, i.e., the increasing number of patients who undergo VAD implantation also as a destination therapy (DT), has led to an obvious longer duration of the assistance period with the cardiovascular assistance system. This has also led to a change in the basal characteristics of patients who (especially DT patients) are increasingly older, are more fragile, have greater comorbidities, and, consequently, may have a higher incidence of surgical complications [4]. For several years the choice approach for VAD implantation was sternotomy. However, destination therapy patients suffered a greater intraoperative risk and increased mortality [5]. Nonetheless, Slaughter showed that treatment with VADs significantly increased survival of DT patients. At that time the sternotomy approach was mandatory due to the size of the VADs [6]. Technological progress has allowed a miniaturization of the devices and their better hemodynamic performance. This has allowed the development of mini-invasive implant techniques that allow a lower surgical risk for patients, less trauma, less incidence of bleeding, and obviously less patient stay in intensive therapy [7]. The purpose of this chapter is to describe the mini-invasive VAD implantation techniques and to describe the possible benefits that these techniques can bring to the patient's outcome.

### **2. Indication and standard approach**

The indications for the implantation of left ventricular device mainly concern patients suffering from left ventricular failure with ejection fraction ≤25% and a preserved right ventricular function (**Table 1** summarizes the main indications as indicated by the European guidelines on heart failure 2016) [8]. The standard approach for left ventricular assist device (LVAD) implantation is full sternotomy; it is done as the "first choice" in many centers around the world based on the long-term experience. The advantages of this approach are various: certainly full sternotomy provides the best anatomical overview of the heart and the major vessel and structures; moreover full sternotomy allows to approach different procedures that can be correlated and necessary to the LVAD implantation such as closure of septal defects, repair of the tricuspid valve, or ligation of the left atrium due to atrial fibrillation [9]. The classical implant operation through median sternotomy also involves the use of the heart-lung machine; the operation is divided into three main steps:


The cannulation sites to establish the heart-lung machine are classically the right atrium and ascending aorta. The main advantages in using the heart-lung machine are two: the first one is the possibility to view and resect the trabeculae that could later cause blood turbulence and thrombus formation; the second one is the possibility to do intraoperative ventricular inspection if there's echocardiography evidence of left ventricle thrombus. However the standard surgical approach has several disadvantages: sternotomy causes pericardial adhesions and possible dangerous conditions in case of reoperations (e.g., in case of transplantation in BTT patients or in the case of pump exchange). Moreover, sternotomy leads to greater risk of postoperative bleeding, sternal infections, and wound dehiscences and therefore increases the patient's surgical trauma and risk of secondary right heart failure [7].

As previously mentioned traditionally, the implantation of the LVAD is performed with the help of the heart-lung machine. It is known, however, that this machine plays an important role in the activation of inflammatory mediators, increased pulmonary vascular resistance, platelet activation, coagulopathy, and impaired renal function [10]. The patient population that requires VAD implantation often has evidence of end-organ dysfunction, including liver congestion, renal insufficiency, and pulmonary edema. VAD placement under cardiopulmonary

**3**

two steps.

complications [11].

*Indication for implantation of LVAD.*

**Table 1.**

aortic calcification and aneurysm [12].

2.Outflow graft (OG) insertion.

3.Driveline insertion.

1.Inflow cannula and pump insertion.

The LVAD implantation is divided into three steps:

*Minimally Invasive Ventricular Assist Device Surgery DOI: http://dx.doi.org/10.5772/intechopen.90911*

bypass (CPB) often exacerbates these pre-existing conditions, resulting in postoperative coagulopathy, bleeding, and worsening right heart failure. VAD implantation without the use of CPB could help to minimize these postoperative

**3. Minimally invasive LVAD implantation (off-pump technique)**

Minimally invasive implantation techniques require patient assessment and evaluation. Echocardiography helps identify patients with valvular disease who need concomitant valve procedure and would preferably be approached through a standard midline sternotomy. In the presence of left ventricle thrombus, an onpump approach should be performed for thrombus removal. Noncontrast chest computed tomography is helpful in determining which intercostal space to be used and whether an anterolateral or lateral mini-thoracotomy should be utilized (most of the time, fifth or sixth intercostal space). Chest computed tomography will also be useful for the evaluation of the outflow aortic anastomosis site and to rule out

The minimally invasive implantation procedure could be done for the first

*Cardiac Surgery Procedures*

**2. Indication and standard approach**

is divided into three main steps:

2.Tunneling of the driveline.

outcome.

with VADs significantly increased survival of DT patients. At that time the sternotomy approach was mandatory due to the size of the VADs [6]. Technological progress has allowed a miniaturization of the devices and their better hemodynamic performance. This has allowed the development of mini-invasive implant techniques that allow a lower surgical risk for patients, less trauma, less incidence of bleeding, and obviously less patient stay in intensive therapy [7]. The purpose of this chapter is to describe the mini-invasive VAD implantation techniques and to describe the possible benefits that these techniques can bring to the patient's

The indications for the implantation of left ventricular device mainly concern patients suffering from left ventricular failure with ejection fraction ≤25% and a preserved right ventricular function (**Table 1** summarizes the main indications as indicated by the European guidelines on heart failure 2016) [8]. The standard approach for left ventricular assist device (LVAD) implantation is full sternotomy; it is done as the "first choice" in many centers around the world based on the long-term experience. The advantages of this approach are various: certainly full sternotomy provides the best anatomical overview of the heart and the major vessel and structures; moreover full sternotomy allows to approach different procedures that can be correlated and necessary to the LVAD implantation such as closure of septal defects, repair of the tricuspid valve, or ligation of the left atrium due to atrial fibrillation [9]. The classical implant operation through median sternotomy also involves the use of the heart-lung machine; the operation

1.Connection between the left ventricle (LV) and inflow cannula.

3.Anastomosis of the outflow cannula to the ascending aorta.

The cannulation sites to establish the heart-lung machine are classically the right atrium and ascending aorta. The main advantages in using the heart-lung machine are two: the first one is the possibility to view and resect the trabeculae that could later cause blood turbulence and thrombus formation; the second one is the possibility to do intraoperative ventricular inspection if there's echocardiography evidence of left ventricle thrombus. However the standard surgical approach has several disadvantages: sternotomy causes pericardial adhesions and possible dangerous conditions in case of reoperations (e.g., in case of transplantation in BTT patients or in the case of pump exchange). Moreover, sternotomy leads to greater risk of postoperative bleeding, sternal infections, and wound dehiscences and therefore increases the patient's surgical trauma and risk of secondary right heart failure [7]. As previously mentioned traditionally, the implantation of the LVAD is performed with the help of the heart-lung machine. It is known, however, that this machine plays an important role in the activation of inflammatory mediators, increased pulmonary vascular resistance, platelet activation, coagulopathy, and impaired renal function [10]. The patient population that requires VAD implantation often has evidence of end-organ dysfunction, including liver congestion, renal insufficiency, and pulmonary edema. VAD placement under cardiopulmonary

**2**

#### **Table 1.** *Indication for implantation of LVAD.*

bypass (CPB) often exacerbates these pre-existing conditions, resulting in postoperative coagulopathy, bleeding, and worsening right heart failure. VAD implantation without the use of CPB could help to minimize these postoperative complications [11].
