Initial approaches for less invasive LVAD surgery were hampered by large devices which even required external or abdominal pump placement [7, 12, 13]. Hill et al. introduced the concept of less invasive implantation in three patients receiving the paracorporeal Thoratec LVAD (Thoratec Corporation, USA) [12]. They advocated a combination of a right minithoracotomy and a left subcostal incision. Of 3 LVAD patients with dilated cardiomyopathy, 2 experienced postoperative bleeding and needed drainage (by chest tubes) and blood transfusions. One patient died (for technically unrelated reasons), but the other 2 were able to safely undergo a heart transplant. After those early results reported by Hill et al., the new minimally invasive technique was applied by other groups using new-generation devices, with significant improvements. Gregoric et al. described a less invasive approach for implanting the Heartmate II LVAD (Thoratec Corporation, USA) [13]. They advocated a subcostal incision, followed by separating the interfering muscles (stopping extraperitoneally above the transverse muscle fascia). Then the pleura should be opened, in order to allow access to the pericardium and the left ventricular apex below. Before LVAD placement, a pocket must be created subcostally for the pump housing. A parasternal minithoracotomy on the third right intercostal space is done in order to perform the aortic anastomosis of the outflow graft [38]. Overall, Gregoric et al. performed the procedure successfully in three patients [14].

More recently, Anyanwu et al. also successfully applied this sternotomy-avoiding technique with minor modifications [15]. Samuels et al. used a less invasive approach including an upper hemisternotomy, a left-sided lateral thoracotomy, and a partial midline upper abdominal pre-peritoneal laparotomy; the upper pre-peritoneal incision created the LVAD pocket in the subrectus muscle plane, while 2 lateral dissections connected to both inflow and outflow pathways [16]. An alternative approach was described by Riebandt et al. from Vienna: in the setting of severe thoracic aortic calcification, they anastomosed the outflow graft to the right subclavian artery [17].

The first pump to be completely placed inside the pericardium by less invasive surgery was the HVAD (HeartWare Inc., Framingham, MA, USA) [9, 18–20, 36–37]. Before surgery we recommend to assess each patient by using preoperative and intraoperative checklists (◘ Tables 23.1 and 23.2). In order to perform the implant by LIS, two independent surgical steps have to be performed: (1) access to the apex of the left ventricle and (2) access to the upper mediastinum. While the first step is routinely performed by a left-sided thoracotomy (see ◘ Fig. 23.5), there are two different approaches to gain access to the ascending aorta: upper hemisternotomy or right-sided thoracotomy [9, 18]. Even though the sternum is preserved entirely, the right-sided thoracotomy can be associated with more pain, and also the access to the ascending aorta might be more challenging, too. Since surgical access to the ascending aorta is superior, the hemisternotomy is better suited for redo LVAD cases and concomitant procedures. This is important because a growing number of LVAD candidates already received prior surgical treatment such as coronary artery bypass grafting, valvular repairs, or replacements [21].

After checking the perioperative checklist, the procedure starts by placing the wire for venous cannulation through the right femoral vein into the right atrium. This should be performed under TEE control. In redo cases, it makes sense to place an additional wire or an arterial sheath into the right femoral artery previous to sternotomy. Afterward, the access to the ascending aorta is achieved either by hemisternotomy or right-sided thoracotomy with opening of the aorta-covering pericardium. Once the pericardial holding stitches are in place, aortic purse strings should be positioned. Ensure that there is enough space for later partial aortic clamping in order to perform outflow-graft anastomosis to the aorta. According to surgeon’s preference, arterial cannulas especially designed for MIC surgery can help to save space. By these steps, initiation of extracorporeal circulation can be achieved fast and safely in case of unexpected instability. Next the thoracotomy is performed after echo-controlled marking of the incision and thoracic projection of the apex. This is of importance as the position of the apex varies from case to case. Usually it is found in the sixth intercostal space within the intersection of the left midclavicular line. After dissection of the pectoralis muscle, the pleura is opened, and the rip spreaders (usually two) are inserted. Even if the skin incision is kept as minimal as possible, it is important to thoroughly dissect the intracostal muscles to the left midaxillary line to avoid rip fracture. After performing the thoracotomy, the apex surrounding pericardium is opened, and the epicardial HVAD sewing ring is sutured to the left ventricular apex off-pump (see ◘ Fig. 23.6).

This step can still be performed without full heparinization, reducing apical-associated bleeding. The sewing ring is primarily fixed by 12 pledget-armed epicardial sutures. Consequently, a running suture with 4-0 prolene is performed to seal the space between epicardium and sewing ring. In addition surgical glue can be used as sealant too. Next, cardiopulmonary bypass is performed targeting a mean pulmonary artery pressure of 12 mmHg. The myocardium is cored throughout the ring with the specialized tool. After coring, a careful inspection of the LV cavity should be performed in order to resect trabecular tissue that has the potential to occlude the inflow cannula. Now the HVAD pump is placed through the sewing ring into the left ventricular apex. Once the pump is placed and the apex inspected for eventual bleeding, it might be useful to vent the outflow graft for deairing LVAD and LV. Now the driveline has to be tunneled to the exit site and connected to the controller. The outflow graft is then tunneled through the pericardium and then anastomosed end to side to the ascending aorta through the upper hemisternotomy. Before securing the suture by knots, it is possible to start the LVAD at minimum speed to further deair the system through the opened anastomosis. Deairing process should be controlled by transesophageal echocardiography before opening the partial clamp. Once the anastomosis is finished and the system deaired, it is time for LVAD onset and decrease of extracorporeal circulation. For this purpose, NO application and continuous application of epinephrine support RV function during and after LVAD onset. The transition from full extracorporeal circulation to full LVAD support should be performed stepwise by surgeon, anesthesiologist, and perfusionist. In this context, a key benefit of the LIS approach is that the part of pericardium that surrounds the right ventricle remains mainly closed, preserving the natural right ventricular delimitations and thereby avoiding right ventricular dilatation. In addition, the heart remains within its original position (more or less “no-touch-technique”), which avoids the RV from failing, too. Thus, right ventricular function remains passively sustained [9].