Giacomo Bortolussi

HeartWare Ventricular Assist Device as Bridge to Transplant in Children and Adolescents

Limited options do exist for mechanical circulatory support as a bridge to transplantation in the pediatric population. This is especially true when it comes to intracorporeal technologies. We describe our successful experience with the use of HeartWare ventricular assist devices (HeartWare, Inc., Framingham, MA, USA) in three patients <16 years of age, as a successful and feasible bridge to transplant in patients weighing greater than 20 kg.

Hemorrhage and thrombosis with different LVAD technologies: a matter of flow?

BACKGROUND Much of the morbidity and mortality associated with ventricular assist devices (VADs) is due to haemorrhagic and thrombotic complications. To manage antithrombotic therapy, interactions between the patient and pump should be better understood. METHODS We have compared the Jarvik 2000, an axial flow left ventricular assist device (LVAD), with the HeartWare ventricular assist device (HVAD) centrifugal pump, regarding conventional laboratory findings, thromboelastometric and aggregometric tests. RESULTS Patients with the Jarvik 2000 experienced a significant reduction in platelet count following implantation, a phenomenon not seen with the HeartWare model. Conversely, we observed that levels of platelet activation, as assessed by a platelet function analyzer, and activation of the coagulation system, as assessed by thromboelastometry, were significantly greater in the HeartWare group. CONCLUSIONS It seems that axial flow pumps, being more destructive on blood cells, tend to reduce platelet numbers. On the other hand, centrifugal flow is associated with a hypercoagulable state, possibly resulting from the activation of the coagulation system in the absence of platelet destruction.

Impact of vacuum-assisted closure therapy on outcomes of sternal wound dehiscence †

OBJECTIVES Sternal wound dehiscence (SWD) after cardiac surgery is a rare but serious condition associated with considerable costs and morbidity. We sought to evaluate the results of the introduction of vacuum-assisted closure (VAC) therapy in the management of sternal wound dehiscence, compared with those of previous conventional treatments. METHODS We retrospectively collected 7148 patients who underwent cardiac surgery at our institution between January 2002 and June 2012. A total of 152 (2.1%) patients had a sternal wound dehiscence: 107 were treated with conventional treatments (Group A) and 45 were managed with VAC therapy (Group B). Patients were stratified according to preoperative risk factors and type of sternal wound dehiscence (superficial or deep; infected or not) and compared by means of a propensity-matched analysis. A cost analysis was also performed. RESULTS Forty-five patients of each group matched for all preoperative risk factors and type of sternal wound dehiscence. SWD-related mortality rate was significantly lower in Group B (11 vs 0%; P = 0.05). Incidence of mediastinitis (P < 0.0001), sepsis (P = 0.04), delayed SWD infection (P = 0.05), other complication (P = 0.05), surgical sternal revision (P = 0.04) and surgical superficial revision (P < 0.0001) were all significantly lower in Group B. Mean patient cost was 31 106€ in Group A and 24 383€ in Group B, thus achieving a mean saving of 6723€ per patient. CONCLUSIONS In our experience, the use of VAC therapy for the management of SWD was considerably effective in decreasing mortality (SWD related), incidence of complications and need for surgical procedures; thus, leading to a significant reduction of costs.

Less invasive implantation of HeartWare left ventricular assist device

Mechanical support by means of ventricular assist devices is at present the most promising alternative of efforts aimed at increasing the supply of donor organs. The support of the left dysfunctional ventricle enables appropriate haemodynamic stabilization and recovery of secondary organ failure, often present in these severely ill patients. The current results of left ventricular assist device (LVAD) therapy for bridge to transplantation are excellent when compared with the outcome without the availability of this therapy. Additionally, a rapid extubation of these patients has demonstrated to be efficient in cardiac surgery for faster recovery and rehabilitation. Consequently, in recent years, surgical objectives have become much more clearly defined, and the concept of less invasive cardiac surgery can be applied to make this operation less complicated, anatomically focused with a greater clinical impact. We describe an LVAD implantation technique, applying the concept of less invasive cardiac surgery, consisting in the association of reduced surgical approaches, off-pump implantation and reduced administration of heparin dose, in order to achieve rapid extubation and rehabilitation of the patient, preserving low morbidity, and still meeting all the goals of the standard procedure.

Implantation of the HeartWare HVAD: from full sternotomy to less invasive techniques.

Left ventricular assist devices (LVADs) are increasingly used for the treatment of end-stage congestive heart failure, both as a bridge to transplantation and as destination therapy (1). The HeartWare HVAD (HeartWare Inc, Framingham, MA, USA) is a continuous centrifugal-flow left ventricular assist device with a magnetic levitating rotor pump. The pump weighs just 140 g and its small design allows for intra-pericardial placement. It is powered by two portable batteries that connect to the pump via a driveline tunneled through the abdominal wall, and these can be worn on a belt, allowing out of hospital support (2). The HVAD is currently indicated for use in patients with refractory end stage congestive heart failure. We outline two techniques for implanting the HeartWare HVAD: via a full median sternotomy, and using minimal access incision (Video 1). Video 1 Implantation of the HeartWare HVAD: from full sternotomy to less invasive techniques. Case 1 Clinical vignette A 56-year-old man with refractory shock due to end-stage dilated cardiomyopathy was transferred to our institution. He was initially placed on peripheral veno-arterial Extra-Corporeal Membrane Oxygenator (ECMO), as a bridge to decision, and then underwent implantation of a HeartWare HVAD as a bridge to transplantation. After three months of HVAD support, he underwent successful heart transplantation.

From bench to bedside: Can the improvements in left ventricular assist device design mitigate adverse events and increase survival?

OBJECTIVE In vitro tests demonstrated that the new cone-bearing configuration of the Jarvik 2000 (Jarvik Heart Inc, New York, NY) left ventricular assist device exhibits better hydraulic efficiency than the previous pin-bearing design. We investigated the long-term outcomes of patients who received the Jarvik 2000 left ventricular assist device, depending on bearing design. METHODS A retrospective review of prospectively collected data from 18 centers included in the Italian Registry was performed. From May 2008 to September 2013, 99 patients with end-stage heart failure were enrolled. Patients were divided into 2 groups according to their Jarvik 2000 suspending mechanism: Group pin included patients with pin bearings (May 2008 to June 2010), and group cone included patients with newer cone bearings (July 2010 to September 2013). The 2 groups did not differ significantly in terms of baseline characteristics. RESULTS A total of 30 of 39 patients (group pin) and 46 of 60 patients (group cone) were discharged. During follow-up, 6 patients underwent transplantation, and in 1 patient the left ventricular assist device was explanted. The cumulative incidence competing risk of the entire cohort for noncardiovascular-related death was 28% (20%-40%); the cumulative incidence competing risk for cardiovascular-related death was 56% (42%-73%): 71% in group pin versus 26% in group cone (P = .034). The multivariate analyses confirmed that the pin-bearing design was a risk factor for cardiovascular death, along with Interagency Registry for Mechanically Assisted Circulatory Support class. Right ventricular failures and ischemic and hemorrhagic strokes were significantly higher in group pin. CONCLUSIONS Patients with the new pump configuration showed a better freedom from cardiovascular death and lower incidence of fatal stroke and right ventricular failure. Further studies are needed to prove the favorable impact of pump-enhanced fluid dynamics on long-term results.

Less-invasive off-pump ventricular assist device implantation in regional paravertebral analgesia

We describe the clinical course and treatment of a 58-year-old male with a primary cardiogenic shock, who underwent a minimally invasive off-pump ventricular-assist-device (VAD) implantation with the aid of paravertebral regional analgesia. He was extubated soon after the procedure, in the operating room, with the aim to reduce the right ventricle impairment. We illustrate how a minimally invasive implant may improve the clinical outcomes of VAD patients shortening their return time to active life.

The Coagulative Profile of Cyanotic Children Undergoing Cardiac Surgery: The Role of Whole Blood Preoperative Thromboelastometry on Postoperative Transfusion Requirement

The objective of this study is to evaluate the preoperative coagulation pattern and its association to postoperative blood products transfusion in children with congenital heart disease (CHD), focusing on cyanotic patients (oxygen saturation, SATO 2  < 85%). From January to August 2014, preoperative standard coagulation tests and rotational thromboelastometry assays were performed on 81 pediatric patients (<16 years old) who underwent surgery for CHD with the aid of cardiopulmonary bypass. Sixty patients (74%) were acyanotic and 21 (26%) cyanotic. Mean age at time of surgery was 7.9 months (interquartile range 2.9-43.6 months). Cyanotic patients had a significantly higher hematocrit (P < 0.001), a reduced prothrombin activity (PT) (P = 0.01) level, and a lower platelet count (P = 0.02) than acyanotic patients. An inverse linear association was found between patients SATO2 and clot formation time (CFT) (INTEM, P = 0.001, and EXTEM, P < 0.0001). A direct linear association was found between patients SATO2 and maximum clot firmness (MCF) (INTEM, P = 0.04, and EXTEM, P = 0.05). Preoperative cyanosis was also associated with a lower median MCF in FIBTEM (P = 0.02). Cyanotic patients required more frequent postoperative transfusions of fibrinogen (7/21 patients, 33% vs. 4/60 patients, 6.7%, P = 0.01) and fresh frozen plasma (14/21, 67% vs. 25/60, 42%, P = 0.08). Patients with a lower presurgery PT and platelet count subsequently required more fibrinogen transfusion P = 0.02 and P = 0.003, respectively); the same goes for patients with a longer CFT (INTEM, P = 0.01 and EXTEM, P = 0.03) and a reduced MCF (INTEM, P = 0.02 and FIBTEM, P = 0.01) as well. Cyanotic patients showed significant preoperative coagulation anomalies and required a higher postoperative fibrinogen supplementation. The preoperative MCF FIBTEM has become an important factor in our postoperative thromboelastometry-guided transfusion protocols.

Single vs double antiplatelet therapy in acute coronary syndrome: Predictors of bleeding after coronary artery bypass grafting.

AIM To investigate the contribution of anti-platelet therapy and derangements of pre-operative classical coagulation and thromboelastometry parameters to major bleeding post-coronary artery bypass grafting (CABG). METHODS Two groups of CABG patients were studied: Group A, treated with aspirin alone (n = 50), and Group B treated with aspirin and clopidogrel (n = 50). Both had similar preoperative, clinical, biologic characteristics and operative management. Classic coagulation parameters and rotational thromboelastometry (ROTEM) profiles were determined preoperatively for both groups and the same heparin treatment was administered. ROTEM profiles (INTEM and EXTEM assays) were analyzed, both for traditional parameters, and thrombin generation potential, expressed by area-under-curve (AUC). RESULTS There was no significant difference between rates of major bleeding between patients treated with aspirin alone, compared with those treated with aspirin and clopidogrel (12% vs 16%, P = 0.77). In the 14 cases of major bleeding, pre-operative classic coagulation and traditional ROTEM parameters were comparable. Conversely we observed that the AUC in the EXTEM test was significantly lower in bleeders (5030 ± 1115 Ohm*min) than non-bleeders (6568 ± 548 Ohm*min) (P < 0.0001). CONCLUSION We observed that patients with a low AUC value were at a significantly higher risk of bleeding compared to patients with higher AUC, regardless of antiplatelet treatment. This suggests that thrombin generation potential, irrespective of the degree of platelet inhibition, correlates with surgical bleeding.

Left Ventricular Assist Device End-to-End Connection to the Left Subclavian Artery: An Alternative Technique

We describe a modified implantation technique for the HeartWare ventricular assist device. We access the apex through a left minithoracotomy. The outflow graft is tunneled through a small incision in the fourth intercostal space and then subcutaneously to the subclavian region. After division of the left axillary artery, an end-to-end anastomosis is performed to the proximal part, and the distal vessel is connected end-to-side through a fenestration in the outflow graft. We believe that this technique, particularly suitable for redo scenarios or severely calcified aorta, achieves a more direct blood flow into the aorta and reduces cerebrovascular events while avoiding excessive flow to the arm.