Strategies for left ventricular assist device insertion after the Dor procedure

Advancements in left ventricular assist devices to prevent pump thrombosis and blood coagulopathy

Mechanical circulatory support (MCS) devices, such as left ventricular assist devices (LVADs) are very useful in improving outcomes in patients with advanced-stage heart failure. Despite recent advances in LVAD development, pump thrombosis is one of the most severe adverse events caused by LVADs. The contact of blood with artificial materials of LVAD pumps and cannulas triggers the coagulation cascade. Heat spots, for example, produced by mechanical bearings are often subjected to thrombus build-up when low-flow situations impair washout and thus the necessary cooling does not happen. The formation of thrombus in an LVAD may compromise its function, causing a drop in flow and pumping power leading to failure of the LVAD, if left unattended. If a clot becomes dislodged and circulates in the bloodstream, it may disturb the flow or occlude the blood vessels in vital organs and cause internal damage that could be fatal, for example, ischemic stroke. That is why patients with LVADs are on anti-coagulant medication. However, the anti-coagulants can cause a set of issues for the patient-an example of gastrointestinal (GI) bleeding is given in illustration. On account of this, these devices are only used as a last resort in clinical practice. It is, therefore, necessary to develop devices with better mechanics of blood flow, performance and hemocompatibility. This paper discusses the development of LVADs through landmark clinical trials in detail and describes the evolution of device design to reduce the risk of pump thrombosis and achieve better hemocompatibility. Whilst driveline infection, right heart failure and arrhythmias have been recognised as LVAD-related complications, this paper focuses on complications related to pump thrombosis, especially blood coagulopathy in detail and potential strategies to mitigate this complication. Furthermore, it also discusses the LVAD implantation techniques and their anatomical challenges.

Ventricular assist devices implantation: surgical assessment and technical strategies

Along with the worldwide increase in continuous left ventricular assist device (LVAD) strategy adoption, more and more patients with demanding anatomical and clinical features are currently referred to heart failure (HF) departments for treatment. Thus surgeons have to deal, technically, with re-entry due to previous cardiac surgery procedures, porcelain aorta, peripheral vascular arterial disease, concomitant valvular or septal disease, biventricular failure. New surgical techniques and surgical tools have been developed to offer acceptable postoperative outcomes to all mechanical circulatory support recipients. Several less invasive and/or thoracotomic approaches for surgery combined with various LVAD inflow and outflow graft alternative anastomotic sites for system placement have been reported and described to solve complex clinical scenarios. Surgical techniques have been upgraded with further technical tips to preserve the native anatomy in case of re-entry for heart transplantation, myocardial recovery or device explant. The current continuous-flow miniaturized and intrapericardial devices provide versatility and technical advantages. However, the surgical planning requires a careful multidisciplinary evaluation which must be driven by a dedicated and well-trained Heart Failure team. Biventricular assist device (BVAD) implantation by adoption of the newer radial pumps might be a challenge. However, the results are encouraging thus remaining a valid option. This paper reviews and summarizes LVAD preoperative assessment and current surgical techniques for implantation.

Opening the "Dor," Not Always an Inferior Approach

The Dor procedure was historically used to restore the geometry of the heart in a patient with a left ventricular (LV) aneurysm via reduction and reshaping of the LV with an aneurysmectomy. Unfortunately, morbidity and mortality remain high with this procedure, with many patients little to no recovery of their ejection fraction while developing severe diastolic failure, often requiring further support; however, the natural history of these patients remains largely unknown. Heart transplant has long been considered the most durable of treatment for patients with end-stage heart failure (HF), but because of the scarcity of donor hearts, the implantation of left ventricular assist devices (LVAD) for mechanical circulatory support has also proven to be an essential tool in the treatment of the advanced heart failure patient. While various techniques for LVAD implantation have been well outlined, there is very limited literature on placement of a VAD in patients with a history of LV aneurysmectomy or Dor procedures, particularly with regard to the challenging aspects of apical cannulation in those with prior apical ventriculotomy and patch placement. In this series, we describe three patients with a history of LV aneurysmectomy procedures who underwent Heartware ventricular assist device (HVAD) implantations for end-stage HF.

Nipro extra-corporeal left ventricular assist device fitting after left ventricular reconstruction with mitral valve plasty

Both left ventricular assist device and left ventricular reconstruction are treatment choices for severe heart failure conditions. Our institution performed a left ventricular assist device installation following a left ventricular reconstruction procedure on a 42-year-old male patient who presented with dilated cardiomyopathy and low cardiac output syndrome. A mitral valve plasty was used to correct the acute mitral valve regurgitation and we performed a Nipro extra-corporeal left ventricular assist device installation on post-operative day 14. Due to the left ventricular reconstruction that the patient had in a previous operation, we needed to attach an apical cuff on posterior apex, insert the inflow cannula with a large curve, and shift the skin insertion site laterally to the left. We assessed the angle between the cardiac longitudinal axis and the inflow cannula using computed tomography. The patient did not complain of any subjective symptoms of heart failure. Although Nipro extra-corporeal left ventricular assist device installation after left ventricular reconstruction has several difficulties historically, we have experienced a successful case.

Left ventricular assist device implantation with concomitant left ventricular reconstruction without patchplasty

In this case report, we describe a 66-year-old patient with a massive LV aneurism which resulted after myocardial infarction. Due to severe LV function impairment, it was decided to perform left ventricular reconstruction surgery and, at the same time, left ventricular assist device implantation as a bridge to transplantation. The entire procedure was completed without using any patch material. The patient had an uneventful recovery and was discharged home after 18 days. After 1-year follow-up no adverse events were observed.

Implantation of a left ventricular assist device in patients with a complex apical anatomy

Implantation of a left ventricular assist device can be challenging in patients with an altered apical anatomy after cardiac surgery or as the result of the presence of a calcified apical aneurysm. In this paper we present 2 cases with a challenging apical anatomy and introduce a new surgical technique facilitating left ventricular assist device implantation in these patients.