I-Wen Wang

Minimally invasive is the future of left ventricular assist device implantation.

There have been many factors that have allowed for progressive improvement in outcomes and lower complication rates. These include the improvement in left ventricular assist device (LVAD) technologies, combined with better understanding of patient management, all these. Nowadays the numbers of LVAD implantations exceed the number of annual heart transplants worldwide. Minimally invasive procedures are shown to improve the surgical outcome in both LVAD insertion and replacement. These minimally invasive techniques can be grouped grossly into shifting from on-pump to off-pump implantation, alternative access for implantation other than sternotomy, and a combination of both, which should be the ultimate aim of minimally invasive LVAD implantation. Here we describe the alternative techniques and configurations of minimally invasive and sites of implantation.

Use of distal perfusion in peripheral extracorporeal membrane oxygenation

Extra corporeal membrane oxygenation (ECMO) is a life-saving technique to manage refractory cardiopulmonary failure. Its usage and indication continue to increase. Femoral venoarterial ECMO (VA ECMO) is relatively less invasive and the cardiac support may be more rapidly instituted in in these extremely tenuous patients. Vascular injuries and limb ischemia unfortunately occur in these emergent access settings. Here we will discuss the optimal techniques of preventing this complication which might affect patient survival and impact the patient quality of life.

New horizons of non-emergent use of extracorporeal membranous oxygenator support

The expansion of the extra corporeal membrane oxygenation (ECMO) use and its indication is strikingly increased in the past few years. ECMO use expanded to lung transplantation, difficult general thoracic resections, transcatheter aortic valve replacement (TAVR) and LVAD implantation. Here we will discuss the indications and the outcomes of non-emergent use of ECMO.

B-Type Natriuretic Peptide-Guided Therapy and Length of Hospital Stay Post Left Ventricular Assist Device Implantation

B-type natriuretic peptide (BNP)-guided therapy during the early postoperative period following left ventricular assist device (LVAD) implantation has not been well described in the literature. We conducted a retrospective cohort study consisting of consecutive patients who underwent LVAD implantation at our institution during May 2009 to March 2013. The study was limited to patients receiving HeartMate II (Thoratec) or HVAD (HeartWare) LVADs. Patients with acute myocardial infarction were excluded. We compared between patients with multiple postoperative BNP tests (BNP-guided therapy) and earlier period patients who typically had only a baseline BNP measurement (non-BNP-guided therapy). A total of 85 patients underwent LVAD implantation during the study period. Eight patients were excluded (five acute myocardial infarction, three without BNP measurements). The only differences in the baseline characteristics of BNP versus non-BNP-guided therapy included age and female gender. The postoperative length of hospital stay (LOS) in the BNP-guided therapy group was 5 days shorter when compared with the non-BNP-guided therapy group. In multivariate analysis, BNP-guided therapy remained a significant predictor of reduced LOS. The use of repeated BNP measurements during the early postoperative period was associated with a significantly lower LOS post LVAD implantation.

Pulse Oximeter Derived Blood Pressure Measurement in Patients With a Continuous Flow Left Ventricular Assist Device

Currently, blood pressure (BP) measurement is obtained noninvasively in patients with continuous flow left ventricular assist device (LVAD) by placing a Doppler probe over the brachial or radial artery with inflation and deflation of a manual BP cuff. We hypothesized that replacing the Doppler probe with a finger-based pulse oximeter can yield BP measurements similar to the Doppler derived mean arterial pressure (MAP). We conducted a prospective study consisting of patients with contemporary continuous flow LVADs. In a small pilot phase I inpatient study, we compared direct arterial line measurements with an automated blood pressure (ABP) cuff, Doppler and pulse oximeter derived MAP. Our main phase II study included LVAD outpatients with a comparison between Doppler, ABP, and pulse oximeter derived MAP. A total of five phase I and 36 phase II patients were recruited during February-June 2014. In phase I, the average MAP measured by pulse oximeter was closer to arterial line MAP rather than Doppler (P = 0.06) or ABP (P < 0.01). In phase II, pulse oximeter MAP (96.6 mm Hg) was significantly closer to Doppler MAP (96.5 mm Hg) when compared to ABP (82.1 mm Hg) (P = 0.0001). Pulse oximeter derived blood pressure measurement may be as reliable as Doppler in patients with continuous flow LVADs.

B‐Type Natriuretic Peptide Levels Predict Ventricular Arrhythmia Post Left Ventricular Assist Device Implantation

B-type natriuretic peptide (BNP) levels have been shown to predict ventricular arrhythmia (VA) and sudden death in patients with heart failure. We sought to determine whether BNP levels before left ventricular assist device (LVAD) implantation can predict VA post LVAD implantation in advanced heart failure patients. We conducted a retrospective study consisting of patients who underwent LVAD implantation in our institution during the period of May 2009-March 2013. The study was limited to patients receiving a HeartMate II or HeartWare LVAD. Acute myocardial infarction patients were excluded. We compared between the patients who developed VA within 15 days post LVAD implantation to the patients without VA. A total of 85 patients underwent LVAD implantation during the study period. Eleven patients were excluded (five acute MI, four without BNP measurements, and two discharged earlier than 13 days post LVAD implantation). The incidence of VA was 31%, with 91% ventricular tachycardia (VT) and 9% ventricular fibrillation. BNP remained the single most powerful predictor of VA even after adjustment for other borderline significant factors in a multivariate logistic regression model (P < 0.05). BNP levels are a strong predictor of VA post LVAD implantation, surpassing previously described risk factors such as age and VT in the past.

Left ventricular thrombus associated with arteriovenous extra corporeal membrane oxygenation.

Extra corporeal membrane oxygenation (ECMO) has remarkably progressed over the recent years. It has become an invaluable tool in the care of adults and pediatric patients with severe cardiogenic shock. At the initiation of ECMO support, the left ventricular contractility is profoundly impaired. Inadequate right ventricular drainage and bronchial circulation can lead to left ventricular distension, with potential deleterious consequences, ranging from inadequate myocardial rest, pulmonary edema, or intracardiac clot formation. Therefore, it is of extreme importance to ensure an adequate left ventricular drainage. Here we present a case of LV thrombus developed while the patient is on central venoarterial (VA) ECMO.

Successful Delivery in a Patient With Left Ventricular Assist Device and Unplanned Pregnancy

We report the case of a woman supported by a left ventricular assist device (LVAD) who presented at 20 weeks of gestation and decided against recommendations to continue with her pregnancy. This was managed with well-developed plan for a multidisciplinary team approach. With close and regular follow-up and regular adjustment of the patient’s medications and LVAD parameters, successful delivery and outcome for both the mother and the newborn were achieved. (Ann Thorac Surg 2017;104:e31–3) 2017 by The Society of Thoracic SurgeonsWe report the case of a woman supported by a left ventricular assist device (LVAD) who presented at 20 weeks of gestation and decided against recommendations to continue with her pregnancy. This was managed with well-developed plan for a multidisciplinary team approach. With close and regular follow-up and regular adjustment of the patients medications and LVAD parameters, successful delivery and outcome for both the mother and the newborn were achieved.

Severe epistaxis in patients on extracorporeal membranous oxygenator support occurrence and management

We would like to thank Dr. Mazzeffi and colleagues (1) for the comments on our recently published article entitled “Extra corporeal membrane oxygenation (ECMO) review of a lifesaving technology” (2), as well as reporting their own data regarding severe epistaxis during ECMO support. We agree that bleeding is a frequently encountered complication during ECMO support with reported rates ranging from 10-30%. Bleeding may also occur at surgical sites, cannula sites, or sites of previous invasive procedures. Intrathoracic, abdominal, or retroperitoneal hemorrhage may also occur (2). Case reports of epistaxis associated with ECMO support have been seen in the literature (3,4). Harrison et al. (5) reported 11 patients (30% of all their ECMO series) with aerodigestive bleeding. Among these, seven patients experienced nose or nasopharyngeal bleeding and a total of eight patients needed nasal packing.

B-TYPE NATRIURETIC PEPTIDE LEVELS PREDICT VENTRICULAR ARRHYTHMIA POST LEFT VENTRICULAR ASSIST DEVICE IMPLANTATION

B Type Natriuretic Peptide (BNP) levels have been shown to predict Ventricular Arrhythmia (VA) and sudden death in heart failure. We sought to determine whether BNP can predict VA post Left Ventricular Assist Device (LVAD) implantation. We conducted a retrospective nested case-control study