Howard Todd Massey

Cannulation‐Related Complications on Veno‐Arterial Extracorporeal Membrane Oxygenation: Prevalence and Effect on Mortality

Cannulation-related complications are a known source of morbidity in patients supported on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Despite its prevalence, little is known regarding the outcomes of patients who suffer such complications. This is a single institution review of cannulation-related complications and its effect on mortality in patients supported on VA-ECMO from January 2010-2015 using three cannulation strategies: axillary, femoral, and central. Complications were defined as advanced if they required major interventions (fasciotomy, amputation, site conversion). Patients were divided into two groups (complication present vs. not present) and Kaplan-Meier analysis was performed to determine any differences in their survival distributions. There were 103 patients supported on VA-ECMO: 41 (40%), 36 (35%), and 26 (25%) were cannulated via axillary, femoral, and central access, respectively. Cannulation-related complications occurred in 33 (32%) patients and this did not differ significantly between either axillary (34%), femoral (36%), or central (23%) strategies (P = 0.52). The most common complications encountered were hemorrhage and limb ischemia in 19 (18%) and 11 (11%) patients. Hemorrhagic complications did not differ between groups (P = 0.37), while limb ischemia and hyperperfusion were significantly associated with femoral and axillary cannulation, at a rate of 25% (P < 0.01) and 15% (P = 0.01), respectively. There was no difference in the incidence of advanced complications between cannulation groups: axillary (12%) vs. femoral (14%) vs. central (8%; P = 0.75). In addition, no increase in mortality was noted in patients who developed a cannulation-related complication by Kaplan-Meier estimates (P = 0.37). Cannulation-related complications affect a significant proportion of patients supported on VA-ECMO but do not differ in incidence between different cannulation strategies and do not affect patient mortality. Improved efforts at preventing these complications need to be developed to avoid the additional morbidity in an already critical patient population.

Long-term total cardiac support in a Fontan-type circulation with HeartMate II left ventricular assist device

Interest in utilizing long-term mechanical circulatory support for Fontan-type circulation has been high. Unfortunately, so far such attempts have not been successful. Herein, we are presenting the first case of an individual with biventricular heart failure and Fontan-type circulation on long-term mechanical circulatory support with a continuous-flow left ventricular assist device.

Early and late outcomes with prolonged open chest management after cardiac surgery

Objectives: Open chest management (OCM) is an important intervention for patients who are unable to undergo sternal closure after cardiac surgery. This study reviews the factors associated with a prolonged need for this intervention and investigates its association with early and late mortality. Methods: Patients undergoing OCM from January 2009 to December 2014 were reviewed. Differences in the median duration of OCM when a perioperative variable was present versus its absence were determined and variables significant at P ≤ .1 were analyzed using Poisson regression for factors associated with prolonged OCM. Multivariable logistic regression and Cox proportional hazards models were developed to investigate perioperative factors that were associated with early and late mortality. Results: A total of 201 patients (5%) required OCM and the overall median duration of this intervention was 3 days. The use a temporary assist device (median, 7 vs 2 days; P < .001), pneumonias (median, 11 vs 3 days; P < .001), sternal re‐explorations (median, 6 vs 2 days; P < .001), and renal failure (median, 6 vs 3 days; P = .02) were among the factors that were highly associated with prolonged OCM using Poisson regression. Thirty‐day mortalities occurred in 32 patients (16%) and were significantly associated with emergency surgery (P = .03), sternal re‐explorations (P = .001), and OCM duration (median, 6 vs 3 days; P = .02). On multivariable logistic regression and Cox analysis, delaying sternal closure by 1‐day increments increased the risk of early and late mortality by 11% (P = .01), and 9% (P < .001), respectively. Conclusions: Prolonged OCM was associated with increasing perioperative morbidity and a higher risk of early and late mortality.

Single‐Center Experience With HeartMate II Left Ventricular Assist Device Explantation

In patients with continuous flow left ventricular assist devices (CF-LVADs) myocardial recovery is uncommon. Given the heterogeneity of the population implanted and low incidence of recovery, the discovery of native left ventricular (LV) recovery and criteria for explantation of CF-LVAD system is not clearly determined. We sought to analyze the characteristics of the patients who underwent CF-LVAD explantation at our institution. Prospectively collected data on patients supported with CF-LVADs were reviewed retrospectively. Patients who underwent CF-LVAD explants were identified and their characteristics were analyzed with a focus on patient presentation and determinants of explantability. From November 2006 to June 2014, 223 patients (181 male, 42 female) underwent implantation of HeartMate II LVAD. Seven female (16.7%) and one male (0.6%) patients were explanted (P < 0.001). Mean age was 43 ± 9 years and etiology for cardiomyopathy was ischemic in three (37.5%) patients, nonischemic in four (50%) patients, and mixed in the one (12.5%) male patient of the cohort. Five (62.5%) patients presented acutely with significant hemolysis, and were found to have LV improvement as well as reduced, absent, or reversed diastolic flow velocities on echocardiography. Overall, mean lactate dehydrogenase level before explantation was 1709 ± 1168 U/L compared to the mean baseline level of 601 ± 316 U/L (P = 0.048). Mean LV ejection fraction (LVEF) improved from 17 ± 7% preimplant to 56 ± 11% pre-explantation (P < 0.001). Median number of days on CF-LVAD support was 870 (interquartile range, 209-975) while mean duration of follow-up after the CF-LVAD explantation was 276 ± 240 days. Mean LVEF dropped from 46 ± 19% postexplantation to 34 ± 10% during the most recent follow-up (P = 0.015). At our institution, patients who underwent LVAD explants were predominantly women with nonischemic cardiomyopathy. Clinical evidence of hemolysis and echocardiographic evidence of reduced or absent diastolic flow velocities were common findings in these patients. Over time, patients native LV function declined in the absence of LVAD (after LVAD explantation). Significant challenges remain in predicting LV recovery and identifying those individuals who have recovered myocardial function significant enough to be explanted.

Echocardiographic detection of left ventricular thrombus in patients undergoing HeartMate II left ventricular assist device implantation

Purpose Transthoracic (TTE) and transesophageal echocardiograms (TEE) are considered accurate in detecting the presence of left ventricular (LV) thrombus. A persistent LV thrombus poses risks of pump thrombosis and stroke in LVAD recipients. The relationship between pre-operative echocardiography and intraoperative findings at LVAD implantation has not previously been studied. Methods A retrospective review examined all patients undergoing LVAD placement or exchange from October 2011 to March 2014. Pre-Operative TTE and TEE data were validated with presence of LV thrombus during the direct inspection at the time of LVAD placement, and the findings were analyzed quantitatively. Results Between October 2011 and March 2014, 99 patients underwent a total of 107 LVAD implants. Pre-Operative TTE was available in 93 (86.9%) cases, while pre-operative TEE was available in 37 cases (34.6%). On pre-operative TTE, LV thrombus was correctly identified in only two cases, while on pre-operative TEE no cases of LV thrombus were identified correctly, and there were 2 false positive reports. Intraoperative inspection revealed presence of LV thrombus in 14 cases. The sensitivity of pre-operative TTE was 16.7% and the specificity 100% in detecting LVT, compared to 0% and 93.8%, respectively, for TEE. Conclusions Pre-Operative echocardiogram offers low accuracy for presence of LV thrombus. Overall, the sensitivity is too low to reliably exclude thrombus. This could have significant implications in planning off-pump LVAD exchange as thrombus could be missed. More data are necessary to determine whether this could have significant effects on thromboembolic complications and survival.

Large left main coronary artery aneurysm with fistula to the right atrium

Coronary artery fistula can present as a rare congenital anomaly or can be formed after chest trauma, repeated insult to the heart by coronary angiography, endomyocardial biopsy (iatrogenic), or may be idiopathic in nature.

Pulmonary arteriovenous extracorporeal membrane oxygenation to avoid pulmonary overflow during total artificial heart implantation

Total artificial hearts (TAH) can be used as a bridge to transplant or, occasionally, as destination therapy for patients with severe biventricular dysfunction. Not infrequently TAHs are placed in patients with severe low flow states, in which the lungs of these patients are unable to adjust rapidly to the “normal” right ventricular output of a TAH. These patients may develop variable degrees of pulmonary edema secondary to stress failure of the pulmonary capillaries requiring increased respiratory support, which can occasionally be fatal. In this “how to do it” article, we describe the technique for a pulmonary arteriovenous extracorporeal membrane oxygenation with TAH to avoid sudden pulmonary overflow and gradually expose the lungs to increasing flow.

Prospective analysis of bleeding events in left ventricular assist device patients

Background: Bleeding is a major cause of morbidity in patients with continuous flow left ventricular assist devices (LVADs). We sought to identify clinical predictors of bleeding within the first year of LVAD implantation. Methods: A prospective study was performed on 30 patients with HeartMate II implantation at the University of Rochester Medical Center, Rochester, New York, United States. Blood was collected within 1 week before implantation, and at 1, 3, and 30 ± 10 days after implantation. Blood samples were analyzed for prothrombin time (PT), international normalized ratio (INR), von Willebrand factor (vWF) activity, vWF antigen, vWF multimers, collagen binding assay, factor VIII, and epinephrine closure time. The first bleeding event within 1 year of implantation was recorded. Results: There were 17 (57%) patients with a bleeding event. The cumulative incidence of bleeding was 50% at 304 days. Age at the time of LVAD implantation was associated with higher risk of bleeding (hazard ratio (HR) = 1.05, 95% confidence interval (CI) = 1.01–1.10, p = 0.013). Higher baseline INR was also associated with increased risk of bleeding after adjusting for age at the time of implant (HR = 6.58, 95% CI = 1.21–35.70, p = 0.028). The bleeders and non-bleeders had similar hemostatic markers at all four time points. Prior to LVAD, mean epinephrine closure time was similar between bleeders and non-bleeders. However, post LVAD measurement of epinephrine, closure time was frequently limited by platelet clumping. Conclusion: Older age and baseline INR are associated with higher risk of bleeding in LVAD patients. Platelet clumping may suggest underlying platelet dysfunction and associated high risk of bleeding

Impact of Concomitant Mitral Valve Surgery With LVAD Placement: Systematic Review and Meta-Analysis: MV Surgery During LVAD Placement

The aim of this systematic review and meta-analysis was to evaluate the outcomes of concomitant mitral valve surgery for significant preexisting mitral regurgitation (MR) in patients undergoing continuous-flow left ventricular assist device (CF-LVAD) implantation. Electronic search was performed to identify all studies in the English literature examining concurrent mitral valve surgery in patients with CF-LVAD implantation. Identified articles were systematically assessed for inclusion and exclusion criteria. Of 2319 studies identified, 8 studies were included. Among 445 patients with moderate to severe or severe MR, 113 (25.4%) patients received concurrent mitral valvular intervention during CF-LVAD implantation. There were no significant differences in cardiopulmonary bypass time (MR Surgery 154 min vs. no MR Surgery 119 min, P = 0.64) or hospital length of stay (MR Surgery 21 days vs. no MR Surgery 18 days, P = 0.93). On follow-up, there were no significant differences in freedom from greater than moderate MR (MR Surgery 100% vs. no MR Surgery 74%, P = 0.12) or left ventricular end-diastolic diameter (MR Surgery: 60 mm vs. no MR Surgery 65 mm, P = 0.51). Survival was comparable at 6-months (MR Surgery 77% vs. no MR Surgery 81%, P = 0.75), 1-year (MR Surgery 72% vs. no MR Surgery 80%, P = 0.36), and 2-years of follow-up (MR Surgery 65% vs. no MR Surgery 70%, P = 0.56). The results of our systematic review and meta-analysis of 8 studies consisting of 445 patients demonstrates that the addition of mitral valve intervention to CF-LVAD implantation appears to be safe with comparable survival to those undergoing CF-LVAD implantation alone. Large prospective randomized clinical trials are needed to elucidate whether concomitant mitral valve intervention during CF-LVAD implantation in patients with severe MR is necessary.

Repair of pectus excavatum during HeartMate II left ventricular assist device placement

Pectus excavatum deformity often remains clinically asymptomatic even in cases of a severely diminished thoracic volume and frequently remains uncorrected. In the patient population that requires left ventricular assist device (LVAD) placement, a diminished thoracic volume can be problematic and lead to significant challenges in pump and outflow cannula positioning. Here we present a case of pectus excavatum correction during LVAD placement to show that this deformity can be successfully addressed with minimal, if any, additional operative risk at the time of LVAD implant.