Jonathan Yang

Use of bicaval dual-lumen catheter for adult venovenous extracorporeal membrane oxygenation

BACKGROUND Extracorporeal membrane oxygenation (ECMO) provides supplementary oxygenation and carbon dioxide removal for selected patients on mechanical ventilatory support. Venovenous ECMO is traditionally established by dual cannulation of the internal jugular and femoral veins. We report our institutional experience using single-site, dual-lumen cannula for venovenous ECMO as an alternative to the 2-catheter approach. This approach minimizes recirculation and avoids use of the femoral site, which confers potential advantages. METHODS This is a retrospective review of a single institutions experience with a new bicaval dual lumen ECMO cannula. During a 19-month period, 27 consecutive patients were placed on ECMO using this catheter inserted through the right internal jugular vein. RESULTS Single-site venovenous ECMO support was uneventfully initiated in 26 of the 27 patients (median age, 42 years; interquartile range, 31 to 58 years) and achieved full flows and adequate gas exchange. Median ventilator days before ECMO was 1 day (interquartile range, 0.25 to 3.5 days). The median duration of ECMO support was 9 days (interquartile range, 5.5 to 11.5 days). Decannulation was achieved in 70% of the patients and extubation in 59%. Two were bridged to lung transplantation and are still alive. The overall survival and hospital discharge rate was 56%. There was no device failure or in-cannula thrombosis. One superior vena cava injury occurred, and one cannula required repositioning. CONCLUSIONS Single-site venovenous ECMO has advantages compared with traditional venovenous ECMO. Using image guidance, the cannula can reliably be used in prolonged venovenous ECMO cases.

Listing and Transplanting Adults With Congenital Heart Disease

Background— An increasing number of patients with congenital heart disease (CHD) are reaching adulthood and may require heart transplantation. The survival of these patients after listing and transplantation has not been evaluated. Methods and Results— A total of 41 849 patients (aged >18 years) were listed for primary transplantation during 1995–2009. Patients with a history of CHD (n=1035; 2.5%) were compared with those with other causes (non-CHD group) (n=40 814; 97.5%); 26 055 (62.3%) reached transplantation and were subdivided into those with (reoperation group; n=10 484; 40.2%) and without (nonreoperation group; n=15 571; 59.8%) a previous sternotomy. Survival on the waiting list was similar between groups, but mechanical ventricular assistance was not associated with superior survival to transplantation among CHD patients. CHD patients were more likely to have body mass index <18.5 at transplantation (P<0.0001), were younger, and had fewer comorbidities. Early mortality among patients with CHD was high (reoperation, 18.9% versus 9.6%; P<0.0001; nonreoperation, 16.6% versus 6.3%; P<0.0001), but by 10 years, overall survival was equivalent (53.8% versus 53.6%). Analysis was limited by the lack of specific information regarding the CHD diagnosis in most patients. Conclusions— Adults with CHD have high 30-day mortality but better late survival after heart transplantation. Mechanical circulatory assistance does not improve waiting list survival in these patients. This may be due to a combination of highly complex reoperative surgery and often poor preoperative systemic health.

Pre-operative and post-operative risk factors associated with neurologic complications in patients with advanced heart failure supported by a left ventricular assist device

BACKGROUND Neurologic complications (NCs) are the major adverse events after left ventricular assist device (LVAD) surgery. Pre-operative and post-operative factors associated with NCs in patients with LVADs were investigated. METHODS We reviewed 307 consecutive patients undergoing LVAD surgery (167 HeartMate I and 140 HeartMate II devices) at Columbia University Medical Center between November 2000 and December 2010. Clinical characteristics and hemodynamic and laboratory indexes were analyzed. NC was defined according to the Interagency Registry for Mechanically Assisted Circulatory Support definition of neurologic dysfunction, including transient ischemic attack (TIA) and ischemic or hemorrhagic cerebrovascular accident (CVA). RESULTS NCs developed in 43 patients (14.0%) at 91.8 ± 116.3 days post-operatively. The frequency of NC development was similar in HeartMate I and II patients. Patients with NC showed a higher frequency of pre-LVAD CVA history (27.9% vs 15.5%, p = 0.046), lower pre-operative sodium (129.0 ± 7.0 vs 132.1 ± 8.1 mg/dl, p = 0.018) and albumin concentrations (3.5 ± 0.7 vs 3.7 ± 0.6 mg/dl, p = 0.049), lower post-operative hematocrit (34.9% ± 5.1% vs 37.8% ± 6.1%, p = 0.0034), sodium (131.6 ± 7.7 vs 134.4 ± 6.4 mg/dl, p = 0.010) and albumin concentrations (3.7 ± 0.5 vs 3.9 ± 0.5 mg/dl, p = 0.0016), and higher frequency of post-operative infection (39.5% vs 19.3%, p = 0.003) than those without NC. Multiple regression analysis revealed that CVA history (odds ratio, 2.37, 95% confidence interval, 1.24-5.29; p = 0.011) and post-operative infection (odds ratio, 2.99, 95% confidence interval, 1.16-10.49; p = 0.011) were highly associated with NC development. The combination of CVA history, pre-operative and post-operative sodium and albumin, and post-operative hematocrit and infection could discriminate patients developing NCs with a probability of 76.6%. CONCLUSIONS Previous stroke, persistent malnutrition and inflammation, severity of heart failure, and post-LVAD infections are key factors associated with development of NCs after LVAD implantation.

Liver dysfunction as a predictor of outcomes in patients with advanced heart failure requiring ventricular assist device support: Use of the Model of End-stage Liver Disease (MELD) and MELD eXcluding INR (MELD-XI) scoring system

BACKGROUND Liver dysfunction increases post-surgical morbidity and mortality. The Model of End-stage Liver Disease (MELD) estimates liver function but can be inaccurate in patients receiving oral anti-coagulation. We evaluated the effect of liver dysfunction on outcomes after ventricular assist device (VAD) implantation and the dynamic changes in liver dysfunction that occur during VAD support. METHODS We retrospectively analyzed 255 patients (147 with pulsatile devices and 108 with continuous-flow devices) who received a long-term VAD between 2000 and 2010. Liver dysfunction was estimated by MELD and MELD-eXcluding INR (MELD-XI), with patients grouped by a score of ≥ 17 or < 17. Primary outcomes were on-VAD, after transplant, and overall survival. RESULTS MELD and MELD-XI correlated highly (R ≥ 0.901, p < 0.0001) in patients not on oral anti-coagulation. Patients with MELD or MELD-XI < 17 had improved on-VAD and overall survival (p < 0.05) with a higher predictive power for MELD-XI. During VAD support, cholestasis initially worsened but eventually improved. Patients with pre-VAD liver dysfunction who survived to transplant had lower post-transplant survival (p = 0.0193). However, if MELD-XI normalized during VAD support, post-transplant survival improved and was similar to that of patients with low MELD-XI scores. CONCLUSIONS MELD-XI is a viable alternative for assessing liver dysfunction in heart failure patients on oral anti-coagulation. Liver dysfunction is associated with worse survival. However, if MELD-XI improves during VAD support, post-transplant survival is similar to those without prior liver dysfunction, suggesting an important prognostic role. We also found evidence of a transient cholestatic state after LVAD implantation that deserves further examination.

Outcome of unplanned right ventricular assist device support for severe right heart failure after implantable left ventricular assist device insertion

BACKGROUND The use of a right ventricular assist device (RVAD) becomes necessary for severe right ventricular (RV) failure after left ventricular assist device (LVAD) insertion. Although temporary support could lead to successful RVAD weaning in certain patients, the data remain scarce. METHODS We retrospectively reviewed 398 patients who underwent implantable LVAD insertion between January 2000 and December 2012. Of these patients, 44 (11%) required unplanned RVAD support due to severe RV failure after LVAD insertion. For comparison, 37 patients who underwent planned biventricular assist device (BiVAD) insertion were identified during the same study period. We analyzed the early and late outcomes in these patients. RESULTS The mean duration of RVAD support was 21 ± 23 days. Of the 44 patients, 21 (49%) were weaned from the RVAD (weaning group), whereas 23 (51%) required continued biventricular support (failure group). The failure group had ongoing end-organ dysfunction after RVAD insertion. Hospital mortality was significantly lower in the weaning group (24%) and in the planned BiVAD group (30%) as compared to the failure group (74%, p = 0.0009). The 6-month actuarial survival rate was 75% in the weaning group, 62% in the planned BiVAD group and 13% in the failure group (p < 0.0001). Successful bridge to transplant was achieved in 14 patients (67%) in the weaning group as compared with 8 patients (35%) in the failure group (p = 0.03). On multivariate logistic regression analyses, pre-operative white blood cell (odds ratio [OR] 1.3, 95% confidence interval [CI] 1.04 to 1.50, p = 0.016) and creatinine (OR 0.26, 95% CI 0.079 to 0.88, p = 0.03) levels were significant predictors for RVAD removal. CONCLUSIONS Among patients who developed acute RV failure after LVAD insertion, only half could be weaned from the temporary RVAD support. An alternative strategy is necessary in patients who require continuous RVAD support.

The golden age of minimally invasive cardiothoracic surgery: current and future perspectives

Over the past decade, minimally invasive cardiothoracic surgery (MICS) has grown in popularity. This growth has been driven, in part, by a desire to translate many of the observed benefits of minimal access surgery, such as decreased pain and reduced surgical trauma, to the cardiac surgical arena. Initial enthusiasm for MICS was tempered by concerns over reduced surgical exposure in highly complex operations and the potential for prolonged operative times and patient safety. With innovations in perfusion techniques, refinement of transthoracic echocardiography and the development of specialized surgical instruments and robotic technology, cardiac surgery was provided with the necessary tools to progress to less invasive approaches. However, much of the early literature on MICS focused on technical reports or small case series. The safety and feasibility of MICS have been demonstrated, yet questions remain regarding the relative efficacy of MICS over traditional sternotomy approaches. Recently, there has been a growth in the body of published literature on MICS long-term outcomes, with most reports suggesting that major cardiac operations that have traditionally been performed through a median sternotomy can be performed through a variety of minimally invasive approaches with equivalent safety and durability. In this article, we examine the technological advancements that have made MICS possible and provide an update on the major areas of cardiac surgery where MICS has demonstrated the most growth, with consideration of current and future directions.

Comparison of extracorporeal membrane oxygenation versus cardiopulmonary bypass for lung transplantation

OBJECTIVE This study compared differences in patient outcomes and operative parameters for extracorporeal membrane oxygenation (ECMO) versus cardiopulmonary bypass (CPB) in patients undergoing lung transplants. METHODS Between January 1, 2008, and July 13, 2013, 316 patients underwent lung transplants at our institution, 102 requiring intraoperative mechanical cardiopulmonary support (CPB, n=55; ECMO, n=47). We evaluated survival, blood product transfusions, bleeding complications, graft dysfunction, and rejection. RESULTS Intraoperatively, the CPB group required more cell saver volume (1123±701 vs 814±826 mL; P=.043), fresh-frozen plasma (3.64±5.0 vs 1.51±3.2 units; P=.014), platelets (1.38±1.6 vs 0.43±1.25 units; P=.001), and cryoprecipitate (4.89±6.3 vs 0.85±2.8 units; P<.001) than the ECMO group. Postoperatively, the CPB group received more platelets (1.09±2.6 vs 0.13±0.39 units; P=.013) and was more likely to have bleeding (15 [27.3%] vs 3 [6.4%]; P=.006) and reoperation (21 [38.2%] vs 7 [14.9%]; P=.009]. The CPB group had higher rates of primary graft dysfunction at 24 and 72 hours (41 [74.5%] vs 23 [48.9%]; P=.008; and 42 [76.4%] vs 26 [56.5%]; P=.034; respectively). There were no differences in 30-day and 1-year survivals. CONCLUSIONS Relative to CPB, the ECMO group required fewer transfusions and had less bleeding, fewer reoperations, and less primary graft dysfunction. There were no statistically significant survival differences at 30 days or 1 year.

Relation of Preoperative Serum Albumin Levels to Survival in Patients Undergoing Left Ventricular Assist Device Implantation

Hypoalbuminemia has been recognized as a prognostic indicator in patients with heart failure. We aimed to investigate the association of hypoalbuminemia with postoperative mortality in patients undergoing left ventricular assist device (LVAD) implantation. We studied 272 consecutive patients undergoing LVAD implantation from 2000 to 2010 at our institution. Preoperative clinical characteristics and laboratory variables associated with mortality were analyzed. Postoperative survival of patients with preoperative hypoalbuminemia (<3.5 g/dl, n = 125) and those with normal albumin concentration (≥3.5 g/dl, n = 147) was compared. Survival after LVAD surgery was better in patients with normal albumin levels compared with those with hypoalbuminemia before surgery (3 and 12 months: 93.2% vs 82.4% and 88.4% vs 75.2%, respectively, p <0.001). Multivariate analysis revealed that preoperative albumin was independently associated with mortality after LVAD implantation (hazard ratio 0.521, 95% confidence interval 0.290 to 0.934; p = 0.029.) Furthermore, the impact of normalization of albumin levels during LVAD support on postoperative survival was analyzed in both groups. Subgroup analysis of patients with preoperative hypoalbuminemia and postoperative normalization of albumin levels (n = 81) showed improved survival compared with those who remained hypoalbuminemia (n = 44) or those who had decreasing albumin levels during LVAD support (n = 40; 3-month survival: 92.6% vs 63.6% and 65.0%; p <0.01). In conclusion, preoperative hypoalbuminemia is associated with poor prognosis after LVAD surgery. Postoperative normalization of albumin level is associated with improved survival. Attention to albumin levels by correcting nutrition, inflammation, and hepatic function could be an effective way to improve prognosis in patients evaluated for LVAD implantation.

Timing of temporary right ventricular assist device insertion for severe right heart failure after left ventricular assist device implantation.

Data on how the timing of a temporary right ventricular assist device (RVAD) insertion affects outcome are limited in patients receiving left ventricular assist device (LVAD). Of the 282 patients who underwent LVAD placement between January 2000 and November 2010, 40 (14%) required concomitant (n = 26) or delayed (n = 14) RVAD insertion as temporary support. We analyzed early and 1-year outcomes. Preoperative variables were similar in the concomitant and delayed RVAD groups. The hospital mortality rate was approximately 50% in both groups (p = 0.82). The 1-year actuarial survival was similar in both groups (p = 0.42). Patients who required RVAD support had higher in-hospital mortality and worse 1-year survival rates than those who received LVAD only (48% vs. 9.5%, p < 0.0001; 40% vs. 82%, p < 0.0001). Multivariate logistic regression analysis indicated RVAD use as a significant risk factor for 1-year mortality (odds ratio, 18; p = 0.0003; 95% confidence interval, 3.765–86.74). Timing of temporary RVAD insertion did not affect overall survival. Necessity of RVAD support is associated with significantly worse early and late mortality at any rate. The decision to place the RVAD can be made once it is clinically necessary.

Preoperative Assessment of High-Risk Candidates to Predict Survival After Heart Transplantation

Background—Alternate waiting list strategies expand listing criteria for patients awaiting heart transplantation (HTx). We retrospectively analyzed clinical events and outcome of patients listed as high-risk recipients for HTx. Methods and Results—We analyzed 822 adult patients who underwent HTx of whom 111 patients met high-risk criteria. Clinical data were collected from medical records and outcome factors calculated for 61 characteristics. Significant factors were summarized in a prognostic score. Age >65 years (67%) and amyloidosis (19%) were the most common reasons for alternate listing. High-risk recipients were older (63.2±10.2 versus 51.4±11.8 years; P<0.001), had more renal dysfunction, prior cancer, and smoking. Survival analysis revealed lower post-HTx survival in high-risk recipients (82.2% versus 87.4% at 1-year; 59.8% versus 76.3% at 5-year post-HTx; P=0.0005). Prior cerebral vascular accident, albumin <3.5 mg/dL, re-HTx, renal dysfunction (glomerular filtration rate <40 mL/min), and >2 prior sternotomies were associated with poor survival after HTx. A prognostic risk score (CARRS [CVA, albumin, re-HTx, renal dysfunction, and sternotomies]) derived from these factors stratified survival post-HTx in high-risk (3+ points) versus low-risk (0–2 points) patients (87.9% versus 52.9% at 1-year; 65.9% versus 28.4% at 5-year post-HTx; P<0.001). Low-risk alternate patients had survival comparable with regular patients (87.9% versus 87.0% at 1-year and 65.9% versus 74.5% at 5-year post-HTx; P=0.46). Conclusions—High-risk patients had reduced survival compared with regular patients post-HTx. Among patients previously accepted for alternate donor listing, application of the CARRS score identifies patients with unacceptably high mortality after HTx and those with a survival similar to regularly listed patients.