Hemodynamic evaluation of a new pulsatile blood pump during low flow cardiopulmonary bypass support.

BACKGROUND: The VentriFlo® True Pulse Pump (VentriFlo, Inc, Pelham, NH, USA) is a new pulsatile blood pump intended for use during short-term circulatory support. The purpose of this study was to evaluate the feasibility of the VentriFlo and compare it to a conventional centrifugal pump (ROTAFLOW, Getinge, Gothenberg, Sweden) in acute pig experiments. METHODS: Pigs (40-45 kg) were supported by cardiopulmonary bypass (CPB) with the VentriFlo (n = 9) or ROTAFLOW (n = 5) for 6 h. Both VentriFlo and ROTAFLOW circuits utilized standard CPB components. We evaluated hemodynamics, blood chemistry, gas analysis, plasma hemoglobin, and microcirculation at the groin skin with computer-assisted video microscopy (Optilia, Sollentuna, Sweden). RESULTS: Pigs were successfully supported by CPB for 6 h without any pump-related complications in either group. The VentriFlo delivered an average stroke volume of 29.2 ± 4.8 ml. VentriFlo delivered significantly higher pulse pressure (29.1 ± 7.2 mm Hg vs. 4.4 ± 7.0 mm Hg, p < 0.01) as measured in the carotid artery, with mean aortic pressure and pump flow comparable with those in ROTAFLOW. In blood gas analysis, arterial pH was significantly lower after five hours support in the VentriFlo group (7.30 ± 0.07 vs. 7.43 ± 0.03, p = 0.001). There was no significant difference in plasma hemoglobin level in both groups after six hours of CPB support. In microcirculatory assessment, VentriFlo tended to keep normal capillary flow, but it was not statistically significant. CONCLUSIONS: VentriFlo-supported pigs showed comparable hemodynamic parameters with significantly higher pulse pressure compared to ROTAFLOW without hemolysis.

Effectiveness and Safety of E-aminocaproic Acid in Overall and Less-Invasive Cardiac Surgeries.

OBJECTIVES: To examine E-aminocaproic acid effectiveness in reducing transfusion requirements in overall and less-invasive cardiac surgery, and to assess its safety. DESIGN: Retrospective cohort study. SETTING: Single-center tertiary academic medical center. PARTICIPANTS: A total of 19,111 adult patients who underwent elective surgery requiring cardiopulmonary bypass from January 1, 2008, through December 31, 2016. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Propensity matching was used to create well-balanced groups and separately compare both overall cohort and less-invasive surgery with and without E-aminocaproic acid. Supplementary zero-inflated negative binomial regression analysis was used because outcome data were zero-inflated. Effectiveness was assessed by transfusion requirements, and safety by comparison of in-hospital outcomes. In the overall cohort, patients receiving E-aminocaproic acid received fewer red blood cells postoperatively and fewer intra- and postoperativel blood products. In a less-invasive cohort, there was no significant difference in red blood cell transfusion either intra- or postoperatively, but the E-aminocaproic group received fewer intra- and postoperative platelets, intraoperative cryoprecipitate, and postoperative plasma. There were no significant differences for in-hospital outcomes in both less-invasive and overall cohorts. CONCLUSIONS: The reduction of postoperative red blood cell requirement observed when analyzing the overall cohort did not translate to less-invasive cardiac surgery in the authors' patient population; however, both overall and less-invasive cohorts had lower requirements for other blood components with E-aminocaproic acid. There was no association with major Society of thoracic surgeons (STS)-defined morbidity and mortality in both groups.

Comparing outcomes of general anesthesia and monitored anesthesia care during transcatheter aortic valve replacement: The Cleveland Clinic Foundation experience.

BACKGROUND: Monitored anesthesia care (MAC) has become more widely used during transcatheter aortic valve replacement (TAVR) to avoid the complications of general anesthesia (GA). METHODS: We included consecutive patients who underwent transfemoral-TAVR at our institution between January 2012 and April 2017. We compared outcomes with GA versus MAC. RESULTS: Of 998 patients, MAC was used in 43.9%. MAC was associated with shorter procedural time (96.9 ± 30.9 vs. 135 ± 64.6 mins; p < .001), fluoroscopy time (20.4 ± 8.9 vs. 29 ± 18.7 mins; p < .001), lower contrast volume (45.5 ± 27 vs. 60.4 ± 43 cc; p < .001), and decreased radiation exposure (12,869 ± 8,099 vs. 20,630 ± 16,276 cGy-cm2 ; p < .001). Patients who underwent MAC had a briefer median (IQR) intensive care unit stay [23.3 (21-24) vs. 23.4 (20.8-26) hrs; p < .001], and hospital stay [2 (2, 3) vs. 3 (2-6) days; p < .001], and were more frequently discharged to home (93.4% vs. 82.9%; p < .001). MAC was associated with lower mortality at 30 days (0.5% vs. 2.9%; log-rank p = .012; adjHR 0.22, 95% CI 0.06-0.82; p = .024), but not at 1 year (11.7% vs. 14.6%; log-rank p = .157) or 3 years (36.8% vs. 38.4%; log-rank p = 0.433). There were no differences in major adverse cardiac and cerebrovascular events (MACCE) at either 30 days (4.6% vs. 9.3%; log-rank p = .14) or 1 year (21.1% vs. 21.5%; log-rank p = .653). Similar findings were seen among patients who received newer-generation SAPIEN-3 valves. CONCLUSION: Utilizing MAC and omitting intraprocedural transesophageal echocardiography during TAVR seems to be more efficient without compromising safety. Better TAVR outcomes can be achieved with newer generation valves without needing GA.

Predicting Right Ventricular Failure After LVAD Implantation: Role of Tricuspid Valve Annulus Displacement.

OBJECTIVES: Right ventricular failure after left ventricular assist device implantation increases postoperative morbidity and mortality. Whether intraoperative echocardiographic and hemodynamic measurements predict right ventricular failure is unclear. Speckle-tracking-derived tricuspid annulus displacement may provide a useful, effective, and straightforward predictor of severe right ventricular failure in patients having left ventricular device implantation. The aim of this study was to determine if intraoperative tricuspid annulus displacement is a stronger discriminator compared with the global longitudinal strain and modified tricuspid annular plane systolic excursion, the Michigan risk score, and pulmonary artery pulsatility index. DESIGN: Retrospective analysis. SETTING: A tertiary-care referral center. PARTICIPANTS: Patients scheduled for left ventricular assist device implantation from January 2010 to December 2017. INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: The authors examined 86 patients undergoing left ventricular assist device implantation with adequate intraoperative echocardiographic images. The analyses did not demonstrate an association between tricuspid annulus displacement and severe right ventricular failure (univariate C-statistics <0.60 for all 4 echocardiographic measures). The discrimination ability was not significantly better than strain (DeLong test p = 0.44) and modified tricuspid annular plane systolic excursion (p = 0.89). The discrimination ability of tricuspid annulus displacement measurements was not better than the Michigan risk score (p = 0.65) and pulmonary artery pulsatility index (p = 0.73). CONCLUSIONS: Intraoperative echocardiographic parameters, including tricuspid annulus displacement, modified tricuspid annular plane systolic excursion, and strain, are poor discriminators of severe right ventricular failure after left ventricular assist device implantation. The preoperative Michigan risk-scoring system and intraoperative pulmonary artery pulsatility index are equally unreliable.

A Comparison of Global Longitudinal, Circumferential, and Radial Strain to Predict Outcomes After Cardiac Surgery.

OBJECTIVE: Myocardial strain measured by speckle-tracking echocardiography detects subtle regional and global left ventricular dysfunction. Myocardial strain is measured in the longitudinal, circumferential, and radial dimensions; however, it is unclear which dimension of strain is the best predictor of postoperative outcomes. DESIGN: A secondary analysis of prospectively collected data from a clinical trial (NCT01187329). SETTING: The cardiothoracic surgical operating rooms of an academic tertiary-care center. PARTICIPANTS: Cardiothoracic surgery patients with aortic stenosis having aortic valve replacement (AVR) with or without coronary artery bypass grafting enrolled in a clinical trial. INTERVENTIONS: Myocardial deformation analysis from standardized investigative transesophageal echocardiographic examinations performed after induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: The authors compared the ability of intraoperative global longitudinal strain (GLS), global circumferential strain (GCS), and global radial strain (GRS) strain to predict adverse postoperative outcomes, including prolonged hospitalization and the need for pharmacologic hemodynamic support after cardiac surgery. The association of GLS, GCS, and GRS with prolonged hospitalization (>7 days) and the need for pharmacologic hemodynamic support, with epinephrine or norepinephrine after cardiopulmonary bypass, were assessed using separate multivariable logistic regression models with adjustment for multiple comparisons. Of 100 patients, 86 had acceptable measurements for GLS analysis, 73 for GCS, and 72 for GRS. Worse GLS was associated with prolonged hospitalization [odds ratio [OR] (98.3% confidence interval [CI]) of 1.21 (1.01-1.46) per-unit worsening in strain (p = 0.01, significance criterion <0.0167)] and the need for inotropic support with epinephrine [OR (99.2% CI) of 1.81 (1.10-2.97) per-unit worsening in strain (p = 0.002, significance criterion <0.0083)], but not norepinephrine. GCS and GRS were not associated with adverse outcomes. CONCLUSION: GLS, but not GCS or GRS, predicts prolonged hospitalization and the requirement for inotropic support with epinephrine after AVR.

Continuous-flow total artificial heart: hemodynamic and pump-related changes associated with posture in a chronic calf model.

This study aimed to evaluate the effects of posture (sitting [lying down]/standing) on hemodynamic and pump-related parameters in calves implanted with our institution's continuous-flow total artificial heart (CFTAH). These parameters were analyzed with posture information in four calves that had achieved the intended 14-, 30-, or 90-day durations of implantation. In each animal, postoperative hourly data gathered throughout the study were used to compare average values with the animal sitting vs. standing. Pump flow became significantly higher in the standing than sitting position at the same pump speed (standing 7.9 ± 0.8, sitting 7.4 ± 1.0 L/min, p = 0.028). Systemic vascular resistance (SVR) and aortic pressure (AoP) were significantly lower in the standing than sitting position (SVR standing 779 ± 145, sitting 929 ± 206 dyne s/cm5, p = 0.027; AoP standing 93 ± 7, sitting 103 ± 7 mm Hg, p < 0.001). No substantial change occurred in pulmonary vascular resistance (PVR) or pulmonary arterial pressure (PAP) with posture (PVR standing 161 ± 39, sitting 164 ± 48 dyne s/cm5, p = 0.639; PAP standing 32 ± 3, sitting 33 ± 4 mm Hg, p = 0.340). Posture affected some hemodynamic and pump-related parameters in calves with CFTAH, with implications for patients with implanted pumps.

Value of perioperative inhaled epoprostenol with low tidal volume ventilation for complex endocarditis surgery.

BACKGROUND AND AIM: To compare outcomes of patients treated with inhaled epoprostenol and low tidal volume ventilation during cardiopulmonary bypass with those who did not receive this medication in the operating room at all, and those who received it as a rescue therapy at the end of the case. METHODS: Retrospective chart review between 2014 and 2017, follow-up included the entire hospital stay. RESULTS: Seventy-one patients were included, and mean age was 54 years. 78.9% of the patients were male. Procedures included 96% (n = 68) aortic valve replacement, 28% (n = 20) reconstruction of the intravalvular fibrosa, and 13% (n = 9) repair of an endocarditis-related intracardiac fistula. Patients who received epoprostenol (iEpo) (treatment and rescue groups), when compared with the control group had more intra-aortic balloon pump placement (23% vs 2.5%, P = .018), open chest after surgery (32% vs 7.5%, P = .012), and duration of mechanical ventilation (8.3 ± 2.7 vs. 2.4 ± 0.4 days, P = 0.01). There was no significant difference between the two groups in terms of extracorporeal circulatory support (6.5% vs 2.5%, P = .577) and hospital death (13% vs 10%, P = .72). In a subanalysis, hospital death and duration of mechanical ventilation were higher in the recue group when compared with the treatment group (P = .004 and .056, respectively). CONCLUSIONS: Prophylactic application of iEpo with low tidal volume ventilation for an anticipated complex endocarditis operation may contribute to favorable outcome when compared with postoperative epoprostenol rescue.

Reduced Left Ventricular Global Longitudinal Strain Predicts Prolonged Hospitalization: A Cohort Analysis of Patients Having Aortic Valve Replacement Surgery.

BACKGROUND: Left ventricular ejection fraction (LVEF) is often preserved in patients with aortic stenosis and thus cannot distinguish between normal myocardial contractile function and subclinical dysfunction. Global longitudinal strain and strain rate (SR), which measure myocardial deformation, are robust indicators of myocardial function and can detect subtle myocardial dysfunction that is not apparent with conventional echocardiographic measures. Strain and SR may better predict postoperative outcomes than LVEF. The primary aim of our investigation was to assess the association between global longitudinal strain and serious postoperative outcomes in patients with aortic stenosis having aortic valve replacement. Secondarily, we also assessed the associations between global longitudinal SR and LVEF and the outcomes. METHODS: In this post hoc analysis of data from a randomized clinical trial (NCT01187329), we examined the association between measures of myocardial function and the following outcomes: (1) need for postoperative inotropic/vasopressor support; (2) prolonged hospitalization (>7 days); and (3) postoperative atrial fibrillation. Standardized transesophageal echocardiographic examinations were performed after anesthetic induction. Myocardial deformation was measured using speckle-tracking echocardiography. Multivariable logistic regression was used to assess associations between measures of myocardial function and outcomes, adjusted for potential confounding factors. The predictive ability of global longitudinal strain, SR, and LVEF was assessed as area under receiver operating characteristics curves (AUCs). RESULTS: Of 100 patients enrolled in the clinical trial, 86 patients with aortic stenosis had acceptable images for global longitudinal strain analysis. Primarily, worse intraoperative global longitudinal strain was associated with prolonged hospitalization (odds ratio [98.3% confidence interval], 1.22 [1.01-1.47] per 1% decrease [absolute value] in strain; P = .012), but not with other outcomes. Secondarily, worse global longitudinal SR was associated with prolonged hospitalization (odds ratio [99.7% confidence interval], 1.68 [1.01-2.79] per 0.1 second(-1) decrease [absolute value] in SR; P = .003), but not other outcomes. LVEF was not associated with any outcomes. Global longitudinal SR was the best predictor for prolonged hospitalization (AUC, 0.72), followed by global longitudinal strain (AUC, 0.67) and LVEF (AUC, 0.62). CONCLUSIONS: Global longitudinal strain and SR are useful predictors of prolonged hospitalization in patients with aortic stenosis having an aortic valve replacement.

New Technology Mimics Physiologic Pulsatile Flow During Cardiopulmonary Bypass.

The VentriFlo True Pulse Pump (Design Mentor, Inc., Pelham, NH, USA) is the first blood pump designed to mimic human arterial waveforms in a standard oxygenation circuit. Our aim was to demonstrate the feasibility and safety of this pump in preparation for future studies to determine possible clinical advantages. We studied four piglets (41.4-46.2 kg): three with an implanted VentriFlo pulsatile pump and one with the nonpulsatile ROTAFLOW pump (MAQUET Holding B.V. & Co. KG, Rastatt, Germany) as a control. Hemodynamics was monitored during 6-h cardiopulmonary bypass (CPB) support and for 2 h after weaning off CPB. The VentriFlo demonstrated physiologic arterial waveforms with arterial pulse pressure of 24.6 ± 5.7 mm Hg. Pump flows (2.0 ± 0.1 L/min in ROTAFLOW; 1.9 ± 0.1 L/min in VentriFlo) and plasma free hemoglobin levels (27.9 ± 12.5 mg/dL in ROTAFLOW; 28.5 ± 14.2 mg/dL in VentriFlo) were also comparable, but systemic O2 extraction (as measured by arterial minus venous O2 saturation) registered slightly higher with the VentriFlo (63.2 ± 6.9%) than the ROTAFLOW (55.4 ± 6.5%). Histological findings showed no evidence of ischemic changes or thromboembolism. This pilot study demonstrated that the VentriFlo system generated pulsatile flow and maintained adequate perfusion of all organs during prolonged CPB.

Transvenous Lead Extraction: A Clinical Commentary for Anesthesiologists.

With increasing use of cardiovascular implantable electronic devices, the need for lead extractions has increased to an annual volume of more than 10,000 extractions worldwide. This article provides a focused clinical commentary on the perioperative management, identification, and treatment of life-threatening complications associated with lead extractions. In addition, a summary of indications, techniques, and lead extraction complications is provided. Although uncommon, lead extractions are associated with a consistent rate of major procedure-related complications and mortality. Major life-threatening complications include vascular laceration, cardiac avulsion, hemothorax, pericardial effusion, and cardiac arrest. Comprehensive preoperative risk assessment and adequate planning and preparedness are crucial to decreasing all procedure-related adverse events. The location of the procedure (electrophysiology suite v hybrid operating room) and the nature of cardiac surgical backup are determined after meticulous risk stratification. In addition to decisions on vascular access, invasive monitoring, and modality of rhythm support, transesophageal echocardiography plays a crucial role in early diagnosis, timely management, and potential prevention of these complications.

Early Left and Right Ventricular Response to Aortic Valve Replacement.

BACKGROUND: The immediate effect of aortic valve replacement (AVR) for aortic stenosis on perioperative myocardial function is unclear. Left ventricular (LV) function may be impaired by cardioplegia-induced myocardial arrest and ischemia-reperfusion injury, especially in patients with LV hypertrophy. Alternatively, LV function may improve when afterload is reduced after AVR. The right ventricle (RV), however, experiences cardioplegic arrest without benefiting from improved loading conditions. Which of these effects on myocardial function dominate in patients undergoing AVR for aortic stenosis has not been thoroughly explored. Our primary objective is thus to characterize the effect of intraoperative events on LV function during AVR using echocardiographic measures of myocardial deformation. Second, we evaluated RV function. METHODS: In this supplementary analysis of 100 patients enrolled in a clinical trial (NCT01187329), 97 patients underwent AVR for aortic stenosis. Of these patients, 95 had a standardized intraoperative transesophageal echocardiographic examination of systolic and diastolic function performed before surgical incision and repeated after chest closure. Echocardiographic images were analyzed off-line for global longitudinal myocardial strain and strain rate using 2D speckle-tracking echocardiography. Myocardial deformation assessed at the beginning of surgery was compared with the end of surgery using paired t tests corrected for multiple comparisons. RESULTS: LV volumes and arterial blood pressure decreased, and heart rate increased at the end of surgery. Echocardiographic images were acceptable for analysis in 72 patients for LV strain, 67 for LV strain rate, and 54 for RV strain and strain rate. In 72 patients with LV strain images, 9 patients required epinephrine, 22 required norepinephrine, and 2 required both at the end of surgery. LV strain did not change at the end of surgery compared with the beginning of surgery (difference: 0.7 [97.6% confidence interval, -0.2 to 1.5]%; P = 0.07), whereas LV systolic strain rate improved (became more negative) (-0.3 [-0.4 to -0.2] s; P < 0.001). In contrast, RV systolic strain worsened (became less negative) at the end of surgery (difference: 4.6 [3.1 to 6.0]%; P < 0.001) although RV systolic strain rate was unchanged (0.0 [97.6% confidence interval, -0.1 to 0.1]; P = 0.83). CONCLUSIONS: LV function improved after replacement of a stenotic aortic valve demonstrated by improved longitudinal strain rate. In contrast, RV function, assessed by longitudinal strain, was reduced.

Deairing Techniques for Double-Ended Centrifugal Total Artificial Heart Implantation.

The unique device architecture of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) requires dedicated and specific air-removal techniques during device implantation in vivo. These procedures comprise special surgical techniques and intraoperative manipulations, as well as engineering design changes and optimizations to the device itself. The current study evaluated the optimal air-removal techniques during the Cleveland Clinic double-ended centrifugal CFTAH in vivo implants (n = 17). Techniques and pump design iterations consisted of developing a priming method for the device and the use of built-in deairing ports in the early cases (n = 5). In the remaining cases (n = 12), deairing ports were not used. Dedicated air-removal ports were not considered an essential design requirement, and such ports may represent an additional risk for pump thrombosis. Careful passive deairing was found to be an effective measure with a centrifugal pump of this design. In this report, the techniques and design changes that were made during this CFTAH development program to enable effective residual air removal and prevention of air embolism during in vivo device implantation are explained.

Novel technique for airless connection of artificial heart to vascular conduits.

Successful implantation of a total artificial heart relies on multiple standardized procedures, primarily the resection of the native heart, and exacting preparation of the atrial and vascular conduits for pump implant and activation. Achieving secure pump connections to inflow/outflow conduits is critical to a successful outcome. During the connection process, however, air may be introduced into the circulation, traveling to the brain and multiple organs. Such air emboli block blood flow to these areas and are detrimental to long-term survival. A correctly managed pump-to-conduit connection prevents air from collecting in the pump and conduits. To further optimize pump-connection techniques, we have developed a novel connecting sleeve that enables airless connection of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) to the conduits. In this brief report, we describe the connecting sleeve design and our initial results from two acute in vivo implantations using a scaled-down version of the CFTAH.

Generating pulsatility by pump speed modulation with continuous-flow total artificial heart in awake calves.

The purpose of this study was to evaluate the effects of sinusoidal pump speed modulation of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) on hemodynamics and pump flow in an awake chronic calf model. The sinusoidal pump speed modulations, performed on the day of elective sacrifice, were set at ±15 and ± 25% of mean pump speed at 80 bpm in four awake calves with a CFTAH. The systemic and pulmonary arterial pulse pressures increased to 12.0 and 12.3 mmHg (±15% modulation) and to 15.9 and 15.7 mmHg (±25% modulation), respectively. The pulsatility index and surplus hemodynamic energy significantly increased, respectively, to 1.05 and 1346 ergs/cm at ±15% speed modulation and to 1.51 and 3381 ergs/cm at ±25% speed modulation. This study showed that it is feasible to generate pressure pulsatility with pump speed modulation; the platform is suitable for evaluating the physiologic impact of pulsatility and allows determination of the best speed modulations in terms of magnitude, frequency, and profiles.

The response to Trendelenburg position is minimally affected by underlying hemodynamic conditions in patients with aortic stenosis.

PURPOSE: Trendelenburg positioning is commonly used to temporarily treat intraoperative hypotension. The Trendelenburg position improves cardiac output in normovolemic or anesthetized patients, but not hypovolemic or non-anesthetized patients. Therefore, the response to Trendelenburg positioning may vary depending on patient population or hemodynamic conditions. We thus tested the hypothesis that the effectiveness of the Trendelenburg position, as indicated by an increase in cardiac output, improves after replacement of a stenotic aortic valve. Secondarily, we evaluated whether measurements of left ventricular preload, systolic function, or afterload were associated with the response to Trendelenburg positioning. METHODS: This study is a secondary analysis of a clinical trial which included patients having aortic valve replacement (AVR) who were monitored with pulmonary artery catheters (NCT01187329). We examined changes in thermodilution cardiac output with Trendelenburg positioning before and after AVR. We also examined whether echocardiographic and hemodynamic measurements of preload, afterload, and systolic function were associated with changes in cardiac output during Trendelenburg positioning. RESULTS: Thirty-seven patients were included. The median [IQR] cardiac output change with Trendelenburg positioning was -3% [-10%, 5%] before AVR versus +4% [-4%, 15%] after AVR. Estimated median difference in cardiac output with Trendelenburg was 5% (95% CI 1, 15%, P = 0.04) greater after AVR. The response to Trendelenburg positioning was largely independent of hemodynamic conditions. CONCLUSION: The response to Trendelenburg positioning improved following AVR, but by a clinically unimportant amount. The response to Trendelenburg positioning was independent of hemodynamic conditions.

Median Sternotomy or Right Thoracotomy Techniques for Total Artificial Heart Implantation in Calves.

The choice of optimal operative access technique for mechanical circulatory support device implantation ensures successful postoperative outcomes. In this study, we retrospectively evaluated the median sternotomy and lateral thoracotomy incisions for placement of the Cleveland Clinic continuous-flow total artificial heart (CFTAH) in a bovine model. The CFTAH was implanted in 17 calves (Jersey calves; weight range, 77.0-93.9 kg) through a median sternotomy (n = 9) or right thoracotomy (n = 8) for elective chronic implantation periods of 14, 30, or 90 days. Similar preoperative preparation, surgical techniques, and postoperative care were employed. Implantation of the CFTAH was successfully performed in all cases. Both methods provided excellent surgical field visualization. After device connection, however, the median sternotomy approach provided better visualization of the anastomoses and surgical lines for hemostasis confirmation and repair due to easier device displacement, which is severely limited following right thoracotomy. All four animals sacrificed after completion of the planned durations (up to 90 days) were operated through full median sternotomy. Our data demonstrate that both approaches provide excellent initial field visualization. Full median sternotomy provides larger viewing angles at the anastomotic suture line after device connection to inflow and outflow ports.

Hyperinsulinemic Normoglycemia Does Not Meaningfully Improve Myocardial Performance during Cardiac Surgery: A Randomized Trial.

BACKGROUND: Glucose-insulin-potassium (GIK) administration during cardiac surgery inconsistently improves myocardial function, perhaps because hyperglycemia negates the beneficial effects of GIK. The hyperinsulinemic normoglycemic clamp (HNC) technique may better enhance the myocardial benefits of GIK. The authors extended previous GIK investigations by (1) targeting normoglycemia while administering a GIK infusion (HNC); (2) using improved echocardiographic measures of myocardial deformation, specifically myocardial longitudinal strain and strain rate; and (3) assessing the activation of glucose metabolic pathways. METHODS: A total of 100 patients having aortic valve replacement for aortic stenosis were randomly assigned to HNC (high-dose insulin with concomitant glucose infusion titrated to normoglycemia) versus standard therapy (insulin treatment if glucose >150 mg/dl). The primary outcomes were left ventricular longitudinal strain and strain rate, assessed using speckle-tracking echocardiography. Right atrial tissue was analyzed for activation of glycolysis/pyruvate oxidation and alternative metabolic pathways. RESULTS: Time-weighted mean glucose concentrations were lower with HNC (127 ± 19 mg/dl) than standard care (177 ± 41 mg/dl; P < 0.001). Echocardiographic data were adequate in 72 patients for strain analysis and 67 patients for strain rate analysis. HNC did not improve myocardial strain, with an HNC minus standard therapy difference of -1.2% (97.5% CI, -2.9 to 0.5%; P = 0.11). Strain rate was significantly better, but by a clinically unimportant amount: -0.16 s (-0.30 to -0.03 s; P = 0.007). There was no evidence of increased glycolytic, pyruvate oxidation, or hexosamine biosynthetic pathway activation in right atrial samples (HNC, n = 20; standard therapy, 22). CONCLUSION: Administration of glucose and insulin while targeting normoglycemia during aortic valve replacement did not meaningfully improve myocardial function.

Anatomy of the bovine ascending aorta and brachiocephalic artery found unfavorable for total artificial heart implant.

The biocompatibility assessment of the Cleveland Clinic continuous-flow total artificial heart is an important part of the device developmental program. Surgical and postoperative management are key factors in achieving optimal outcomes. However, the presence of vascular anatomical abnormalities in experimental animal models is often unpredictable and may worsen the expected outcomes. We report a technical impediment encountered during total artificial heart implantation complicated by unfavorable bovine anatomy of the ascending aorta and brachiocephalic arterial trunk.