Current Issue of JECT
The premier source of the most current research and information related to extracorporeal technology including Cardiopulmonary Bypass, Extracorporeal Life Support, Mechanical Assist Devices, and Perioperative Blood Management.
|Volume 50 / Issue 3 / September 2018||Contents|
Incidence of Cerebral Microemboli in Single-Dose vs. Multidose Cardioplegia in Adult Cardiac Surgery
Laith Mukdad, BA; William Toppen, MD; Yas Sanaiha, MD; Aditya Mantha, MPH; Stephanie Bland, MS; Richard Shemin, MD; Peyman Benharash, MD
Abstract: Cerebral microemboli have been associated with neurocognitive deficits after cardiac operations using cardiopulmonary bypass (CPB). Interventions by the perfusionist and alterations in blood flow account for a large proportion of previously unexplained microemboli. This study compared the incidence of microemboli during cardiac operations using conventional (multidose) and del Nido (single-dose) cardioplegia delivery. Transcranial Doppler ultrasonography was used to detect microemboli in bilateral middle cerebral arteries of 30 adult patients undergoing cardiac operations using CPB and aortic clamping. Multidose conventional blood cardioplegia (CBC) was used in 15 patients and single-dose del Nido cardioplegia (DNC) in 15. Manual count of microemboli during cross-clamp and during administration of cardioplegia was performed. Baseline preoperative characteristics were similar between groups. There were no differences in the ascending aortic atheroma grade (1.4 6 .4 CBC vs. 1.6 6 .7 DNC, p 5 .44), bypass times (141 6 36 minutes CBC vs. 151 6 33 minutes DNC, p 5 .64), and cross-clamp times (118 6 32 minutes CBC vs. 119 6 45 minutes DNC, p 5 .95). The use of multidose CBC was associated with a seven-fold increase in the number of microemboli per minute of bypass (1.656 1 vs. .246 .18 emboli/min DNC, p 5 .0004). In this prospective pilot study, we found that the use of single-dose cardioplegia strategy led to fewer cerebral microemboli when compared with the traditional multidose approach. Our findings warrant further investigation of various cardioplegia strategies and neurologic outcomes in larger cohorts.
Keywords: cardioplegia, cerebral microemboli, transcranial Doppler ultrasonography, cardiac surgery. J ExtraCorpor Technol. 2018;50:143–8
Use of Thromboelastography to Predict Thrombotic Complications in Pediatric and Neonatal Extracorporeal Membranous Oxygenation
Natalie Henderson, Janice E. Sullivan, John Myers, Terri Wells, Aaron Calhoun, John Berkenbosch, and Deanna Todd Tzanetos
Abstract: The objectives of this study were to investigate the correlation between thromboelastography (TEG) and conventional measures of anticoagulation, and to determine optimum values for citrated kaolin TEG R time (TEG RCK) and anti-Xa activity that would minimize both bleeding and thrombotic complications in pediatric and neonatal patients requiring extracorporeal membranous oxygenation (ECMO). A retrospective chart review of patients requiring veno-venous (VV) and venoarterial (VA)ECMOwas performed. Combined medical and cardiac ICU within a single-center, tertiary care, freestanding, children’s hospital. Non-pregnant patients <18 years and >2 kilograms requiring VV or VA ECMO from July 2013 through July 2015. Anti-Xa (OR 5 0.62, 95% CI 0.53–0.72, p < .001) and TEG RCK (OR51.19, 95% CI 1.07–1.34, p5.003) were the only independent predictors for a significant thrombotic event. Receiver operating characteristic curves and traditional epidemiological data (sensitivity, specificity, PPV, NPV) were used to determine optimal target Anti-Xa and TEG RCK values. No independent predictors for significant bleeding events were identified in this cohort. A anti-Xa activity of .25 IU/mL (sensitivity 5 81%, specificity 5 67%, PPV 5 81%, NPV 5 58%) and TEG RCK time of 17.85 minutes (sensitivity 5 84%, specificity 5 68%, PPV 5 82%, NPV 5 59%) were established as the optimal thresholds for preventing thrombotic events. Anti-Xa and TEG RCK were independent predictors of thrombosis in this cohort of pediatric and neonatal ECMO patients. Targeting an anti-Xa activity greater than .25 IU/mL and a TEG RCK greater than 17.85 minutes may minimize the risk of thrombosis in pediatric and neonatal ECMO patients. Future investigation should evaluate targets for anti-Xa and TEG RCK, which additionally minimize the risk of significant bleeding in this patient population.
Keywords: thromboelastography, extracorporeal membrane oxygenation, thrombosis, pediatrics, neonatal, heparin management. J Extra Corpor Technol. 2018;50:149–54
Distal Perfusion Cannulation and Limb Complications in Venoarterial Extracorporeal Membrane Oxygenation
Adham Elmously, Thomas Bobka, Sandi Khin, Ashwad Afzal, Andreas R. de Biasi, William J. DeBois, T. Sloane Guy, Marcus D’ayala, Iosif Gulkarov, Arash Salemi, and Berhane Worku
Abstract: The utility of distal perfusion cannula (DPC) placement for the prevention of limb complications in patients undergoing femoral venoarterial (VA) extracorporeal membrane oxygenation (ECMO) is poorly characterized. Patients undergoing femoral VA ECMO cannulation at two institutions were retrospectively assessed. Patients were grouped into those who did and those who did not receive a DPC at the time of primary cannulation. The primary outcome was any limb complication. Secondary outcomes included successfully weaning ECMO and in-hospital mortality. A total of 75 patients underwent femoral cannulation between December 2010 and December 2017. Of those, 65 patients (86.7%) had a DPC placed during primary cannulation and 10 patients (13.3%) did not. Baseline demographics, indications for ECMO, and hemodynamic perturbations were well matched between groups. The rate of limb complications was 14.7% (11/75) for the overall cohort and did not differ between groups (p 5 .6). Three patients (4%) required a four-compartment fasciotomy for compartment syndrome in the DPC group; no patients without a DPC required fasciotomy. Of the three patients who required a thrombectomy for distal ischemia, two were in the DPC group and one was in the no DPC group (p 5 .3). Two patients (2.7%) underwent delayed DPC placement for limb ischemia with resolution of symptoms. The inhospital morality rate was 59.5% and did not differ between groups (p 5 .5). Patients in the present study, undergoing femoral VA ECMO without preemptive DPC placement did not experience a higher rate of limb complications. However, the two patients who underwent delayed DPC placement for post-cannulation ischemia experienced resolution of symptoms, suggesting that a DPC may be used as an effective limb salvage intervention.
Keywords: extracorporeal membrane oxygenation, distal perfusion catheter, femoral cannulation, limb ischemia. J Extra Corpor Technol. 2018;50:155–60
Bivalirudin Anticoagulation Dosing Protocol for Extracorporeal Membrane Oxygenation: A Retrospective Review
Jared Netley, PharmD;* James Roy, PharmD;* Joseph Greenlee, MD;† Shaun Hart, NP;† Michael Todt, PharmD;* Bryan Statz, PharmD*
Abstract: Anticoagulation with unfractionated heparin during extracorporeal membrane oxygenation (ECMO) is common, but alternative agents are being evaluated for safety and efficacy. The objective of this analysis was to assess if a comprehensive bivalirudin dosing and monitoring protocol effectively guides dose adjustments and monitoring of bivalirudin in patients during ECMO. Our analysis included 11 patients who received bivalirudin during ECMO therapy and had dosing managed using our hospital derived protocol. Patients treated over a 1-year period were included in this retrospective analysis. Clinical characteristics and changes in activated partial thromboplastin time (aPTT) were evaluated from medical records to determine the efficacy of the dosing protocol. ECMO was initiated for acute respiratory distress syndrome in eight (72.7%) patients and for cardiac arrest in three (27.3%) patients. A total of 178 protocol guided dose adjustments were made during the study. Among the dose adjustments, 56 (31.5%) attained the protocol predicted aPTT level change, 96 (53.9%) of the measured aPTT changes were less than predicted, and 26 (14.6%) of the measured aPTT changes were more than predicted. On average, patients were within their defined therapeutic aPTT target range 66.3% of the time. All patients reached their designated aPTT target range within the first 24 hours of therapy. Significant bleeding was documented in eight (72.7%) patients. No clinically evident thromboembolic events were identified in vivo while cannulated. This analysis suggests that bivalirudin can be managed using a dosing protocol to provide anticoagulation therapy to patients during ECMO and can provide foundational guidance for dose adjustment and monitoring for other institutions.
Keywords: extracorporeal membrane oxygenation, blood, anticoagulation, bivalirudin, pharmacology. J Extra Corpor Technol. 2018;50:161–6
Malposition of the Extracorporeal Membrane Oxygenation Venous Cannula in an Accessory Hepatic Vein
Hadrien Winiszewski, Andrea Perrotti, Sidney Chocron, Gilles Capellier, and Ga¨el Piton
Abstract: We report a case of a refractory cardiogenic shock secondary to myocardial infarction in a 70-year-old patient requiring femoral venoarterial extracorporeal membrane oxygenation (VA-ECMO). At initial transesophageal echocardiography, the venous cannula tip was seen in the inferior vena cava (IVC), but not in right atrium. On day 8, ultrasonic examination identified that the end of the venous cannula was in the hepatic vein (HV). Despite such malposition, no disturbance in extracorporeal membrane oxygenation (ECMO) venous return was observed.Moving or replacing the cannula was considered a high-risk maneuver potentially resulting in hepatic laceration with hemoperitoneum. Because of adequate venous drainage, allowing sufficient blood flow, venous cannula repositioning was delayed until day 10, when a ventricular defect was repaired and ECMO was weaned off. At the time of VA-ECMO implantation, the venous cannula has to be positioned in the right atrium using real time echo monitoring. Visualization of the guide wire in the IVC but not in the right atrium is insufficient to ensure appropriate venous cannula positioning. Indeed, either accidental catheterization or cannula migration into the HV is possible during ECMO. Health care professionals dealing with ECMO have to be aware of this possible malposition, to correct it and prevent insufficient venous drainage or traumatic complications.
Keywords: shock, extracorporeal membrane oxygenation, echocardiography. J Extra Corpor Technol. 2018;50:167–9
Recombinant Factor VIII Measurement in a Hemophilia A Patient Undergoing Cardiopulmonary Bypass–Supported Cardiac Surgery
Jennifer Bezaire, Dorothy Thomson, and Erick McNair
Abstract: Patients with hemophilia A (Hem A) requiring cardiopulmonary bypass–supported cardiac surgery pose unique challenges for perioperative hemostatic management. This report describes a staged perioperative approach to clinical hematologic management as applied to an 80-year-old male of O-positive blood type with mild Hem A, who underwent successful, uncomplicated coronary artery bypass graft surgery. Hematologic management primarily consisted of normalization of plasma factor VIII levels followed by standard care. Conventional laboratory methods and point-of-care-testing methods such as thromboelastography and heparin management assays were combined to guide patient care. Minimal blood loss and minimal hemodilution techniques were also used to achieve favorable outcomes. The thorough preparation and execution of care by our multidisciplinary team from perfusion, pathology and laboratory medicine, cardiovascular surgery, transfusion services, nursing, and anesthesia, facilitated a safe, smooth, clinical course and an optimal outcome.
Keywords: hemophilia A, factorVIII, recombinant factor VIII, thromboelastography, point-of-care testing. J Extra Corpor Technol. 2018;50:170–7
The Novel Use of a Low Prime Modified Ultrafiltration Apparatus in a 13-kg Jehovah’s Witness Patient: A Case Report
Bharat Datt, Hamish M. Munro, and William M. DeCampli
Abstract: Modified ultrafiltration (MUF) is used in neonates and infants to reduce volume overload and increase oxygencarrying capacity post cardiopulmonary bypass (CPB). In addition, it decreases edema, attenuates complementation activation and immunogenic response to CPB. Hemodilution in the pediatric patient has always been a challenge, countered in part by miniaturization of CPB circuits. We describe a case in which we maintained an acceptable hematocrit level greater than 24%, considered the nadir below which the adverse effects of hemodilution can become evident. We performed this by the novel use of an intravenous warming device (enFlow, Vyaire Medical, Mettawa, IL) to reduce the prime volume of our MUF circuit by more than 50%. We present the case and discuss the advantages and disadvantages of using a low-prime MUF circuit. We were able to conduct “bloodless” CPB, with the use of acute normovolemic hemodilution, miniaturization of the CPB and MUF circuits.
Keywords: modified ultrafiltration, cardiopulmonary bypass, Jehovah’s Witness, enFlow. J Extra Corpor Technol. 2018;50: 178–83
Bloodless Heart Surgery for an 11-kg Infant of the Jehovah’s Witness Faith Undergoing Second Repair for Complete Atrioventricular Canal
Gary Plancher, Bharat Datt, Moui Nguyen, Hamish Munro, William M. DeCampli, and Kamal Pourmoghadam
Abstract: Bloodless pediatric cardiac surgery is the intent of most surgical centers especially in the Jehovah’s Witness population where it is a desire not to administer blood products because of religious belief. It is a tremendous feat, considering that most pediatric cardiovascular prime volumes are more than 20% of the patient’s estimated blood volume (EBV). We report on our bloodless strategy for a 2-year old Jehovah’s Witness with trisomy 21 and complete atrioventricular canal repair, who underwent atrial septal defect and ventricular septal defect patch closure, pulmonary artery debanding, and pulmonary arterioplasty. We modified our circuit to reduce our prime volume to approximately 10% of the EBV and removed 200 mL of the patient’s blood before surgery as acute normovolemic hemodilution. We did not alter our institutional standards for transfusion of blood and blood products. The post cardiopulmonary bypass (CPB) hematocrit was 30%. We conclude that bloodless CPB surgery can be performed safely in Jehovah’s Witness patients with a carefully planned interdisciplinary approach.
Keywords: bloodless, Jehovah’s Witness, blood transfusion, cardiopulmonary bypass, infant. J Extra Corpor Technol. 2018;50:184–6
Asanguinous Del Nido Cardioplegia for an Aortic Valve Replacement Patient with Cold Agglutinins
Michael Rosenbloom, Michael Hancock, Perry Weinstock, Allyson Paterek, Richard Highbloom, Frank Bowen, and Kinjal Patel
Abstract: A patient with known cold agglutinins requiring an aortic valve replacement was referred for surgery. Asanguinous, Del Nido cardioplegia was used for myocardial protection. Warm induction followed by cold infusion prevented any agglutination and eliminated the need for subsequent cardioplegia doses. Following the cross-clamp period, the heart returned to normal sinus rhythm without need for defibrillation. Postoperative ejection fraction and systolic function were normal.
Keywords: aortic valve replacement, cardiopulmonary bypass, CPB, inflammatory response, CPB pathophysiology, CPB complications, myocardial protection, Del Nido, cardioplegia, cold agglutinins. J Extra Corpor Technol. 2018;50:187–8
Complete Myocardial Function Recovery with ECMO in a Woman Presenting with Cardiogenic Shock during Peripartum Period
Mukund Das, Anil Rathi, Ashwad Afzal, and Kumudha Ramasubbu
Abstract: Peripartum cardiomyopathy is a potentially life threatening cause of heart failure (HF) that affects women toward the end of pregnancy or in months after delivery. Treatment is similar to the treatment for HF with reduced ejection fraction (EF). Most women make full myocardial function recovery within 6 months on conventional HF therapy. In rare instances, catastrophic presentations may occur with hemodynamic instability requiring the use of mechanical support. Because of the small patient population, limited information is available regarding the recovery of myocardial function in women who received mechanical support. We present a case of a woman in her peripartum period who presented with cardiogenic shock and made complete myocardial function recovery after 4 days of extracorporeal membrane oxygenation (ECMO). Our patient’s EF at the time of catastrophe was 5–10%, which improved to 60% on day 4 on ECMO.
Keywords: cardiomyopathy, postpartum, heart failure, mechanical circulatory support, extracorporeal membrane oxygenation (ECMO). J Extra Corpor Technol. 2018;50:189–92
Technique of Complete Heart Isolation with Continuous Cardiac Perfusion During Cardiopulmonary Bypass: New
Opportunities for Gene Therapy
Michael G. Katz, Anthony S. Fargnoli, Charles Yarnall, Angel Perez, Alice Isidro, Roger J. Hajjar, and Charles R. Bridges
Abstract: Cardiopulmonary bypass (CPB) featuring complete heart isolation and continuous cardiac perfusion is a very promising approach for solving the problem of efficient gene delivery. In the technique presented here, separate pumps are used for the systemic and cardiac circuits. This system permits continuous isolated arrested heart perfusion through optimizing a number of delivery parameters including temperature, flow rate, driving pressure, ionic composition, and exposure time to the cardiac vessels. During complete cardiac isolation, the blood vector concentration trended from 11.51 6 1.73 log genome copies (GCs)/cm3 to 9.84 6 1.65 log GC/cm3 (p > .05). Despite restructuring a very high concentration to the heart, GCs were detectable in the systemic circuit. These values over time were near negligible by comparison but detectable 1.66 6 .26 during 20 minutes of recirculation and did not change (p > .05). After the completion of the recirculation interval and subsequent washing procedure, the initial systemic blood vector GC concentration slightly increased to 2.08 6 .38 log GCs/cm3 (p > .05). During the recirculation period, we supported flow via the cardiac circuit around 300 mL/min. In this technique of heart isolation with continuous cardiac perfusion, >99% of the vector remains in coronary circulation during recirculation period. The animal’s non recirculation blood, or that in the system, was routinely tested during and after recirculation to contain much less than 1% of the original dose obtained via logging concentration of therapeutic over time. All of the sheep in this group recovered from anesthesia and received critical postoperative care, including all organ function, in the first 24–36 hours. Twenty-one sheep (84%) survived to euthanasia at 12 weeks. Average CPB time was 107 6 19.0 minutes and cross-clamp time was 49 6 7.9 minutes. This technology readily provides multiple pass recirculation of genes through the heart with minimal side effects of collateral expression of other organs.
Keywords: heart isolation, gene therapy, heart perfusion, cardiopulmonary bypass. J Extra Corpor Technol. 2018;50:193–8
Charles A. Rowland and Joanne P. Formicola