John P. Costello

Utilizing three-dimensional printing technology to assess the feasibility of high-fidelity synthetic ventricular septal defect models for simulation in medical education

Background: The current educational approach for teaching congenital heart disease (CHD) anatomy to students involves instructional tools and techniques that have significant limitations. This study sought to assess the feasibility of utilizing present-day three-dimensional (3D) printing technology to create high-fidelity synthetic heart models with ventricular septal defect (VSD) lesions and applying these models to a novel, simulation-based educational curriculum for premedical and medical students. Methods: Archived, de-identified magnetic resonance images of five common VSD subtypes were obtained. These cardiac images were then segmented and built into 3D computer-aided design models using Mimics Innovation Suite software. An Objet500 Connex 3D printer was subsequently utilized to print a high-fidelity heart model for each VSD subtype. Next, a simulation-based educational curriculum using these heart models was developed and implemented in the instruction of 29 premedical and medical students. Assessment of this curriculum was undertaken with Likert-type questionnaires. Results: High-fidelity VSD models were successfully created utilizing magnetic resonance imaging data and 3D printing. Following instruction with these high-fidelity models, all students reported significant improvement in knowledge acquisition (P < .0001), knowledge reporting (P < .0001), and structural conceptualization (P < .0001) of VSDs. Conclusions: It is feasible to use present-day 3D printing technology to create high-fidelity heart models with complex intracardiac defects. Furthermore, this tool forms the foundation for an innovative, simulation-based educational approach to teach students about CHD and creates a novel opportunity to stimulate their interest in this field.

Minimally Invasive Resynchronization Pacemaker: A Pediatric Animal Model

PURPOSE We developed a minimally invasive epicardial pacemaker implantation method for infants and congenital heart disease patients for whom a transvenous approach is contraindicated. The piglet is an ideal model for technical development. DESCRIPTION In 5 piglets we introduced a needle through subxiphoid approach under thoracoscopic guidance, inserting a wire into the pericardial space. Pacing leads were affixed to the left ventricular free wall and left atrial appendage. After verifying functionality with atrial and ventricular pacing and sensing, animals were euthanized. Pacemaker monitoring occurred daily for 4 days in the fifth animal. EVALUATION Through minimally invasive pericardial access, we directly visualized and fixated pacing leads to the left ventricle and left atrial appendage, successfully pacing atrium and ventricle. Epicardial structures were visualized. One piglet had contralateral pneumothorax, which resolved with needle decompression. No other adverse events occurred. CONCLUSIONS Minimally invasive epicardial pacemaker implantation in an infant model is feasible and effective. This innovation may be of value for pacing and resynchronization in infants and congenital heart disease patients. Survival studies with permanent generator implantation are under way.

Acquired von Willebrand Syndrome in a Child Following Berlin Heart EXCOR Pediatric Ventricular Assist Device Implantation Case Report and Concise Literature Review

The development of acquired von Willebrand syndrome (AVWS) after placement of a pulsatile-flow left ventricular assist device (LVAD) is rare and only recently recognized. We report the case of a young infant who was diagnosed with ventricular assist device (VAD)-related AVWS following implantation of a Berlin Heart EXCOR Pediatric Ventricular Assist Device (Berlin Heart Inc., The Woodlands, Texas, USA) for treatment of severe heart failure. Despite significant bleeding, the patient was successfully managed with von Willebrand factor-containing concentrate until VAD explantation led to definitive resolution of the AVWS. This case demonstrates that the possibility of this diagnosis should be considered in pediatric patients when extensive, nonsurgical bleeding is encountered after pulsatile-flow VAD implantation.

Timing of Gastrostomy Tube Feeding in Three‐stage Palliation of Single‐ventricle Physiology

OBJECTIVE Gastrostomy tube (G-tube) placement during three-stage surgical palliation of single-ventricle cardiac physiology has been shown to improve weight gain in this population of infants who often suffer from inadequate feeding. The optimal timing of this intervention is unclear and requires further investigation. DESIGN A retrospective review of all patients who underwent G-tube placement at any stage of surgical palliation of single-ventricle physiology from January 2005 to December 2012 was performed at a single congenital cardiac surgery center. Analysis of weight gain and survival was undertaken by comparing patients who received the G-tube either less than or greater than 90 days after the first surgical stage. RESULTS Fifty-four patients were identified that met the criteria, 26 (48%) of which received the G-tube within 90 days of stage 1, while 28 (52%) patients received the tube at greater than 90 days. Percentage of weight gain at time of discharge from stage 1 was significantly higher for group B (A: median 9.9%, interquartile range [IQR] 4.9-29.8; B: median 29.0%, IQR 16.0-44.3; P = .05). However, total hospital length of stay was decreased for the patients who received G-tubes earlier (A: median 60 days, IQR 35-100; B: median 83, IQR 48-184) as was intensive care unit length of stay (A: median 27 days, IQR 13-69; B: median 48, IQR 16-119) by nearly half, although not statistically significant (P = .47). Survival to time of discharge from stage 1 surgery was not significantly different between earlier tube placements vs. later (92% vs. 100%, respectively; P = .14). Multivariable analysis found inclusion of fundoplication to predict weight gain (P = .006) at time of first discharge. CONCLUSION Earlier placement of G-tube may increase the rate of recovery from stage 1 of multistage palliative cardiac surgery for single-ventricle physiology. Fundoplication may improve perioperative weight gain when indicated.

Surgical cardiac denervation therapy for treatment of congenital ion channelopathies in pediatric patients: a contemporary, single institutional experience.

Background: Congenital ion channel disorders, including congenital long QT syndrome (LQTS), cause significant morbidity in pediatric patients. When medication therapy does not control symptoms or arrhythmias, more invasive treatment strategies may be necessary. This study examines our institution’s clinical experience with surgical cardiac denervation therapy for management of these arrhythmogenic disorders in children. Methods: An institutional review board–approved retrospective review identified ten pediatric patients with congenital ion channelopathies who underwent surgical cardiac denervation therapy at a single institution between May 2011 and April 2014. Eight patients had a diagnosis of congenital LQTS, two patients were diagnosed with catecholaminergic polymorphic ventricular tachycardia (CPVT). All patients underwent sympathectomy and partial stellate ganglionectomy via video-assisted thoracoscopic surgery (VATS). Results: Six of the ten patients had documented ventricular arrhythmias preoperatively, and 70% of the patients had preoperative syncope. The corrected QT interval decreased in 75% of patients with LQTS following sympathectomy. Postoperative arrhythmogenic symptoms were absent in 88% of congenital LQTS patients, but both patients with CPVT continued to have symptoms throughout the duration of follow-up. All patients were alive after a median follow-up period of 10 months. Conclusions: Surgical cardiac denervation therapy via VATS is a useful treatment strategy for congenital LQTS patients who fail medical management, and its potential benefit in the management of CPVT is unclear. A prospective comparison of the efficacy of surgical cardiac denervation therapy and implantable cardioverter-defibrillator use in congenital ion channelopathies is timely and crucial.

Outcomes of Tracheostomy Following Congenital Heart Surgery: A Contemporary Experience

INTRODUCTION Following congenital heart surgery, pediatric patients may experience persistent respiratory failure that requires tracheostomy placement. Currently, definitive knowledge of the optimal timing for tracheostomy placement in this patient population is lacking. METHODS An 8-year retrospective review of 17 pediatric patients who underwent congenital heart surgery and subsequently required tracheostomy placement was performed. Patients were evaluated with regard to the timing of tracheostomy and mortality. RESULTS The overall study mortality was 24%. The median duration of intubation prior to tracheostomy was 60 days (interquartile range: 19-90 days); there was no difference in the average time between intubation and tracheostomy for survivors compared with nonsurvivors (51 vs. 73 days, P = .37). No difference was observed in the overall duration of positive pressure ventilation when tracheostomy was performed within 30 days of intubation compared with greater than 30 days following intubation (481 vs. 451 days, P = .88). Overall, 18% of patients were successfully weaned from the ventilator after a median duration of positive pressure ventilation of 212 days. CONCLUSION The timing of tracheostomy placement may be an important factor in clinical outcomes for pediatric patients with persistent dependence on mechanical ventilatory support following congenital heart surgery. A larger, multi-institution study may help further elucidate our observed clinical findings in this patient population.

Normovolemic hemodilution using hydroxyethyl starch 130/0.4 (Voluven) in a Jehovah’s Witness child requiring cardiopulmonary bypass for ventricular septal defect repair

Surgical repair of congenital heart disease during cardiopulmonary bypass is common, and performing these complicated procedures in the absence of blood transfusions is especially challenging. A case of a Jehovahs Witness child who underwent surgical repair of a ventricular septal defect utilizing a new tetrastarch for autologous normovolemic hemodilution is reported. A successful operative repair was achieved without the need for non-autologous blood transfusion.

Extracorporeal life support for a 5-week-old infant with idiopathic pulmonary hemosiderosis

Idiopathic pulmonary hemosiderosis is a rare disease defined by the triad of iron deficiency anemia, hemoptysis, and diffuse pulmonary infiltrates on chest radiograph. Idiopathic pulmonary hemosiderosis is known to cause dyspnea and, in some cases, acute onset of massive pulmonary hemorrhage which is traditionally treated with conventional mechanical ventilation or high-frequency oscillation in conjunction with immunosuppressive therapy. In this case report, we describe a 5-week-old infant presenting with hemoptysis, massive pulmonary hemorrhage, and significant hypercapnic respiratory failure. The patient failed conventional ventilation but responded well to extracorporeal life support that was initiated early in his course. Idiopathic pulmonary hemosiderosis was suspected in light of his response to high-dose steroids and was confirmed by subsequent lung biopsies. Conclusion: Patients with severe pulmonary hemorrhage secondary to idiopathic pulmonary hemosiderosis can be safely supported with extracorporeal life support when conventional therapies have been exhausted.

Intermediate-Term Results of Extracorporeal Membrane Oxygenation Support Following Congenital Heart Surgery

Background: Although there are considerable data regarding in-hospital results of congenital heart surgery (CHS) patients requiring postoperative extracorporeal membrane oxygenation (ECMO) support, there is limited information on intermediate-term outcomes. Methods: A single-institution retrospective review of 25 consecutive postoperative CHS patients who required ECMO and survived to hospital discharge between January 2003 and June 2008. Survival was estimated by the Kaplan-Meier method. Results: At a median follow-up of 3.3 years (interquartile range: 1.2-5.9 years), there was one death which occurred at six months postsurgery. Kaplan-Meier-estimated survival at three years was 95% (95% confidence interval: 90%-100%). Indications for ECMO included extracorporeal cardiopulmonary resuscitation (48%), systemic hypoxia (4%), postoperative low-cardiac output syndrome (28%), and intraoperative failure to wean off cardiopulmonary bypass (20%). Following ECMO support, 65% of patients had unplanned cardiac reinterventions (three requiring operative interventions, six requiring percutaneous interventions, and four requiring both), and 47% of patients required unplanned hospitalizations. In all, 29% of patients developed neurological deficits and 12% of patients developed chronic respiratory failure. No patients developed renal failure. Overall, systemic ventricular (SV) function normalized in 83% of patients, whereas 17% of patients had persistent mild-to-moderate SV dysfunction. Conclusions: Intermediate-term patient survival of ECMO following CHS is encouraging. However, neurological impairment and unplanned cardiac reinterventions remain significant concerns. Further delineation of risk factors to improve patient outcomes is warranted.

Ethical Dilemma Offering Short-Term Extracorporeal Membrane Oxygenation Support for Terminally Ill Children Who Are Not Candidates for Long-Term Mechanical Circulatory Support Or Heart Transplantation

The use of extracorporeal membrane oxygenation (ECMO) in terminally ill pediatric patients who are not candidates for long-term mechanical circulatory support or heart transplantation requires careful deliberation. We present the case of a 16-year-old female with a relapse of acute lymphoid leukemia and acute-on-chronic cardiomyopathy who received short-term ECMO therapy. In addition, we highlight several ethical considerations that were crucial to this patient’s family-centered care and demonstrate that this therapy can be accomplished in a manner that respects patient autonomy and family wishes.