Daniel A. Velez

Total artificial heart in the pediatric patient with biventricular heart failure.

Mechanical circulatory support emerged for the pediatric population in the late 1980s as a bridge to cardiac transplantation. The Total Artificial Heart (TAH-t) (SynCardia Systems Inc., Tuscon, AZ) has been approved for compassionate use by the Food and Drug Administration for patients with end-stage biventricular heart failure as a bridge to heart transplantation since 1985 and has had FDA approval since 2004. However, of the 1,061 patients placed on the TAH-t, only 21 (2%) were under the age 18. SynCardia Systems, Inc. recommends a minimum patient body surface area (BSA) of 1.7 m2, thus, limiting pediatric application of this device. This unique case report shares this pediatric institution’s first experience with the TAH-t. A 14-year-old male was admitted with dilated cardiomyopathy and severe biventricular heart failure. The patient rapidly decompensated, requiring extracorporeal life support. An echocardiogram revealed severe biventricular dysfunction and diffuse clot formation in the left ventricle and outflow tract. The decision was made to transition to biventricular assist device. The biventricular failure and clot formation helped guide the team to the TAH-t, in spite of a BSA (1.5 m2) below the recommendation of 1.7m2. A computed tomography (CT) scan of the thorax, in conjunction with a novel three-dimensional (3D) modeling system and team, assisted in determining appropriate fit. Chest CT and 3D modeling following implantation were utilized to determine all major vascular structures were unobstructed and the bronchi were open. The virtual 3D model confirmed appropriate device fit with no evidence of compression to the left pulmonary veins. The postoperative course was complicated by a left lung opacification. The left lung anomalies proved to be atelectasis and improved with aggressive recruitment maneuvers. The patient was supported for 11 days prior to transplantation. Chest CT and 3D modeling were crucial in assessing whether the device would fit, as well as postoperative complications in this smaller pediatric patient.

Alternative methods for virtual heart transplant-Size matching for pediatric heart transplantation with and without donor medical images available

Listed pediatric heart transplant patients have the highest solid‐organ waitlist mortality rate. The donor‐recipient body weight (DRBW) ratio is the clinical standard for allograft size matching but may unnecessarily limit a patients donor pool. To overcome DRBW ratio limitations, two methods of performing virtual heart transplant fit assessments were developed that account for patient‐specific nuances. Method 1 uses an allograft total cardiac volume (TCV) prediction model informed by patient data wherein a matched allograft 3‐D reconstruction is selected from a virtual library for assessment. Method 2 uses donor images for a direct virtual transplant assessment.

Retrograde Cardioplegia for Myocardial Protection During Arterial Switch Operation

cardioplegia with microplegia, there was no statistical significance concerning incidence of postoperative low output syndrome (relative risk [RR], 0.95; 95% confidence interval [CI] 0.55–1.62), rate of spontaneous return to sinus rhythm (RR, 1.64; 95% CI, 0.61–4.41), and perioperative myocardial infarction (RR, 0.62; 95% CI, 0.19– 2.08). Theonlydifferencebetween these twogroupswas thevolume of cardioplegia (weightedmean difference, –514.79; 95%CI, –705.37 to –324.21) used during surgery. The authors thought that standard diluted cardioplegia could causemyocardial edema comparedwith microplegia; however, they might have ignored the fact that microplegia could cause coronary artery endothelium dysfunction [4]. In addition, the potential consequence of endothelium dysfunction is a predisposition to postoperative cardiac dysfunction, thrombosis, or larger infarction size. It is likely that myocardial edema and endothelium dysfunction are the two countervailing forces between the two groups that produced equal rates of postoperative low output syndrome in the surgical setting. Although the results could be the same with using these kinds of cardioplegia, another benefit of microcardioplegia is its lack of extra volume to dilute the pump system. It could be used as a part of blood conservation during cardiopulmonary compared with diluted cardioplegia. More evidence from large, randomized, controlled trials is needed to settle the dispute and to determinewhichone is better andmore suitable forCABGpatients.