Generation of vascular chimerism within donor organs.

Whole organ perfusion decellularization has been proposed as a promising method to generate non-immunogenic organs from allogeneic and xenogeneic donors. However, the ability to recellularize organ scaffolds with multiple patient-specific cells in a spatially controlled manner remains challenging. Here, we propose that replacing donor endothelial cells alone, while keeping the rest of the organ viable and functional, is more technically feasible, and may offer a significant shortcut in the efforts to engineer transplantable organs. Vascular decellularization was achieved ex vivo, under controlled machine perfusion conditions, in various rat and porcine organs, including the kidneys, liver, lungs, heart, aorta, hind limbs, and pancreas. In addition, vascular decellularization of selected organs was performed in situ, within the donor body, achieving better control over the perfusion process. Human placenta-derived endothelial progenitor cells (EPCs) were used as immunologically-acceptable human cells to repopulate the luminal surface of de-endothelialized aorta (in vitro), kidneys, lungs and hind limbs (ex vivo). This study provides evidence that artificially generating vascular chimerism is feasible and could potentially pave the way for crossing the immunological barrier to xenotransplantation, as well as reducing the immunological burden of allogeneic grafts.

Pediatric Extracorporeal Membrane Oxygenation Reach-Out Program: Successes and Insights.

The shortage of dedicated pediatric extracorporeal membrane oxygenation (ECMO) centers and the expanding indications for pediatric ECMO necessitate a regional program for transport of ECMO-supported patients. Data about feasibly and safety of pediatric ECMO transport are scarce. Our aim is to describe our experience with a pediatric ECMO reach-out program and review pertinent literature. Demographic, clinical, and outcome data were collected retrospectively from the charts of all patients cannulated onto ECMO at referring centers and transported to our center from 2003 to 2018. Similar data were recorded for patients who were referred for ECMO support from within the hospital. The cohort included 80 patients cannulated at 17 referring centers. The transport team included a senior pediatric cardiac surgeon and an ECMO specialist. All transfers but one were done by special emergency medical service ambulance. No major complications or deaths occurred during transport, and all patients were stable upon arrival to our unit. Mortality was lower in the ECMO reach-out cohort than in-house patients referred for ECMO support. This is the first study from Israel and one of the largest to date describing a dedicated pediatric ECMO transport program. Extracorporeal membrane oxygenation transport appears to be feasible and safe when conducted by a small, highly skilled mobile team. Successful reach-out program requires open communication between the referring physician and the accepting center. As survival correlates with ECMO volume, maintaining a large ECMO center with 24/7 retrieval capabilities may be the best strategy for pediatric mechanical circulatory support program.

Direct innominate artery cannulation for antegrade cerebral perfusion in neonates undergoing arch reconstruction.

BACKGROUND: Antegrade cerebral perfusion (ACP) is performed in neonates either by direct cannulation (DC) or indirect cannulation (IC) of the innominate artery. IC is achieved by a graft sutured to the innominate artery or advancement of a cannula through the ascending aorta into the innominate artery, whereas DC is performed by directly cannulating the innominate artery. These techniques may be limited by technical problems that can compromise perfusion. The purpose of the present study was to evaluate the flow measurements and safety of DC when compared with IC. METHODS: This was a retrospective chart review of consecutive neonates who underwent ACP from January 2007 to December 2010. Patient characteristics, surgical and hemodynamic measurements, and postoperative neurologic findings were recorded. RESULTS: Seventy neonates underwent ACP during the study period (46 using DC and 24 using IC). The groups were similar in age and weight. Operative variables were similar regarding cardiopulmonary bypass (CPB), cross-clamp times, maximal flow at full CPB, minimal temperature, ACP time, flow and flow index, and upper extremity blood pressure and proximal cannula pressure during ACP. There was a significantly higher flow index at full CPB in the DC group (217 ± 40 mL/kg/min versus 190 ± 46 mL/kg/min; p = 0.013), which correlated with higher proximal cannula pressures at full CPB (172 ± 27 mm Hg versus 158 ± 26 mm Hg; p = 0.04). Sixty-two of the 65 survivors (95%) had normal neurologic evaluations on discharge. CONCLUSIONS: ACP using DC is comparable to that using IC, with appropriate pressures in the proximal aortic line at full CPB and adequate upper extremity pressures during ACP, reflecting suitable flows in the cerebral circulation.

Favorable outcome of pediatric fulminant myocarditis supported by extracorporeal membranous oxygenation.

Myocarditis among pediatric patients varies in severity from mild disease to a fulminant course with overwhelming refractory shock and a high risk of death. Because the disease is potentially reversible, it is reasonable to deploy extracorporeal membranous oxygenation (ECMO) to bridge patients until recovery or transplantation. This study aimed to review the course and outcome of children with acute fulminant myocarditis diagnosed by clinical and echocardiographic data only who were managed by ECMO because of refractory circulatory collapse. A chart review of a single center identified 12 children hospitalized over an 8-year period who met the study criteria. Data were collected on demographics, diagnosis, disease course, and outcome. The patients ranged in age from 20 days to 8 years (25.5 ± 29.6 months). Echocardiography showed a severe global biventricular decrease in myocardial function, with a shortening fraction of 12% or less. Ten children (83.3%) were weaned off extracorporeal support after 100-408 h (mean, 209.9 ± 82.4 h) and discharged home. Two patients died: one due to multiorgan failure and one due to sustained refractory heart failure. During a long-term follow-up period, all survivors showed normal function in daily activities and normal myocardial function. The study showed that ECMO can be safely and successfully used for children with acute fulminant myocarditis diagnosed solely on clinical and radiographic grounds who need mechanical support. These patients usually have a favorable outcome, regaining normal or near normal heart function without a need for heart transplantation.