Temporary ventricular assist device support with a catheter-based axial pump: Changing the paradigm at a pediatric heart center.

OBJECTIVE: We report the largest pediatric single-center experience with an Impella (Abiomed Inc) catheter-based axial pump support. METHODS: We conducted a retrospective cohort study of all patients with acute decompensated heart failure or cardiogenic shock requiring catheter-based axial pump support between October 2014 and February 2022. The primary outcome per individual encounter (hospital admission) was defined as bridge-to-recovery, bridge-to-durable ventricular assist device support, bridge-to-cardiac transplantation, or death at 6 months after catheter-based axial pump explantation. Adverse events were defined according to the Pediatric Interagency Registry for Mechanical Circulatory Support criteria. RESULTS: Our final study cohort included 37 encounters with 43 catheter-based axial pump implantations. A single catheter-based axial pump device was used for support in 33 encounters (89%), with 2 catheter-based axial pump devices used in 3 (8%) separate encounters and 3 catheter-based axial pump devices used in 1 (3%) encounter. The median [range] age, weight, and body surface area at implantation were 16.8 [6.9-42.8] years, 61.1 [23.1-123.8] kg, and 1.7 [0.8-2.5] m2, respectively. The predominant causes of circulatory failure were graft failure/rejection in 16 patients (43%), followed by cardiomyopathy in 7 patients (19%), arrhythmia refractory to medical therapies in 6 patients (16%), myocarditis/endocarditis in 4 patients (11%), and heart failure due to congenital heart disease in 4 patients (11%). Competing outcomes analysis showed a positive outcome with bridge-to-recovery in 58%, bridge-to-durable VAD support in 14%, and bridge-to-cardiac transplantation in 14% at 6 months. Fourteen percent of encounters resulted in death at 6 months. CONCLUSIONS: We demonstrate that catheter-based axial pump support in children results in excellent 1- and 6-month survival with an acceptable adverse event profile.

Outcomes of temporary ventricular assist device: A pediatric institutional experience over 25 years.

BACKGROUND: There are scarce data describing outcomes of pediatric temporary ventricular assist device support. METHODS: A retrospective single-center study was conducted to review clinical outcomes of all consecutive patients with temporary ventricular assist device between 1996 and 2021. Given the complex clinical course in some patients requiring multiple temporary ventricular assist device runs, outcome analysis was based on "encounters" (hospitalizations with temporary ventricular assist device, regardless of the number of devices used). RESULTS: In total, 126 temporary ventricular assist devices were implanted in 108 patients, resulting in a total of 114 encounters: 70 (61%) extracorporeal centrifugal pumps and 44 (39%) catheter-based axial pumps. The median (range) age and weight at temporary ventricular assist device implant were 10.1 years (1 day to 42.8 years) and 33.6 (2.5-128) kg, respectively. Underlying etiologies of cardiac dysfunction were cardiomyopathy (34, 30%), cardiac transplant graft dysfunction (29, 25%), congenital heart disease (23, 20%; 9 single ventricle), myocarditis (22, 19%), and other (6, 5%). Interagency Registry for Mechanically Assisted Circulatory Support Profile was 1 in 75 (66%) and 2 in 39 (34%). Support configuration was left ventricular assist device (104, including 9 systemic ventricular assist devices), right ventricular assist device (5), and biventricular assist device (5). The median (range) support duration was 6 (1-61) days. Overall, 97 (85%) encounters reached a positive primary end point: bridge-to-recovery (55), bridge-to-bridge (31), and bridge-to-transplant directly with temporary ventricular assist device (11). Seventeen (15%) encounters resulted in death during temporary ventricular assist device support: multiorgan failure (12), stroke (4), and cardiac arrest (1). The 6-month survivals with catheter-based axial pumps and extracorporeal centrifugal pumps were 84% (95% confidence interval, 74-96) and 67% (95% confidence interval, 57-79), respectively (P = .08). The 1- and 5-year survivals of 82 hospital survivors were 90% and 84%, respectively. CONCLUSIONS: This study suggests temporary ventricular assist device support is feasible in children with favorable outcomes.

Nanoengineered Shear-Thinning Hydrogel Barrier for Preventing Postoperative Abdominal Adhesions.

More than 90% of surgical patients develop postoperative adhesions, and the incidence of hospital re-admissions can be as high as 20%. Current adhesion barriers present limited efficacy due to difficulties in application and incompatibility with minimally invasive interventions. To solve this clinical limitation, we developed an injectable and sprayable shear-thinning hydrogel barrier (STHB) composed of silicate nanoplatelets and poly(ethylene oxide). We optimized this technology to recover mechanical integrity after stress, enabling its delivery though injectable and sprayable methods. We also demonstrated limited cell adhesion and cytotoxicity to STHB compositions in vitro. The STHB was then tested in a rodent model of peritoneal injury to determine its efficacy preventing the formation of postoperative adhesions. After two weeks, the peritoneal adhesion index was used as a scoring method to determine the formation of postoperative adhesions, and STHB formulations presented superior efficacy compared to a commercially available adhesion barrier. Histological and immunohistochemical examination showed reduced adhesion formation and minimal immune infiltration in STHB formulations. Our technology demonstrated increased efficacy, ease of use in complex anatomies, and compatibility with different delivery methods, providing a robust universal platform to prevent postoperative adhesions in a wide range of surgical interventions.

Nanostructured Non-Newtonian Drug Delivery Barrier Prevents Postoperative Intrapericardial Adhesions.

With the increasing volume of cardiovascular surgeries and the rising adoption rate of new methodologies that serve as a bridge to cardiac transplantation and that require multiple surgical interventions, the formation of postoperative intrapericardial adhesions has become a challenging problem that limits future surgical procedures, causes serious complications, and increases medical costs. To prevent this pathology, we developed a nanotechnology-based self-healing drug delivery hydrogel barrier composed of silicate nanodisks and polyethylene glycol with the ability to coat the epicardial surface of the heart without friction and locally deliver dexamethasone, an anti-inflammatory drug. After the fabrication of the hydrogel, mechanical characterization and responses to shear, strain, and recovery were analyzed, confirming its shear-thinning and self-healing properties. This behavior allowed its facile injection (5.75 ± 0.15 to 22.01 ± 0.95 N) and subsequent mechanical recovery. The encapsulation of dexamethasone within the hydrogel system was confirmed by 1H NMR, and controlled release for 5 days was observed. In vitro, limited cellular adhesion to the hydrogel surface was achieved, and its anti-inflammatory properties were confirmed, as downregulation of ICAM-1 and VCAM-1 was observed in TNF-α activated endothelial cells. In vivo, 1 week after administration of the hydrogel to a rabbit model of intrapericardial injury, superior efficacy was observed when compared to a commercial adhesion barrier, as histological and immunohistochemical examination revealed reduced adhesion formation and minimal immune infiltration of CD3+ lymphocytes and CD68+ macrophages, as well as NF-κß downregulation. We presented a novel nanostructured drug delivery hydrogel system with unique mechanical and biological properties that act synergistically to prevent cellular infiltration while providing local immunomodulation to protect the intrapericardial space after a surgical intervention.