Aortic exclusion: a method of handling aortic insufficiency in the pediatric population needing mechanical circulatory support.

Aortic insufficiency (AI) is generally regarded as a contraindication for mechanical circulatory support in children. In the current Berlin EXCOR trial, moderate to severe AI is an exclusion criterion. There are reports in the literature of successful mechanical circulatory support (MCS) in adult patients with significant AI via "aortic exclusion" or bioprosthetic aortic valve replacement. We report the first case of aortic exclusion in an infant with moderate to severe aortic insufficiency in need of MCS.

Successful congenital heart surgery for a toddler with idiopathic infantile arterial calcification.

We present the first case report of successful cardiac surgery in a child with idiopathic infantile arterial calcification (IIAC), a disease that is generally lethal within the first 6 months of life. This 27-month-old Hispanic American boy with IIAC successfully underwent cardiothoracic surgery for severe pulmonary valve (PV) stenosis after unsuccessful balloon valvotomy in the cardiac catheterization laboratory.

Left main coronary artery-to-pulmonary artery fistula with severe aneurysmal dilatation.

Coronary artery fistulas (CAF) are rare abnormalities that can be symptomatic or asymptomatic. Most drain into the right ventricle or pulmonary artery, though a variety of other drainage sites have been reported. We report the results of the surgical closure of a symptomatic left coronary-to-pulmonary artery fistula associated with a giant 10-cm aneurysm and discuss the management of coronary artery fistulas.

Including aortic valve morphology in computational fluid dynamics simulations: initial findings and application to aortic coarctation.

Computational fluid dynamics (CFD) simulations quantifying thoracic aortic flow patterns have not included disturbances from the aortic valve (AoV). 80% of patients with aortic coarctation (CoA) have a bicuspid aortic valve (BAV) which may cause adverse flow patterns contributing to morbidity. Our objectives were to develop a method to account for the AoV in CFD simulations, and quantify its impact on local hemodynamics. The method developed facilitates segmentation of the AoV, spatiotemporal interpolation of segments, and anatomic positioning of segments at the CFD model inlet. The AoV was included in CFD model examples of a normal (tricuspid AoV) and a post-surgical CoA patient (BAV). Velocity, turbulent kinetic energy (TKE), time-averaged wall shear stress (TAWSS), and oscillatory shear index (OSI) results were compared to equivalent simulations using a plug inlet profile. The plug inlet greatly underestimated TKE for both examples. TAWSS differences extended throughout the thoracic aorta for the CoA BAV, but were limited to the arch for the normal example. OSI differences existed mainly in the ascending aorta for both cases. The impact of AoV can now be included with CFD simulations to identify regions of deleterious hemodynamics thereby advancing simulations of the thoracic aorta one step closer to reality.

Initial pediatric cardiac experience with decellularized allograft patches.

PURPOSE: This study examines use patterns, early outcomes, and technical surgical adaptability of a newly approved decellularized allograft pulmonary artery patch for right ventricular outflow tract reconstructions in neonates and infants, including primary operations and reoperations. DESCRIPTION: The study includes the 44 consecutive initial patients in which 46 patches were used for cardiovascular reconstruction between September 2009 and September 2010. Recorded variables include sex, age at operation, adverse outcome end points (eg, death, stenosis, aneurysm), congenital diagnoses, postoperative complications, and number, type, and location of patches. EVALUATION: Patients were a mean age of 290±343 days at operation, and 54.5% were boys. Three types of patch were used: 58.7% thin, 21.7% thick, and 19.6% hemipulmonary. No device-related deaths or adverse events occurred. A biopsy specimen of one patch at elective reoperation demonstrated active recellularization, with no inflammation. CONCLUSIONS: These patches have a wide range of applicability. Handling and technical flexibility is excellent and superior to standard options. There appears to be potential for autologous revitalization of the tissue.

Tolerance induction by hematopoietic cell transplantation: combined use of stem cells and progenitor cells.

BACKGROUND: Donor-specific hematopoietic cell transplantation (HCT) in the form of bone marrow transplantation has been long recognized experimentally as a means of inducing tolerance for subsequently transplanted organs. Clinical translation has been limited, however, due to HCT-associated complications. Unrelated myeloid progenitors (MP) can be administered simultaneously with hematopoietic stem cells (HSC). This reduces susceptibility to bacterial and fungal infections in neutropenic mice in laboratory studies. It is not known, however, if the addition of third-party MP interferes with tolerance induction. METHODS: BALB/c (H-2d) mice were irradiated and reconstituted with 4,000 AKR (H-2k) HSC or with 4,000 AKR HSC combined with 10(5) FVB (H-2q) MP. After 2 months, the mice received skin grafts from these three strains or from an unrelated strain, C57BL/6 (H-2b). Composition and origin of hematopoietic cells was analyzed using flow cytometry. RESULTS: Mice in both groups accepted all the host-type- and HSC-donor-matched grafts, and rejected unrelated grafts. Surprisingly, recipients of both HSC and MP also accepted MP-matched skin grafts (14 of 14), even with very low levels of MP-derived cells in circulation. The analysis revealed that, although most hematopoietic cells were derived from HSC donors, regulatory T cells were derived from both donors as well as the recipient. CONCLUSION: The addition of third-party MP cells does not interfere with HCT-induced tolerance induction and, surprisingly, induces MP-specific tolerance.

Sternal plating to prevent malunion of transverse sternotomy in lung transplantation.

Sternal malunion can be a significant cause of morbidity in double-lung transplantation when it is performed through a thoracosternotomy or clamshell incision. Some patients experience increased pain with malunion and have delayed or decreased functional recovery. We propose a method of sternal plating to decrease the incidence of sternal malunion encountered with this incision. The transverse sternotomy can be rigidly fixed with two titanium interlocking plates during chest closure, a procedure that offers the potential for timely and consistent union of the sternum. The interlocking plate configuration also affords a unique quality to this closure; a pin securing the two plates can be quickly released allowing expedient access to mediastinal structures if emergent re-entry is necessary.