Current profile and outcome of 100 esophageal atresia patients in the Kyushu area of Japan

Objectives: Since Spitz et al. reported the prognostic classification of esophageal atresia (EA) patients in 1994, decades have been past and there have been many advances in surgery and neonatology. Nevertheless, there have been very few reports according to the recent outcome of the neonates with EA, and otherwise, time has come to re-evaluate the credibility of this classification. The aim of this study was to validate the recent prognosis of the EA. Methods: Patient data were collected from 22 cooperative facilities during the 5 year period from 2005 to 2009 in Kyushu area, Japan. Total of 100 EA patients were retrospectively reviewed according to their characteristics and the outcome. Patient who missed the characteristics and outcome was excluded from the respective data. Results: Only 29.8% (28/94) was prenatally diagnosed and 52.0 (52/100) had associated anomalies including major congenital heart disease (CHD), abnormal chromosome, and others. According to the operation, primary anastomosis was performed 57.0% (57/100) and the staged operation was performed 34.0% (34/100). Survival rate in the neonatal period was 89.0% (89/ 100), and overall survival rate was 78.0% (78/100). According to the Spitz classification, if patients with associated anomalies were excluded, survival rate of Group 1 (>1500 g and no CHD) was 93.8% (61/65), Group 2 (<1500 g or CHD) was 68.4% (13/19), and Group 3 (<1500 g and CHD) was 50% (1/2). Conclusion: EA was proved to be rarely diagnosed prenatally. Primary outcome of the Group 1 and Group 3 in Spitz classification were fairly good, but Group 2 was worse as ever. The comprehensive treatment strategy for EA patients with birth weight under 1500 g or CHD should be reconsidered to improve the overall outcome.

Dynamics and geometry of developing planar jets based on the invariants of the velocity gradient tensor

Based on the direct numerical simulation （DNS）, the developing planar jets under different initial conditions, e.g., the con- ditions of the exit Reynolds number and the exit mean velocity profile, are investigated. We mainly focus on the characteristics of the invariants of the velocity gradient tensor, which provides insights into the evolution of the dynamics and the geometry of the planar jets along with the flow transition. The results show that the initial flow near the jet exit is strongly predominated by the dissipation over the enstrophy, the flow transition is accompanied by a severe rotation and straining of the flow elements, where the vortex structure evolves faster than the fluid element deformation, in the fully-developed state, the irrotational dissipation is dominant and the most probable geometry of the fluid elements should remain between the biaxial stretching and the axisymmetric stretching. In addition, with a small exit Re and a parabolic profile for the exit mean streamwise velocity, the decay of the mean flow field and the magnitude of the turbulent variables will be strengthened in the process of the flow transition, however, a large exit Re will promote the flow transition to the fully-developed state. The cross-impact between the exit Re and the exit mean velocity profile is also observed in the present study.