Impact of Retrograde Arch Extension in Acute Type B Aortic Dissection on Management and Outcomes

Background. Optimal management of acute type B aortic dissection with retrograde arch extension is controversial. The effect of retrograde arch extension on operative and long-term mortality has not been studied and is not incorporated into clinical treatment pathways. Methods. The International Registry of Acute Aortic Dissection was queried for all patients presenting with acute type B dissection and an identifiable primary intimal tear. Outcomes were stratified according to management for patients with and without retrograde arch extension. Kaplan-Meier survival curves were constructed. Results. Between 1996 and 2014, 404 patients (mean age, 63.3 +/- 13.9 years) were identified. Retrograde arch extension existed in 67 patients (16.5%). No difference in complicated presentation was noted (36.8% vs 31.7%, p = 0.46), as defined by limb or organ malperfusion, coma, rupture, and shock. Patients with or without retrograde arch extension received similar treatment, with medical management in 53.7% vs 56.5% (p = 0.68), endovascular treatment in 32.8% vs 31.1% (p = 0.78), open operation in 11.9% vs 9.5% (p = 0.54), or hybrid approach in 1.5% vs 3.0% (p = 0.70), respectively. The in-hospital mortality rate was similar for patients with (10.7%) and without (10.4%) retrograde arch extension (p = 0.96), and 5-year survival was also similar at 78.3% and 77.8%, respectively (p = 0.27). Conclusions. The incidence of retrograde arch dissection involves approximately 16% of patients with acute type B dissection. In the International Registry of Acute Aortic Dissection, this entity seems not to affect management strategy or early and late death

Measurement of K(+) production cross section by 8 GeV protons using high-energy neutrino interactions in the SciBooNE detector

The SciBooNE Collaboration reports K[superscript +] production cross section and rate measurements using high-energy daughter muon neutrino scattering data off the SciBar polystyrene (C[subscript 8]H[subscript 8]) target in the SciBooNE detector. The K[superscript +] mesons are produced by 8 GeV protons striking a beryllium target in Fermilab Booster Neutrino Beam line (BNB). Using observed neutrino and antineutrino events in SciBooNE, we measure d[superscript 2]σ/dpdΩ=(5.34±0.76)  mb/(GeV/c×sr) for p+Be→K[superscript +]+X at mean K[superscript +] energy of 3.9 GeV and angle (with respect to the proton beam direction) of 3.7 degrees, corresponding to the selected K[superscript +] sample. Compared to Monte Carlo predictions using previous higher energy K[superscript +] production measurements, this measurement, which uses the NUANCE neutrino interaction generator, is consistent with a normalization factor of 0.85±0.12. This agreement is evidence that the extrapolation of the higher energy K[superscript +] measurements to an 8 GeV beam energy using Feynman scaling is valid. This measurement reduces the error on the K[superscript +] production cross section from 40% to 14%.Japan. Ministry of Education, Culture, Sports, Science and TechnologyJapan Society for the Promotion of ScienceJapan Society for the Promotion of Science (Grant-in-Aid for Scientific Research A 19204026)Japan Society for the Promotion of Science (Young Scientists S 20674004)Japan Society for the Promotion of Science (Young Scientists B 18740145