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BACKGROUND Postoperative acute kidney injury (AKI) is a major complication associated with increased morbidity and mortality after surgery for acute type A aortic dissection (AAAD). To the best of our knowledge, risk prediction models for AKI following AAAD surgery have not been reported. The goal of the present study was to develop a prediction model to predict severe AKI after AAAD surgery. METHODS A total of 485 patients who underwent AAAD surgery were enrolled and randomly divided into the training cohort (70%) and the validation cohort (30%). Severe AKI was defined as AKI stage III following the Kidney Disease: Improving Global Outcomes criteria. Preoperative variables, intraoperative variables and postoperative data were collected for analysis. Multivariable logistic regression analysis was performed to select predictors and develop a nomogram in the study cohort. The final prediction model was validated using the bootstrapping techniques and in the validation cohort. RESULTS The incidence of severe AKI was 23.0% (n = 78), and 14.7% (n = 50) of patients needed renal replacement treatment. The hospital mortality rate was 8.3% (n = 28), while for AKI patients, the mortality rate was 13.1%, which increased to 20.5% for severe AKI patients. Univariate and multivariate analyses showed that age, cardiopulmonary bypass time, serum creatinine, and D-dimer were key predictors for severe AKI following AAAD surgery. The logistic regression model incorporated these predictors to develop a nomogram for predicting severe AKI after AAAD surgery. The nomogram showed optimal discrimination ability, with an area under the curve of 0.716 in the training cohort and 0.739 in the validation cohort. Calibration curve analysis demonstrated good correlations in both the training cohort and the validation cohort. CONCLUSIONS We developed a prognostic model including age, cardiopulmonary bypass time, serum creatinine, and D-dimer to predict severe AKI after AAAD surgery. The prognostic model demonstrated an effective predictive capability for severe AKI, which may help improve risk stratification for poor in-hospital outcomes after AAAD surgery. [ABSTRACT FROM AUTHOR]

Background Optimal management of complicated chronic type B dissection with involvement of the distal aortic arch is controversial. Late complications related to thoracic endovascular aortic repair (TEVAR) are much more common than those using open aortic surgery. We reviewed our experience of left subclavian artery (LSCA) transposition with implantation of a stented elephant trunk for complicated chronic type B dissection with involvement of the distal aortic arch. Materials and Methods From January 2011 to June 2015, 20 patients with complicated chronic type B dissection with involvement of the distal aortic arch underwent LSCA transposition with implantation of a stented elephant trunk via a median sternotomy under hypothermic cardiopulmonary bypass with selective antegrade cerebral perfusion (SACP). Preoperative renal dysfunction was observed in three patients, left heart failure in one patient, and spinal cord ischemia in one patient. Results There was one (5.0%, 1/20) in-hospital death. All but one patient required mechanical ventilation for < 24 hours. Mean duration of mechanical ventilation and mean duration of stay in the intensive care unit was 16 ± 4 and 35 ± 16 hours, respectively. No severe complications occurred. There was one death because of unknown cause during follow-up. One case received thoracoabdominal aortic replacement 9 months after surgery. Conclusion Acceptable surgical outcomes were obtained using LSCA transposition with implantation of a stented elephant trunk. This method is an alternative to TEVAR for complicated chronic type B dissection with involvement of the distal aortic arch. [ABSTRACT FROM AUTHOR]

Background A combined endovascular and debranching hybrid procedure was performed for descending aortic pathologies involving the distal aortic arch. We reviewed our results of this procedure to summarize clinical experiences. Methods From April 2009 to April 2013, 36 patients (21 males and 15 females) underwent the hybrid operation. Hospital stay and complications were closely monitored after operation. Follow-up CT scan was performed at postoperative 3 months and 12 months. Results The hospital stay ranged from 7 to 25 (15.1 ± 5.0) days. The mean age at operation was 67.6 ± 4.8 years (range: 60-79 years). In-hospital mortality and stroke rates were 2.8% (1/36) and 2.8% (1/36). At a mean follow-up of 22 months (4-52 months), themortality was 0% (0/35). All remaining 35 patients returned to normal life. During the follow-up period, one patient required secondary endovascular reintervention for a type 1 distal endovascular leak. Conclusion Hybrid repair for descending aortic pathologies involving the distal arch proves to be effective and safe at midterm follow-up with acceptable surgical risks and satisfactory results. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The presence of an isolated left vertebral artery (ILVA) remains a challenging issue for thoracic endovascular aortic repair (TEVAR) of type B dissection if the proximal landing zones are inadequate. We retrospectively reviewed our experience of the surgical management of complicated type B dissection with an ILVA using the stented elephant trunk technique. METHODS: Between February 2009 and May 2013, 7 patients with complicated type B dissection (acute = 2 and chronic = 5) underwent the stented elephant trunk procedure under hypothermic cardiopulmonary bypass with selective antegrade cerebral perfusion. All the patients were males with a median age of 53 ± 6 (range 42-59) years. Preoperative lower limb ischaemia was observed in 1 patient, renal dysfunction in 1 patient and visceral ischaemia in 1 patient. ERSULTS: There were no in-hospital deaths. The median ventilator support time was 16 ± 3 (range 11-20) h. Ischaemia of the lower limb and viscera was ameliorated after surgical stent-graft implantation. Continuous renal replacement therapy was not required in patients with preoperative renal dysfunction after surgery. No neurological deficits were observed in any patients prior to hospital discharge. One patient underwent TEVAR due to distal aortic dilatation within the mean follow-up period, which was 44 ± 19 months. CONCLUSION: Repair of complicated type B dissection with an ILVA using the stented elephant trunk technique was associated with satisfactory surgical results in patients with inadequate proximal fixation zones. This technique is an alternative to TEVAR for complicated type B dissection with inadequate proximal landing zones. [ABSTRACT FROM AUTHOR]

We have studied the compound periodic boundary problem in the upper half plane above the real axis. Under proper conditions, we obtain a periodic and sectionally holomorphic function in the upper half plane. In addition, we have also solved the compound boundary problem with discontinuities of the first kind of the coefficients in the Hilbert condition. [ABSTRACT FROM AUTHOR]

Jacobi's triple product identity is proved from one of Euler's q-exponential functions in an elementary way. [ABSTRACT FROM AUTHOR]

(J Card Surg 2010;25:719-720) [ABSTRACT FROM AUTHOR]