Do obese patients with type A aortic dissection benefit from total arch repair through a partial upper sternotomy?

Background: Minimal research has been performed regarding total arch replacement through partial upper sternotomy in patients with acute type A aortic dissection who are obese, and the safety and feasibility of this procedure need to be further investigated. The present study investigated the potential clinical advantages of using a partial upper sternotomy versus a conventional full sternotomy for total arch replacement in patients who were obese. Methods: This was a retrospective study. From January 2017 to January 2020, a total of 65 acute type A aortic dissection patients who were obese underwent total arch replacement with triple-branched stent graft. Among them, 35 patients underwent traditional full sternotomy, and 30 patients underwent partial upper sternotomy. The perioperative clinical data and postoperative follow-up results of the two groups were collected, and the feasibility and clinical effect of partial upper sternotomy in total arch replacement were summarized. Results: The in-hospital mortality rates of the two groups were similar. The total operative time, cardiopulmonary bypass, aortic cross-clamp, cerebral perfusion, and deep hypothermic circulatory arrest times were also similar in both groups. The thoracic drainage and postoperative red blood cell transfusion volumes in the partial upper sternotomy group were significantly lower than those in the full sternotomy group. Mechanical ventilation time was shorter in the partial upper sternotomy group than that in the full sternotomy group. Additionally, the incidences of pulmonary infection, hypoxemia, and sternal diaphoresis were lower in the partial upper sternotomy group than those in the full sternotomy group. Conclusion: This study showed that total arch replacement surgery through a partial upper sternotomy in patients with acute type A aortic dissection who are obese is safe, effective, and superior to full sternotomy in terms of blood loss, postoperative blood transfusion, and respiratory complications.

Do obese patients benefit from isolated aortic valve replacement through a partial upper sternotomy?

OBJECTIVE: Controversial opinions exist for aortic valve replacement (AVR) through partial upper sternotomy in obese patients. Moreover, this study sought to investigate the potential clinical advantage of partial upper sternotomy aortic valve replacement (mini-AVR) over conventional full sternotomy aortic valve replacement (con-AVR) in obese patients. METHODS: This was a retrospective and observational study. From January 2015 to December 2020, a total of 184 obese [body mass index (BMI) ≥ 30 kg  m2] patients undergoing isolated primary AVR were included: 98 patients underwent conventional full sternotomy, and 86 patients underwent partial upper sternotomy. Propensity score (PS) matching was applied to eliminate the bassline imbalances in the mini-AVR and the con-AVR groups. RESULTS: After one-to-one propensity score matching, two groups of 60 patients were obtained. No in-hospital death occurred in the two groups. In addition, cardiopulmonary bypass time and total operative time were similar across the 2 groups, but the aortic cross-clamp time was significantly shorter in the con-AVR group (P = .0.022). The amount of mediastinal drainage at 48 h after surgery (P = 0.018) and postoperative blood transfusions (P = 0.014) were significantly lower in the mini-AVR group. There was no difference in ventilation time (P = .0.145), but a shorter intensive care unit stay time (P = 0.021) in the mini-AVR group. CONCLUSION: This study demonstrates that aortic valve replacement through a mini-AVR in obese patients is a safe and effective procedure. It outperformed con-AVR in terms of blood loss, blood product transfusion, and ICU stay.

Extensive repair of acute type A aortic dissection through a partial upper sternotomy and using complete stent-graft replacement of the arch.

BACKGROUND: Partial upper sternotomy (mini-ER) can be used in some adult cardiac surgeries but is seldom performed in the treatment of acute type A aortic dissection (AAAD). This study aimed to assess the feasibility and short-term outcomes of complete stent-graft replacement of the arch with triple-branched stent graft for AAAD through a mini-ER. METHODS: From 2015 to 2018, 254 patients with AAAD underwent complete stent-graft replacement of the arch with a triple-branched stent graft. Replacement was performed with conventional full sternotomy (con-ER) in 142 patients and with mini-ER in the other 112 patients. Using propensity score matching, the clinical data were compared between 100 patients in the mini-ER group and 100 patients in the con-ER group. RESULTS: After propensity score matching, there were no significant between-group differences in aortic cross-clamp time, cardiopulmonary bypass time, or total operative time. The amount of mediastinal drainage and number of red blood cell units were significantly lower in the mini-ER group compared with the con-ER group (P < .001). The intubation time was significantly shorter in the mini-ER group (P < .001). The treatment costs were also lower in the mini-ER group (P < .001). There were no significant between-group differences in 30-day mortality (9% vs 8%; P > .99) or postoperative complications. CONCLUSIONS: This study shows that extensive repair of AAAD through a mini-ER is feasible. It was superior to con-ER in terms of blood loss, postoperative ventilation time, and treatment costs.

Biotemplate derived three dimensional nitrogen doped graphene@MnO2 as bifunctional material for supercapacitor and oxygen reduction reaction catalyst.

Natural diatomite with abundant pores was used as a biotemplate for the massive production of three-dimensional (3D) porous graphene by chemical vapor deposition method. Subsequent template removal and nitrogen doping treatment yield nitrogen doped 3D graphene with preserved shape and complex internal features of the diatomite. After further deposition with MnO2 nanosheets, the N-doped 3D graphene@MnO2 (N-G@MnO2) hybrid exhibited excellent supercapacitor and good oxygen reduction reaction (ORR) performance. Accordingly, the porous N-G@MnO2 electrode exhibited a high specific capacitance (411.5 F g-1) and a good cycling performance (88.3% capacitance retention after 4000 charge/discharge cycling test). When tested in a two-electrode configuration, N-G@MnO2 achieved a wide potential window up to 1.8 V with a high energy density of 46.1 Wh kg-1. Furthermore, the as-prepared N-G@MnO2 showed good performance in oxygen reduction reaction, which is comparable to those of commercially available Pt/C electrode. The enhanced capacitive and electrocatalytic properties and stability is due to the synergistic interactions between the porous 3D graphene and MnO2 nanosheets. The results indicate that the 3D N-G@MnO2 could be useful for supercapacitor and ORR catalyst.

2D-2D growth of NiFe LDH nanoflakes on montmorillonite for cationic and anionic dye adsorption performance.

NiFe layered double hydroxides nanoflakes decorated montmorillonite (MMT@NiFe LDH) was successfully prepared by a one-pot hydrothermal method. The 2D-2D growth MMT@NiFe LDH was utilized as an effective adsorbent for removal of anionic dye of methyl orange (MO) and cationic dye of methylene blue (MB). The mole ratio of Ni2+/Fe3+ could quite influence the interlayer spacing, surface area per unit charge and the ultrathin hexagonal laminated morphology of NiFe LDH decorated on the surface of MMT. Various characterization techniques were conducted to identify it, such as XRD, FT-IR, TG-DTA, BET, XPS and SEM. Under the optimal conditions, the Langmuir-fitted maximum adsorption capacities for MO and MB are 108.80 mg g-1 and 99.18 mg g-1, respectively. Adsorption kinetics for MO and MB are both verified to be fit in with pseudo-second-order model. This work suggests a facile pathway to synthesize desirable bifunctional adsorbent for cationic and anionic dyes, which provides the potential application for the actual wastewater purification.

Tuning Hierarchical Ferric Nanostructures-Decorated Diatomite for Supercapacitors.

FeOOH nanosheets on porous diatomite have been successfully prepared by a facile two-step hydrothermal approach for supercapacitors, and then α-Fe2O3 and γ-Fe2O3 nanostructures are obtained via calcination under different atmospheres and temperatures. The morphologies and structures of all the samples are investigated in detail to make the hierarchical architecture clear. Besides, systemic tests are carried out in 1 M Na2SO4 electrolyte to characterize the electrochemical properties of these materials. Among the iron-related composite electrodes, diatomite@FeOOH owns the highest specific capacitance (157.9 F g-1 at a current density of 0.5 A g-1) and best cycling performance (98.95% retention after 1000 cycles), which is considered to be a potential material for high-performance supercapacitors. Furthermore, the synthesizing strategy can be extended to the preparation of other metallic oxide-derived functional materials towards energy storage and conversion.

Evaluation of MnO2-templated iron oxide-coated diatomites for their catalytic performance in heterogeneous photo Fenton-like system.

Herein, iron oxide-coated diatomites were prepared through hydrothermal synthesis and sacrificial template redox etching reaction. The microstructure characterization results revealed that the Fe2O3 nanorods were uniformly distributed on the surface of diatomite. The effects of diverse synthetic parameters on morphology of as-synthesized Fe2O3@diatomite were investigated. When the reaction time was prolonged from 12h to 24h, the morphology of FeOOH would change from nanorods into nanoflowers. Two different crystal phases of Fe2O3@diatomite were obtained from the FeOOH@diatomite samples calcined under different atmospheres. The catalytic activity of α-Fe2O3@diatomite was evaluated by the heterogeneous photo Fenton-like system through degradation of methylene blue (MB, 10 - 40mgL-1) in the presence of hydrogen peroxide (H2O2, 9mM - 120mM) under UV light irradiation. It was found that α-Fe2O3@diatomite composites showed very excellent degradation efficiency, which was about 99% within 120min under UV irradiation. This catalyst extended the range of pH values of homogeneous Fenton reaction, in which the MB removal rate was maintained over 80.8%. Moreover, the α-Fe2O3@diatomite catalyst still showed sound reusability after 5 rounds of degradation of MB dye. In principles, a possible photo-catalytic mechanism was proposed to testify metal oxides composites for heterogeneous photo Fenton-like reaction.

Synthesis of MnO2 nanosheets on montmorillonite for oxidative degradation and adsorption of methylene blue.

In this research, MnO2 nanosheets on montmorillonite (MnO2 nanosheets@MMt) was synthesized by one-pot hydrothermal method and characterized by X-ray diffraction, Fourier transform infrared spectra, nitrogen adsorption and scanning electron microscopy. It was found that honeycomb-like MnO2 nanosheets vertically grew on the surface of montmorillonite. MnO2 nanosheets@MMt exhibited high methylene blue (MB) removal rate, which reached 97.7% within 5min under the condition of pH 2, MnO2 nanosheets dosage of 0.1gL-1 and initial dye concentration of 10mgL-1. Additionally, the influencing factors such as pH value, amount of MnO2 nanosheets@MMt, and MB concentration were also investigated in this paper. Results showed the MB degradation process was correlated with pH value, and the MnO2 nanosheets@MMt achieved MB removal rate of 92.8% within 5min under pH 11 because of its absorption capacity of MB. The kinetics of the adsorption process complied with the Pseudo-second-order model. The Langmuir model was found to be the most suitable for describing the experimental equilibrium data of MnO2 nanosheets@MMt. The MnO2 nanosheets@MMt showed high adsorption capacity of 363.63mgg-1 for MB dye. The oxidative decomposition of MB was conducted in the presence of MnO2 nanosheets@MMt in the low pH, finding that the lower the pH was, the faster the degradation rate was. This research demonstrates that MnO2 nanosheets@MMt has potential applications in wastewater treatment.