Predictive Factors for In-Hospital Preoperative Rupture in Hyperacute Type A Aortic Dissection.

OBJECTIVE: This study aims to figure out risk factors of in-hospital preoperative rupture of hyperacute type A aortic dissection (haTAAD) patients and build a prediction and risk stratification model. METHODS: From January 2011 to December 2019, 830 patients diagnosed as haTAAD from Nanjing Drum Tower Hospital were enrolled. Among them, 799 patients received prompt surgery and 31 suffered aortic rupture before operation. The association between in-hospital preoperative rupture and perioperative parameters were examined. Best subset selection was used for feature selection and ROC curve was used to identify the model. RESULTS: Age, winter season, back pain, preoperative hypotension, albumin and globulin ratio, high serum phosphorus level are risk factors for in-hospital preoperative rupture of haTAAD. On the basis of six variables with AUC 0.828, a nomogram was established. According to the robustness test, actual in-hospital preoperative ruptures were fitted well. CONCLUSIONS: The in-hospital rupture prediction model was developed using logistic regression analysis. High serum phosphorus level is one of the strongest predictors. This nomogram may be useful when evaluating the risk of aortic dissection in-hospital rupture in future trials.

Extraction and Characterization of Cellulose from Broccoli Stems as a New Biopolymer Source for Producing Carboxymethyl Cellulose Films.

The use of food and agricultural waste-derived carboxymethyl cellulose (CMC) has become of interest due to their biodegradability and cost-effectiveness. In the current research, cellulose was extracted from broccoli stems to produce carboxymethyl cellulose using a carboxymethylation reaction via chloroacetic acid (CAA) and sodium hydroxide (5-10 M). The effects of different synthesis conditions on the degree of substitution (DS) and viscosity of the synthesized CMC powder were investigated. The mechanical properties, water vapor permeability (WVP), and colour of CMC films were also evaluated. The results showed that CMC with the highest DS value (0.60) and the highest viscosity of 0.5 Pa·s could be synthesized from broccoli stems at a concentration of 7.5 M NaOH and a cellulose-to-chloroacetic acid ratio of 1 : 1.2. At CMC concentration of 4 g/100 mL with 0.8 g/100 mL of glycerol, the films had the highest tensile strength (31.91 MPa), whereas with 1.2 g/100 mL glycerol, more flexible films with elongation at break of 27.56% were produced. CMC films with the highest WVP (7.87 × 103 gm2·mmHg-1/day) were made with 6 g/100 mL of CMC and 1.8 g/100 mL of glycerol. This research proposes a new source of cellulose to produce biodegradable packaging materials to initiate a practical basis for food waste reuse.

[Clinical study of modified suspension reduction method combined with percutaneous vertebroplasty in the treatment of thoracolumbar osteoporotic compression fracture].

OBJECTIVE: To investigate the clinical effect of modified suspension reduction method combined with percutaneous vertebroplasty in the treatment of osteoporotic thoracolumbar compression fractures. METHODS: From February 2020 to October 2021, 92 patients with thoracolumbar osteoporotic compression fracture were treated by percutaneous vertebroplasty. According to different treatment methods, they were divided into the observation group and the control group. The observation group was treated with modified suspension reduction and then percutaneous vertebroplasty, while the control group was treated with percutaneous vertebroplasty alone. The observation group (47 cases), including 20 males and 27 females, the age ranged from 59 to 76 years old with an average of (69.74±4.50) years old, fractured vertebral bodies:T10(2 cases), T11(7 cases), T12(19 cases), L1(14 cases), L2(5 cases);the control group(45 cases), including 21 males and 24 females, the age ranged from 61 to 78 years old with an average of (71.02±3.58) years old, fractured vertebral bodies:T10(3 cases), T11(8 cases), T12(17 cases), L1(12 cases), L2(5 cases);The leakage of bone cement were observed, the visual analogue scale (VAS), Oswestry lumbar dysfunction index (ODI), anterior vertebrae height (AVH), Cobb angle of kyphosis and the amount of bone cement injected before and after operation were recorded and compared between the two groups. RESULTS: All patients were followed up, ranged from 6 to10 with an average of (8.45±1.73) months. Two patients ocurred bone cement leakage in observation group and 3 patients in control group. AVH of observation group increased (P<0.05) and Cobb angle of injured vertebrae decreased (P<0.05). Cobb angle of injured vertebrae and AVH of the control group were not significantly changed (P>0.05). Cobb angle of injured vertebrae of the observation group was lower than that of control group (P<0.05) and AVH was higher than that of the control group (P<0.05). In the observation group, VAS before operation and 1 week, 3 and 6 months after operation respectively were(7.32±1.05) scores, (3.56±1.18) scores, (1.83±0.67) scores, (1.27±0.34) scores, and ODI were(40.12±14.69) scores, (23.76±10.19) scores, (20.15±6.39) scores, (13.45±3.46) scores. In the control group, VAS before operation and 1 week, 3 and 6 months after operation respectively were(7.11±5.26) scores, (3.82±0.68) scores, (1.94±0.88) scores, (1.36±0.52) scores, and ODI were(41.38±10.23) scores, (25.13±14.22) scores , (20.61±5.82) scores, (14.55±5.27) scores . The scores of VAS and ODI after operation were lower than those before operation (P<0.05), but there was no significant difference between the two groups (P<0.05). CONCLUSION: Modified suspension reduction method combined with PVP surgery for osteoporotic thoracolumbar compression fractures has achieved good clinical results, which can effectively relieve lumbar back pain, restore vertebral height, correct kyphosis, improve lumbar function and patients' quality of life.

Facile Synthesis of Light-Switchable Polymers with Diazocine Units in the Main Chain.

Unlike azobenzene, the photoisomerization behavior of its ethylene-bridged derivative, diazocine, has hardly been explored in synthetic polymers. In this communication, linear photoresponsive poly(thioether)s containing diazocine moieties in the polymer backbone with different spacer lengths are reported. They were synthesized in thiol-ene polyadditions between a diazocine diacrylate and 1,6-hexanedithiol. The diazocine units could be reversibly photoswitched between the (Z)- and (E)-configurations with light at 405 nm and 525 nm, respectively. Based on the chemical structure of the diazocine diacrylates, the resulting polymer chains differed in their thermal relaxation kinetics and molecular weights (7.4 vs. 43 kDa) but maintained a clearly visible photoswitchability in the solid state. Gel permeation chromatography (GPC) measurements indicated a hydrodynamic size expansion of the individual polymer coils as a result of the Z→E pincer-like diazocine switching motion on a molecular scale. Our work establishes diazocine as an elongating actuator that can be used in macromolecular systems and smart materials.

Double arterial cannulation versus right axillary artery cannulation for acute type A aortic dissection: a retrospective study.

BACKGROUND: Cannulation strategy in surgery for acute type A aortic dissection (ATAAD) remains controversial. We aimed to retrospectively analyze the safety and efficacy of double arterial cannulation (DAC) compared with right axillary cannulation (RAC) for ATAAD. METHODS: From January 2016 to December 2018, 431 ATAAD patients were enrolled in the study. Patients were divided into DAC group (n = 341) and RAC group (n = 90). Propensity score matching analysis was performed to compare the early and mid-term outcomes between these two groups. To confirm the organ protection effect by DAC, intraoperative blood gas results and cardiopulmonary bypass parameters were compared between the two groups. RESULTS: Demographics and preoperative comorbidities were comparable between two groups, while patients in DAC group were younger than RAC group (51.55 ± 13.21 vs. 56.07 ± 12.16 years, P < 0.001). DAC had a higher incidence of limb malperfusion (18.2% vs. 10.0%, P = 0.063) and lower incidence of coronary malperfusion (5.3% vs. 12.2%, P = 0.019). No significant difference in cardiopulmonary bypass and cross-clamp time was found between the two groups. The in-hospital mortality was 13.5% (58/431), while there was no difference between the two groups (13.5% vs. 13.3%; P = 0.969). Patients who underwent DAC had higher incidence of postoperative stroke (5.9% vs. 0%, P = 0.019) and lower incidence of postoperative acute kidney injury (AKI) (24.7% vs. 40.3%; P = 0.015). During a mean follow-up period of 31.8 (interquartile range, 25-45) months, the overall survival was 81.5% for DAC group and 78.0% for RAC group (P = 0.560). Intraoperative blood gas results and cardiopulmonary bypass parameters showed that DAC group had more intraoperative urine output volume than RAC group (P = 0.05), and the time of cooling (P = 0.04) and rewarming (P = 0.04) were shorter in DAC group. CONCLUSIONS: DAC will not increase the surgical risks compared to RAC, but could reduce the incidence of postoperative AKI which may be benefit for renal protection.

Prompt surgery is effective for acute type A aortic dissection with cerebral ischemia.

BACKGROUND: Acute type A aortic dissection (aTAAD) with preoperative cerebral ischemia (CI) is common and lethal, but the timing and treatment method remain uncertain. We retrospectively reviewed our aTAAD patients with CI and analyzed the outcomes and related risk factors. METHODS: From January 2011 to December 2019, 1,173 patients diagnosed with aTAAD from Nanjing Drum Tower Hospital were enrolled. Among them, 131 patients had CI preoperatively (CI group), and 1,042 patients were in the non-CI group. One hundred eight in the CI group and 984 in the non-CI group received central repair surgery. Fifteen patients had postoperative cerebral complications (CC) and 93 had non-CCs. ROC curves were used to identify the safe duration of preoperative CI. RESULTS: The CI group was older (56.3 vs. 53.2 years, P=0.013) and had lower rates of pain, chest pain and back pain (77.9% vs. 94.4%, 75.4% vs. 87.5% and 30.8% vs. 42.3%, respectively) than the non-CI group. The CI group had a higher rate of preoperative hypotension and tamponade (13.7% vs. 6.0%, 26.9% vs. 10.4%, respectively; P=0.000). More patients in the CI group did not receive central repair surgery, and the CI had higher mortality (28.2% vs. 15.9%). CI without central repair surgery was a strong risk factor for mortality. CI patients with CC after central repair had a higher mortality, and preoperative coma was the strongest risk factor for postoperative CC.A duration between CI symptoms and central repair surgery of less than 12.75 hours is recommended. CONCLUSIONS: Prompt surgery is effective for aTAAD with CI, and preoperative coma and a safe duration longer than 12.75 hours would predict worse outcomes.

Management strategy of Type A Aortic Dissection in a developing center from China: 16 years experiences.

BACKGROUND: Type A Aortic Dissection (TAAD) remains a lethal disease of increasing incidence. However the incidence, standardized treatment and survival rates of TAAD is still a lack in China. This study aims to share the management strategy of TAAD from a developing center of this country. METHODS: All subjects identified with TAAD in Nanjing Drum Tower Hospital, China, from Jan. 2002 to Dec. 2018 were included in this study. Of 1,037 individuals, 932 (89.9%) were underwent surgery. Based on annual case volume patients underwent surgery were stratified into three operative stages: Early, Middle and Current stage, and patient characteristics, operative trends and outcomes across the operative stages were assessed. RESULTS: The annual admissions of patients increased from approximately 20 during 2002-2013 (early era), 100 during 2014-2016 (middle era) to 200 during 2017-2018 (current era). The median age of patients increased from 49.0 to 53.0 among different eras (P<0.001). The overall in-hospital mortality was 16.5%, which significantly decreased from 21.3% to 13.1% with eras (P=0.023). The median time from admission to surgery was remarkedly shorted from 30.4 h during the early era to 14.0 h during the current era. Compared with in the early era, the percentages of aortic arch repair were increased in middle or current eras, while total arch replacement decreased. CONCLUSIONS: During the last 16 years, the prevalence of TAAD was increasing, and the annual number of operations increased substantially in China. Hospital survival improved over time was challenging prompt management and suitable operations.