Porous chitosan microspheres containing zinc ion for enhanced thrombosis and hemostasis.

Quick hemostats for non-lethal massive traumatic bleeding in battlefield and civilian accidents are important for reducing mortality and medical costs. Chitosan (CS) has been widely used as a clinic hemostat. To enhance its hemostatic efficiency, Zn2+ in the form of zinc alginate (ZnAlg) was introduced to CS to make porous CS@ZnAlg microspheres with ZnAlg component on the surface. Such microspheres were prepared by successive steps of micro-emulsion, polyelectrolyte adhesion, and thermally induced phase separation. Their structure and hemostatic performance were analyzed by SEM, FT-IR, XPS and a series of in vitro hemostatic experiments including thromboelastography analysis. The composite microspheres had an outer and internal interconnected porous structure. Their size, surface area, and water absorption ratio were ca. 70µm, 48m2/g, and 1850%, respectively. Compared to the neat chitosan microspheres, the CS@ZnAlg microspheres showed shorter onset of clot formation, much faster in vitro and in vivo whole blood clotting, bigger clot, less blood loss, and shorter hemostatic time in the rat liver laceration and tail amputation models. The synergetic hemostatic effects from (1) the electrostatic attraction between chitosan component and red blood cells, (2) the activation of coagulation factor XII by Zn2+ of zinc alginate component, and (3) physical blocking by microsphere matrix, contributed to the enhanced hemostatic performance of CS@ZnAlg microspheres.

Porous chitosan microspheres for application as quick in vitro and in vivo hemostat.

Controlling massive hemorrhage is of great importance to lower transfusional medical cost, and to reduce death and mobility rate in battlefield and civilian accidents. We reported the fabrication of porous chitosan microspheres (CSMS) with tunable surface pore size by microemulsion combined with thermally induced phase separation technique, and its application as a quick hemostat. Their hemostatic property was characterized by blood clotting kinetics, adherence interaction between red blood cells/platelets and CSMS, in vitro and in vivo hemostasis by rat tail amputation and liver laceration models, and histological analysis. Their density, surface area, porosity, water absorption ratio were 0.04-0.06g/cm3, 28.2-31.5m2/g, 98%, and 15.5-23.2g/g, respectively. The surface pore was controlled to be smaller than 2.0µm. The porous CSMS showed increasing hemostatic efficacy with decreasing surface pore size. Compared to the conventional compact chitosan particles (CCSP), the porous CSMS had much improved in vitro and in vivo hemostatic potential with respect to formation of blood clot, hemostatic time, and blood loss. For instance, the hemostatic time and blood loss of CSMS in the rat liver laceration model were down to respectively 70s and 0.026g from 175s and 0.28g of CCSP. Histological examination showed that application of porous CSMS to liver laceration caused no destruction of underlying hepatocytes, inflammatory reaction, and thermal injury to liver tissue. The porous CSMS is a biodegradable, quick and safe hemostat, which can be used in various wounds including complex and non-compressive ones.

Video-assisted thoracic surgical technique versus conventional surgical technique for mitral valve replacement: A case control study / 中国胸心血管外科临床杂志

@#Objective    To compare video-assisted thoracic surgical technique (VATS) and conventional surgical technique (CSM) in mitral valve replacement (MVR). Methods    We retrospectively analyzed clinical data of 93 patients in our hospital with mitral valve replacement between January 2010 and January 2015. The patients were divided into two groups including a VATS group and a CSM group.There were 43 patients with 25 males and 18 females at age of 57.43±5.65 years in the VATS group, and 50 patients with 27 males and 23 females at age of 56.40±6.32 years in the CSM group.The clinical outcomes of the two groups were compared. Results    There was no mortality. Echocardiography was normal in both groups during 1-year follow-up. There was no significant difference between the two groups in the operative time, aortic clamping time, cardiopulmonary bypass (CPB) time, or ventilation time. As compared with the CSM group, the patients in the VATS group had a significantly lower complication rate, shorter chest incision length (5.23±1.36 cm vs. 18.21±3.89 cm), less blood transfusion (1.75±0.25 U vs. 3.15±1.50 U), less chest drainage (202.34±12.12 ml vs. 412.32±21.56 ml) and lower pain score (1.26±0.86 vs. 3.01±1.13), shorter time of postoperative hospital stay (8.20±2.36 d vs. 12.10±3.26 d). Conclusion    MVR under VATS is not only technically feasible, but also with excellent clinical results.

Comparison of long-term clinical outcomes and costs between video-assisted thoracoscopic surgery and transcatheter amplatzer occlusion of the patent ductus arteriosus.

The current study was designed to compare long-term clinical outcomes and costs between video-assisted thoracoscopic surgery (VATS) and transcatheter Amplatzer occlusion (TAO). This study enrolled 294 patients with isolated patent ductus arteriosus (PDA) from April 2002 to April 2007, and 290 of these patients were followed up until April 2010. Of the 294 patients, 196 underwent VATS and 98 accepted TAO for PDA closure. The two groups were similar in terms of demographics and preoperative clinical characteristics. No cardiac deaths occurred in either group. All the patients in the VATS group had successful PDA closure, and 94 patients (94/98, 95.9%) in the TAO group had successful PDA occlusion. The incidence of acute procedure-related complications recorded was 1.5% in the VATS group compared with 10.2% in TAO group (P < 0.05). The cost per patient was $1,309.40 ± $312.20 in the VATS group and $3,415.80 ± $637.30 in the TAO group (P < 0.05). There were no cardiac deaths or newly occurring arrhythmias in either group during the fellow-up period. Up to the latest follow-up, no late recanalization or residual shunting was documented, and heart structure returned to normal level in the VATS group. However, residual shunting was detected in four more TAO patients. This study confirmed the long-term safety and efficacy of VATS clipping of PDA. Compared with TAO, PDA interrupted with VATS can achieve both excellent clinical results and satisfying cost effectiveness. The cost for VATS is only a little more than one third the cost for TAO.

Comparison of posterolateral thoracotomy and video-assisted thoracoscopic clipping for the treatment of patent ductus arteriosus in neonates and infants.

This study was designed to compare the long-term clinical outcomes and costs between video-assisted thoracic surgery (VATS) and posterolateral thoracotomy (PT) in neonates and infants. This study enrolled 302 patients with isolated patent ductus arteriosus (PDA) from January 2002 to 2007 and followed them up until April 2010. A total of 134 patients underwent total VATS (VATS group), and 168 underwent PDA closure through PT (PT group). The two groups were compared according to clinical outcomes and costs. The demographics and preoperative clinical characteristics of the patients were similar in the two groups. No cardiac deaths occurred, and the closure rate was 100% successful in both groups. The operating, recovery, and pleural fluid drainage times were significantly shorter in the VATS group than in the PT group. Statistically significant differences in length of incision, postoperative temperature, and acute procedure-related complications were observed between the two groups. The cost was $1,150.3 ± $221.2 for the VATS group and $2415.8 ± $345.2 for the PT group (P < 0.05). No cardiac deaths or newly occurring arrhythmias were detected in either group during the follow-up period. Statistically significant differences in the rate of residual shunt and scoliosis were observed between the two groups. The left ventricular end-diastolic diameter and the pulmonary artery diameter could be restored to normal in the VATS group but not in the PT group. The study confirmed that VATS offers a minimally traumatic, safe, and effective technique for PDA interruption in neonates and infants.