Risk factors of distal segment aortic enlargement after complicated type B aortic dissection

Objectives:Distal segment aortic enlargement(DSAE)is a common complication that influences the long-term prognosis of type B aortic dissection(TBAD)after thoracic endovascular aortic repair(TEVAR).In this study,a multivariate analysis was performed to find potential factors predictive of DSAE.Methods:A single-center retrospective study was performed from 1999 to 2016.Included in the study were complicated TBAD patients who underwent TEVAR with uncovered residual tears.Based on the diameter of the distal segment of the uncovered aorta,we assigned patients to an enlargement group and a non-enlargement group.Data extracted from the medical records included demographic and clinical characteristics and followup computed tomography angiography data.The primary endpoints were the all-cause mortality and the presumably aortic-related events that required reintervention during the follow-up period.Results:For the 333 patients,all-cause mortality was 38(11.41%),and 76(22.82%)patients underwent reintervention.A total of 70(21.02%)patients experienced DSAE,among them were 2 patients who died of aortic rupture and 58 patients who accepted reintervention.Multivariate analysis reviewed independent risk factors of postoperative DSAE,including current smoking,the residual length of the patent false lumen,the postoperative number of dissection tears in the thoracic aorta and type III aortic arch;as well as protective factors,including the application of a restrictive bare stent(RBS),the length of covered stent in the descending thoracic aorta,and the distance from the residual first tear to the left subclavian artery(LSA).Conclusion:DSAE after TEVAR for patients with a complicated TBAD can be influenced by their current smoking habit,the residual length of patent false lumen,the postoperative number of dissection tears in the thoracic aorta and the aortic arch type.Meanwhile,RBS usage,the length of the covered stent in the descending thoracic aorta and the distance from the residual first tear to the LSA could have positive effect on the prognosis.

Morphology of the ascending aorta: a study on 114 Chinese patients

Purpose: This study aimed to investigate the morphological characteristics of ascending aortic dissection in detail. Materials and Methods: The ascending aorta was morphologically assessed in a consecutive series of patients between January 2009 and October 2014. A new assessment and evaluation method was used to describe 114 patients with ascending aortic dissection. Results: A large difference was found in the degree of curvature between the ascending aorta with and without dissection. The shape of the former was straighter and steeper(control group R, 47.46 ± 6.40 mm; experimental group R, 59.70 ± 10.27 mm, P < 0.001). In the case of aortic dissection involving the valves, the proximal edge of the first entry was obviously close to the aortic sinus. The orientation of the entries was mainly around the 10 o'clock and 1–2 o'clock positions, and most of their shapes were fusiform(111; 70.02%). The distance of the distal extending dissection was associated with cases involving the branch arteries(involving three branches 441.40 ± 101.13 mm vs 159.85 ± 131.86 mm in others, P < 0.001). Conclusion: The morphological features of the ascending aorta after dissection and the correlations among dissections, entries, and related factors were found.

Preoperative evaluation of transcatheter aortic valve replacement with assistance of 3D printing technique:Reanalysis of 4 death cases

Introduction:Transcatheter aortic valve replacement(TAVR)can have some fatal complications during and after the operation.Until recently,pre-procedural imaging with cardiac computed tomography(CT),which is required to evaluate for TAVR,had its own imperfections.We aimed to determine whether 3 D printed models can predict complications when other pre-procedural imaging techniques failed.Methods:Vascular center patients with aortic valve stenosis,who died after TAVR between June 2011 and June2016,were enrolled in this retrospective study.The CT datasets of the patients were imported into a threedimensional(3 D)construction software and then printed by flexible material.To predict complications during and after operations,we designed a release test using the non-valved stent mode that was consistent with the Edwards Sapien XT valve in size and radial support force.Result:The 3 D model predicted the coronary obstruction and annular rupture in the in vitro release process,which was consistent with what happened in the actual operation.Conclusion:Three-dimensional modeling facilitates pre-operative assessment of patients receiving TAVR,with accurate simulation of intraoperative status.

Donkey pericardium as a select sourcing to manufacture percutaneous heart valves:Decellularization has not yet demonstrated any clear cut advantage to glutaraldehyde treatment

Background:The donkey pericardium is considered a good candidate to manufacture percutaneous heart valves based upon its thinness,low cellularity and undulating collagen bundles and laminates.Decellularization represents an avenue worth exploring,should its superiority to glutaraldehyde-treated pericardium be demonstrated.Materials and methods:Donkey pericardium was divided into two groups:regular glutaraldehyde fixation and mild decellularization.The treated pericardia were observed using scanning electron microscopy,histology and transmission electron microscopy.Tensile tests were performed along the axial and perpendicular directions,with the data fitted into both the Gasser–Ogden–Holzapfel(GOH)material model and the Fung’s anisotropic one.Results:The microstructures of the pericardia processed by the two protocols were similar,showing collagen bundles and laminates free of flaws.The decellularization eliminated most of the cells,however leaving the structure somehow compressed.The collagen filaments in bundles were slightly blurry.The anisotropy rates of the non-decellularized specimens were almost identical to the decellularized ones.The decellularized pericardium appeared stiffer.Conclusion:The decellularization proved to be effective.However,it makes the tissue stiffer,which may lead to higher shear concentration during cardiac cycles and reduce its wavy microstructure.Therefore,it appears premature to select decellularized donkey pericardium to manufacture heart valves.