自主研制镍钛合金左心耳封堵器置入后封堵材料的表面内皮化

背景：国内外研究表明镍钛合金在体内长期置入可释放镍离子,引起血浆镍含量增高。目的：通过大体、扫描电镜及血浆镍含量的测定,了解左心耳封堵器置入后封堵材料表面的内皮化效应。设计、时间及地点：对比观察实验,于2005-09/2006-08在南京医科大学第一附属医院江苏省实验动物中心完成。材料：选用南京农科院种猪养殖厂提供的苏钟小型种猪17只,随机分为实验组12只和对照组5只。方法：实验组使用自主研制的镍钛合金左心耳封堵器行左心耳封堵,对照组手术步骤相同而不施行左心耳封堵。主要观察指标：封堵前、封堵后1,3,6个月取外周静脉血浆,采用石墨炉原子吸收分光光度法测定镍离子含量;大体及扫描电镜观察封堵器表面内皮细胞生长情况。结果：实验组血浆镍含量于封堵后1个月达高峰,与术前相比差异有显著性意义（P〈0.001）,封堵后6个月基本回复至术前水平,与术前相比差异无显著性意义（P〉0.05）;大体及电镜结果表明封堵器表面内皮化在封堵后4周基本完成。结论：镍离子可以从封堵器表面释放导致血循环引起血浆镍含量升高,而封堵材料表面内皮化的形成阻碍镍离子的进一步释放。     

体外电复律治疗房颤对植入左心耳封堵器患者的影响

目的：探讨植入左心耳封堵器的房颤患者接受体外电复律治疗的可行性和安全性。方法：选取2016年5月至2019年12月北京医院收治的经皮成功植入左心耳封堵器患者51例，其中接受体外电复律治疗7例（13.7%），观察电复律对装置的影响及相关不良事件。结果：51例患者中，接受电复律治疗的7例（13.7%）患者未发生封堵器移位或脱落，围手术期未发生严重不良事件。结论：植入左心耳封堵器的房颤患者接受体外电复律治疗是安全、可行的。     

自主研制镍钛记忆合金左心耳封堵器封闭左心耳对实验动物左心功能的影响

目的:应用经胸彩色多普勒超声技术评价自主研制的镍钛记忆合金左心耳封堵器封闭左心耳对实验动物猪左心房、左心室功能的影响。方法:实验于2005-09/2006-08在南京医科大学第一附属医院江苏省实验动物中心完成。①实验分组:选用苏钟小型种猪17只,随机分为实验组12只和对照组5只。②实验干预:实验组12只苏钟小型种猪使用自主研制的左心耳封堵器(发明专利号码:200610037789.3,公开号CN1799521,由镍钛合金骨架、多聚四氟乙烯膜和传送连接部分等构成。其外观呈单盘状,封堵器的左心房面呈圆盘状,直接连接放入心耳内的圆柱体结构)行左心耳封堵,对照组5只手术步骤相同而不采用封堵器行左心耳封堵。③实验评估:两组动物分别于术前、术后1周、2周、4周采用经胸超声心动图检查观察心功能的改变,测量左心房内径、最大及最小容积、左房射血分数、左心房搏出量、血流分数等左房功能参数以及左室射血分数、左室短轴缩短率、Tei指数、E/A比值等指标。结果:①实验动物数量分析:在施行左心耳封堵后,1头猪于术中出血过多并出现室颤后死亡,1头猪因封堵器脱入左房,卡在二尖瓣口导致死亡。其余动物封堵效果良好。②两组动物术后1,2,4周左房功能指标各参数与术前比较无明显变化(P>0.05);与术前相比,实验组术后1周、2周左室射血分数、左心室短轴缩短率、E/A比值分别由术前的0.70±0.04、0.39±0.03、1.33±0.28降低至术后1周的0.59±0.05、0.31±0.03、0.95±0.11(P<均0.01)及术后2周的0.62±0.05、0.33±0.05、0.90±0.05(P<均0.01);Tei指数由术前的0.48±0.02增加至术后1周的0.59±0.03(P<0.01)及术后2周的0.58±0.04(P<0.01)。对照组手术前后左室功能指标差异无显著性。结论:自主研制左心耳封堵器可以有效的封堵左心耳;左心耳封堵后短期内对实验动物左房功能无明显影响;封堵后短期内对左心室功能具有短期的减弱,更长期的安全性有待于进一步研究。     

Measurement of left atrial appendage size by transesophageal echocardiography

Transesophageal echocardiography (TEE) is the most common imaging method for evaluating left atrial morphology. Recent advances in 64-slice multidetector computed tomography (64-MDCT) allow accurate measurement of left atrial appendage (LAA) volume. The aim of this study was to evaluate the accuracy of LAA sizing by TEE in comparison with 64-MDCT in patients with atrial fibrillation. Electrocardiogram-gated 64-MDCT and TEE were performed within 2 days in 18 consecutive patients (63 ± 9 years old, 12 males, 5 paroxysmal atrial fibrillation) with nonvalvular atrial fibrillation. LAA area and LAA volume were measured at end-systole by TEE and 64-MDCT, respectively. The largest LAA area was measured on TEE image. Five patients were in sinus rhythm during examinations. In all patients, LAA was clearly visualized; the largest area of LAA was 9.3 ± 3.9 mm² and the LAA volume was 21.6 ± 7.5 ml. A significant correlation between LAA area and LAA volume was observed (p = 0.0003, r = 0.75). TEE allows a detailed evaluation of the LAA structure by two-dimensional imaging. LAA size could be evaluated by TEE despite its morphological complexity, i.e., sac-like or multilobed structure.     

Statistical shape analysis of the left atrial appendage predicts stroke in atrial fibrillation

The shape of the left atrium (LA) and left atrial appendage (LAA) have been shown to predict stroke in patients with atrial fibrillation (AF). Prior studies rely on qualitative assessment of shape, which limits reproducibility and clinical utility. Statistical shape analysis (SSA) allows for quantitative assessment of shape. We use this method to assess the shape of the LA and LAA and predict stroke in patients with AF. From a database of AF patients who had previously undergone MRI of the LA, we identified 43 patients with AF who subsequently had an ischemic stroke. We also identified a cohort of 201 controls with AF who did not have a stroke after the MRI. We performed SSA of the LA and LAA shape to quantify the shape of these structures. We found three of the candidate LAA shape parameters to be predictive of stroke, while none of the LA shape parameters predicted stroke. When the three predictive LAA shape parameters were added to a logistic regression model that included the CHA₂DS₂-VASc score, the area under the ROC curve increased from 0.640 to 0.778 (p?=?.003). The shape of the LA and LAA can be assessed quantitatively using SSA. LAA shape predicts stroke in AF patients, while LA shape does not. Additionally, LAA shape predicts stroke independent of CHA₂DS₂-VASc score. SSA for assessment of LAA shape may improve stroke risk stratification and clinical decision making for AF patients.

     

Cardiac PET-CT and CT Angiography

Today coronary artery disease (CAD) is widely understood to constitute an advanced stage of atherosclerosis, an inflammatory pathology involving both coronary and extracoronary arteries. It is increasingly appreciated that perfusion imaging brings additional prognostic value as compared to morphological imaging alone, where myocardial perfusion abnormalities can be understood as the functional consequence of a broad range of present atherosclerotic vessel alterations, baring considerable significance for the diagnostic and prognostic work-up of CAD. Using recently introduced PET/CT hybrid scanners, the favorable characteristics of PET perfusion imaging and quantification can be further strengthened by adding CT morphological information, both components contributing to a comprehensive view on the heart and enabling combined morphological and functional imaging including three dimensional image fusion. Thus, cardiac PET/CT can provide both a reliable allocation of perfusion abnormalities to their supplying coronary artery and improved individual risk stratification for further clinical management.     

CT based 3D printing is superior to transesophageal echocardiography for pre-procedure planning in left atrial appendage device closure

Accurate assessment of the left atrial appendage (LAA) is important for pre-procedure planning when utilizing device closure for stroke reduction. Sizing is traditionally done with transesophageal echocardiography (TEE) but this is not always precise. Three-dimensional (3D) printing of the LAA may be more accurate. 24 patients underwent Watchman device (WD) implantation (71?±?11 years, 42% female). All had complete 2-dimensional TEE. Fourteen also had cardiac computed tomography (CCT) with 3D printing to produce a latex model of the LAA for pre-procedure planning. Device implantation was unsuccessful in 2 cases (one with and one without a 3D model). The model correlated perfectly with implanted device size (R²?=?1; p?<?0.001), while TEE-predicted size showed inferior correlation (R²?=?0.34; 95% CI 0.23–0.98, p?=?0.03). Fisher’s exact test showed the model better predicted final WD size than TEE (100 vs. 60%, p?=?0.02). Use of the model was associated with reduced procedure time (70?±?20 vs. 107?±?53 min, p?=?0.03), anesthesia time (134?±?31 vs. 182?±?61 min, p?=?0.03), and fluoroscopy time (11?±?4 vs. 20?±?13 min, p?=?0.02). Absence of peri-device leak was also more likely when the model was used (92 vs. 56%, p?=?0.04). There were trends towards reduced trans-septal puncture to catheter removal time (50?±?20 vs. 73?±?36 min, p?=?0.07), number of device deployments (1.3?±?0.5 vs. 2.0?±?1.2, p?=?0.08), and number of devices used (1.3?±?0.5 vs. 1.9?±?0.9, p?=?0.07). Patient specific models of the LAA improve precision in closure device sizing. Use of the printed model allowed rapid and intuitive location of the best landing zone for the device.     

Three-dimensional assessment of left atrial appendage orifice geometry and potential implications for device closure

Transcatheter placement of left atrial closure device is an attractive therapy for patients with atrial fibrillation (AF), to avoid anticoagulation and reduce cerebrovascular events; however peri-device leaks occur. The geometry of the left atrial appendage (LAA) is not well understood, largely owing to limitations of 2-dimensional imaging techniques. We sought to better define the LAA orifice geometry, by performing 3-dimensional multi-detector computed tomography measurements. We prospectively recruited 105 consecutive patients referred for pulmonary vein ablation (PVA) and age-matched controls. Area, short and long-axis measurements were performed. Eccentricity was calculated as 1-(short axis/long axis). Multiple clinical variables were tested for their ability to predict appendage orifice eccentricity using univariate linear regression models. The PVA cohort demographics included; 25 (24 %) females, mean age 59 years (SD = 10), median height (1.55–2.03), weight 89 (56–139) kg and body surface area 2.1 (1.61–2.58). In the PVA cohort, there was a significant difference between the long and short-axis; median short-axis dimension was 20.5 (12.9–35.4) mm, versus long-axis median 30.4 (17.7–43.8) (p < 0.001). Mean eccentricity score was 0.4. When compared with controls, there was a significant difference in the short and long-axis measurements (p < 0.001) as well as eccentricity (p = 0.04). All clinical variables tested showed limited ability to predict appendage eccentricity (p = NS). LAA ostium is an elliptical structure in the setting of AF with a high eccentricity index and uniformly significant differences between short and long-axis. There were significant differences between these parameters when compared with controls. A deeper appreciation of LAA geometry and eccentricity may allow for reduction in peri-closure leaks.     

应用TEE数据源的左心耳3D模型开口参数指导LAmbreTM封堵器型号选择

目的探讨左心耳开口的多个解剖参数与术中最终置入心房颤动(以下简称房颤)患者体内的LAmbre TM封堵器型号之间的关系。方法选取在我院成功进行左心耳LAmbre TM封堵的23例房颤患者,应用交互式医学影像控制系统软件对其左心耳3D经食管超声心动图(TEE)医学数字成像和通信容积数据进行阈值分割等操作,重建左心耳3D模型,测量左心耳开口最大径、周长及面积,并与手术最终选择封堵器型号进行相关性分析。将与封堵器固定盘大小相关性较好的前15例患者的左心耳开口参数与所选择封堵器大小进行线性回归分析。抽取术中更换封堵器2例患者,制作左心耳3D打印模型,并进行体外封堵器释放试验。结果成功对23例房颤患者的左心耳超声容积数据进行后处理,并获取了包括左心耳开口形态在内的5个开口参数。左心耳开口最大径、面积及周长与相应LAmbre TM封堵器固定盘大小的相关性较好(r=0.85、0.74、0.89,均P0.01)。以与封堵器固定盘大小相关性较好的前15例房颤患者的左心耳开口最大径及周长作为预测变量,封堵器型号为因变量,建立的回归方程分别为:封堵器固定盘最大径预测值=11.22+0.71×开口最大径;封堵器固定盘周长预测值=12.71+1.06×开口周长。通过对左心耳开口参数的综合评估,体外试验中成功封堵了所抽取的2例患者的左心耳模型,且所选择的封堵器与手术最终应用的型号一致。结论综合分析左心耳3D模型开口解剖参数可以更好地指导LAmbre TM封堵器型号的选择。     

A low-dose,dual-phase cardiovascular CT protocol to assess left atrial appendage anatomy and exclude thrombus prior to left atrial intervention

Assessment of the left atrial appendage (LAA) for thrombus and anatomy is important prior to atrial fibrillation (AF) ablation and LAA exclusion. The use of cardiovascular CT (CCT) to detect LAA thrombus has been limited by the high incidence of pseudothrombus on single-pass studies. We evaluated the diagnostic accuracy of a two-phase protocol incorporating a limited low-dose delayed contrast-enhanced examination of the LAA, compared with a single-pass study for LAA morphological assessment, and transesophageal echocardiography (TEE) for the exclusion of thrombus. Consecutive patients (n = 122) undergoing left atrial interventions for AF were assessed. All had a two-phase CCT protocol (first-past scan plus a limited, 60-s delayed scan of the LAA) and TEE. Sensitivity, specificity, diagnostic accuracy, positive (PPV) and negative predictive values (NPV) were calculated for the detection of true thrombus on first-pass and delayed scans, using TEE as the gold standard. Overall, 20/122 (16.4 %) patients had filling defects on the first-pass study. All affected the full delineation of the LAA morphology; 17/20 (85 %) were confirmed as pseudo-filling defects. Three (15 %) were seen on late-pass and confirmed as true thrombi on TEE; a significant improvement in diagnostic performance relative to a single-pass scan (McNemar Chi-square 17, p < 0.001). The sensitivity, specificity, diagnostic accuracy, PPV and NPV was 100, 85.7, 86.1, 15.0 and 100 % respectively for first-pass scans, and 100 % for all parameters for the delayed scans. The median (range) additional radiation dose for the delayed scan was 0.4 (0.2–0.6) mSv. A low-dose delayed scan significantly improves the identification of true LAA anatomy and thrombus in patients undergoing LA intervention.     

Chiari network entanglement and herniation into the left atrium by an atrial septal defect occluder device.

The Chiari network is a fenestrated membrane consisting of threads and strands in the right atrium. First described in 1897 by anatomist Hans Chiari, it is a congenital remnant of embryonic development resulting from incomplete resorption of the right valve of the sinus venosus. Found in 2% to 3% of the population, it is generally not of clinical importance. Rarely, however, the network may be associated with serious complications such as thrombus formation, embolus entrapment, arrhythmia, tumor development, and catheter entrapment. We report the entanglement of an Amplatzer septal occluder device catheter in a prominent Chiari network that was herniated into the left atrium. Transesophageal echocardiographic recognition of this before deployment and guidance during disentanglement is described below.     

Computer-aided simple triage (CAST) for coronary CT angiography (CCTA)

Purpose

Following a recent introduction of computer-aided simple triage (CAST) as a new subclass of computer-aided detection/diagnosis (CAD), we present a CAST software system for a fully automatic initial interpretation of coronary CT angiography (CCTA). We show how the system design and diagnostic performance make it CAST-compliant and suitable for chest pain patient triage in emergency room (ER).

Methods

The processing performed by the system consists of three major steps: segmentation of coronary artery tree, labeling of major coronary arteries, and detection of significant stenotic lesions (causing >?50% stenosis). In addition, the system performs an automatic image quality assessment to discards low-quality studies. For multiphase studies, the system automatically chooses the best phase for each coronary artery. Clinical evaluation results were collected in 14 independent trials that included more than 2000 CCTA studies. Automatic diagnosis results were compared with human interpretation of the CCTA and to cath lab results.

Results

The presented system performs a fully automatic initial interpretation of CCTA without any human interaction and detects studies with significant coronary artery disease. The system demonstrated higher than 90% per patient sensitivity and 40?C70% per patient specificity. For the chest pain, ER population, the specificity was 60?C70%, yielding higher than 98% NPV.

Conclusions

The diagnostic performance of the presented CCTA CAD system meets the CAST requirements, thus enabling efficient, 24/7 utilization of CCTA for chest pain patient triage in ER. This is the first fully operational, clinically validated, CAST-compliant CAD system for a fully automatic analysis of CCTA and detection of significant stenosis.     

Use of radiomics to differentiate left atrial appendage thrombi and mixing artifacts on single-phase CT angiography

The International Journal of Cardiovascular Imaging - To assess if radiomics can differentiate left atrial appendage (LAA) contrast-mixing artifacts and thrombi on early-phase CT angiography...     

Interventional left atrial appendage occlusion: added value of 3D transesophageal echocardiography for device sizing

Aim of this study was the assessment of left atrial appendage (LAA) dimensions comparing 2D- to 3D-TEE measurements in patients with nonvalvular atrial fibrillation undergoing percutaneous LAA occlusion. Patients underwent transesophageal echocardiography (TEE) before, during and 45 days after intervention. The maximal LAA orifice diameters in 2D-TEE (LODmax 2D) were obtained from multiple views. Test–retest reliability (screening vs. implantation), inter- and intra-observer variability for echocardiographic parameters were assessed by two independent examiners. Overall, 74 patients underwent percutaneous LAA occlusion. 2D-TEE significantly underestimated the maximal LAA orifice diameter compared with 3D-TEE (screening LODmax 2D 21.11?±?2.75 mm vs. 22.52?±?3.45 mm for LODmax 3D, p?<?0.001; during implantation LODmax 2D 21.56?±?3.48 mm vs. 22.99?±?3.24 mm for LODmax 3D, p?<?0.001). The intraobserver and interobserver variability calculated as coefficient of variation (CV) were both lower for the 3D-TEE quantification of the maximal orifice diameter (intraobserver CV for 3D-TEE 6.07?% vs. 9.31?% for 2D-TEE; interobserver CV for 3D-TEE 6.73?% vs. 9.69?% for 2D-TEE). Compared to 3D-TEE the test–retest reliability of 2D-TEE showed a lower intraclass correlation coefficient calculated as average of raters (0.92 for 3D-TEE vs. for 2D-TEE 0.78). Firstly, 2D-TEE significantly underestimates the maximal LAA orifice diameter compared to 3D-TEE. Secondly, 3D-TEE measurements are associated with a lower observer variability and higher reliability than 2D-TEE.     

256层螺旋CT左心耳定量测量的可重复性研究

目的：评价256层螺旋CT对左心耳定量测量的可重复性.方法：随机选取我院50例行常规冠脉CTA扫描患者,将原始扫描数据行75％期相重建,于工作站对左心耳开口长短径、面积、容积等参数进行测量.比较各参数在同一观察者不同时间及不同观察者间测定的可重复性.结果：同一观察者不同时间测定的各参数结果比较,差别无统计学意义（P＞0.05）;不同观察者两次测定的各参数结果进行比较,差别亦无统计学意义（P＞0.05）.结论：利用Philips 256 MSCT冠脉成像对左心耳进行定量测量有较高的可重复性和一致性,可以为临床房颤射频消融术及左心耳封堵术提供重要参考.     

经胸超声心动图评价左心耳封堵术对猪左心房功能及二尖瓣、肺静脉血流动力学的影响

目的探讨左心耳封堵术对实验动物左心房功能及二尖瓣、肺静脉血流动力学的影响。方法对10只猪使用自主研制的左心耳封堵器行左心耳封堵术,分别于术前、术后1、2及4周行经胸多普勒超声心动图检查,测量左心房内径、最大及最小容积、射血分数、左心房搏出量、血流分数,二尖瓣口血流A峰峰值流速、肺静脉血流S波、D波、Ar波的峰值流速及其时间-速度积分。结果8只实验猪成功实施左心耳封堵术,手术前后超声检测左心房功能参数及二尖瓣、肺静脉血流动力学参数差异无统计学意义(P>0.05)。术前部分实验动物存在的瓣膜关闭不全现象术后无明显变化。结论左心耳封堵术后对实验动物左心房功能、二尖瓣及肺静脉血流无明显影响,长期安全性有待进一步研究。     

Left atrial thrombus two years after placement of a left atrial appendage closure device: Unexplored area of the Watchman

A 72‐year‐old man who underwent a left atrial appendage (LAA) closure device 2 years ago presented with atrial flutter with rapid ventricular rate and was referred for cardioversion. Precardioversion transesophageal echocardiogram showed left atrial thrombus and therefore the procedure was aborted. Currently, there is no guideline on imaging surveillance or anticoagulation in patients with LAA closure device who develop intracardiac thrombus after the initial 6‐month surveillance period.