Valvuloplasty Sizing Balloon Catheter

 描述(由申请人提供)：严重的主动脉狭窄(AS)是一种严重的疾病，最终可能导致死亡，但由于围手术期的高风险，通常不进行治疗。因此，经导管主动脉瓣置换术(TAVR)作为一种经皮主动脉瓣置入治疗AS的方法应运而生。TAVR后的并发症与瓣膜旁渗漏有关，这在一定程度上与人工瓣膜大小的选择不准确有关，与真实的天然主动脉环大小相比。虽然在TAVR前使用成像方式评估主动脉瓣环大小，但这些方法是主观的，可能不准确，而且还增加了额外的时间、成本和临床操作。由于在瓣膜置放前进行瓣膜成形术是标准程序，因此可以从瓣膜成形术球囊中获得瓣环大小信息，并用来选择合适的瓣膜尺寸。球囊的压力/直径关系在这里可能是有用的，然而，不均匀的球囊扩张使得半顺应性瓣膜成形术球囊的主动脉瓣环的大小很难确定。因此，我们开发了一种新的定值瓣膜成形术电导球囊(SVCB)导管系统，其功能与典型的瓣膜成形术球囊导管相同，但具有准确显示实时的附加功能 电导测量用于评估主动脉环的球囊大小。这与依赖标准压力/直径关系来获取整个引出序号上的引出序号大小的其他系统不同。相反，我们的系统使用电学物理定律来获得精确的环形尺寸，尽管在充气期间气球尺寸可能会出现任何不对称。在简单的床边控制台显示器上实时显示尺寸结果，以帮助医生在球囊扩张期间(即，类似于当前显示充气期间压力的显示器)。我们的SVCB导管系统在实验台上和健康的猪身上的初步结果显示，极好的准确性(直径误差2%)、可重复性(直径误差1%)和安全性(无心律失常或死亡)。然而，在转化为MAN(未来的第二阶段应用)之前，还需要额外的工作来改进控制台和导管，并在患病的猪身上进一步验证该系统(这是第一阶段的应用)。因此，在这一阶段的应用中，我们建议建立一种临床上可用的SVCB导管系统，并在患病的猪身上进行体内验证。基于该技术的物理基础以及出色的初步测量和安全性结果，SVCB导管系统有望提供高精度和可重复的实时数字显示主动脉环大小，几乎不需要医生培训。该项目有能力影响患有多种合并症的患者，并覆盖包括NHLBI和NINDS在内的各种NIH研究所和中心。

 DESCRIPTION (provided by applicant): Severe aortic stenosis (AS) is a serious medical condition that can ultimately lead to death, but is often left untreated because of high perioperative surgical risk. As a result, transcatheter aortic valve replacement (TAVR) therapy has emerged as a percutaneous approach for prosthetic aortic valve delivery for the treatment of AS. Complications following TAVR are related to paravalvular leakage, which has been linked in part to inaccurate prosthetic valve size selection compared to the true native aortic annulus size. Although imaging modalities are used to assess aortic valve annulus size prior to TAVR, these methods are subjective, can be inaccurate, and also add additional time, cost, and clinical procedures. Since it is standard procedure to perform valvuloplasty just prior to valve deployment, annular sizing information can be obtained from the valvuloplasty balloon and used to select the proper valve size. The pressure/diameter relationship of the balloon could be useful here, however, non-uniform balloon expansion makes sizing of the aortic valve annulus difficult for semi-compliant valvuloplasty balloons. Consequently, we have developed a novel sizing valvuloplasty conductance balloon (SVCB) catheter system that functions as a typical valvuloplasty balloon catheter, but with additional functionality for accurate display of real-time balloon size for aortic annulus assessment using electrical conductance measurements. This is unlike other systems that rely on standard pressure/diameter relationships to acquire balloon size across the entire balloon. Rather our system uses an electrical law of physics to obtain precise annular dimension despite any asymmetries that could arise in the balloon dimension during inflation. The sizing results are displayed in real-time on a simple bed-side console display to aid the physician during balloon expansion (i.e., similar to current displays that show pressure during inflation). The preliminary results with our SVCB catheter system on the bench and in healthy swine showed excellent accuracy (2% diameter error), as was the repeatability (<1% diameter error), and safety (no arrhythmias or death). However, additional work is needed to refine the console and catheter and to further validate the system in diseased swine (this Phase I application) before translation to man (future Phase II application). Therefore, in this Phase I application, we propose the creation of a clinically ready SVCB catheter system and its validation in vivo in diseased swine. Based on the physics foundation of the technology and the excellent preliminary sizing and safety results, the SVCB catheter system is expected to provide highly accurate and repeatable real-time digital display of aortic annulus size with virtually no physician training required. This project has the ability to impact patients with multiple comorbidities and reach across various NIH Institutes and Centers including the NHLBI and NINDS.