PHASE II MAGNETIC ALTERATION OF PECTUS EXCAVATUM

描述(由申请人提供)： 漏斗胸是儿童最常见的先天性胸壁畸形。外科矫正需要在全身麻醉下进行一次大的、往往是残酷的手术，迫使胸骨向前移动，并使用金属胸壁支撑将其固定到位。胸壁在巨大压力下变形会导致并发症和复发，以及术后疼痛，需要住院接受长达一周的区域麻醉和麻醉，疼痛和残疾长达数周或数月。矫正胸壁和其他畸形的一个更好的原则是用几个月的最小力逐步矫正(就像用正畸矫治器移动牙齿)。 申请人正在开发一种新的方法，实现胸壁软骨的逐渐变形/重建，而不需要透皮矫形装置或重复手术。磁场被用来施加受控的间歇力，以促进结构软骨的生物重建(与牵引成骨相同的原理)。 在胸骨下植入一块磁铁，并使用固定策略固定，这种固定策略可以通过一个3厘米的颧骨下切开完成，这是一个简短的门诊手术。磁铁(和胸骨)被另一块磁铁向外拉，该磁铁悬挂在一个先前模制在患者胸壁前的低调、轻便的设备中。悬挂在四个独立应变片上的外部磁铁测量产生的磁力，并允许单独调整施加在胸骨上的力的距离和方向的小增量。低调、非阻塞型前胸壁假体通过两个磁铁之间的力场固定在适当的位置。 申请者将在10名其他健康的患者身上测试这一程序/装置的安全性和可能的益处，并通过每月激光扫描来记录矫正率，通过改变胸部严重程度指数(来自胸部X光)来记录最终结果。如果成功，将提交人道主义使用装置指定申请，以便根据人道主义装置豁免提供治疗。

DESCRIPTION (provided by applicant): Pectus excavatum is the most common congenital chest wall abnormality in children. Surgical correction requires a big and often brutal operation under general anesthesia which forces the sternum forward and holds it in place using a metal chest wall strut. Deformation of the chest wall under great pressure results in complications and relapses as well as postoperative pain requiring hospitalization for regional and narcotic anesthesia for up to a week and pain and disability for weeks or months. A better principle for correction of chest wall and other deformities is gradual correction using minimal force applied over many months (like moving teeth with orthodontic braces). The applicant is developing a novel method of achieving gradual deformation/reformation of chest wall cartilage without the need for transdermal orthopedic devices or repeated surgeries. A magnetic force field is used to apply controlled, intermittent force to promote biologic reformation of structural cartilage (the same principle as distraction osteogenesis). A magnet is implanted under the sternum and secured using a fixation strategy that can be accomplished through a 3-cm subzyphoid incision as a brief outpatient procedure. The magnet (and sternum) is pulled outward by another magnet suspended in a low-profile, lightweight device previously molded to the patient's anterior chest wall. The external magnet suspended from four independent strain gauges measures the magnetic force generated and allows individual adjustment in small increments of the distance and orientation of the force applied to the sternum. The low-profile, non-obstrusive anterior chest wall prosthesis is held in place by the force field between the two magnets. The applicant will test the safety and probable benefit of this procedure/device in 10 otherwise healthy patients and document the rate of correction by monthly laser scan and the end result by change in pectus severity index (from chest X-ray). If successful, an application for Humanitarian Use Device designation will be submitted to make the treatment available under Humanitarian Device Exemption.