Covered metal stents for treatment of post-liver transplant biliary strictures

描述（由申请人提供）：肝移植后10-30%的患者发生术后吻合口胆管狭窄，并通过连续内镜扩张和支架置入术进行治疗，通常需要在一年或更长时间内进行多次手术。尽管与手术翻修相比非常成功且发病率较低，但内窥镜方法涉及在狭窄处放置多个塑料支架（PS），每3个月连续增大尺寸，直到狭窄完全扩张。这通常需要长时间的多次手术，增加了医疗保健支出，同时使患者面临多次干预和不便的风险。较新的全涂层自膨式金属支架（cSEMS）可以允许对这些狭窄进行内镜治疗，同时需要更少的时间和更少的手术。美国每年进行超过6，000例肝移植手术，医疗保健支出超过通货膨胀，迫切需要确定一种更具成本效益的方法来治疗移植后吻合口狭窄。 我们建议进行一项随机试验研究，比较cSEMS与塑料支架（目前的护理标准）作为肝移植后胆管狭窄的一线治疗。我们将入组原位肝移植术后吻合口胆管狭窄的患者，因为这些患者代表了大多数良性术后胆管狭窄。PS组的患者将以3个月的间隔接受连续扩张和支架尺寸增大，直至狭窄消退（标准治疗）。cSEMS组的患者将接受cSEMS的初始放置，并在6个月后返回;届时，cSEMS将被移除，仅在狭窄未解决的情况下再更换6个月。与PS相比，cSEMS的上级通畅性允许手术之间的支架植入间隔更长。胆道梗阻消退定义为无提示胆道梗阻的临床体征或症状，残余胆管直径>近端和远端胆管的75%。我们将测量6个月时（我们在本初步研究中的主要结局）、不超过12个月的连续支架治疗后的狭窄缓解情况以及支架植入后随访1年后的持续缓解情况。 公共卫生相关性：目前肝移植后胆管狭窄的标准治疗包括在内窥镜和荧光镜引导下连续放置多个塑料支架，以逐渐扩张或拉伸打开。这种方法需要多次手术，在狭窄充分扩张之前可能会持续一年以上。我们提出了一个试点研究比较塑料支架的标准方法与使用新的，完全涂层的金属支架，是自膨胀，从而允许良性胆管狭窄的成功扩张，在更短的时间内，更少的程序。

DESCRIPTION (provided by applicant): Postoperative anastomotic bile duct strictures develop in 10-30% of patients post-liver transplant and are managed by serial endoscopic dilation and stenting, often requiring multiple procedures over a period of one year or longer. Although highly successful and with lower morbidity compared to surgical revision, the endoscopic approach involves the placement of multiple plastic stents (PS) across the stricture, serially upsizing every 3 months until the stricture has been fully dilated. This typically requires multiple procedures over a long duration, increasing health care expenditures while exposing the patient to the risks of multiple interventions and inconvenience. Newer, fully coated, self-expandable metallic stents (cSEMS) may allow endoscopic treatment of these strictures while requiring less time and significantly fewer procedures to do so. With more than 6,000 liver transplants performed in the U.S. each year and health care expenditures outpacing inflation, there is a critical need to identify a more cost effective approach to the treatment of post-transplant anastomotic strictures. We propose conducting a randomized pilot study to compare cSEMS with plastic stents (the current standard of care) for the first-line treatment of post-liver transplant bile duct strictures. We will enroll patients with anastomotic, post-orthotopic liver transplant bile duct strictures since these represent the majority of benign, postoperative bile duct strictures. Patients in the PS group will undergo sequential dilation and stent upsizing at 3 month intervals until the stricture has resolved (standard of care). Patients in the cSEMS group will undergo initial placement of a cSEMS and return after six months; at that time, the cSEMS will be removed and only replaced for an additional six months if the stricture has not resolved. The superior patency of cSEMS compared to PS allows for a longer stenting interval between procedures. Stricture resolution will be defined as the absence of clinical signs or symptoms to suggest biliary obstruction and a residual duct diameter of > 75% of the proximal and distal duct. We will measure stricture resolution at 6 months (our primary outcome in this pilot study), after no more than 12 months of continuous stent therapy, and persistent resolution after one year of post-stenting follow-up. PUBLIC HEALTH RELEVANCE: The current standard of care for post-liver transplant bile duct strictures involves serial placement of multiple plastic stents under endoscopic and fluoroscopic guidance to progressively dilate or stretch it open. This approach necessitates multiple procedures which may extend over one year before the stricture is adequately dilated. We propose a pilot study comparing the standard approach of plastic stenting with the use of newer, fully coated metallic stents which are self-expandable, thereby permitting successful dilation of benign bile duct strictures with fewer procedures over a shorter time.