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

描述（由申请人提供）：10-30%的肝移植后患者出现术后吻合胆管狭窄，通过连续内镜扩张和支架置入治疗，通常需要在一年或更长时间内进行多次手术。虽然与手术翻修相比非常成功且发病率较低，但内镜入路涉及在狭窄处放置多个塑料支架（PS），每3个月连续扩大一次，直到狭窄完全扩张。这通常需要在很长时间内进行多次手术，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、自膨胀金属支架（cems）可能允许内窥镜治疗这些狭窄，同时需要更少的时间和更少的程序。美国每年进行的肝移植手术超过6000例，医疗保健支出超过通货膨胀，迫切需要找到一种更经济有效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点研究，比较cems与塑料支架（目前的护理标准）在肝移植后胆管狭窄的一线治疗中的作用。我们将纳入吻合，原位肝移植后胆管狭窄的患者，因为这些患者代表了大多数良性，术后胆管狭窄。PS组患者将每隔3个月进行连续扩张和支架增大，直到狭窄消退（标准护理）。cems组的患者将接受cems的初始安置，并在6个月后返回；届时，cems将被移除，只有在结构没有解决的情况下才会再更换六个月。与PS相比，cems的优越的通畅性允许更长的手术间隔。狭窄消退定义为没有提示胆道梗阻的临床体征或症状，残余胆道直径为近端和远端胆道的75%。我们将在连续支架治疗不超过12个月后的6个月（我们在该试点研究中的主要结局）测量狭窄消退，并在支架植入后随访1年后测量持续消退。

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.