PDF(Pubmed)
Abstract：
Background: Esophageal self-expandable metal stents (SEMS) are an important endoscopic tool. These stents have now been adapted successfully to manage post-bariatric surgery complications such as anastomotic leaks and strictures. In centers of expertise, this has become the primary standard-of-care treatment given its minimally invasive nature, and that it results in early oral feeding, decreased hospitalization, and overall favorable outcomes. Self-expandable metal stents (SEMS) fractures are a rare complication of unknown etiology. We aimed to investigate possible causes of SEMS fractures and highlight a unique endoscopic approach utilized to manage a fractured and impaled SEMS. Methods: This is a retrospective study of consecutive patients who underwent esophageal SEMS placement between 2015-2021 at a tertiary referral center to identify fractured SEMS. Patient demographics, stent characteristics, and possible etiologies of fractured SEMS were identified. A comprehensive literature review was also conducted to evaluate all prior cases of fractured SEMS and to hypothesize fracture theories. Results: There were seven fractured esophageal SEMS, of which six were used to manage post-bariatric surgery complications. Five SEMS were deployed with their distal ends in the gastric antrum and proximal ends in the distal esophagus. All stents fractured within 9 weeks of deployment. Most stents (5/7) were at least 10 cm in length with fractures commonly occurring in the distal third of the stents (6/7). The wires of a fractured SEMS were embedded within the esophagogastric junction in one case, prompting the use of an overtube that was synchronously advanced while steadily extracting the stent. Discussion: We suggest the following four etiologies of SEMS fractures: anatomical, physiological, mechanical, and chemical. Stent curvature at the stomach incisura can lead to strain- and stress-related fatigue due to mechanical bending with exacerbation from respiratory movements. Physiologic factors (gastric body contractions) can result in repetitive squeezing of the stent, adding to metal fatigue. Intrinsic properties (long length and low axial force) may be contributing factors. Lastly, the stomach acidic environment may cause nitinol-induced chemical weakness. Despite the aforementioned theories, SEMS fracture etiology remains unclear. Until more data become available, it may be advisable to remove these stents within 6 weeks.
摘要：
背景：食管自膨式金属支架（SEMS）是一种重要的内镜工具。这些支架现已成功地用于治疗减肥手术后的并发症，例如吻合口漏和狭窄。在专业中心，鉴于其微创性，这已成为主要的护理标准治疗方法，它导致早期口服喂养，住院率下降,和总体有利的结果。自膨式金属支架（SEMS）骨折是病因不明的罕见并发症。我们旨在调查SEMS骨折的可能原因，并强调一种独特的内窥镜方法来处理骨折和刺穿的SEMS。方法：这是一项回顾性研究，对2015年至2021年在三级转诊中心接受食管SEMS放置的连续患者进行了回顾性研究，以确定断裂的SEMS。患者人口统计学，支架特性,并确定了SEMS骨折的可能病因。还进行了全面的文献综述，以评估所有先前的SEMS骨折病例并假设骨折理论。结果:食管SEMS共7例,其中6项用于治疗减肥手术后并发症.五个SEMS的远端位于胃窦，近端位于食道远端。所有支架在部署后9周内断裂。大多数支架（5/7）的长度至少为10厘米，骨折通常发生在支架的远端三分之一（6/7）。在一种情况下，断裂的SEMS的导线嵌入食管胃交界处，提示使用同步推进的外套管，同时稳定地取出支架。讨论：我们建议SEMS骨折的以下四种病因：解剖学，生理,机械,和化学。胃切开处的支架弯曲可由于机械弯曲和呼吸运动加剧而导致与应变和应力相关的疲劳。生理因素（胃体收缩）可导致支架的重复挤压，增加金属疲劳。固有特性(长长度和低轴向力)可能是促成因素。最后,胃的酸性环境可能导致镍钛诺引起的化学衰弱。尽管有上述理论，SEMS骨折的病因尚不清楚。在获得更多数据之前，建议在6周内移除这些支架。
