Self-expandable metal stent (SEMS) for malignant colorectal obstruction is widely used as a bridge to elective surgery or palliative treatment. However, with the increasing use of SEMS for treatment, complication rates associated with stents have been raised as a concern. We experienced a rare migration-related complication that a stent partially migrated out of the anus with an incarceration. A 62-year-old man was admitted with sigmoid malignant obstruction. Due to multiple metastases, he refused to undergo colostomy, and an uncovered SEMS was placed. Subsequently, he started chemotherapy. Seven months after placement, the stent migrated into the rectum. After unsuccessful attempts to extract the stent, he sought our assistance. We observed that half of the stent was outside the anus, and a 15 mm lump of mucosa was embedded in the proximal end of the stent. After several attempts, we successfully removed the SEMS. Stent incarceration following migration is not a common occurrence, but it serves as a reminder that clinicians need to be more vigilant about complications that may arise after stent implantation. We describe this unusual complication and share our experience about the removal of the stent.

中文翻译：

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恶性乙状结肠梗阻中自扩张金属支架置入的罕见并发症。

用于恶性结直肠梗阻的自扩张金属支架（SEMS）被广泛用作择期手术或姑息治疗的桥梁。然而，随着越来越多地使用 SEMS 进行治疗，与支架相关的并发症发生率已引起人们的关注。我们经历了一种罕见的与移位相关的并发症，即支架部分移位出肛门并出现嵌顿。一名 62 岁男性因乙状结肠恶性梗阻入院。由于多处转移，他拒绝接受结肠造口术，并放置了未覆盖的SEMS。随后，他开始化疗。放置七个月后，支架迁移到直肠中。在尝试取出支架失败后，他寻求我们的帮助。我们观察到支架的一半在肛门外，支架近端嵌入了一个15毫米的粘膜肿块。经过多次尝试，我们成功移除了SEMS。移位后支架嵌顿并不常见，但这提醒临床医生需要更加警惕支架植入后可能出现的并发症。我们描述了这种不寻常的并发症，并分享了我们关于移除支架的经验。