Cases J. 2008; 1: 226. Published on

Cases J. 2008; 1: 226.
Published online 2008 Oct 7. doi: 10.1186/1757-1626-1-226PMCID: PMC2572608Recurrent airway obstructions in a patient with benign tracheal stenosis and a silicone airway stent: a case report
KB Sriram1 and PC Robinson1
1Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia 5000, AustraliaCorresponding author.KB Sriram: moc.liamg@anhsirkeejab; PC Robinson: [e-mail]
Author information ► Article notes ► Copyright and License information ►
Received 2008 Aug 3; Accepted 2008 Oct 7.
Copyright © 2008 Sriram and Robinson; licensee BioMed Central Ltd.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract
Airway stents (silicone and metal stents) are used to treat patients with benign tracheal stenosis, who are symptomatic and in whom tracheal surgical reconstruction has failed or is not appropriate. However airway stents are often associated with complications such as migration, granuloma formation and mucous hypersecretion, which cause significant morbidity, especially in patients with benign tracheal stenosis and relatively normal life expectancy. We report a patient who had frequent critical airway obstructions over 8 years due to granuloma and mucus hypersecretion in a silicone airway stent. The problem was resolved when the silicone stent was removed and replaced with a covered self expanding metal stent.

Background
Benign tracheal stenosis secondary to prolonged intubation and/or tracheostomy has been treated by airway stenting in selected patients1.

There are four categories of airway stents – silicone stents, balloon-dilated metal stents, self-expanding metal stents (SEMS) and covered SEMS. There are no randomized controlled trials comparing different stents and each category has its merits and limitations [1]. The silicone Dumon® stent (Novatech, Boston Medical, Massachusetts, USA) is widely popular and often used to treat benign tracheal stenosis. Complications include stent migration, granuloma formation and mucostatsis [2]. Covered SEMS, such as the Ultraflex™ stent (Boston Scientific, Massachusetts, USA) are more biocompatible and some reports suggest fewer complication rates compared with silicone stents. We report a patient who developed major complications with a Dumon® stent which were ameliorated when it was replaced by an Ultraflex™ stent.

Case report
A 19 year old woman developed Guillain-Barre syndrome and respiratory failure in 1999, whilst living in a different city. Prolonged intubation followed by tracheostomy was complicated by tracheal stenosis. Tracheal reconstruction surgery was performed but was unsuccessful in maintaining airway patency. Immediately afterwards a 12 mm × 40 mm Dumon® silicone stent was inserted. However this stent was complicated by frequent obstructions due to granulation tissue and mucous plugs.

Due to work commitments she relocated to our city in March 2006. In July 2006 she presented to the emergency department of our institution with acute dyspnea and stridor. Emergency bronchoscopy revealed extensive granulation tissue and mucous plugging within the Dumon® stent. Over the next 16 months she had 9 emergency presentations with stent obstructions. Each episode was resolved with bronchoscopic piecemeal removal of granulation tissue and suctioning of mucus.

In Nov 2007 she presented with severe respiratory distress and bronchoscopy revealed that the Dumon® stent had moved proximally (Figure ​(Figure1)1) with granulation tissue in the distal end (Figure ​(Figure2)2) causing 90% obstruction in mid-trachea. The Dumon® stent was removed and replaced with a 14 mm × 60 mm Ultraflex™ stent. The new stent was successful with resolution of tracheal obstruction. The patient has remained asymptomatic since, with no further episodes of airway obstruction.

Figure 1Silicone tracheal (Dumon®) stent has migrated proximally.Figure 2Granulation tissue obstructing distal end of silicone tracheal (Dumon®) Dumon stent.Discussion
Benign tracheal stenosis is most often caused by prolonged intubation and/or tracheostomy. 67–90% of patients who are intubated develop laryngotracheal injury and 12–14% develop tracheal stenosis [3]. Symptomatic benign tracheal stenosis is optimally treated by tracheal reconstruction surgery [4]. However, if this procedure is medically contraindicated or has failed previously then prosthetic stents are used to maintain airway patency.

Silicone stents are relatively inexpensive, generally do not fracture, resist extrinsic compression (e.g. from scar tissue or tumour) and can be easily repositioned or removed if required. However stent complications have been reported to occur in up to 42% of patients [5]. Long-term complications include migration (17%), granuloma (6%), and mucostasis causing airway obstruction (6%) [5]. One study found that 42% of patients require emergency bronchoscopy for stent related complications within 3 months of stent insertion [6]. Provocation of local inflammatory reaction results in growth of granulation tissue. Laser resection of in-stent granuloma must be performed with caution as there have been reports of flash fire and stent damage [4]. An additional problem with silicone stents is that the ratio of wall thickness to internal diameter is higher when compared to metal stents resulting in a smaller internal diameter in most cases [7]. Silicone stent-specific complications have raised the question of whether metallic stents might overcome some of these difficulties.

There has been increasing enthusiasm for using covered SEMS such as Ultraflex™ stents, which are built from a single layer of braided knitted flexible nitinol (nickel-titanium alloy) with an outer covering of silicone [1]. They have excellent flexibility, good biocompatibility and the self-expanding force is an important factor that enables the nitinol mesh to attach directly to the tracheal wall. While some reports have shown that there are few complications when SEMS are used to treat benign tracheal stenosis [8,9] others have found complications occurring in 52–87% of patients [3,4]. These include granuloma, mucus retention and stent fracture [3,4]. Such concerns have prompted the Food and Drug Administration to publish a cautionary advisory on the use of metallic stents in patients with benign airway disease [10].

Our report illustrates the complications associated with silicone airway stents when used to treat benign tracheal stenosis. Interestingly while the patient had frequent airway obstructions with the Dumon® stent, she did not experience these with the Ultraflex™ stent. Careful patient selection and recognition of complications is paramount before considering patients with benign tracheal stenosis for treatment with prosthetic airway stents.

結果 (中文) 1:

例 J.2008 年;1:226。发布在线 2008 年 10 月 7日。doi: 10.1186/1757年-1626年-1-226PMCID: PMC2572608Recurrent 气道阻塞患者气管良性狭窄和硅胶气道支架: 一例报告KB Sriram1 和 PC Robinson1胸肺科、 皇家阿德莱德医院，阿德莱德，南澳大利亚 5000、 AustraliaCorresponding 作者 1Department。第 moc.liamg@anhsirkeejab KB 拉姆:;PC 罗宾逊: [e-mail]作者信息 ► 条笔记 ► 版权和许可信息 ►接收的 2008 Aug 3;公认的 2008 年 10 月 7日。版权所有 © 2008年拉姆和罗宾逊;持牌人医学中心 Ltd.This 是在创意共同性归属许可证 (http://creativecommons.org/licenses/by/2.0，) 哪些许可证不受限制地的使用、 分布和繁殖在任何介质中，提供正确引用原始工作的条款下发布开放访问文章。摘要气道支架 (硅胶和金属支架) 用于治疗良性气管狭窄患者有症状和人气管外科重建已失败，否则是不合适。然而气道支架往往伴有并发症移徙、 肉芽肿形成和粘液分泌过多，导致显著的发病率，尤其是在患者气管良性狭窄和相对正常的寿命。我们报告一个病人曾频繁临界气道阻塞超过 8 年由于肉芽肿、 粘液在硅胶气道支架中。当硅胶支架被删除和替换一个满身自我膨胀金属支架，解决了问题。背景继发于长期气管插管或气管切开气管良性狭窄已被选定 patients1 气道支架置入术。有四种类别的气道支架 — — 硅胶支架球囊扩张的金属支架，自膨胀金属支架 (SEMS) 和覆盖中小企业。有没有比较不同支架的随机对照的试验，每个类别都有其优点和局限性 [1]。硅胶 Dumon ® 支架 (高德，波士顿医疗，马萨诸塞州，美国) 是广受欢迎，经常用于治疗良性气管狭窄。并发症包括支架移位、 肉芽肿形成和 mucostatsis [2]。覆盖的中小型企业，如 Ultraflex ™ 支架 (波士顿科学，马萨诸塞州，美国) 更相容性，一些报告表明更少的并发症发生率相比硅胶支架。我们报告一个病人开发 Dumon ® 支架的主要并发症，这亦得到改善，当它被替换 Ultraflex ™ 支架。一例报告19 岁的女子吉兰-巴雷综合征并呼吸衰竭 1999 年制定的虽然生活在不同的城市。长期气管插管，其次是气管切开术被伴气管狭窄。气管重建手术进行，但没有成功地维持气道通畅。Dumon ® 硅胶支架植立即之后 12 毫米 × 40 毫米。然而这种支架是复杂由频繁障碍由于肉芽组织及粘膜插头。由于工作承诺她搬到我们的城市在 2006 年 3 月。2006 年 7 月她介绍给我们的机构与急性呼吸困难和喘鸣的急诊部。紧急支气管镜检发现大量肉芽组织及粘液堵塞 Dumon ® 支架内。未来 16 个月她已经 9 紧急的演示文稿与支架的障碍物。每一集被解决同经支气管镜零敲碎打移除的肉芽组织、 粘液吸痰。在 2007 年 11 月，她提出了严重的呼吸窘迫和支气管镜检查显示 Dumon ® 支架已经下部 (1) 与远端的肉芽组织图 (图 1) (图 (图 2) 2) 在中期气管造成 90%阻塞。Dumon ® 支架被删除，并替换为 14 毫米 × 60 毫米 Ultraflex ™ 支架。新的支架是成功的与决议的气管阻塞。病人一直以来，与气道阻塞没有进一步发生无症状。图 1Silicone 气管 (Dumon ®) 支架下部已迁移。图 2Granulation 组织阻碍远端的硅胶气管 (Dumon ®) Dumon 支架。讨论良性气管狭窄最常引起长期气管插管或气管切开术。67 — — 90%的患者气管插管喉气管损伤研发 12-14%发展为气管狭窄 [3]。症状性良性气管狭窄是最佳治疗气管重建手术 [4]。然而，如果此过程医学上的禁忌或已失败以前然后义肢支架用于维持气道通畅。硅胶支架价格相对便宜，一般做不断裂，抵抗外在压缩 (例如从疤痕组织或肿瘤) 和可以轻松地重新定位或删除如果需要。但是有报道支架并发症发生达 42%的患者 [5]。远期并发症包括迁移 (17%)、 肉芽肿 (6%) 和 mucostasis 引起气道阻塞 (6%)[5].一项研究发现，42%的患者需要紧急支气管镜支架置入术 [6] 3 个月内相关并发症。挑衅的局部炎症反应导致的肉芽组织的生长。激光切除术支架内肉芽肿必须谨慎地执行，因为一直闪火和支架破坏 [4] 的报告。硅胶支架与另一个问题是，墙身厚度为内部直径比高时相比，金属支架造成较小的内部直径在大多数情况下 [7]。硅胶支架特定并发症有提出是否金属支架可能克服这些困难的一些的问题。已越来越热衷使用的硅胶 [1] 的外层覆盖物覆盖的中小企业 Ultraflex ™ 支架，从单层编织针织弹性镍钛诺 (镍钛合金) 的生成等。他们有优良的弹性、 良好的生物相容性和自我膨胀力是使镍钛记忆合金网直接附着在气管内壁上的一个重要因素。尽管一些报道表明有并发症少当中小型企业用来治疗良性气管狭窄 [8，9] 别人发现并发症的发生在 52-87%的患者 [3，4]。这些包括肉芽肿、 粘液潴留和支架断裂 [3，4]。这种担忧促使食品和药物管理局发布警示咨询上使用金属支架患者良性气道疾病 [10]。我们的报告阐述了有机硅气道支架时用于治疗良性气管狭窄的并发症。有趣的是虽然病人有频繁的气道阻塞 Dumon ® 支架，她没有经历这些 Ultraflex ™ 支架。注意病人的选择和并发症的识别，然后才考虑用人工气道支架治疗良性气管狭窄患者是至关重要的。

結果 (中文) 3:

病例2008；1：226。发表在线2008月7日。关键词：10.1186/1757-1626-1-226pmcid：在良性气管狭窄和硅酮气道支架置入患者pmc2572608recurrent气道阻塞：病例报告
KB sriram1和PC robinson1
医院胸腔内科，皇家阿德莱德医院，阿德莱德，南澳大利亚5000，australiacorresponding author.kb Sriram：liamg @ anhsirkeejab MOC；鲁滨孙：PC [e-mail]
作者信息►指出的►版权和许可信息►
收到2008月3月2008；接受7。2008
版权©Sriram和鲁滨孙；被许可人BioMed Central的公司，这是一个开放获取文章的知识共享署名许可条款下发布（HTTP：/ /组织/协议。许可证/ / 2），允许无限制的使用，分布和复制在任何介质中，提供了原始的工作是正确的引用。”，”，”，”，”气管支架（硅和金属支架）是用于治疗良性气管狭窄，谁是有症状的气管重建失败或不恰当。然而气道支架通常会如迁移相关并发症，肉芽肿形成和粘液分泌过多，造成显著的发病率，尤其是在良性气管狭窄患者相对正常的寿命。我们报告一例危重呼吸道阻塞频繁超过8年由于硅酮气道支架肉芽肿和黏液高分泌。当硅胶支架被拆除，并用覆盖的自膨式金属支架代替时，这个问题得到了解决。良性气管狭窄气管插管和/或已在选定的患者气道内支架置入术治疗。

有四类–气道支架硅胶支架，球囊扩张金属支架，金属支架（SEMS）和覆膜金属支架。有没有随机对照试验比较不同支架和每一类有其优点和局限性[ 1 ]。硅杜蒙®支架（该公司，波士顿医疗，马萨诸塞州，美国）是广受欢迎，经常用于治疗良性气管狭窄。并发症包括支架移位，肉芽肿形成和mucostatsis [ 2 ]。覆膜金属支架，如™UltraFlex支架（波士顿科学，马萨诸塞州，美国）是更好的生物相容性和一些报告显示，减少并发症的发生率与硅胶支架相比。我们报告一个病人谁开发的主要并发症，杜蒙®支架进行了改进，它是由一种金属™支架更换。

病例报告
一个19岁的女人，吉兰-巴雷综合征和呼吸衰竭1999，虽然生活在不同的城市。长期插管后气管切开并发气管狭窄。气管重建手术，但在保持气道通畅是不成功的。紧接着一个12毫米40毫米×杜蒙®硅酮支架置入。