Granulomatosis with polyangiitis (GPA) or Wegener granulomatosis (WG) is a necrotizing granulomatous vasculitis affecting the upper and lower respiratory tract. Although characteristics have been well described, endobronchial involvement is less common in the literature. In addition, tracheobronchial abnormalities may be the only site of involvement.1,2 Inflammation can lead to ulcerative tracheobronchitis and subsequent airway stricture. Immunosuppressive therapy may be effective in controlling systemic inflammation but only yield a partial or temporal response to endobronchial disease.
ENDOSCOPIC MANAGEMENT OF CENTRAL AIRWAY INVOLVEMENT FROM GPA
Endoscopic interventions play a critical role in airway obstruction from the GPA. Publications in several diseases show dilatation and placement of stents results in improvement of airflow and relief of symptoms.2 Self-expandable metallic stents (SEMs) have been used in the management of both benign3 and malignant central airway obstruction. SEMs are more easily deployed under local anesthesia using flexible bronchoscopy.4 However, the use of SEMs is not without risk of complications. Granulation tissue formation is a major complication from SEMs, particularly in benign disease. The constant friction, a foreign body reaction, and localized pressure against the mucosa can promote granulation tissue. SEMs can result in impairment of mucociliary ladder, bacterial colonization, mucus plugging, and halitosis. Therefore, the primary role of SEMs should be in malignant central airway obstruction. SEMs may be used in benign airway disease if all therapeutic options have been exhausted, in accordance with the FDA black box warning (http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/PublicHealthNotifications/ucm062115.htm).
We present a case of a 23-year-old male with longstanding endobronchial GPA with recurrent bronchial stenosis despite adequate systemic immunosuppressive therapy. This patient was transferred from another institution for management of complications from his SEMs, possible stent removal, or a left-sided pneumonectomy. Three SEMs had been deployed in the left main bronchus to the lower lobe bronchus 10 years prior. As a result of the stenting across the left upper take-off granulation tissue and stricture had completely and irreversibly obstructed this lobe. He was left with recurrent stenosis, requiring multiple bronchoscopic interventions, frequent infections, and occasional left lung atelectasis. SEMs removal was felt to be critical. Two SEMs were removed over 2 years but an additional uncovered stent had become completely embedded in the bronchial mucosa making removal formidable. A chest computed tomography scan reveals an embedded SEM in the left main stem bronchus (Fig. 1A).
A REVIEW OF CONVENTIONAL METHODS OF SEMS REMOVAL
SEMs may incorporate into the bronchial mucosa quickly. Although some authors have reported 8 weeks,5 we have seen the more rapid incorporation if active inflammatory airway disease exists. Removal of embedded SEMs is a technical challenge due to several potential complications (Table 1). Cardiothoracic surgical teams should be on standby for high-risk cases.6 In addition, SEMs placed in the left main bronchus are considered a high-risk procedure because the left main stem bronchus is close to major vessels. The indications of SEMs removal are shown in Table 2. Previously published methods of SEMs removal typically involves rigid bronchoscopy or open extractions. We reported the use of balloon bronchoplasty to dissect the stent from the airway wall with success.7 This method may minimize trauma and bleeding. Nashef et al8 reported an endoscopic removal of Gianturco stents (Cook Incorporated, Bloomington, IN) without major complications. Their removal method is time consuming and occasionally piecemeal. This method is described as “rolling spaghetti on a fork, but much more difficult and at least equally messy.”
NOVEL METHOD OF SEMS REMOVAL IN OUR PATIENT
This SEMS was in place for 10 years, deeply incorporated in an inflamed and strictured bronchial wall, making its removal formidable. On the basis of those observations, there was concern using the conventional removal methods, in an attempt to minimize potential complications. We postulated placing an oversized stent may facilitate debulking of granulation tissue by causing pressure necrosis of the overgrown tissue between the silicone stent and the SEMs/airway wall. A silicone custom-cut Dumon 9×22 mm stent was placed inside the embedded SEM (Fig. 1B) to ensure patency while leading to necrosis of the overgrown tissue. One week later this led to easier removal of the SEMs than anticipated. After SEM removal, a silicone stent was placed to maintain airway patency (Fig. 1C). This silicone stent was removed in 10 weeks. Our patient is currently stent free 3 years later. However, patient still has GPA in addition to his airway injury from the 10+ year old stent, so his bronchoscopic therapies are occasionally related to a GPA flare and at other times related to stricture from chronic airway injury.
The levels of complications related to an in situ stent are far more serious than recurrent bronchoplasties. A longstanding SEMs placed in the left main bronchus are considered as a high-risk location because the left main stem bronchus is between the pulmonary artery, the descending aorta, and esophagus. The foreign body was removed minimizing the issues related to biofilm/infection, erosion, and increased coughing. Fatal complications are well known and reported from vascular erosion-related to SEMs.9,10
Embedded SEMs can be safely removed with meticulous planning.11 In addition to conventional SEMs removal by rigid bronchoscopy or surgical extraction,5 this case demonstrates an alternative method of metallic stent extraction in longstanding SEMs deployment.
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Keywords:© 2014 by Lippincott Williams & Wilkins.
bronchoscopy; self-expandable metallic stent; stent removal