Stenting for Benign Airway Obstruction

Qualitative criteria

Quantitative criteria


Extent (vertical length)






Severity of airway narrowing




Mild (<50 %)


Moderate (50–75 %)


Severe (75–100 %)

Dynamic features

Functional impairment





Table 42.2
Investigation/Intervention Comparator Outcome (PICO) questions for the role of airway stent insertion in benign central airway obstruction

PICO question 1

Among patients with CAO from benign tracheal or bronchial stenosis, does airway stent insertion improve health outcomes (defined as performance status, quality of life, frequency and duration of hospitalizations, incidence of respiratory failure, need for repeat bronchoscopic procedures, and survival)?

PICO question 2

Among patients with CAO from benign tracheal or bronchial stenosis, does airway stent insertion adversely affect health outcomes (defined as performance status, quality of life, frequency and duration of hospitalizations, incidence of respiratory failure, need for repeat bronchoscopic procedures, and survival)?

PICO question 3

Among patients with CAO from tracheobronchomalacia, does airway stent insertion improve health outcomes (defined as performance status, quality of life, frequency and duration of hospitalizations, incidence of respiratory failure, need for repeat bronchoscopic procedures, and survival)?

PICO question 4

Among patients with CAO from tracheobronchomalacia, does airway stent insertion adversely affect health outcomes (defined as performance status, quality of life, frequency and duration of hospitalizations, incidence of respiratory failure, need for repeat bronchoscopic procedures, and survival)?

Search Strategy

Study Identification

Systematic methods were used to find relevant studies, assess their eligibility for inclusion, and evaluate study quality. An attempt was made to retrieve all published studies that reported on post-stent insertion outcomes for patients with benign CAO since the introduction of dedicated airway stents. The online database MEDLINE was searched for papers published in English between January 1st, 1990 and September 10th, 2013. The start date was selected in order to assure inclusion of relevant studies on the subject matter at the time of the introduction of the dedicated silicone airway stent in the early 1990s in Europe. The following terms were used in Pubmed advanced search engine: Search details: (((((((((((“stents”[MeSH Terms] OR stenting[Text Word]) AND “airway obstruction”[MeSH Terms]) OR “tracheal stenosis”[MeSH Terms]) OR bronchial stenosis[Text Word]) OR laryngotracheal stenosis[Text Word]) OR subglottic stenosis[Text Word]) OR “tracheomalacia”[MeSH Terms]) OR “tracheobronchomalacia”[MeSH Terms]) OR “bronchomalacia”[MeSH Terms]) AND English[Language]) AND (“1990/01/01”[EDAT] : “3000”[EDAT])) AND “adult”[MeSH Terms]. Additional articles were captured by reviewing the reference lists from identified studies and pertinent review articles.

Study Eligibility and Data Abstraction

Articles deemed potentially eligible for inclusion were reviewed and assessed according to predefined criteria (Fig. 42.1). Data were summarized in a table of evidence (Table 42.3) based on the type of study, patient demographics, type of benign CAO, stent type, length of follow up, and reported outcomes including benefits and harms [156]. Specific outcomes including performance status, lung function, quality of life, incidence of respiratory failure, need for repeat bronchoscopic procedures, and survival were included when available. The population of interest for this systematic review was adult patients. Stent insertion options included silicone, metal and hybrid stents inserted using rigid, flexible bronchoscopic and fluoroscopic techniques.


Fig. 42.1
Study inclusion form illustrating inclusion and exclusion criteria

Table 42.3
PICO table of evidence summarizing original research articles on stent insertion for benign central airway obstruction for years 2004–2013


Study design

Patients (indications)/follow up time

Type of intervention/comparison

Primary outcome

Adverse events/risk factors

Evidence quality

Redmond et al. [1]

Retro; case series

N = 22 lung transplant

Metallic stents (N = 43) via rigid bronch

42 % (18/43) complications

Stent collapse, fracture, migration, granulation tissue, and coughing up pieces of stent

Very low


Comparison: none

9 % (4/43) required stent removal

Mean 285 days

Terra et al. [2]

Retro; cohort study

N = 92 with benign, inoperable TS

T tubes

Successful decannulation (no need for intervention for >6 months) achieved in 19/92

Tracheostomy before stent : threefold increase in the likelihood of the patient remaining with a tracheal stent


Mean 34.3 +/− 33.9 months

Dumon stents
Y stents
Comparison: none

Chen et al. [3]

Case series

N = 21 with PITS; 20 pts had stent removal

Covered SEMS (N = 27) inserted fluoroscopically

Improved airway patency, FEV1 and Hugh-Jones classification of greater than one grade post stent removal

Complications in 19 (91 %): granulation tissue formation (n = 18), stent migration and stent expectoration (n = 2), mucus plugging (n = 1), and halitosis (n = 6)

Very low

Median for stent placement = 5 months

CT and bronch follow up
Comparison: none

Verma et al. [4]

Retro; case series

N = 17 inoperable, post TB stenosis

Median 72 months (12–114)

Silicone stents (N stent)

Comparison: none

Increase in the FEV1% and FVC% (Δ26.5 % and Δ16.5 %, respectively) in the long term; The median duration for which N-stents tolerated 7.9 (3–11) years

Granulation tissue formation (76 %), migration (70 %), and mucostasis (17 %)

Very low

Gallo et al. [5]

Retro; case series

N = 70 with LTS

T tube (either a single dilation or with endoscopic/open neck surgery)

77.1 % (54/70) were decannulated

13 % were decannulated after more than 5 surgical procedures; patients over 60 years of age and with a higher grade of stenosis had a significantly lower success rate

Very low

Iatrogenic 55

Total of 257 surgeries

72.2 % underwent 3 or fewer surgical procedures; no significant correlation between the rate of decannulation and gender, etiology, site of stenosis or surgery

Post traumatic 11

Comparison: none

Others 4

Jeong et al. [6]

Retro; case series

N = 30 patients with inoperable post op stenosis 19/30 (63 %) had stent placement

106 procedures (balloon, bouginage, Nd:YAG, and stent insertion)

37 % had stents removed at a median of 7 months after insertion

Stent-related late complications (70 %): restenosis (43 %), granulation tissue (33 %), migration (32 %), mucostasis (30 %), and malacia after stent removal (16 %)

Very low

Median 34 months

Follow up bronch
Comparison: N/A

Lim et al. [7]

Retro, case series

N = 55 patients with inoperable PITS

Silicone stent placement after laser and mechanical dilation

Stent removal in 40 % of the patients after median 12 months

The stent could be removed in those pts without cardiac disease ((OR) = 12.195] and the intervention was performed within 6 months after intubation (OR = 13.029)

Very low

Median 12 months

Comparison: none

In 60 %, surgery was needed after initial stabilization

Chen and Ruan [8]

Retro; case series

N = 13 pts with LTS; 9 with 1 stent; 4 with two stents

Follow up: N/R

Nickel-titanium alloy stent (SEMS)

Comparison: none

Glottic and/or subglottic extension of cervical tracheal stenosis (n = 6), new tracheal stricture (n = 4), severe left bronchial stricture with massive left pulmonary collapse (n = 1), and cervical tracheoesophageal fistula (n = 2)

6 patients with glottic and/or subglottic to cervical tracheal stenosis underwent successful laryngotracheal reconstruction; 1 patient with tracheoesophageal fistula died from massive hemorrhage and asphyxiation induced by the stent

Very low

Lari et al. [9]

Retro; case series

N = 12 pts with post transplant airway complications (BI stenosis or malacia)

T-Tube in BI

FEV1 improved post stent placement

Migration (33 %)

Very low

Follow up: N/R

Comparison: N/A

Perotin et al. [10]

Retro; case series

N- = 23 pts with weblike (61 %) or complex (39 %) TS, located in the upper part of the trachea

Follow up: 41 ± 34 months post treatment

Stent placement (18 %): 2 for weblike and 2 for complex strictures when the stricture was at 3 +/− 1 cm below the cords

Comparison: N/A

Recurrences were frequent (30 % at 6 months, 59 % at 2 years, and 87 % at 5 years) with a delay of 14 +/− 16 months

N = 2 recurred in the stent group (50 %)

No correlation between the risk or the number of recurrence and the type (weblike versus complex), the severity of obstruction, the height of stenosis (<1 cm versus >1 cm), the distance from the vocal cords or the endoscopic treatment performed

Very low

Lim et al. [11]

Retro; case series

N = 71 pts with Post TB stenosis

Median 12.5 months

Silicone stents

Comparison: none

Stent removal in 40/71 pts at a median of 12.5 months; in 27, stent was re-inserted; 4 had surgery

Predictors of successful stent removal: atelectasis <1 month before bronchoscopic intervention, and absence of complete lobar atelectasis

Very low

Chung et al. [12]

Retro; cohort study

N = 72 with benign and 77 with malignant CAO; 429 days for the benign group

SEMS (N = 116) placed for benign disorders

Comparison: none

Symptoms improved more after SEMS insertion for benign than in malignant disease (76.7 % vs. 51.6 %; p < 0.0001)

Complication rate after SEMS in patients with benign conditions was higher than that in patients with malignancy (42.2 % vs. 21.1 %; p = 0.001)


Fernandez-Bussy et al. [13]

Retro; cohort study

N = 223 pts with 345 anastomoses

Stent insertion after failed balloon dilation

FEV1 improved post stent insertion

Granulation 57.3 % of patients


N = 70 (20.23 %) anastomoses complications post transplant

N = 631 bronchoscopic interventions in 52 pts

Follow up: N/R

N = 33 had BS and BM
N = 18 with BS
N = 47 had stent placement
Comparison: none

Charokopos et al. [14]

Retro; case series

N = 12 with PITS

SEMS in 11pts; follow up bronchoscopy and CT

Immediate improvement in all 11/12 pts

2 migration post procedure

Very low

3 with subglottic stenosis

Comparison: none

4 granulation tissue 12–43 months requiring electrocautery or tracheostomy

Follow up: 6–96 months

Tan et al. [15]

Retro; case series

N = 3 pts with post transplant BI strictures

SEMS (covered) n = 6

5/6 migrated immediately post placement

Stent retrieval successful in 3/5

Very low

Follow up: N/R

Comparison: none

Secretions in 6/6

Fruchter et al. [16]

Retro; case series

N = 24/305 (7.8 %) pts with post transplant BM and BS

SEMS retrieval via flexible bronch using moderate sedation

25 % required stent removal due to granulation and obstruction by mucus

Stent was removed in 5/6 patients

Very low

Follow up: 30 months

Comparison: none

Yu et al. [17]

Retro; case series

N = 32 pts with TS

SEMS follow up with CT (3D recon)

17/32 had stent fracture detected by 3D recon CT

Fracture of SEMS can be predicted by CT measurements

Very low

Median 865 days

Comparison: none

Alazemi et al. [18]

Retro; case series

N = 46 pts with SEMS; 80 % were for benign CAO

SEMS removal (N = 55)

Median no of removal procedures/encounter = 1

The estimated median total cost per encounter to remove the stents was $10,700

Very low

Mean in situ SEMS 292 days

Comparison: none

Median no of total procedures/encounter = 2

The measured outcomes were statistically significantly better when in situ stent duration was < or = 30 days (P < 0.05)
Hospitalization and ICU admission in 78 % and 39 % of the encounters with a median length of stay of 3.5 and 0 days, respectively

Kim et al. [19]

Retro; case series

N = 41 pts with TS

T tube placement

Successful decannulation

Predictors of decannulation failure: The longitudinal extent of stenosis and greater circumferential involvement

Very low

Follow up: N/R

Comparison: none

Age, sex, and multiplicity and severity of stenoses were not significantly related to successful decannulation

Chung et al. [20]

Retro; case series

N = 67 pts with benign TS and TM

SEMS placement (N = 75)

47.8 % had granulation

Structural airway obstruction prior to SEMS implantation predicts obstructive granulation tissue formation after SEMS implantation (odds ratio: 3.84; 95 % CI: 1.01–8.7; P = 0.04)

Very low

Median = 106 days

Comparison: none

Time to granulation tissue detection was shorter in patients with structural airway obstruction before SEMS implantation (structural airway obstruction vs. dynamic collapse airway: median (IQR] 95 (38–224, n = 26] vs. 396 days (73–994, n = 9]; P = 0.02)

Melkane et al. [21]

Retro; cohort study

N = 33 consecutive patients with Post intubation LTS; The endoscopic candidates were chronically ill patients presenting with simple, strictly TS not exceeding 4 cm in length

N = 19 endoscopic treatments

50 % of the patients were decannulated in the surgically treated group versus 84.2 % in the endoscopically treated group (p = 0.03)

In the surgically treated group, 2/14 patients needed more than one procedure versus 8/19 patients in the endoscopically treated group


Follow up: 6 months

Stents were placed if the stenosis was associated with TM or exceeded 2 cm in total length
Comparison: N = 14 surgical treatment: healthy patients presenting with complex
TS, subglottic involvement or associated TM

Rahman et al. [22]

Retro; case series

N = 115 pts with benign TS due to PITS (N = 76) PTTS (N = 30), Wegener’s granulomatosis (N = 2), sarcoidosis (N = 2), amyloidosis (N = 2) and ITS (N = 3)

Flexible bronchoscopy balloon dilatation and laser treatment (N = 98)

The overall success rate was 87 %

26 % died, mostly due to exacerbation of their underlying conditions

Very low

Median 51 months

Stent was placed in 33 pts of whom 28 also underwent brachytherapy
Comparison: none

Ko et al. [23]

Retro; case series

N = 55 procedures for TS

Follow up: N/R

T tubes N = 46

Dumon silicone stent N = 9

Comparison: none

Granulation (23 procedures, 41.82 %)

The granulation complication rate was higher in those with a stent-to-vocal fold distance of <10 mm

Very low

Nam et al. [24]

Retro; case series

N = 11 pts with carinal stenosis included post TB stricture in 7 pts (64 %), PITS in 2 (18 %), postoperative TM in 2 (18 %)

Balloon dilation; Nd:YAG laser resection, or bougienation (by rigid bronchoscopy) to dilate the airway, followed by placement of the Natural Y stent

100 % subjective symptomatic relief immediately after stent placement

No procedurally related deaths or immediate major complications occurred

Very low

Median duration of stent placement = 439 days

Comparison: none

Stent-related late complications included granulation (64 %) and mucostasis (18 %)

Fernandez-Bussy et al. [25]

Retro; cohort study

N = 24 consecutive pts with post transplant bronchial anastomoses complications

SEMS N = 49 (hybrid) via flexible bronchoscopy

The average degree of stenosis decreased from 80 % to 20 %

Complications included granulation in 10 stents, migration in 9, mucus in 2, and fracture in 3


BS in 12, bronchomalacia in 12, BS plus

Adjunctive procedures included EC in 1, balloon dilatation in 7, and EC plus balloon dilatation in 4

The average increase was 0.28 L in FVC and 0.44 l in FEV1

BM in 20, and partial bronchial dehiscence in 5

Comparison: none

Abi-Jaoudeh et al. [26]

Retro; case series

N = 41 pts with post transplant BS

Stent placed when balloon dilation failed; 56 % received a stent because of balloon dilation failure or stenosis recurrence

After the first treatment, airway patency was higher in patients treated with stents (71 %) than in those who underwent bronchoplasty (19 %) (P = 0.037)

Mean survival in patients with stents was longer than that in those who underwent bronchoplasty (82 vs 22 months, respectively) stent insertion: associated with a 66 % reduction in the risk of death (P < 0.02)


10–40 months

Comparison: balloon dilation

Airway patency: 40 months for stented strictures versus 10 months for strictures treated with bronchoplasty (P < 0.02)
Dyspnea and cough were improved after intervention (P < 0.001), and FEV1 was improved by 17 % (P < 0.00003) at last follow-up

Gottlieb et al. [27]

Retro; cohort study

N = 65 (9.2 %) out of 706 lung transplant

111 (91 % uncovered) SEMS were inserted a median (range) 133 (55–903) days after lung transplantation

Clinical improvement in 80 % of pts

Re-stenosis occurred in 34 (52 %) out of 65 pts at 85 (7–629) days after insertion

Very low

Recipients with post transplant BS

Comparison: none

The FEV1 increased by 21 +/− 33 % (mean +/− SD)

Stent insertion before post-operative day 90 was independently associated with an increased risk of re-stenosis (HR 3.29, 95 % CI 1.50–7.18; p = 0.003); 40 % of pts had new bacterial airway colonization after SEMS insertion

777 (7–3.655) days
In SEMS patients, 5-year survival was significantly lower than in the total cohort (60 % versus 76 %; p = 0.02)

Park et al. [28]

Retro; case series

N = 32 pts with PITS

Silicone stent (N stent)

100 % symptomatic and spirometric improvement without immediate complications

Late complications were migration (34 %), mucostasis (31 %), granulation (38 %) and re-stenosis (40 %)

Very low

Median 22 months

Nd:YAG laser, ballooning or bougienage was followed by N stent insertion

Removal of the stent without re-stenosis was successful in 38 % of pts at a median time of 7 months after insertion
Comparison: none

The stent could not be removed or needed reinsertion in 31 % of patients; 16 % of pts had surgery after initial stenting

Carretta et al. [29]

Retro; cohort study

N = 75 pts with benign TS complex lesions or comorbidities

T-tube in 51 pts with contraindication to surgery (group I), a temporary measure in 15 pts prior to surgery (group II), and in 9 pts (group III) for complications of airway reconstruction

In group I, the T-tube was removed in 24 % of pts after 35.3 +/− 8.2 months following resolution of the stenosis

Migration in 3 (4 %) pts, granulation in 14 (19 %), subglottic edema in 3 (4 %), and mucus retention in 7 (9 %); Treatment of complications (tracheostomy cannula, steroid infiltration, Argon/laser coagulation bronchoscopy) was required in 27 % of pts


N = 7 had undergone unsuccessful treatment with Dumon stents

Comparison: none

In group II, the T-tubes were maintained in place before surgery for 17.1 +/− 4.8 months

Follow up: 5 years
In group III, 3 stents were removed following tracheal healing after 115.3 +/− 3.7 months
After 5 years the stents were in place in 82 %, 7 % and 100 % of the pts, respectively in groups I, II and III

Dooms et al. [30]

Retro; case series

N = 17 pts with 10 stents were deployed in a structural PITS Other indications were multinodular goiter, anastomotic stricture, Post TB stenosis, damaged cartilage and relapsing polychondritis

7 Silmet, 8 Taewoong 5 Alveolus stents

Short-term (<12 weeks after stent deployment) complication rate was 75 %, requiring stent removal in 60 %

Migration 65 %

Very low

Follow up:12 weeks

Comparison: none

Stent fracture 15 %
Shriveling of the stent in 10 %
Granulation 10 %

Thistlethwaite et al. [31]

Retro, cohort study

N = 20/240 (8.3 %) pts with post transplant BS (>50 % narrowing)

Dilation and silicone stent placement

The mean time to diagnosis of BS was 81.5 +/− 26.9 days

Pulmonary aspergillosis and pseudomonal infection, age less than 45 years, and early rejection correlated with BS; ischemic time, side of transplant, and preoperative disease did not


Follow up: 4.9 +/− 3.5 years after stent removal

Comparison: none

Airway patency and symptom improvement in 18/20 pts
N = 16 pts were able to have their stents removed at a mean of 362.3 +/− 126.4 days with permanent resolution of airway stenosis; Overall survival was similar for patients with and without BS

Galluccio et al. [32]

Retro; cohort study

N = 209 consecutive pts with PITS (N = 167) and PTTS (N = 34)

Mechanical dilatation, laser resection and placement of a silicone stent

Simple stenoses (N = 167) treated by 346 endoscopic procedures (mean of 2.07/patient), 16 stents and 1 end-to-end anastomosis

Among the 42 complex stenoses, 9 were immediately treated by surgical resection and the remaining 33 lesions underwent 123 endoscopic procedures (3.27/patient), with 34 stents and 1 end-to-end anastomosis subsequent to recurrence after stent removal


8 other benign TS

Comparison: none

N = 38 granulomas treated by 59 procedures (1.56/patient)

In this group the success rate was 69 %

Follow up: 2 years
N = 97 concentrical stenoses by 228 procedures (2.35/patient) and 32 web-like lesions with 59 operative endoscopies (1.84/patient) Overall success rate was 96 %

Shlomi et al. [33]

Cohort study

N = 19 pts with benign obstructions and 11 with post transplant stenosis on immunosuppressive therapy

SEMS in transplant

Granulation was significantly lower in the transplant recipients than in the non-transplant pts at 3, 15 and 18 months

Transplant recipients underwent significantly fewer laser resections and brachytherapy treatments for stent granulation


Follow up: 2 years

Comparison: SEMS in other benign strictures

Chan et al. [34]

Retro; case series

N = 35 pts with inoperable benign CAO

82 SEMS (67 % Ultraflex, 33 % Wallstent)

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Dec 30, 2016 | Posted by in CARDIOLOGY | Comments Off on Stenting for Benign Airway Obstruction
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