Table 3. Factors related to successful stent removal at the first attempt (N = 285).
| Variables | Univariable analysis | Multivariable analysis | ||||
|---|---|---|---|---|---|---|
| Unadjusted OR (95% CI) | P | Adjusted OR (95% CI) | P | |||
| Patient-related factors | ||||||
| Age, yr | 1.03 (1.01–1.05) | 0.016 | 1.04 (1.02–1.07) | 0.001 | ||
| Sex, male | 3.61 (1.25–10.47) | 0.018 | 5.73 (1.49–22.03) | 0.011 | ||
| BMI, kg/m2 | 1.07 (0.98–1.17) | 0.140 | ||||
| ASA classa | ||||||
| I, II | Reference | |||||
| III, IV | 1.40 (0.56–3.54) | 0.472 | ||||
| CT finding | ||||||
| Atelectasis more than one lobe | 0.53 (0.26–1.08) | 0.078 | ||||
| Calcified enlarged lymph nodes around the airway | 0.51 (0.27–0.96) | 0.038 | ||||
| Active inflammation in airway | 0.20 (0.08–0.48) | < 0.001 | ||||
| Lung parenchymal lesion | ||||||
| Parenchymal calcification | 0.16 (0.06–0.43) | < 0.001 | 0.07 (0.02–0.25) | < 0.001 | ||
| Atelectasis with bronchiectatic volume loss | 1.05 (0.22–5.06) | 0.956 | ||||
| Segmental consolidation with bronchiolitis | 0.24 (0.12–0.50) | < 0.001 | 0.26 (0.11–0.59) | 0.002 | ||
| Atelectasis within 1 month | 1.20 (0.54–2.63) | 0.658 | ||||
| FEV1 (% predicted)b | ||||||
| ≥ 50% | Reference | |||||
| < 50% & ≥ 30% | 0.42 (0.20–0.87) | 0.019 | ||||
| < 30% & no results of PFT | 0.48 (0.18–1.24) | 0.129 | ||||
| Lesion-related factors | ||||||
| Location of stenosis | ||||||
| Non-trachea lesion | Reference | Reference | ||||
| Trachea lesion | 0.27 (0.14–0.54) | < 0.001 | 0.21 (0.09–0.49) | < 0.001 | ||
| Severity of stenosis (Myer and Cotton grade)c | ||||||
| II | Reference | |||||
| III, IV | 0.86 (0.45–1.66) | 0.658 | ||||
| Type of stenosis | ||||||
| Fibrosis | 1.05 (0.41–2.72) | 0.920 | ||||
| Malacia | 1.41 (0.59–3.35) | 0.439 | ||||
| Granulation tissue & inflammation | 0.83 (0.35–1.94) | 0.665 | ||||
| Stenosis length, mm | 0.97 (0.95–1.00) | 0.047 | ||||
| Procedure-related factors | ||||||
| Type of stent | ||||||
| Tube stent | Reference | |||||
| Y stent | 0.51 (0.09–2.87) | 0.448 | ||||
| Stent angulation, yes | 2.03 (0.45–9.12) | 0.358 | ||||
| Duration of stent, mon | ||||||
| < 6 | Reference | Reference | ||||
| ≥ 6 & < 12 | 2.76 (0.81–9.38) | 0.105 | 3.76 (0.88–15.98) | 0.073 | ||
| ≥ 12 & < 18 | 4.91 (1.39–17.30) | 0.013 | 6.20 (1.48–25.97) | 0.013 | ||
| ≥ 18 & < 24 | 2.84 (0.93–8.67) | 0.066 | 5.34 (1.42–20.04) | 0.013 | ||
| ≥ 24 | 1.48 (0.57–3.83) | 0.420 | 2.79 (0.87–8.95) | 0.084 | ||
OR = odds ratio, CI = confidence interval, BMI = body mass index, CT = computed tomography, ASA = American Society of Anesthesiologists, FEV1 = forced expiratory volume in 1 second, PFT = pulmonary function test.
aASA physical status class ≥ 3 means severe systemic disease with functional limitation
bTwenty-seven patients had no results of pre-procedure PFT for the following reasons: PFT fail due to severe dyspnea (n = 12), emergency procedure decided while hospitalized through emergency room (n = 11), admitted to the intensive care unit in an intubation state (n = 4). Patients without PFT results were assigned to the same group as those with predicted FEV1 less than 30%.
cCategorization based on the percentage of reduction in cross-sectional area. Grade 1, ≤ 50% lumenal stenosis; Grade II, 51–70% lumenal stenosis; Grade III, 71–99% lumenal stenosis; Grade IV, no lumen.