Abstract
BACKGROUND:
There is significant variation between physicians in terms of how they perform therapeutic bronchoscopy, but there are few data on whether these differences impact effectiveness.
METHODS:
This was a multicenter registry study of patients undergoing therapeutic bronchoscopy for malignant central airway obstruction. The primary outcome was technical success, defined as reopening the airway lumen to > 50% of normal. Secondary outcomes were dyspnea as measured by the Borg score and health-related quality of life (HRQOL) as measured by the SF-6D.
RESULTS:
Fifteen centers performed 1,115 procedures on 947 patients. Technical success was achieved in 93% of procedures. Center success rates ranged from 90% to 98% (P = .02). Endobronchial obstruction and stent placement were associated with success, whereas American Society of Anesthesiology (ASA) score > 3, renal failure, primary lung cancer, left mainstem disease, and tracheoesophageal fistula were associated with failure. Clinically significant improvements in dyspnea occurred in 90 of 187 patients measured (48%). Greater baseline dyspnea was associated with greater improvements in dyspnea, whereas smoking, having multiple cancers, and lobar obstruction were associated with smaller improvements. Clinically significant improvements in HRQOL occurred in 76 of 183 patients measured (42%). Greater baseline dyspnea was associated with greater improvements in HRQOL, and lobar obstruction was associated with smaller improvements.
CONCLUSIONS:
Technical success rates were high overall, with the highest success rates associated with stent placement and endobronchial obstruction. Therapeutic bronchoscopy should not be withheld from patients based solely on an assessment of risk, since patients with the most dyspnea and lowest functional status benefitted the most.
Malignant airway obstruction occurs frequently in patients with lung cancer and in patients with pulmonary metastases from other malignancies, including breast, colon, and renal cell cancer.1 There are three main types of malignant airway obstruction: endobronchial, extrinsic compression, and a mixed pattern. Ablative techniques that destroy tissue are useful for endobronchial obstruction. Ablative techniques include lasers, electrocautery, argon plasma coagulation (APC), photodynamic therapy, microdebriders, and cryotherapy. Stents are the primary modality used for patients with extrinsic compression. For mixed patterns, multiple modalities are usually required. Practice patterns vary significantly between bronchoscopists in terms of the type of bronchoscopy used (flexible vs rigid), ablative technique preferred (eg, laser vs electrocautery), and stent strategy and preference (eg, silicone vs metal). Whether these practice variations impact effectiveness is unknown.
Prior studies of therapeutic bronchoscopy for central airway obstruction2‐6 have included both malignant and benign cases, and most were done retrospectively. However, outcomes and complications differ significantly depending upon the indication (eg, malignant airway obstruction vs postintubation tracheal stenosis). In many studies there was significant heterogeneity in terms of patient population and indications.1,3,4 Other studies have focused on individual technologies, such as microdebriders3 or APC.7 These studies are useful for evaluating new technologies, but they are not designed to show comparative effectiveness. In clinical practice, a multimodality approach using a variety of technologies is the norm, but there is relatively scant evidence comparing techniques. In addition, the impact of interventions on quality of life has not always been quantified with validated instruments. This makes clinical decision-making more difficult, since physicians must be able to quantify the potential benefits and weigh them against the risks. Finally, most of these studies were performed at centers of excellence as part of clinical research studies and used relatively small and highly selected patient populations. Whether these results can be generalized to everyday clinical practice is unknown.8,9
We used the American College of Chest Physicians Quality Improvement Registry, Evaluation, and Education (AQuIRE) program to evaluate therapeutic bronchoscopy for malignant central airway obstruction. Registries offer the benefit of providing clinical effectiveness data that are more generalizable than those obtained from more focused clinical trials.8,9 Our primary objective was to quantify the technical success rate of therapeutic bronchoscopy, defined as anatomic reopening of the airways, and to identify techniques and factors associated with technical success. Secondary objectives were to assess the impact of therapeutic bronchoscopy on dyspnea and changes in health-related quality of life (HRQOL) in a subset of these patients. Data on complications are presented separately.
Materials and Methods
Patients undergoing therapeutic bronchoscopy from January 2009 to February 2013 were entered into AQuIRE.10 Not all centers started participating at the same time; some centers participated for the entire duration, and others participated for ≥ 1 year. However, participating physicians agreed to enter all consecutive patients for the duration of their participation. Institutional review board approval was obtained from The University of Texas MD Anderson institutional review board committee 4, protocol DR09-0101 (e-Appendix 1 (320KB, pdf) ). The principal investigator for each site was primarily responsible for data quality for that site. Informed consent or a waiver of consent was obtained in accordance with institutional guidelines. Data were entered via the AQuIRE web-based interface using standardized definitions, quality control checks, and protocols as previously described.8,9,11
Patients undergoing therapeutic flexible or rigid bronchoscopy for malignant central airway obstruction were included. Central airway obstruction was defined as occlusion of ≥ 50% of the trachea, mainstem bronchi, bronchus intermedius, or a lobar bronchus. All clinical decisions, including type of interventions used, were left to the discretion of the attending bronchoscopist.
Information extracted from AQuIRE included patient demographics, clinical characteristics, physician and hospital information, sedation information, procedural information, and technical success of the procedure. Technical success was based on anatomic criteria and was defined bronchoscopically as reopening the airway lumen to > 50% of the normal diameter. The airway also had to connect to a viable area of distal lung. If a physician successfully reopened a proximal airway, only to discover that there was distal disease that occluded all the segmental and subsegmental levels, this was classified as a technical failure. All clinical outcomes were assessed by the attending physician using standardized definitions from a code book. See e-Appendix 1 (320KB, pdf) for additional details on definitions. Center volume was determined by calculating the average number of cases per month for each center, and this was used as a center-level variable in hierarchical models. A subset of centers agreed prospectively to collect preprocedure and 30-day postprocedure data on dyspnea and self-reported HRQOL. Dyspnea was measured using the Borg score, and HRQOL was measured using the SF-6D.12 The SF-6D provides a means to estimate a preference-based single index measure for health using general population data.
The primary outcome was technical success of the procedure. All centers decided in advance whether to collect additional data on dyspnea and HRQOL, since this was an optional module within AQuIRE because most centers do not collect these data as part of their routine clinical care. A secondary analysis was conducted to analyze the outcomes of change in dyspnea as measured by the Borg score and changes in utility as derived from the SF-6D, only using the data from those centers that agreed in advance to participate in that module.
Statistical Analysis
For binary outcomes, the association of the outcome with each of the covariates was checked by χ2 test or Fisher exact test or Wilcoxon-Mann-Whitney two-sample test or Wilcoxon signed-rank test as appropriate. For continuous outcomes, the association of the outcome with each of the covariates was checked by F test in analysis of variance models or t test in linear regression models, as appropriate. Change in dyspnea was calculated as postprocedure − preprocedure Borg score (ΔBorg). For responder analysis we used a ΔBorg of ≤ −1 to define patients having a clinically significant improvement in dyspnea. This was based on the minimal clinically important difference (MCID) of the Borg score, which is a one-unit change.13,14 Change in utility was calculated as postprocedure − preprocedure utility (Δutility) among patients alive 30 days after the procedure. For responder analysis we used a Δutility of + 0.033 to define patients having a clinically significant improvement in utility. This was based on the MCID of the SF-6D.15 Variables that had P values < .20 on univariate analyses were candidates for multivariate models. Predictive models used only clinical information available preprocedure; explanatory models used all available information. Multivariate models used backward selection to retain only variables with P values < .05. To control for regression to the mean when analyzing ΔBorg, we included baseline Borg in the multivariate models.16 Additional information on models and controlling for regression to the mean are in e-Appendix 1 (320KB, pdf) . We used hierarchical models to evaluate the impact of center-level variation on homogeneity. Logistic regression using the maximum likelihood approach was used. For continuous outcomes, an analysis of covariance model was used. P values < .05 were considered to be significant; all tests were two-sided. All statistical analyses were performed in SAS version 9.3 (SAS Institute Inc).
Results
Fifteen centers with 26 physicians enrolled 947 patients who had 1,115 procedures. Baseline patient and clinical characteristics are shown in Table 1. There were significant variations in practice patterns between centers in location of care (P < .001), anesthesia (P < .001), ventilation (P < .001), rigid bronchoscopy (P < .001), ablative techniques (P < .001), stent use (P < .001), and types of stents used (P < .001).
TABLE 1 ] .
Patient and Clinical Characteristics of Procedures
| Characteristics | Frequency (N = 1,115) |
| Age, mean ± SD, y | 62.8 ± 13.3 |
| Baseline Borg score, mean ± SD | 3.6 ± 2.4 |
| Male sex | 620 (55.6) |
| Inpatient | 366 (32.8) |
| Race | |
| Nonwhite | 202 (18.1) |
| White | 913 (81.9) |
| Urgency of the procedure | |
| Elective | 767 (68.8) |
| Emergent | 104 (9.3) |
| Urgent | 244 (21.9) |
| Zubrod score | |
| ≤ 1 | 469 (42.1) |
| > 1 | 646 (57.9) |
| ASA score | |
| ≤ 3 | 701 (62.9) |
| > 3 | 414 (37.1) |
| Therapeutic bronchoscopy | |
| First therapeutic bronchoscopy | 800 (71.7) |
| Redo bronchoscopy (second or later) | 315 (28.3) |
| Comorbiditiesa | |
| Asthma | 55 (4.9) |
| COPD | 339 (30.4) |
| Cardiovascular disease | 566 (50.8) |
| Diabetes | 175 (15.7) |
| GERD | 65 (5.8) |
| Hematologic malignancy | 5 (0.4) |
| Second primary solid tumor presentb | 7 (0.6) |
| Renal failure creatinine > 2 or on HD | 17 (1.5) |
| Bleeding risk high medications | 81 (7.3) |
| Current or prior tobacco use | 872 (78.2) |
| Cancer related | |
| Primary lung cancer | 800 (71.7) |
| Time from cancer diagnosis > 75 d | 556 (49.9) |
| Location(s) of diseasea | |
| Trachea | 255 (22.9) |
| Left main | 416 (37.3) |
| Right main | 459 (41.2) |
| Bronchus intermedius | 268 (24) |
| Lobar | 323 (29) |
| Any tracheoesophageal fistula | 9 (0.8) |
| Type(s) of obstruction presenta | |
| Any endobronchial | 549 (49.2) |
| Any extrinsic | 161 (14.4) |
| Any mixed | 485 (43.5) |
| Procedural variables | |
| Anesthesia | |
| Moderate sedation | 154 (13.8) |
| Deep or general | 961 (86.2) |
| Paralysis | |
| No | 283 (25.4) |
| Yes | 832 (74.6) |
| Type of ventilation | |
| Volume cycled | 714 (64) |
| Jet | 230 (20.6) |
| Spontaneous | 171 (15.3) |
| Type of bronchoscopy | |
| Flexible | 382 (34.3) |
| Rigid | 733 (65.7) |
| Ablative techniques used | |
| Any laser used | 262 (23.5) |
| Any electrocautery used | 238 (21.3) |
| Any APC used | 393 (35.2) |
| Any cryotherapy used | 89 (8) |
| Any dilation done | 448 (40.2) |
| Stent(s) placeda | |
| Any stent placed | 406 (36.4) |
| Any metal stent | 298 (26.7) |
| Any silicone tube stent | 36 (3.2) |
| Any tube stentc | 331 (29.7) |
| Any Y stent | 85 (7.6) |
Data are given as No. (%) unless otherwise indicated. APC = argon plasma coagulation; ASA = American Society of Anesthesiology; GERD = gastroesophageal reflux disease; HD = hemodialysis.
Patients could have multiple comorbidities, disease locations, types of obstruction, and interventions during the same procedure. Therefore, these are not mutually exclusive.
Patients having a second primary cancer present other than the one causing obstruction.
If a patient had any non-Y-shaped stent placed, whether metal or silicone, it was considered a tube stent. See e-Appendix 1 (320KB, pdf) for interpretation of ORs related to stent type.
Technical Success of the Procedure
Out of the 1,115 procedures, 1,039 (93%) were technically successful (> 50% success) (Table 2). On multivariate analysis, endobronchial obstruction and stent placement were associated with higher technical success rates, whereas American Society of Anesthesiology (ASA) score > 3, renal failure, primary lung cancer, left mainstem disease, and tracheoesophageal fistula were associated with lower technical success rates. Among the eight centers that had data on 25 or more cases (n = 1,052), success rates ranged from 90% to 98% (P = .02). We evaluated center-level impact on homogeneity, but the model did not converge if smaller centers were included. When we used only larger centers, we failed to find evidence of heterogeneity, and we did not find evidence of a relationship between center volume and success rates. This is not to say that centers had the same outcomes, but rather that after evaluating for other covariates the between-center variance was negligible.
TABLE 2 ] .
Patient and Clinic Characteristics by Technical Success of the Procedure (> 50% Successful)
| Univariate Analysis | Multivariate Analysis | ||||
| Characteristic | No Technical Success (n = 76) | Yes Technical Success (n = 1,039) | P Value | Multivariate OR (95% CI)a | P Value |
| Age, mean, y | 62.5 | 62.9 | .88b | … | … |
| Inpatient | |||||
| No | 53 (7.1) | 696 (92.9) | … | … | … |
| Yes | 23 (6.3) | 343 (93.7) | .62 | … | … |
| Urgency of the procedure | |||||
| Elective | 53 (6.9) | 714 (93.1) | … | … | … |
| Emergent | 5 (4.8) | 99 (95.2) | … | … | … |
| Urgent | 18 (7.4) | 226 (92.6) | .73c | … | … |
| Zubrod score | |||||
| ≤ 1 | 32 (6.8) | 437 (93.2) | … | … | … |
| > 1 | 44 (6.8) | 602 (93.2) | .99 | … | … |
| ASA score | |||||
| ≤ 3 | 38 (5.4) | 663 (94.6) | … | Reference | … |
| > 3 | 38 (9.2) | 376 (90.8) | .02 | 0.55 (0.33-0.9) | .018 |
| Therapeutic bronchoscopy | |||||
| First therapeutic bronchoscopy | 54 (6.8) | 746 (93.3) | .90 | … | … |
| Redo bronchoscopy (second or later) | 22 (7.0) | 293 (93.0) | … | … | … |
| Comorbidities | |||||
| Asthma | |||||
| No | 75 (7.1) | 985 (92.9) | … | … | … |
| Yes | 1 (1.8) | 54 (98.2) | .17c | … | … |
| COPD | |||||
| No | 46 (5.9) | 730 (94.1) | … | … | … |
| Yes | 30 (8.8) | 309 (91.2) | .08 | … | … |
| Cardiovascular disease | |||||
| No | 42 (7.7) | 507 (92.3) | … | … | … |
| Yes | 34 (6) | 532 (94) | .28 | … | … |
| Second primary solid tumor | |||||
| No | 76 (6.9) | 1,032 (93.1) | … | … | … |
| Yes | 0 (0) | 7 (100) | 1.0c | … | … |
| Renal failure creatinine > 2 or HD | |||||
| No | 72 (6.6) | 1,026 (93.4) | … | Reference | … |
| Yes | 4 (23.5) | 13 (76.5) | .02c | 0.17 (0.04-0.66) | .011 |
| Bleeding risk high medications | |||||
| No | 72 (7) | 962 (93) | … | … | … |
| Yes | 4 (4.9) | 77 (95.1) | .65c | … | … |
| Tobacco use | |||||
| Never user | 10 (4.1) | 233 (95.9) | … | … | … |
| Current or prior use | 66 (7.6) | 806 (92.4) | .06 | … | … |
| Cancer related | |||||
| Time from cancer diagnosis | |||||
| ≤ 75 d | 44 (7.9) | 515 (92.1) | … | … | … |
| > 75 d | 32 (5.8) | 524 (94.2) | .16 | … | … |
| Primary lung cancer | |||||
| No | 13 (4.1) | 302 (95.9) | … | Reference | … |
| Yes | 63 (7.9) | 737 (92.1) | .02 | 0.45 (0.23-0.88) | .019 |
| Location of disease | |||||
| Trachea | |||||
| No | 71 (8.3) | 789 (91.7) | … | … | … |
| Yes | 5 (2) | 250 (98) | .0002c | … | … |
| Left main | |||||
| No | 38 (5.4) | 661 (94.6) | … | Reference | … |
| Yes | 38 (9.1) | 378 (90.9) | .02 | 0.51 (0.31-0.83) | .007 |
| Right main | |||||
| No | 52 (7.9) | 604 (92.1) | … | … | … |
| Yes | 24 (5.2) | 435 (94.8) | .08 | … | … |
| Bronchus intermedius | |||||
| No | 60 (7.1) | 787 (92.9) | … | … | … |
| Yes | 16 (6) | 252 (94) | .53 | … | … |
| Lobar | |||||
| No | 50 (6.3) | 742 (93.7) | … | … | … |
| Yes | 26 (8) | 297 (92) | .30 | … | … |
| Any tracheoesophageal fistula | |||||
| No | 74 (6.7) | 1,032 (93.3) | … | Reference | … |
| Yes | 2 (22.2) | 7 (77.8) | .12c | 0.03 (0-0.17) | < .0001 |
| Type of obstruction | |||||
| Any endobronchial | |||||
| No | 51 (9) | 515 (91) | … | Reference | … |
| Yes | 25 (4.6) | 524 (95.4) | .003 | 2.62 (1.56-4.39) | .0003 |
| Any extrinsic | |||||
| No | 69 (7.2) | 885 (92.8) | … | … | … |
| Yes | 7 (4.3) | 154 (95.7) | .18 | … | … |
| Any mixed | |||||
| No | 30 (4.8) | 600 (95.2) | … | … | … |
| Yes | 46 (9.5) | 439 (90.5) | .001 | … | … |
| Procedural variables | |||||
| Anesthesia | |||||
| Moderate sedation | 15 (9.7) | 139 (90.3) | … | … | … |
| Deep or general anesthesia | 61 (6.3) | 900 (93.7) | .12 | … | … |
| Paralysis | |||||
| No | 24 (8.5) | 259 (91.5) | … | … | … |
| Yes | 52 (6.3) | 780 (93.8) | .20 | … | … |
| Type of ventilation | |||||
| Volume cycled | 51 (7.1) | 663 (92.9) | … | … | … |
| Jet | 9 (3.9) | 221 (96.1) | … | … | … |
| Spontaneous | 16 (9.4) | 155 (90.6) | .08 | … | … |
| Type of bronchoscopy | |||||
| Flexible | 28 (7.3) | 354 (92.7) | … | … | … |
| Rigid | 48 (6.5) | 685 (93.5) | .62 | … | … |
| Any laser used | |||||
| No | 53 (6.2) | 800 (93.8) | … | … | … |
| Yes | 23 (8.8) | 239 (91.2) | .15 | … | … |
| Any electrocautery used | |||||
| No | 58 (6.6) | 819 (93.4) | … | … | … |
| Yes | 18 (7.6) | 220 (92.4) | .60 | … | … |
| Any APC used | |||||
| No | 59 (8.2) | 663 (91.8) | … | … | … |
| Yes | 17 (4.3) | 376 (95.7) | .014 | … | … |
| Any cryotherapy used | |||||
| No | 65 (6.3) | 961 (93.7) | … | … | … |
| Yes | 11 (12.4) | 78 (87.6) | .03 | … | … |
| Any dilation done | |||||
| No | 48 (7.2) | 619 (92.8) | … | … | … |
| Yes | 28 (6.3) | 420 (93.8) | .54 | … | … |
| Stent | |||||
| Stent placed | |||||
| No | 69 (9.7) | 640 (90.3) | … | Reference | … |
| Yes | 7 (1.7) | 399 (98.3) | < .0001 | 11.90 (5.1-27.8) | < .0001 |
| Metal stent | |||||
| No | 69 (8.4) | 748 (91.6) | … | … | … |
| Yes | 7 (2.3) | 291 (97.7) | .0004 | … | … |
| Silicone stent | |||||
| No | 76 (7) | 1,003 (93) | … | … | … |
| Yes | 0 (0) | 36 (100) | .17c | … | … |
| Tube stent | |||||
| No | 69 (8.8) | 715 (91.2) | … | … | … |
| Yes | 7 (2.1) | 324 (97.9) | .0001 | … | … |
| Y stent | |||||
| No | 76 (7.4) | 954 (92.6) | … | … | … |
Data are given as No. (%) unless otherwise indicated. See Table 1 legend for expansion of abbreviations.
Firth penalized likelihood approach used for rare events.
Wilcoxon two-sample test.
Fisher exact test.
Dyspnea
A total of 187 patients had pre- and post-Borg scores measured. We compared this dyspnea assessment subset to other patients from the same centers who did not have dyspnea data collected. We found that the dyspnea assessment subsets were more likely to have elective procedures (P = .006), be inpatients (P < .001), and have rigid bronchoscopy (P < .001). In all other regards they were similar (e-Table 1 (320KB, pdf) ).
Dyspnea decreased following intervention (mean ΔBorg, −0.9 ± 2.2; Wilcoxon signed-rank test, P < .0001). Note that since lower Borg scores indicate less dyspnea, if ΔBorg is negative, then there has been a decrease in dyspnea from preprocedure to postprocedure. On multivariate analysis, a one-unit increase of baseline Borg score was found to be associated with a 0.63-unit decrease in ΔBorg (P < .0001), indicating that higher baseline Borg scores were associated with greater improvements in dyspnea (Table 3). Conversely, smokers, patients with another primary solid tumor, and patients with lobar obstruction tended to have a higher ΔBorg, indicating that these groups were less likely to have improvements in dyspnea. There was no difference between predictive and explanatory models.
TABLE 3 ] .
Patient and Clinical Characteristics by Difference of Borg Score (Post − Pre)
| Univariate Analysis | Multivariate Analysis | ||||
| Characteristic | No. | Mean (SD) of Difference of Borg Score | P Value (F Test) | Coefficient Estimate (Error) | P Value |
| Baseline Borg score, coefficienta (SD) | 187 | −0.61 (0.05)a | < .0001b | −0.63 (0.05) | < .0001 |
| Age, coefficienta (SD), y | 187 | 0.024 (0.012)a | .04b | … | … |
| Inpatient, No. (%) | |||||
| No | 143 | −0.7 (1.8) | … | … | … |
| Yes | 44 | −1.4 (3) | .08 | … | … |
| Urgency of the procedure, No. (%) | |||||
| Elective | 153 | −0.7 (2.1) | … | … | … |
| Emergent | 3 | −4.7 (1.5) | … | … | … |
| Urgent | 31 | −1.3 (2.3) | .004 | … | … |
| Zubrod score | |||||
| ≤ 1 | 85 | −0.6 (2.2) | … | … | … |
| > 1 | 102 | −1.1 (2.1) | .08 | … | … |
| ASA score, No. (%) | |||||
| ≤ 3 | 148 | −0.7 (2) | … | … | … |
| > 3 | 39 | −1.4 (2.7) | .1 | … | … |
| Therapeutic bronchoscopy, No. (%) | |||||
| First therapeutic bronchoscopy | 126 | −1.1 (2.3) | … | … | … |
| Redo bronchoscopy, second or later | 61 | −0.4 (1.7) | .023 | … | … |
| Comorbidities, No. (%) | |||||
| Asthma | |||||
| No | 177 | −0.8 (2.2) | … | … | … |
| Yes | 10 | −2 (2) | .11 | … | … |
| COPD | |||||
| No | 136 | −0.8 (2.2) | … | … | … |
| Yes | 51 | −1 (2) | .64 | … | … |
| Cardiovascular disease | |||||
| No | 100 | −0.8 (2.4) | … | … | … |
| Yes | 87 | −1 (1.9) | .63 | … | … |
| Second primary solid tumor | |||||
| No | 183 | −0.9 (2.1) | … | Reference | … |
| Yes | 4 | 0.6 (3.7) | .16 | 2.19 (0.82) | .008 |
| Renal failure creatinine > 2 or HD | |||||
| No | 183 | −0.9 (2.2) | … | … | … |
| Yes | 4 | −0.3 (0.5) | .56 | … | … |
| Bleeding risk high medications | |||||
| No | 186 | −0.9 (2.2) | … | … | … |
| Yes | 1 | 0 (.) | .69 | … | … |
| Tobacco use | |||||
| Never user | 50 | −1.1 (2.3) | … | Reference | … |
| Current or prior use | 137 | −0.8 (2.1) | .46 | 0.52 (0.27) | .05 |
| Cancer related | |||||
| Time from cancer diagnosis | |||||
| ≤ 75 d | 59 | −1.4 (2.5) | … | … | … |
| > 75 d | 128 | −0.6 (2) | .034 | … | … |
| Primary lung cancer, No. (%) | |||||
| No | 76 | −0.6 (2.3) | … | … | … |
| Yes | 111 | −1.1 (2.1) | .16 | … | … |
| Location of disease, No. (%) | |||||
| Trachea | |||||
| No | 154 | −0.8 (2.1) | … | … | … |
| Yes | 33 | −1.1 (2.7) | .53 | … | … |
| Left main | … | ||||
| No | 114 | −0.8 (2.3) | … | … | |
| Yes | 73 | −1 (1.9) | .66 | … | … |
| Right main | |||||
| No | 126 | −0.8 (1.9) | … | … | … |
| Yes | 61 | −1.1 (2.7) | .25 | … | … |
| Bronchus intermedius | |||||
| No | 118 | −0.9 (2.1) | … | … | … |
| Yes | 69 | −0.8 (2.3) | .81 | … | … |
| Lobar | |||||
| No | 116 | −1.1 (2.2) | … | Reference | … |
| Yes | 71 | −0.6 (2.1) | .13 | 0.51 (0.24) | .04 |
| Any tracheoesophageal fistula | |||||
| No | 187 | −0.9 (2.2) | … | … | … |
| Yes | 0 | NA | … | … | |
| Type of obstruction, No. (%) | |||||
| Any endobronchial | |||||
| No | 58 | −1 (2.4) | … | … | … |
| Yes | 129 | −0.8 (2) | .63 | … | … |
| Any extrinsic | |||||
| No | 166 | −0.9 (2) | … | … | … |
| Yes | 21 | −0.3 (3.3) | .22 | … | … |
| Any mixed | |||||
| No | 137 | −0.8 (2.1) | … | … | … |
| Yes | 50 | −1.1 (2.3) | .51 | … | … |
| Procedural variables | |||||
| Anesthesia, No. (%) | |||||
| Moderate sedation | 45 | −1.1 (2) | … | … | … |
| Deep or general | 142 | −0.8 (2.2) | .5 | … | … |
| Paralysis, No. (%) | |||||
| No | 76 | −1.2 (2) | … | … | … |
| Yes | 111 | −0.7 (2.2) | .1 | … | … |
| Type of ventilation, No. (%) | |||||
| Volume cycled | 58 | −1 (2.6) | … | … | … |
| Jet | 80 | −0.7 (1.9) | … | … | … |
| Spontaneous | 49 | −1 (2) | .7 | … | … |
| Type of bronchoscopy | |||||
| Flexible | 66 | −1.2 (2.3) | … | … | … |
| Rigid | 121 | −0.7 (2.1) | .19 | … | … |
| Any laser used | |||||
| No | 149 | −0.9 (2.1) | … | … | … |
| Yes | 38 | −0.8 (2.4) | .85 | … | … |
| Any electrocautery used | |||||
| No | 143 | −1 (2.1) | … | … | … |
| Yes | 44 | −0.4 (2.3) | .08 | … | … |
| Any APC used | |||||
| No | 102 | −1.2 (2.4) | … | … | … |
| Yes | 85 | −0.5 (1.8) | .045 | … | … |
| Any cryotherapy used | |||||
| No | 151 | −0.8 (2.2) | … | … | … |
| Yes | 36 | −1 (2) | .64 | … | … |
| Any dilation done | |||||
| No | 150 | −0.8 (2.1) | … | … | … |
| Yes | 37 | −1.2 (2.4) | .37 | … | … |
| Stent | |||||
| Stent placed | |||||
| No | 128 | −0.7 (1.9) | … | … | … |
| Yes | 59 | −1.2 (2.7) | .17 | … | … |
| Metal stent | |||||
| No | 143 | −0.8 (1.8) | … | … | … |
| Yes | 44 | −1.2 (3) | .27 | … | … |
| Silicone stent | |||||
| No | 178 | −0.9 (2.2) | … | … | … |
| Yes | 9 | −1.1 (2) | .74 | … | … |
| Tube stent | |||||
| No | 134 | −0.8 (1.8) | … | … | … |
| Yes | 53 | −1.2 (2.9) | .23 | … | … |
| Y stent | |||||
| No | 180 | −0.9 (2.2) | … | … | … |
| Yes | 7 | −0.4 (2.6) | .58 | … | … |
Data are given as mean (SD) unless otherwise indicated. NA = not applicable. See Table 1 legend for expansion of other abbreviations.
Coefficient of linear regression with dependent variable being continuous change in Borg score. Note that lower Borg scores indicate less dyspnea, so a negative post – pre score indicates improvements in dyspnea. Therefore, negative coefficients indicate factors that are associated with improvements in dyspnea from pre to post, whereas positive coefficients indicate factors that are associated with worsening dyspnea from pre to post.
t test.
In a responder analysis, 90 of the 187 patients (48%) had a clinically significant improvement in dyspnea, 81 (43%) stayed the same, and 16 (9%) worsened (e-Table 2 (320KB, pdf) ). On multivariate responder analysis, only higher baseline Borg score and never smoking were associated with clinical improvements in dyspnea.
Quality of Life and Utility
Mean baseline HRQOL was 0.65 ± 0.13 utiles. Pre- and post-utility scores were measured in 183 patients. HRQOL improved following intervention (mean Δutility, 0.023 ± 0.107 utiles; paired t test, P = .004). In multivariate predictive analysis, higher baseline Borg score and not having lobar obstruction were associated with greater improvements in HRQOL (Table 4). In an explanatory multivariate analysis (e-Table 3 (320KB, pdf) ), lower baseline utility, absence of tracheal obstruction, absence of bronchus intermedius obstruction, and greater improvements in dyspnea postprocedure (ie, more negative ΔBorg) were associated with greater improvements in utility. A one-unit increase in ΔBorg (ie, more dyspnea) resulted in a decrease in Δutility of 0.020 utiles (P < .0001).
TABLE 4 ] .
Patient and Clinical Characteristics by Difference in Utility (Post − Pre)
| Univariate Analysis | Predictive Multivariate Analysis | ||||
| No. | Mean (SD) of Difference of Utility | P Value (F test) | Coefficient Estimate (Error) | P Value | |
| Baseline utility, coefficienta (SD) | 183 | −0.314 (0.057)a | < .0001b | … | … |
| Baseline Borg score, coefficienta (SD) | 179 | 0.009 (0.003)a | .007b | 0.010 (0.003) | .005 |
| Post – pre Borg score difference, coefficienta (SD) | 173 | −0.022 (0.004)a | < .0001b | … | … |
| Age, coefficienta (SD), y | 183 | −0.00006 (0.0006) | .92b | … | … |
| Inpatient, No. (%) | |||||
| No | 142 | 0.02 (0.1) | … | … | … |
| Yes | 41 | 0.05 (0.12) | .13 | … | … |
| Urgency of the procedure, No. (%) | |||||
| Elective | 150 | 0.02 (0.11) | … | … | … |
| Emergent | 3 | 0.09 (0.05) | … | … | … |
| Urgent | 30 | 0.05 (0.1) | .18 | … | … |
| Zubrod score | |||||
| ≤ 1 | 88 | 0 (0.11) | … | … | … |
| > 1 | 95 | 0.04 (0.1) | .023 | … | … |
| ASA score, No. (%) | |||||
| ≤ 3 | 148 | 0.01 (0.11) | … | … | … |
| > 3 | 35 | 0.06 (0.11) | .017 | … | … |
| Therapeutic bronchoscopy, No. (%) | |||||
| First therapeutic bronchoscopy | 124 | 0.02 (0.11) | … | … | … |
| Redo bronchoscopy, second or later | 59 | 0.02 (0.11) | .94 | … | … |
| Comorbidities, No. (%) | |||||
| Asthma | |||||
| No | 174 | 0.02 (0.11) | … | … | … |
| Yes | 9 | 0.08 (0.08) | .11 | … | … |
| COPD | |||||
| No | 131 | 0.01 (0.11) | … | … | … |
| Yes | 52 | 0.05 (0.11) | .08 | … | … |
| Cardiovascular disease | |||||
| No | 98 | 0.02 (0.11) | … | … | … |
| Yes | 85 | 0.02 (0.11) | .85 | … | … |
| Second primary solid tumor | |||||
| No | 180 | 0.02 (0.11) | … | … | … |
| Yes | 3 | −0.05 (0.09) | .25 | … | … |
| Renal failure creatinine > 2 or HD | |||||
| No | 179 | 0.02 (0.11) | … | … | … |
| Yes | 4 | 0.09 (0.08) | .19 | … | … |
| Bleeding risk high medications | |||||
| No | 183 | 0.02 (0.11) | … | … | … |
| Yes | 0 | NA | … | … | |
| Tobacco use | |||||
| Never user | 52 | 0.01 (0.12) | … | … | … |
| Current or prior use | 131 | 0.03 (0.1) | .42 | … | … |
| Cancer related | |||||
| Time from cancer diagnosis | |||||
| ≤ 75 d | 58 | 0.03 (0.12) | … | … | … |
| > 75 d | 125 | 0.02 (0.1) | .33 | … | … |
| Primary lung cancer, No. (%) | |||||
| No | 72 | 0.02 (0.11) | … | … | … |
| Yes | 111 | 0.03 (0.1) | .43 | … | … |
| Location of disease, No. (%) | |||||
| Trachea | |||||
| No | 151 | 0.03 (0.1) | … | … | … |
| Yes | 32 | −0.01 (0.13) | .08 | … | … |
| Left main | |||||
| No | 115 | 0.02 (0.11) | … | … | … |
| Yes | 68 | 0.04 (0.1) | .22 | … | … |
| Right main | |||||
| No | 125 | 0.02 (0.1) | … | … | … |
| Yes | 58 | 0.03 (0.12) | .56 | … | … |
| Bronchus intermedius | |||||
| No | 116 | 0.03 (0.1) | … | … | … |
| Yes | 67 | 0.01 (0.12) | .2 | … | … |
| Lobar | |||||
| No | 113 | 0.03 (0.11) | … | Reference | … |
| Yes | 70 | 0.01 (0.11) | .07 | −0.036 (0.016) | .02 |
| Any tracheoesophageal fistula | |||||
| No | 183 | 0.02 (0.11) | … | … | … |
| Yes | 0 | … | NA | … | … |
| Type of obstruction, No. (%) | |||||
| Any endobronchial | |||||
| No | 52 | 0.03 (0.1) | … | … | … |
| Yes | 131 | 0.02 (0.11) | .71 | … | … |
| Any extrinsic | |||||
| No | 165 | 0.03 (0.11) | … | … | … |
| Yes | 18 | 0 (0.12) | .4 | … | … |
| Any mixed | |||||
| No | 137 | 0.02 (0.11) | … | … | … |
| Yes | 46 | 0.03 (0.1) | .75 | … | … |
| Procedural variables | |||||
| Anesthesia, No. (%) | |||||
| Moderate sedation | 47 | 0.04 (0.1) | … | … | … |
| Deep or general anesthesia | 136 | 0.02 (0.11) | .21 | … | … |
| Paralysis, No. (%) | |||||
| No | 78 | 0.04 (0.11) | … | … | … |
| Yes | 105 | 0.01 (0.11) | .036 | … | … |
| Type of ventilation, No. (%) | |||||
| Volume cycled | 60 | 0.02 (0.11) | … | … | … |
| Jet | 73 | 0.01 (0.11) | … | … | … |
| Spontaneous | 50 | 0.04 (0.1) | .35 | … | … |
| Type of bronchoscopy | |||||
| Flexible | 70 | 0.04 (0.11) | … | … | … |
| Rigid | 113 | 0.01 (0.1) | .039 | … | … |
| Any laser used | |||||
| No | 145 | 0.02 (0.11) | … | … | … |
| Yes | 38 | 0.02 (0.11) | .97 | … | … |
| Any electrocautery used | |||||
| No | 143 | 0.03 (0.1) | … | … | … |
| Yes | 40 | −0.01 (0.11) | .034 | … | … |
| Any APC used | |||||
| No | 100 | 0.03 (0.12) | … | … | … |
| Yes | 83 | 0.01 (0.1) | .3 | … | … |
| Any cryotherapy used | |||||
| No | 146 | 0.02 (0.11) | … | … | … |
| Yes | 37 | 0.03 (0.11) | .59 | … | … |
| Any dilation done | |||||
| No | 150 | 0.02 (0.1) | … | … | … |
| Yes | 33 | 0.04 (0.12) | .31 | … | … |
| Stent | |||||
| Stent placed | |||||
| No | 128 | 0.02 (0.1) | … | … | … |
| Yes | 55 | 0.04 (0.12) | .3 | … | … |
| Metal stent | |||||
| No | 143 | 0.02 (0.1) | … | … | … |
| Yes | 40 | 0.05 (0.12) | .08 | … | … |
| Silicone stent | |||||
| No | 174 | 0.02 (0.11) | … | … | … |
| Yes | 9 | 0.02 (0.09) | .86 | … | … |
| Tube stent | |||||
| No | 134 | 0.02 (0.1) | … | … | … |
| Yes | 49 | 0.04 (0.12) | .12 | … | … |
| Y stent | |||||
| No | 177 | 0.03 (0.11) | … | … | … |
| Yes | 6 | −0.03 (0.12) | .22 | … | … |
Data are given as mean (SD) unless otherwise indicated. See Table 1 legend for expansion of abbreviations.
Coefficient of linear regression with dependent variable being change in utility.
t test.
In a responder analysis, 76 of the 183 patients (42%) had a clinically significant improvement in utility, 61 (33%) stayed the same, and 46 (25%) worsened (e-Table 4 (320KB, pdf) ). In a multivariate predictive analysis, Zubrod score > 1, not having extrinsic airway compression, and flexible bronchoscopy were associated with clinically significant improvements in utility.
Adverse Events
Complication occurred in 44 of the 1,115 procedures (3.9%). There was significant variation between centers (range, 0.9%-11.7%; P = .002) in complication rates. Six patients (0.5%) died secondary to procedural complications. Factors associated with complications included ASA > 3 (P = .0002) and Zubrod > 1 (P = .02). The 30-day mortality was 14.8%. There was significant variation between centers (range, 7.7%-20.2%; P = .02). Risk factors for 30-day mortality included ASA > 3 (P ≤ 0.0001) and Zubrod > 1 (P < .0001). Detailed data and analysis of risk factors for complications and 30-day mortality are presented separately.
Discussion
Therapeutic bronchoscopy for malignant central airway obstruction is essentially a palliative intervention, since most patients have advanced disease that is incurable. Although therapeutic bronchoscopy in this setting may indeed prolong life modestly for some patients (eg, enable them to get off the ventilator), the majority of patients benefit from changes in quality of life rather than duration. When comparing the effectiveness of various therapeutic bronchoscopy techniques, it is therefore important to consider technical success and the subsequent impact on dyspnea and HRQOL. The potential benefits in HRQOL must then be weighed against the risks associated with the intervention. In this study, we found that although there were significant differences in technique between centers, technical success was usually achieved. There were differences between centers in the rate of technical success, but these were relatively modest. However, technical success did not always result in a meaningful improvement in dyspnea. Patients who were more short of breath at baseline were more likely to experience improvements in dyspnea, whereas those with lobar disease were less likely to improve. Similarly, HRQOL improvements were greatest in patients with more dyspnea at baseline, whereas those with lobar disease were less likely to improve. HRQOL improvement was also associated with higher ASA score and lower functional status. Thus, patients at the highest risk for complications also had the greatest potential for benefit.
Our study is consistent with and adds to the existing body of evidence by comparing alternative technologies and quantifying the nature and magnitude of the benefits of therapeutic bronchoscopy more precisely.1,2,4,5,17‐24 Prior studies often involved single centers and focused on particular technologies. Because of this, the populations were highly selected and not large enough to compare alternative approaches. Consistent with prior studies, we found a high rate of technical success (93%) with a modest amount of variation in success rates between centers. In addition, because of the number of centers and physicians involved, we were able to compare alternative techniques. We found there was no single best method in terms of ablative techniques. In addition, we found that stenting was associated with higher technical success rates. This association is not necessarily causal, since some patients may prove to have extensive disease beyond the central airways, such that the physician may deem that stenting is of no benefit. Hence there may be confounding by indication present, so caution is warranted when analyzing the factors associated with technical success.
However, measuring technical success alone is not sufficient, since palliation of dyspnea and improvement in HRQOL is the primary clinical goal. Many prior studies were case series and focused on feasibility, proof of concept, and quantifying risks with less emphasis on quantifying impact on HRQOL.1,2,4,5,17‐23 In our subset analysis, 48% of patients had a clinically significant improvement in dyspnea. This is consistent with prior studies of therapeutic bronchoscopy for malignant central airway obstruction, which also demonstrated improvements in dyspnea and HRQOL as measured by disease-specific instruments.2,4,5,17‐23 Although useful, these prior studies are not sufficient to fully inform clinical decision-making, because the trade-offs involve different units that cannot be easily compared. For example, what risk of death is acceptable to achieve success, when success is defined as relief of anatomic obstruction? What if we define success in terms of dyspnea? Since therapeutic bronchoscopy for malignant central airway obstruction is essentially palliative, we need to quantify the HRQOL gains in units that allow physicians to compare the benefits accrued to the risks incurred. This requires a specific type of HRQOL instrument—a generic single-index measure such as the SF-6D that can be used to calculate utilities (additional details on HRQOL instruments can be found in e-Appendix 1 (320KB, pdf) ).
This is the first report, to our knowledge, of therapeutic bronchoscopy for malignant central airway obstruction from a multicenter registry that evaluates technical success and dyspnea relief and combines it with an analysis of utility. The MCID for the SF-6D has been estimated to be 0.033 (95% CI, 0.029-0.037).15,25 This is similar to the MCID for other indirect utility measures, such as the Health Utilities Index Mark 2 (HU12), Health Utilities Index Mark 3 (HU13), and EQ-5D.25,26 Our data suggest that when baseline dyspnea is higher, interventions have a greater impact on utility. We also found that patients with more severe functional impairment were more likely to benefit from intervention. Of note, with respect to the outcomes of dyspnea relief and utility, there was no single best method in terms of ablative techniques, and there was no single best type of stent.
This study provides a more accurate assessment of the relationship between baseline dyspnea, improvements in dyspnea, the resulting improvement in utility, and how physicians might use this to weigh the benefits of intervention vs the possibility of procedure-related complications. Specifically, although high ASA score and more severe functional impairment predict increased risk of complications and adverse events, the benefits of intervention are also higher and probably warrant careful consideration. Based on these findings, high levels of functional impairment and high surgical risk should not necessarily preclude bronchoscopic intervention, provided that there is significant dyspnea and that the dyspnea is contributing to the patient’s poor performance status.
Although these findings are useful, it is important to recognize the limitations of the data. Although we did find that stenting was associated with higher technical success rates, this needs to be weighed against the risk of longer-term complications that may arise.27‐29 Similarly, although this is the first study to our knowledge to evaluate change in utility following therapeutic bronchoscopy, the outcomes measured are short term (ie, 30 days). Longer term studies that measure quality-adjusted survival beyond 30 days will be needed so that quality-adjusted life years can be determined. This has been done for malignant pleural effusions, and a similar method could be used for therapeutic bronchoscopy.30 In addition, although we did not find evidence of a relationship between average number of cases per month and technical success rates, the number of patients enrolled from low-volume centers was small. Therefore, the findings on volume-outcome relationships should be considered as limited and preliminary. In addition, the data on dyspnea and HRQOL were available for only a subset of patients from select centers, and these patients differed from the rest of the cohort in some regards, so the generalizability of the findings needs to be verified. Finally, the indications for the procedures may have differed in subtle but significant ways. Physicians may choose to intervene “early” for lesions that are anatomically significant (> 50% stenosis) even when patients do not have dyspnea, if the perception is that the disease is likely to progress. In such instances, improvements in dyspnea and even HRQOL are likely to be small. This does not necessarily mean that such early interventions are ineffective, since they presumably prevent future deterioration and may allow procedures to be done in an elective manner while patients are more stable. As such, predictors of impact on dyspnea and HRQOL may be subject to subtle confounding by indication, since the indication for some of these procedures may be to avoid future deterioration in dyspnea and HRQOL, whereas in other instances the indication is for immediate relief.
In conclusion, this report from the AQuIRE registry is the first multicenter registry study, to our knowledge, of therapeutic bronchoscopy for malignant central airway obstruction to evaluate patient and hospital predictors of technical success, impact on dyspnea, and changes in utility. Procedures were usually technically successful, with 93% of patients having their central airways reopened. No single ablative technology was superior in terms of achieving technical success, although stenting was associated with improved success rates. Improvements in dyspnea and utility were greatest in patients who had more dyspnea at baseline. Therapeutic bronchoscopy should not be withheld from patients based solely on an assessment of the risks involved, since patients at the highest risk recognized the greatest benefits. The decision process therefore requires not only risk assessment but also consideration of the magnitude of the potential benefits. Future studies should explore the interactions between hospital-level and patient-level variables on outcomes. Longer term studies evaluating quality-adjusted survival following therapeutic bronchoscopy are needed as well.
Supplementary Material
Online Supplement
Acknowledgments
Author contributions: D. E. O. was the principal investigator for this study and contributed to project oversight, organization, data collection and auditing, statistical analysis, and manuscript writing; M. S. contributed to registry design and organization, data collection and auditing, and manuscript writing; X. L., the primary biostatistician for the project, contributed to constructing the multilevel models and analyses and contributed to writing; and A. E., H. B. G., J. D.-M., M. S., T. R. G., M. S. M., C. A. J., J. T., K. L. K., C. R., S. G., R. F. C., F. A. A., M. M. W., G. A. E., D. F.-K., R. C. M., S. B., and A. T. contributed to the data collection and writing.
Financial/nonfinancial disclosures: The authors have reported to CHEST the following conflicts of interest: Dr Eapen is a consultant to Olympus Corporation. Drs Ost, Ernst, Grosu, Lei, Diaz-Mendoza, Slade, Gildea, Machuzak, Jimenez, Toth, Kovitz, Ray, Greenhill, Casal, Almeida, Wahidi, Feller-Kopman, Morice, Benzaquen, Tremblay, and Simoff have reported that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.
Role of sponsors: The data used for this publication were provided through AQuIRE. Although CHEST has reviewed and approved the proposal for this project, the researcher(s) are solely responsible for the analysis and any conclusions drawn from the data presented in this report.
Collaborators: Kevin Kovitz, MD (principal investigator [PI]); Sara Greenhill, MD; Thomas R. Gildea, MD (PI); Michael Machuzak, MD; Francisco A. Almeida, MD; Joseph Cicenia, MD; Momen Wahidi, MD (PI); Kamran Mahmood, MD; Paul MacEachern, MD (PI); Alain Tremblay, MDCM; Michael Simoff, MD (PI); Javier Diaz-Mendoza, MD; Cynthia Ray, MD; David Feller-Kopman, MD (PI); Lonny Yarmus, DO; Rosa Estrada-Y-Martin, MD (PI); Roberto F. Casal, MD (PI); Jennifer Toth, MD (PI); Raj Karunakara, MD (PI); Mark Slade, MD (PI); Armin Ernst, MD (PI); Samaan Rafeq, MD; David Ost, MD, MPH (PI); George A. Eapen, MD; Carlos A. Jimenez, MD; Rodolfo C. Morice, MD; Sadia Benzaquen, MD (PI); Jonathan Puchalski, MD (PI).
Other contributions: Each site principal investigator was responsible for data collection and auditing at their institution. We thank the following AQuIRE staff: Joyce Bruno, MBA, MIPH; Jeff Maitland, BS; and Danielle Jungst, BS.
Additional information: The e-Appendix and e-Tables can be found in the Supplemental Materials section of the online article.
ABBREVIATIONS
- APC
argon plasma coagulation
- AQuIRE
American College of Chest Physicians Quality Improvement Registry, Evaluation, and Education
- ASA
American Society of Anesthesiology score
- ΔBorg
postprocedure − preprocedure Borg score
- Δutility
postprocedure − preprocedure utility
- HRQOL
health-related quality of life
- MCID
minimal clinically important difference
Footnotes
FUNDING/SUPPORT: The American College of Chest Physicians funded the database construction for the AQuIRE program. This research was supported in part by the National Institutes of Health through a Cancer Center Support Grant [Grant P30CA016672], biostatistics core, at the University of Texas, MD Anderson Cancer Center.
Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.
Contributor Information
on behalf of the AQuIRE Bronchoscopy Registry:
Kevin Kovitz, Sara Greenhill, Thomas R. Gildea, Michael Machuzak, Francisco A. Almeida, Joseph Cicenia, Momen Wahidi, Kamran Mahmood, Paul MacEachern, Alain Tremblay, Michael Simoff, Javier Diaz-Mendoza, Cynthia Ray, David Feller-Kopman, Lonny Yarmus, Rosa Estrada-Y-Martin, Roberto F. Casal, Jennifer Toth, Raj Karunakara, Mark Slade, Armin Ernst, Samaan Rafeq, David Ost, George A. Eapen, Carlos A. Jimenez, Rodolfo C. Morice, Sadia Benzaquen, and Jonathan Puchalski
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