Amit K. Mahajan, MD, FCCP

Dr. Mahajan and colleagues present a compelling case for requiring minimum standards to perform an EBUS-guided bronchoscopy. Their opinion piece epitomizes the classic tension between physicians with advanced training and those who can only have practice-based training. A middle ground may exist, as perhaps competence could be achieved by simulation, clinical cases performed, and observation by a regional expert? Physicians in practice must have a pathway to adopt new technology whether it is thoracic ultrasound or endobronchial ultrasound, but it must be done in a safe manner. As a referring physician, I would only send my patients who required mediastinal staging to a pulmonologist who I knew performed EBUS regularly.

Nitin Puri, MD, FCCP

Endobronchial ultrasound (EBUS) bronchoscopy is a tool that has transformed the diagnosis and staging of lung cancer. Through real-time ultrasound imaging, EBUS provides clear images of lymph nodes and proximal lung masses that can be adequately sampled through transbronchial needle aspiration. EBUS is a minimally invasive, outpatient procedure that can also be used for diagnosing benign disease within the chest. Large studies investigating the use of EBUS for mediastinal staging have shown the procedure to be highly sensitive and specific while harboring an excellent safety profile.¹ As a result, EBUS has essentially replaced mediastinoscopy for the staging of lung cancer.

EBUS bronchoscopy was primarily offered at major academic centers when first released and was performed by physicians who were formally trained in the procedure during interventional pulmonology or thoracic surgery fellowships. Over time, the tool has been adopted by established general pulmonologists without formal training in EBUS. Some of these pulmonologists only develop their skills by attending 1- to 2-day courses, which is insufficient supervision to become competent in this important procedure.

An ongoing debate continues as to how many supervised EBUS bronchoscopies should be performed prior to being considered proficient.² As procedural competence has been associated with the number of EBUS procedures performed, the learning curve required to master EBUS is an important component of proficiency. While most consider learning curves to be variable, evidence produced by Fernandez-Villar and colleagues revealed that EBUS performance continues to improve up to 120 procedures.³ This analysis was performed in unselected consecutive patients based on diagnostic yield, procedure length, number of lymph nodes passes performed in order to obtain adequate samples, and the number of lymph nodes studied per patient. The learning curve was evaluated based on consecutive groups of 20 patients, the number of adequate samples obtained, and the diagnostic accuracy. Their results indicated that the diagnostic effectiveness of EBUS-TBNA improves with increasing number of procedures performed, allowing for access to a greater number of lymph nodes without necessarily increasing the length of the procedure, and by reducing the number of punctures at each nodal station. Based on their results, the first 20 procedures performed yielded a 70% accuracy, 21 to 40 procedures performed resulted in 81.8% accuracy, 41 to 60 procedures performed resulted in 83.3% accuracy, 61 to 80 procedures performed resulted in 89.8% accuracy, 81 to 100 procedures performed resulted in 90.5% accuracy, and 101 to 120 procedures performed resulted in 94.5% accuracy.

While the American Thoracic Society (ATS) and the American College of Chest Physicians (CHEST) both recommend a minimum number of 40 to 50 supervised EBUS bronchoscopies prior to performing the procedure independently, along with 20 procedures per year for maintenance of competency, most institutions do not track the number of EBUS procedures performed and they do not follow the ATS or CHEST recommendations.^4,5 As a result, a number of physicians are independently performing EBUS without adequate experience, resulting in possibly poor quality care. Unfortunately, some short courses, intended to generate interest and encourage attendees to pursue further training, are mistakenly assumed to be sufficient by the novice user.

As the number of interventional pulmonary fellowships continues to expand, the growing number of subspecialized pulmonologists with extensive training in EBUS grows. During a dedicated interventional pulmonary fellowship, fellows perform well above the number of EBUS bronchoscopies suggested by the ATS and CHEST in a single year. Recently published accreditation guidelines require a minimum of 100 cases per interventional pulmonary fellow.⁶ These fellowship-trained interventional pulmonologists are then tested to become board-certified in a wide array of minimally invasive procedures, including EBUS. As a result, a model has developed where both board-certified interventional pulmonologists with extensive training in EBUS and general pulmonologists not meeting ATS or CHEST minimum requirements practice at the same institution. Proponents of a more liberal access to credentialing in EBUS have suggested that adhering to competency requirements constitutes a “barrier to entry” in which incumbent practitioners benefit from limiting competition. However, like any other regulatory metric, the rationale is to prevent asymmetric information. In this example, the physician knows more than the patient. The patient cannot make an informed decision on which provider to choose and what are the minimum requirements that are likely to produce the most useful information (ie, complete staging). For these reasons, it is imperative that regulations protect the patient.

Without question, EBUS bronchoscopy should not be performed only by board-certified interventional pulmonologists. Instead, hospital credentialing committees should adhere to both the ATS and CHEST recommendations for the number of supervised cases necessary prior to performing EBUS independently. As EBUS use continues to grow, fellows in 3- or 4-year pulmonary and critical care fellowships will be likely capable of meeting the minimal number of observed cases, but, if these numbers are not achieved, additional training should be required. Understandably, this could be challenging for physicians who are unable to take time away from their practice to gain this training. However, if these numbers cannot be met, credentialing requirements should be enforced.

Even more challenging than establishing quality measures for EBUS, is to ensure the highest level of care delivery for patients when there exist multiple levels of experience in the same institution. Undoubtedly, patients undergoing EBUS bronchoscopy, or any procedure for that matter, would want the most skilled physician who has attained certification in the procedure. Unfortunately, no formal certification of EBUS exists outside of gaining board certification in interventional pulmonology. To ensure excellence in care, physicians performing EBUS should be involved in quality improvement initiatives and review pathologic yields along with complications on a regular basis in a group setting. Unlike emergency interventions, EBUS bronchoscopy is an entirely elective procedure.

The advent of EBUS bronchoscopy has revolutionized the diagnosis and staging of lung cancer. As use of EBUS continues to become more widespread, the incidence of high volume and low volume proceduralists will become a more commonly encountered scenario. Guidelines have been set by the professional pulmonary societies based on the data and observations available. At the local level, stringent guidelines need to be established by hospitals to ensure a high level of quality with appropriate oversight. Patients undergoing EBUS deserve a physician who is skilled in the procedure and has performed at least the minimum number of procedures to provide the adequate care.



Dr. Mahajan is Medical Director, Interventional Pulmonology, Inova Heart and Vascular Institute - Inova Fairfax Hospital, and Associate Professor, Virginia Commonwealth Medical School; Dr. Khandhar is Medical Director, Thoracic Surgery, Inova Heart and Vascular Institute - Inova Fairfax Hospital, and Assistant Clinical Professor, Virginia Commonwealth Medical School; Falls Church, VA. Dr. Folch is Co-Director, Interventional Pulmonology Chief, Complex Chest Diseases Center, Harvard Medical School, Massachusetts General Hospital, Boston, MA.

References

1. Gomez M, Silvestri GA. Endobronchial ultrasound for the diagnosis and staging of lung cancer. Proc Am Thorac Soc. 2009;6(2):180-186.

2. Folch E, Majid A. Point: Are >50 Supervised Procedures Required to Develop Competency in Performing Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Mediastinal Staging? Yes. Chest. 2013;143(4):888-891.

3. Fernandez-Villar A, Leiro-Fernandez V, Botana-Rial M, Represas-Represas C, Nunez-Delgado M. The endobronchial ultrasound-guided transbronchial needle biopsy learning curve for mediastinal and hilar lymph node diagnosis. Chest. 2012; 141(1):278-279.

4. Ernst A, Silvestri GA, Johnstone D. Interventional pulmonary procedures: Guidelines from the American College of Chest Physicians. Chest. 2003;123(5):1693-1717.

5. Bolliger CT, Mathur PN, Beamis JF, et al. ERS/ATS statement on interventional pulmonology. European Respiratory Society/American Thoracic Society. Eur Respir J. 2002;19(2):356-373.

6. Mullon JJ, Burkhart KM, Silvestri G. Interventional Pulmonology Fellowship Accreditation Standards: Executive Summary of the Multi-society Interventional Pulmonology Fellowship Accreditation Committee. Chest. 2017. doi:10.1016/j.chest.2017.01.024.

Dr. Mahajan and colleagues present a compelling case for requiring minimum standards to perform an EBUS-guided bronchoscopy. Their opinion piece epitomizes the classic tension between physicians with advanced training and those who can only have practice-based training. A middle ground may exist, as perhaps competence could be achieved by simulation, clinical cases performed, and observation by a regional expert? Physicians in practice must have a pathway to adopt new technology whether it is thoracic ultrasound or endobronchial ultrasound, but it must be done in a safe manner. As a referring physician, I would only send my patients who required mediastinal staging to a pulmonologist who I knew performed EBUS regularly.

Nitin Puri, MD, FCCP

Endobronchial ultrasound (EBUS) bronchoscopy is a tool that has transformed the diagnosis and staging of lung cancer. Through real-time ultrasound imaging, EBUS provides clear images of lymph nodes and proximal lung masses that can be adequately sampled through transbronchial needle aspiration. EBUS is a minimally invasive, outpatient procedure that can also be used for diagnosing benign disease within the chest. Large studies investigating the use of EBUS for mediastinal staging have shown the procedure to be highly sensitive and specific while harboring an excellent safety profile.¹ As a result, EBUS has essentially replaced mediastinoscopy for the staging of lung cancer.

EBUS bronchoscopy was primarily offered at major academic centers when first released and was performed by physicians who were formally trained in the procedure during interventional pulmonology or thoracic surgery fellowships. Over time, the tool has been adopted by established general pulmonologists without formal training in EBUS. Some of these pulmonologists only develop their skills by attending 1- to 2-day courses, which is insufficient supervision to become competent in this important procedure.

An ongoing debate continues as to how many supervised EBUS bronchoscopies should be performed prior to being considered proficient.² As procedural competence has been associated with the number of EBUS procedures performed, the learning curve required to master EBUS is an important component of proficiency. While most consider learning curves to be variable, evidence produced by Fernandez-Villar and colleagues revealed that EBUS performance continues to improve up to 120 procedures.³ This analysis was performed in unselected consecutive patients based on diagnostic yield, procedure length, number of lymph nodes passes performed in order to obtain adequate samples, and the number of lymph nodes studied per patient. The learning curve was evaluated based on consecutive groups of 20 patients, the number of adequate samples obtained, and the diagnostic accuracy. Their results indicated that the diagnostic effectiveness of EBUS-TBNA improves with increasing number of procedures performed, allowing for access to a greater number of lymph nodes without necessarily increasing the length of the procedure, and by reducing the number of punctures at each nodal station. Based on their results, the first 20 procedures performed yielded a 70% accuracy, 21 to 40 procedures performed resulted in 81.8% accuracy, 41 to 60 procedures performed resulted in 83.3% accuracy, 61 to 80 procedures performed resulted in 89.8% accuracy, 81 to 100 procedures performed resulted in 90.5% accuracy, and 101 to 120 procedures performed resulted in 94.5% accuracy.

While the American Thoracic Society (ATS) and the American College of Chest Physicians (CHEST) both recommend a minimum number of 40 to 50 supervised EBUS bronchoscopies prior to performing the procedure independently, along with 20 procedures per year for maintenance of competency, most institutions do not track the number of EBUS procedures performed and they do not follow the ATS or CHEST recommendations.^4,5 As a result, a number of physicians are independently performing EBUS without adequate experience, resulting in possibly poor quality care. Unfortunately, some short courses, intended to generate interest and encourage attendees to pursue further training, are mistakenly assumed to be sufficient by the novice user.

As the number of interventional pulmonary fellowships continues to expand, the growing number of subspecialized pulmonologists with extensive training in EBUS grows. During a dedicated interventional pulmonary fellowship, fellows perform well above the number of EBUS bronchoscopies suggested by the ATS and CHEST in a single year. Recently published accreditation guidelines require a minimum of 100 cases per interventional pulmonary fellow.⁶ These fellowship-trained interventional pulmonologists are then tested to become board-certified in a wide array of minimally invasive procedures, including EBUS. As a result, a model has developed where both board-certified interventional pulmonologists with extensive training in EBUS and general pulmonologists not meeting ATS or CHEST minimum requirements practice at the same institution. Proponents of a more liberal access to credentialing in EBUS have suggested that adhering to competency requirements constitutes a “barrier to entry” in which incumbent practitioners benefit from limiting competition. However, like any other regulatory metric, the rationale is to prevent asymmetric information. In this example, the physician knows more than the patient. The patient cannot make an informed decision on which provider to choose and what are the minimum requirements that are likely to produce the most useful information (ie, complete staging). For these reasons, it is imperative that regulations protect the patient.

Without question, EBUS bronchoscopy should not be performed only by board-certified interventional pulmonologists. Instead, hospital credentialing committees should adhere to both the ATS and CHEST recommendations for the number of supervised cases necessary prior to performing EBUS independently. As EBUS use continues to grow, fellows in 3- or 4-year pulmonary and critical care fellowships will be likely capable of meeting the minimal number of observed cases, but, if these numbers are not achieved, additional training should be required. Understandably, this could be challenging for physicians who are unable to take time away from their practice to gain this training. However, if these numbers cannot be met, credentialing requirements should be enforced.

Even more challenging than establishing quality measures for EBUS, is to ensure the highest level of care delivery for patients when there exist multiple levels of experience in the same institution. Undoubtedly, patients undergoing EBUS bronchoscopy, or any procedure for that matter, would want the most skilled physician who has attained certification in the procedure. Unfortunately, no formal certification of EBUS exists outside of gaining board certification in interventional pulmonology. To ensure excellence in care, physicians performing EBUS should be involved in quality improvement initiatives and review pathologic yields along with complications on a regular basis in a group setting. Unlike emergency interventions, EBUS bronchoscopy is an entirely elective procedure.

The advent of EBUS bronchoscopy has revolutionized the diagnosis and staging of lung cancer. As use of EBUS continues to become more widespread, the incidence of high volume and low volume proceduralists will become a more commonly encountered scenario. Guidelines have been set by the professional pulmonary societies based on the data and observations available. At the local level, stringent guidelines need to be established by hospitals to ensure a high level of quality with appropriate oversight. Patients undergoing EBUS deserve a physician who is skilled in the procedure and has performed at least the minimum number of procedures to provide the adequate care.



Dr. Mahajan is Medical Director, Interventional Pulmonology, Inova Heart and Vascular Institute - Inova Fairfax Hospital, and Associate Professor, Virginia Commonwealth Medical School; Dr. Khandhar is Medical Director, Thoracic Surgery, Inova Heart and Vascular Institute - Inova Fairfax Hospital, and Assistant Clinical Professor, Virginia Commonwealth Medical School; Falls Church, VA. Dr. Folch is Co-Director, Interventional Pulmonology Chief, Complex Chest Diseases Center, Harvard Medical School, Massachusetts General Hospital, Boston, MA.

References

1. Gomez M, Silvestri GA. Endobronchial ultrasound for the diagnosis and staging of lung cancer. Proc Am Thorac Soc. 2009;6(2):180-186.

2. Folch E, Majid A. Point: Are >50 Supervised Procedures Required to Develop Competency in Performing Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Mediastinal Staging? Yes. Chest. 2013;143(4):888-891.

3. Fernandez-Villar A, Leiro-Fernandez V, Botana-Rial M, Represas-Represas C, Nunez-Delgado M. The endobronchial ultrasound-guided transbronchial needle biopsy learning curve for mediastinal and hilar lymph node diagnosis. Chest. 2012; 141(1):278-279.

4. Ernst A, Silvestri GA, Johnstone D. Interventional pulmonary procedures: Guidelines from the American College of Chest Physicians. Chest. 2003;123(5):1693-1717.

5. Bolliger CT, Mathur PN, Beamis JF, et al. ERS/ATS statement on interventional pulmonology. European Respiratory Society/American Thoracic Society. Eur Respir J. 2002;19(2):356-373.

6. Mullon JJ, Burkhart KM, Silvestri G. Interventional Pulmonology Fellowship Accreditation Standards: Executive Summary of the Multi-society Interventional Pulmonology Fellowship Accreditation Committee. Chest. 2017. doi:10.1016/j.chest.2017.01.024.

Dr. Mahajan and colleagues present a compelling case for requiring minimum standards to perform an EBUS-guided bronchoscopy. Their opinion piece epitomizes the classic tension between physicians with advanced training and those who can only have practice-based training. A middle ground may exist, as perhaps competence could be achieved by simulation, clinical cases performed, and observation by a regional expert? Physicians in practice must have a pathway to adopt new technology whether it is thoracic ultrasound or endobronchial ultrasound, but it must be done in a safe manner. As a referring physician, I would only send my patients who required mediastinal staging to a pulmonologist who I knew performed EBUS regularly.

Nitin Puri, MD, FCCP

Endobronchial ultrasound (EBUS) bronchoscopy is a tool that has transformed the diagnosis and staging of lung cancer. Through real-time ultrasound imaging, EBUS provides clear images of lymph nodes and proximal lung masses that can be adequately sampled through transbronchial needle aspiration. EBUS is a minimally invasive, outpatient procedure that can also be used for diagnosing benign disease within the chest. Large studies investigating the use of EBUS for mediastinal staging have shown the procedure to be highly sensitive and specific while harboring an excellent safety profile.¹ As a result, EBUS has essentially replaced mediastinoscopy for the staging of lung cancer.

EBUS bronchoscopy was primarily offered at major academic centers when first released and was performed by physicians who were formally trained in the procedure during interventional pulmonology or thoracic surgery fellowships. Over time, the tool has been adopted by established general pulmonologists without formal training in EBUS. Some of these pulmonologists only develop their skills by attending 1- to 2-day courses, which is insufficient supervision to become competent in this important procedure.

An ongoing debate continues as to how many supervised EBUS bronchoscopies should be performed prior to being considered proficient.² As procedural competence has been associated with the number of EBUS procedures performed, the learning curve required to master EBUS is an important component of proficiency. While most consider learning curves to be variable, evidence produced by Fernandez-Villar and colleagues revealed that EBUS performance continues to improve up to 120 procedures.³ This analysis was performed in unselected consecutive patients based on diagnostic yield, procedure length, number of lymph nodes passes performed in order to obtain adequate samples, and the number of lymph nodes studied per patient. The learning curve was evaluated based on consecutive groups of 20 patients, the number of adequate samples obtained, and the diagnostic accuracy. Their results indicated that the diagnostic effectiveness of EBUS-TBNA improves with increasing number of procedures performed, allowing for access to a greater number of lymph nodes without necessarily increasing the length of the procedure, and by reducing the number of punctures at each nodal station. Based on their results, the first 20 procedures performed yielded a 70% accuracy, 21 to 40 procedures performed resulted in 81.8% accuracy, 41 to 60 procedures performed resulted in 83.3% accuracy, 61 to 80 procedures performed resulted in 89.8% accuracy, 81 to 100 procedures performed resulted in 90.5% accuracy, and 101 to 120 procedures performed resulted in 94.5% accuracy.

While the American Thoracic Society (ATS) and the American College of Chest Physicians (CHEST) both recommend a minimum number of 40 to 50 supervised EBUS bronchoscopies prior to performing the procedure independently, along with 20 procedures per year for maintenance of competency, most institutions do not track the number of EBUS procedures performed and they do not follow the ATS or CHEST recommendations.^4,5 As a result, a number of physicians are independently performing EBUS without adequate experience, resulting in possibly poor quality care. Unfortunately, some short courses, intended to generate interest and encourage attendees to pursue further training, are mistakenly assumed to be sufficient by the novice user.

As the number of interventional pulmonary fellowships continues to expand, the growing number of subspecialized pulmonologists with extensive training in EBUS grows. During a dedicated interventional pulmonary fellowship, fellows perform well above the number of EBUS bronchoscopies suggested by the ATS and CHEST in a single year. Recently published accreditation guidelines require a minimum of 100 cases per interventional pulmonary fellow.⁶ These fellowship-trained interventional pulmonologists are then tested to become board-certified in a wide array of minimally invasive procedures, including EBUS. As a result, a model has developed where both board-certified interventional pulmonologists with extensive training in EBUS and general pulmonologists not meeting ATS or CHEST minimum requirements practice at the same institution. Proponents of a more liberal access to credentialing in EBUS have suggested that adhering to competency requirements constitutes a “barrier to entry” in which incumbent practitioners benefit from limiting competition. However, like any other regulatory metric, the rationale is to prevent asymmetric information. In this example, the physician knows more than the patient. The patient cannot make an informed decision on which provider to choose and what are the minimum requirements that are likely to produce the most useful information (ie, complete staging). For these reasons, it is imperative that regulations protect the patient.

Without question, EBUS bronchoscopy should not be performed only by board-certified interventional pulmonologists. Instead, hospital credentialing committees should adhere to both the ATS and CHEST recommendations for the number of supervised cases necessary prior to performing EBUS independently. As EBUS use continues to grow, fellows in 3- or 4-year pulmonary and critical care fellowships will be likely capable of meeting the minimal number of observed cases, but, if these numbers are not achieved, additional training should be required. Understandably, this could be challenging for physicians who are unable to take time away from their practice to gain this training. However, if these numbers cannot be met, credentialing requirements should be enforced.

Even more challenging than establishing quality measures for EBUS, is to ensure the highest level of care delivery for patients when there exist multiple levels of experience in the same institution. Undoubtedly, patients undergoing EBUS bronchoscopy, or any procedure for that matter, would want the most skilled physician who has attained certification in the procedure. Unfortunately, no formal certification of EBUS exists outside of gaining board certification in interventional pulmonology. To ensure excellence in care, physicians performing EBUS should be involved in quality improvement initiatives and review pathologic yields along with complications on a regular basis in a group setting. Unlike emergency interventions, EBUS bronchoscopy is an entirely elective procedure.

The advent of EBUS bronchoscopy has revolutionized the diagnosis and staging of lung cancer. As use of EBUS continues to become more widespread, the incidence of high volume and low volume proceduralists will become a more commonly encountered scenario. Guidelines have been set by the professional pulmonary societies based on the data and observations available. At the local level, stringent guidelines need to be established by hospitals to ensure a high level of quality with appropriate oversight. Patients undergoing EBUS deserve a physician who is skilled in the procedure and has performed at least the minimum number of procedures to provide the adequate care.



Dr. Mahajan is Medical Director, Interventional Pulmonology, Inova Heart and Vascular Institute - Inova Fairfax Hospital, and Associate Professor, Virginia Commonwealth Medical School; Dr. Khandhar is Medical Director, Thoracic Surgery, Inova Heart and Vascular Institute - Inova Fairfax Hospital, and Assistant Clinical Professor, Virginia Commonwealth Medical School; Falls Church, VA. Dr. Folch is Co-Director, Interventional Pulmonology Chief, Complex Chest Diseases Center, Harvard Medical School, Massachusetts General Hospital, Boston, MA.

References

1. Gomez M, Silvestri GA. Endobronchial ultrasound for the diagnosis and staging of lung cancer. Proc Am Thorac Soc. 2009;6(2):180-186.

2. Folch E, Majid A. Point: Are >50 Supervised Procedures Required to Develop Competency in Performing Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Mediastinal Staging? Yes. Chest. 2013;143(4):888-891.

3. Fernandez-Villar A, Leiro-Fernandez V, Botana-Rial M, Represas-Represas C, Nunez-Delgado M. The endobronchial ultrasound-guided transbronchial needle biopsy learning curve for mediastinal and hilar lymph node diagnosis. Chest. 2012; 141(1):278-279.

4. Ernst A, Silvestri GA, Johnstone D. Interventional pulmonary procedures: Guidelines from the American College of Chest Physicians. Chest. 2003;123(5):1693-1717.

5. Bolliger CT, Mathur PN, Beamis JF, et al. ERS/ATS statement on interventional pulmonology. European Respiratory Society/American Thoracic Society. Eur Respir J. 2002;19(2):356-373.

6. Mullon JJ, Burkhart KM, Silvestri G. Interventional Pulmonology Fellowship Accreditation Standards: Executive Summary of the Multi-society Interventional Pulmonology Fellowship Accreditation Committee. Chest. 2017. doi:10.1016/j.chest.2017.01.024.

Treating severe, refractory asthma is an ever-evolving challenge and a major source of frustration for patients and clinicians. Failure of inhaler treatment often results in debilitation of the patient and leads to long-term use of corticosteroids, with their insidious side effects.^1–3

See related article

Most asthma research continues to focus on inhibiting the cytokine cascade to reduce inflammation. However, inflammation is not the only pathophysiologic process underlying asthma.

Bronchial thermoplasty takes a novel approach and offers reason for some optimism.^4–6 The aim of this minimally invasive bronchoscopic procedure is to attenuate bronchoconstriction by reducing airway smooth muscle mass.

In this issue of the Cleveland Clinic Journal of Medicine, Dr. Thomas Gildea and colleagues⁷ review the pathophysiology of asthma and the utility of decreasing airway smooth muscle via bronchial thermoplasty, its logistics, and the clinical trials that led to its approval by the US Food and Drug Administration (FDA) for the treatment of severe refractory asthma.

EVIDENCE FROM CLINICAL TRIALS

After studies in animals showed that bronchial thermoplasty was feasible, several randomized trials in humans—the Asthma Intervention Research (AIR) trial,⁶ the Research in Severe Asthma (RISA) trial,⁸ and the Asthma Intervention Research 2 (AIR2) trial⁹—found that the complication rates were acceptable, quality of life was improved, and health care utilization was reduced after the procedure during a 12- to 36-month period. These study results were essential in paving the way for FDA approval.

AIR2: A randomized controlled trial

The latest study to evaluate bronchial thermoplasty, the AIR2 trial,⁹ was designed with a feature that is used relatively infrequently in trials of invasive procedures: a sham control. A sham procedure can be defined as one performed on control-group participants to ensure that they experience the same incidental effects of the procedure as do participants who actually undergo the procedure.¹⁰

Thus, the patients in the control group received the same medications before and after the procedure, they were taken to the procedure room, and the bronchoscope was actually inserted into their lungs—but thermoplasty was not performed. All of this was done in a double-blind manner: neither the patients nor the physicians caring for them before and after the procedure knew which group they were in.

The aim of this exercise was to reduce bias, namely, the placebo effect, and to reinforce results that depend on subjective symptoms, such as the Asthma Quality of Life Questionnaire (AQLQ) score. Clinical trials in severe asthma are notoriously marred by the placebo effect, resulting in spurious improvements in lung function and symptoms.

The AIR2 trial found a significant reduction in severe exacerbations and emergency department visits, and a clinically meaningful improvement in AQLQ score from baseline at 6, 9, and 12 months in the bronchial thermoplasty group. However, 16 patients needed to be hospitalized after the procedure in the bronchial thermoplasty group, compared with two patients in the sham-procedure group.

The AIR2 trial, through the use of a sham-procedure control group, was able to minimize multiple forms of bias and thus provides the most reliable data for clinicians to extrapolate the good and the bad effects of bronchial thermoplasty.

THE PROCEDURE IS STILL IN ITS INFANCY

With any new therapy, we need to look at the benefits and complications not only in the short term but also the long term, ie, to determine whether the benefit is sustainable.

Long-term data on the benefits and side effects of bronchial thermoplasty have yet to be reported. However, radiofrequency ablation has been used in lung cancer therapy during the past decade, with favorable periprocedure complication profiles. Additionally, 5-year follow-up data have shown superior outcomes in stage I non-small-cell lung cancer survival rates with radiofrequency ablation compared with external-beam radiation.¹¹

Ongoing studies will eventually provide insight on long-term outcomes of bronchial thermoplasty in asthma patients. Until such time, patients who have reached the limits of step-up therapy for severe refractory asthma should be informed that clinicians do not yet have a complete understanding of clinical benefits or sustainability of thermoplasty. Still, confidence in bronchial thermoplasty should be grounded in the simplicity of the procedure, the low short-term complication rates, and the long-term success of comparable medical procedures such as radiofrequency ablation in lung cancer, which utilizes similar technology.

Although this procedure is still in its infancy, the potential for long-term effectiveness in improving pulmonary function and quality of life in patients with severe asthma are undeniable. The body of data supporting its use will continue to evolve and hopefully point the way to better control of severe refractory asthma.

Treating severe, refractory asthma is an ever-evolving challenge and a major source of frustration for patients and clinicians. Failure of inhaler treatment often results in debilitation of the patient and leads to long-term use of corticosteroids, with their insidious side effects.^1–3

See related article

Most asthma research continues to focus on inhibiting the cytokine cascade to reduce inflammation. However, inflammation is not the only pathophysiologic process underlying asthma.

Bronchial thermoplasty takes a novel approach and offers reason for some optimism.^4–6 The aim of this minimally invasive bronchoscopic procedure is to attenuate bronchoconstriction by reducing airway smooth muscle mass.

In this issue of the Cleveland Clinic Journal of Medicine, Dr. Thomas Gildea and colleagues⁷ review the pathophysiology of asthma and the utility of decreasing airway smooth muscle via bronchial thermoplasty, its logistics, and the clinical trials that led to its approval by the US Food and Drug Administration (FDA) for the treatment of severe refractory asthma.

EVIDENCE FROM CLINICAL TRIALS

After studies in animals showed that bronchial thermoplasty was feasible, several randomized trials in humans—the Asthma Intervention Research (AIR) trial,⁶ the Research in Severe Asthma (RISA) trial,⁸ and the Asthma Intervention Research 2 (AIR2) trial⁹—found that the complication rates were acceptable, quality of life was improved, and health care utilization was reduced after the procedure during a 12- to 36-month period. These study results were essential in paving the way for FDA approval.

AIR2: A randomized controlled trial

The latest study to evaluate bronchial thermoplasty, the AIR2 trial,⁹ was designed with a feature that is used relatively infrequently in trials of invasive procedures: a sham control. A sham procedure can be defined as one performed on control-group participants to ensure that they experience the same incidental effects of the procedure as do participants who actually undergo the procedure.¹⁰

Thus, the patients in the control group received the same medications before and after the procedure, they were taken to the procedure room, and the bronchoscope was actually inserted into their lungs—but thermoplasty was not performed. All of this was done in a double-blind manner: neither the patients nor the physicians caring for them before and after the procedure knew which group they were in.

The aim of this exercise was to reduce bias, namely, the placebo effect, and to reinforce results that depend on subjective symptoms, such as the Asthma Quality of Life Questionnaire (AQLQ) score. Clinical trials in severe asthma are notoriously marred by the placebo effect, resulting in spurious improvements in lung function and symptoms.

The AIR2 trial found a significant reduction in severe exacerbations and emergency department visits, and a clinically meaningful improvement in AQLQ score from baseline at 6, 9, and 12 months in the bronchial thermoplasty group. However, 16 patients needed to be hospitalized after the procedure in the bronchial thermoplasty group, compared with two patients in the sham-procedure group.

The AIR2 trial, through the use of a sham-procedure control group, was able to minimize multiple forms of bias and thus provides the most reliable data for clinicians to extrapolate the good and the bad effects of bronchial thermoplasty.

THE PROCEDURE IS STILL IN ITS INFANCY

With any new therapy, we need to look at the benefits and complications not only in the short term but also the long term, ie, to determine whether the benefit is sustainable.

Long-term data on the benefits and side effects of bronchial thermoplasty have yet to be reported. However, radiofrequency ablation has been used in lung cancer therapy during the past decade, with favorable periprocedure complication profiles. Additionally, 5-year follow-up data have shown superior outcomes in stage I non-small-cell lung cancer survival rates with radiofrequency ablation compared with external-beam radiation.¹¹

Ongoing studies will eventually provide insight on long-term outcomes of bronchial thermoplasty in asthma patients. Until such time, patients who have reached the limits of step-up therapy for severe refractory asthma should be informed that clinicians do not yet have a complete understanding of clinical benefits or sustainability of thermoplasty. Still, confidence in bronchial thermoplasty should be grounded in the simplicity of the procedure, the low short-term complication rates, and the long-term success of comparable medical procedures such as radiofrequency ablation in lung cancer, which utilizes similar technology.

Although this procedure is still in its infancy, the potential for long-term effectiveness in improving pulmonary function and quality of life in patients with severe asthma are undeniable. The body of data supporting its use will continue to evolve and hopefully point the way to better control of severe refractory asthma.

Treating severe, refractory asthma is an ever-evolving challenge and a major source of frustration for patients and clinicians. Failure of inhaler treatment often results in debilitation of the patient and leads to long-term use of corticosteroids, with their insidious side effects.^1–3

See related article

Most asthma research continues to focus on inhibiting the cytokine cascade to reduce inflammation. However, inflammation is not the only pathophysiologic process underlying asthma.

Bronchial thermoplasty takes a novel approach and offers reason for some optimism.^4–6 The aim of this minimally invasive bronchoscopic procedure is to attenuate bronchoconstriction by reducing airway smooth muscle mass.

In this issue of the Cleveland Clinic Journal of Medicine, Dr. Thomas Gildea and colleagues⁷ review the pathophysiology of asthma and the utility of decreasing airway smooth muscle via bronchial thermoplasty, its logistics, and the clinical trials that led to its approval by the US Food and Drug Administration (FDA) for the treatment of severe refractory asthma.

EVIDENCE FROM CLINICAL TRIALS

After studies in animals showed that bronchial thermoplasty was feasible, several randomized trials in humans—the Asthma Intervention Research (AIR) trial,⁶ the Research in Severe Asthma (RISA) trial,⁸ and the Asthma Intervention Research 2 (AIR2) trial⁹—found that the complication rates were acceptable, quality of life was improved, and health care utilization was reduced after the procedure during a 12- to 36-month period. These study results were essential in paving the way for FDA approval.

AIR2: A randomized controlled trial

The latest study to evaluate bronchial thermoplasty, the AIR2 trial,⁹ was designed with a feature that is used relatively infrequently in trials of invasive procedures: a sham control. A sham procedure can be defined as one performed on control-group participants to ensure that they experience the same incidental effects of the procedure as do participants who actually undergo the procedure.¹⁰

Thus, the patients in the control group received the same medications before and after the procedure, they were taken to the procedure room, and the bronchoscope was actually inserted into their lungs—but thermoplasty was not performed. All of this was done in a double-blind manner: neither the patients nor the physicians caring for them before and after the procedure knew which group they were in.

The aim of this exercise was to reduce bias, namely, the placebo effect, and to reinforce results that depend on subjective symptoms, such as the Asthma Quality of Life Questionnaire (AQLQ) score. Clinical trials in severe asthma are notoriously marred by the placebo effect, resulting in spurious improvements in lung function and symptoms.

The AIR2 trial found a significant reduction in severe exacerbations and emergency department visits, and a clinically meaningful improvement in AQLQ score from baseline at 6, 9, and 12 months in the bronchial thermoplasty group. However, 16 patients needed to be hospitalized after the procedure in the bronchial thermoplasty group, compared with two patients in the sham-procedure group.

The AIR2 trial, through the use of a sham-procedure control group, was able to minimize multiple forms of bias and thus provides the most reliable data for clinicians to extrapolate the good and the bad effects of bronchial thermoplasty.

THE PROCEDURE IS STILL IN ITS INFANCY

With any new therapy, we need to look at the benefits and complications not only in the short term but also the long term, ie, to determine whether the benefit is sustainable.

Long-term data on the benefits and side effects of bronchial thermoplasty have yet to be reported. However, radiofrequency ablation has been used in lung cancer therapy during the past decade, with favorable periprocedure complication profiles. Additionally, 5-year follow-up data have shown superior outcomes in stage I non-small-cell lung cancer survival rates with radiofrequency ablation compared with external-beam radiation.¹¹

Ongoing studies will eventually provide insight on long-term outcomes of bronchial thermoplasty in asthma patients. Until such time, patients who have reached the limits of step-up therapy for severe refractory asthma should be informed that clinicians do not yet have a complete understanding of clinical benefits or sustainability of thermoplasty. Still, confidence in bronchial thermoplasty should be grounded in the simplicity of the procedure, the low short-term complication rates, and the long-term success of comparable medical procedures such as radiofrequency ablation in lung cancer, which utilizes similar technology.

Although this procedure is still in its infancy, the potential for long-term effectiveness in improving pulmonary function and quality of life in patients with severe asthma are undeniable. The body of data supporting its use will continue to evolve and hopefully point the way to better control of severe refractory asthma.