Interventional Pulmonary Medicine¶

Part 7: Disorders of the Respiratory System · Part 7 – Respiratory Disorders · Chapter 310

Key Clinical Points¶

cEBUS is the gold standard for lung cancer staging (sensitivity 90%, specificity 100%) and provides molecular profiling with adequacy rates >95%.
Rigid bronchoscopy is the preferred tool for managing central airway obstruction (CAO) in conjunction with ablative therapies, balloon bronchoplasty, and airway stenting.
Bronchial thermoplasty (BT) improves quality of life and reduces exacerbation rates in severe asthma but does not change FEV1 or airway hyperresponsiveness.
Bronchoscopic lung volume reduction (BLVR) via valve placement offers lower rates of perioperative morbidity and mortality compared to surgical lung volume reduction (SLVR).
Persistent air leak is defined as a nonresolving pneumothorax with an air leak lasting more than 5–7 days.
Airway stents are effective in >90% of patients with CAO but may lead to complications such as migration, mucostasis, infection, and granulation tissue.
The MIST2 trial showed that intrapleural sequential administration of rtPA and DNase allowed >90% of patients to avoid surgery for pleural infections.
Indwelling pleural catheters (IPCs) are as acceptable as chemical pleurodesis for managing symptomatic malignant pleural effusions, effectively relieving dyspnea and reducing hospital stay.
Approximately 50% of lung transplant recipients experience at least one episode of acute rejection in the first year; approximately 50% develop chronic rejection by 5 years.
Donor-derived cell-free DNA is a noninvasive method for detecting allograft dysfunction, particularly in cases of acute and chronic rejection.

DEFINITION & OVERVIEW¶

• Interventional Pulmonary Medicine: A subspecialty of pulmonary and critical care medicine. • Focus Areas: ◦ Thoracic malignancy ◦ Central airway obstruction (CAO) ◦ Pleural disease ◦ Advanced obstructive lung disease (COPD/emphysema and asthma) • Central Airway Obstruction (CAO): ◦ Definition: Obstruction of the trachea, main stem bronchi, bronchus intermedius, and/or lobar bronchi. ◦ Classification: ◦ Intrinsic (endoluminal) ◦ Extrinsic (extraluminal) ◦ Mixed (extraluminal tumor resulting in mass effect and endoluminal involvement)

DIAGNOSTIC BRONCHOSCOPY¶

Endobronchial Ultrasound (cEBUS)¶

• Technology: Flexible bronchoscope combined with ultrasound technology. • Clinical Utility: ◦ Real-time visualization during transbronchial needle aspiration (TBNA) of mediastinal and hilar lymph nodes/masses. ◦ Gold standard for lung cancer staging: Sensitivity 90%, Specificity 100%. ◦ Molecular profiling: Adequacy rates >95% to guide targeted therapies. ◦ Diagnosis of mediastinal and hilar adenopathy in sarcoidosis. • Lymphoma Note: Historically limited utility due to lack of tissue architecture; however, cryobiopsy techniques show promise for providing adequate histopathologic architecture.

Peripheral Bronchoscopy¶

• Purpose: Evaluation of pulmonary nodules and lung masses. ◦ Historical yield: <60%. • Advanced Platforms: ◦ Small or ultrathin bronchoscopes (<4 mm). ◦ Radial-probe endobronchial ultrasound (real-time image of target lesion). ◦ Electromagnetic navigation bronchoscopy (ENB): Uses 3D CT maps for guided navigation. ◦ Robotic-assisted platforms: Enhanced articulation and stability. ◦ Mobile cone beam CT: Allows intraprocedural confirmation of biopsy within the lesion.

THERAPEUTIC BRONCHOSCOPY¶

Central Airway Obstruction (CAO)¶

• Clinical Presentation: ◦ Early: Cough and exertional dyspnea. ◦ Progression: Dyspnea at rest, stridor, respiratory failure, wheezing, hemoptysis, or postobstructive infection. • Management Strategy: ◦ Preferred Tool: Rigid bronchoscopy. ◦ Combined Modalities: Ablative therapies, balloon bronchoplasty, and airway stenting. ◦ Outcome: Significant improvement in quality of life and survival.

Ablative Therapies for CAO¶

• Heat Modalities: Laser, electrocautery, and argon plasma coagulation (APC). ◦ Use: Destroy tumor and provide hemostasis. • Cold Modalities: Cryotherapy. ◦ Use: Destroy tumor, provide hemostasis, or foreign-body removal. • Other Modalities: Brachytherapy (BRT) and photodynamic therapy (PDT). ◦ Note: Delayed therapeutic effect; not suitable for immediate relief of airway obstruction. • Endobronchial Intratumoral Chemotherapy (EITC): ◦ Goal: Improve/maintain patency, potentially eliminating need for radiotherapy. ◦ Status: Not recommended for clinical use in early-stage lung cancer until longitudinal studies demonstrate noninferiority to SBRT.

Bronchoplasty¶

• Method: Balloon or rigid bronchoscope barrel. • Indication: Dilation of stenotic airways or disruption of webs (nonmalignant causes). • Outcome: Immediate relief, but results can be short-lived; often combined with stenting. • Risk: Airway tears if proper techniques are not followed.

Airway Stenting¶

• Indication: Prevent recurrence of CAO from extrinsic compression (malignant/nonmalignant). ◦ Success: Symptomatic relief in >90% of patients. • Complications: Migration, mucostasis, infection, and development of granulation tissue. • Future Tech: First-generation biodegradable stents, 3D printed stents, and drug-coated stents.

Bronchoscopic Therapies for Asthma¶

• Bronchial Thermoplasty (BT): ◦ Target: Severe persistent asthma with maximal medical treatment failure. ◦ Mechanism: Radiofrequency energy to reduce smooth muscle mass. ◦ Clinical Impact: Improved quality of life and reduced exacerbation rates/ER visits; no change in FEV1 or airway hyperresponsiveness.

Bronchoscopic Therapies for COPD¶

• Lung Volume Reduction (LVR): ◦ Evidence: NETT trial showed LVR surgery improves survival and exercise capacity. ◦ Comparison: LVR mimics effects of surgical lung volume reduction (SLVR) in a less invasive fashion. • MIST2 Trial: ◦ Intervention: Intrapleural sequential administration of rtPA and DNase. ◦ Result: Significant radiographic/clinical improvements; >90% of patients avoided surgery. • Other Modalities: Valves, coils, steam, stents, and foam.

PLEURAL INTERVENTIONS¶

Diagnostic Approach¶

Thoracic ultrasound: Initial evaluation of pleural effusion and pneumothorax.
Medical thoracoscopy (pleuroscopy):
Indication: Recurrent exudative pleural effusions.
Yield: >95%.

Management & Treatment¶

Malignant Pleural Effusion:
Option A: Indwelling pleural catheters (IPCs) (equally acceptable to chemical pleurodesis).
Option B: Pleurodesis via talc slurry.
Comparison: IPCs effectively relieve dyspnea, decrease hospital stay, and reduce need for future procedures.
Pleural Infection (Empyema/Complex Parapneumonic):
Step 1: Antibiotics.
Step 2: Drainage of infected space with tube thoracostomy.
Step 3: Surgical decortication (if required).

Persistent Air Leak¶

• Definition: Nonresolving pneumothorax with an air leak lasting more than 5–7 days. • Management: Spiration Valve System (used for post-lobectomy, segmentectomy, or LVR; also used off-label for spontaneous pneumothoraces).

LUNG TRANSPLANTATION MANAGEMENT¶

• Survival Statistics: ◦ Lower survival rates than other solid organs. ◦ 50% experience at least one episode of acute rejection in the first year. ◦ ~50% develop chronic rejection by 5 years post-transplant. • Rejection Types: ◦ Acute Cellular Rejection: - Mechanism: Lymphocytic infiltrate (distal small vessels/capillaries) or lymphocytic bronchiolitis. - Trigger: Often stimulated by infection (e.g., CMV). - Treatment: Augmented oxygenation and immune suppression. ◦ Antibody-mediated Rejection: - Note: Clinical status of allograft dysfunction, including acute and chronic rejection, is increasingly monitored via donor-derived cell-free DNA. • Clinical Considerations: ◦ CLAD (Chronic Lung Allograft Dysfunction): Overarching syndrome of long-term allograft rejection. ◦ Management: Multidisciplinary team required to manage complications like hypertension, diabetes, renal insufficiency, and bone loss.

DIFFERENTIAL DIAGNOSIS¶

Table 310-1: Differential Diagnosis of Central Airway Obstruction • MALIGNANT: ◦ Primary airway carcinoma (Bronchogenic, Carcinoid, Adenoid cystic, Mucoepidermoid) ◦ Metastatic carcinoma to the airway (Renal cell, Breast, Thyroid, Colon) ◦ Sarcoma ◦ Laryngeal carcinoma ◦ Mediastinal tumors • NONMALIGNANT: ◦ Lymphadenopathy ◦ Infectious (e.g., tuberculosis, histoplasmosis) ◦ Relapsing polychondritis ◦ Tracheostomy tubes ◦ Foreign bodies ◦ Granulomatosis with polyangiitis ◦ Hamartomas ◦ Papillomatosis ◦ Tracheomalacia ◦ Idiopathic

INVESTIGATIONS & DIAGNOSIS¶

• cEBUS: ◦ Use: Gold standard for lung cancer staging (90% sens, 100% spec) and molecular profiling (>95% adequacy). ◦ Utility: Diagnosing mediastinal/hilar adenopathy in sarcoidosis. • Peripheral Bronchoscopy Tools: ◦ Radial-probe endobronchial ultrasound. ◦ Electromagnetic navigation bronchoscopy (ENB). ◦ Robotic-assisted platforms. ◦ Mobile cone beam CT scanners. • Thoracic Ultrasound: ◦ Use: Evaluation of pleural effusion and pneumothorax. • Medical Thoracoscopy: ◦ Use: Evaluate recurrent exudative pleural effusions (yield >95%).

PROGNOSIS & COMPLICATIONS¶

• Lung Transplant Survival Predictors (Table 309-3): ◦ Donor Factors: ◦ HCV donor (negative) ◦ Age <70 years ◦ Diagnosis other than pulmonary fibrosis, pulmonary hypertension, sarcoidosis, A1AT ◦ Oxygen requirement <5 L ◦ CI >2 ◦ Outpatient at time of transplant ◦ Preserved recipient eGFR ◦ Total bilirubin <2 ◦ Donor/recipient factors: ◦ Non-female-to-male transplant ◦ Higher levels of HLA matching ◦ Donor/recipient weight ratio >0.7 ◦ Avoidance of unplanned conversion to cardiopulmonary bypass ◦ Decreased ischemic time ◦ Posttransplant Factors: ◦ PaO2/FiO2 >260 at 72 h ◦ Fewer hospitalizations for rejection ◦ Absent need for postoperative ECMO support ◦ Higher center volume • Stent Complications: ◦ Migration, mucostasis, infection, and granulation tissue.

SPECIAL CONSIDERATIONS¶

• Multidisciplinary Care: Essential for lung transplant recipients to manage complex needs (hypertension, diabetes, renal insufficiency, bone loss). • Research Frontiers: ◦ Bronchoscopic ablation of early-stage lung cancer. ◦ Treatment of chronic bronchitis.

KEY PEARLS & HIGH-YIELD POINTS¶

• cEBUS: Gold standard for staging (90% sens, 100% spec) and molecular profiling (>95%). • CAOs: Rigid bronchoscopy is the preferred tool for management. • Bronchial Thermoplasty: Improves QoL/reduces exacerbations in severe asthma; no change in FEV1 or AHR. • BLVR vs SLVR: BLVR via valve placement has lower morbidity/mortality than SLVR. • Persistent Air Leak: Defined as nonresolving pneumothorax >5–7 days. • MIST2 Trial: rtPA and DNase allowed >90% of patients to avoid surgery for pleural infections. • Lung Transplant: ◦ 50% experience acute rejection in year 1. ◦ 50% develop chronic rejection by year 5.

Reference Tables¶

TABLE 309-3 Predictors of Survival After Lung Transplantation Donor factors Recipient factors¶

Harrison's 22e, p.2287

	1-YEAR SURVIVAL	≥10-YEAR SURVIVAL
Donor factors	HCV donor
	Age <70 years Diagnosis other than pulmonary fibrosis, pulmonary hypertension, sarcoidosis, A1AT O requirement <5 L 2 CI >2 Outpatient at time of transplant Preserved recipient eGFR Total bilirubin <2
Donor/recipient factors	Non–female-to-male transplant	Higher levels of HLA matching
	Donor/recipient weight ratio >0.7
	Avoidance of unplanned conversion to cardiopulmonary bypass Decreased ischemic time
Posttransplant factors	PaO/FIO >260 at 72 h 2 2	Fewer hospitalizations for rejection
	Absent need for postoperative ECMO support
	Higher center volume
310	Interventional Pulmonary Medicine Lonny Yarmus, David Feller-Kopman

TABLE 310-1 Differential Diagnosis of Central Airway Obstruction MALIGNANT Primary airway carcinoma Bronchogenic…¶

Harrison's 22e, p.2289

MALIGNANT	NONMALIGNANT
Primary airway carcinoma	Lymphadenopathy
Carcinoid adenoid cystic	Infectious (i.e., tuberculosis, histoplasmosis)
Metastatic carcinoma to the airway	Relapsing polychondritis
Renal cell	Tracheostomy tubes
Thyroid	Foreign bodies
Sarcoma	Granulomatosis with polyangiitis
Laryngeal carcinoma	Hamartomas
Mediastinal tumors	Papillomatosis
Thyroid	Tracheomalacia
Lymphadenopathy	Idiopathic