Bronchoscopy Indications

Bronchoscopy is an endoscopic procedure for direct visualization and sampling of the tracheobronchial tree and lung parenchyma using a flexible or rigid scope; performed by pulmonologists, interventional pulmonologists, and thoracic surgeons; one of the most commonly performed pulmonary procedures with millions of procedures annually worldwide.

Types of bronchoscopy: 1) Flexible bronchoscopy — most common (>95 percent of procedures), uses flexible fiberoptic or video bronchoscope, typically 4-6 mm outer diameter, allows visualization to 5th-7th order bronchi (peripheral lesions require electromagnetic navigation or robotic bronchoscopy), performed under conscious sedation (midazolam, fentanyl) or moderate sedation, oral or nasal route; 2) Rigid bronchoscopy — performed under general anesthesia, allows passage of larger instruments and stents, indications include massive hemoptysis (>600 mL/24h), foreign body retrieval, tumor debulking, large airway stent placement, pediatric airway emergencies; 3) Endobronchial ultrasound (EBUS) — combined ultrasound with bronchoscopy for evaluation of mediastinal lymph nodes and parabronchial structures; convex probe EBUS for mediastinal lymph node sampling (TBNA — transbronchial needle aspiration), radial probe EBUS for peripheral parenchymal lesions; revolutionary advance for lung cancer staging; 4) Electromagnetic navigation bronchoscopy (ENB) — uses electromagnetic position tracking with planning software based on patient CT scan to guide bronchoscope to peripheral pulmonary nodules; 5) Robotic bronchoscopy — newer modality (Ion robotic, Monarch) using flexible robotic catheter system with continuous shape-sensing fiber optics for navigation to small peripheral nodules; 6) Cryobronchoscopy — uses cryoprobe for cryobiopsy (larger tissue samples preserving architecture for ILD diagnosis), cryotherapy for tumor or stenosis treatment, cryoextraction of foreign bodies and large blood clots.

Major diagnostic indications: 1) Hemoptysis — quantity defines management (mild < 100 mL, moderate 100-600 mL, massive > 600 mL/24h); diagnostic bronchoscopy localizes source 70-90 percent of time; therapeutic options include direct interventions (electrocautery, argon plasma coagulation, balloon tamponade with Fogarty), with bronchial artery embolization being primary treatment for massive recurrent hemoptysis; differential diagnosis includes infection (TB, fungal, bacterial), malignancy (lung cancer most common in smokers > 40), bronchiectasis, pulmonary embolism, vasculitis (granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, anti-GBM disease), iatrogenic; 2) Pulmonary nodule and mass evaluation — high-risk nodules (Brock model, NCCN risk calculator suggesting > 5-15 percent malignancy probability) warrant tissue diagnosis; bronchoscopic approach success depends on size and location (central versus peripheral, > 2 cm with bronchus sign), techniques include endobronchial biopsy for visible lesions, transbronchial biopsy with fluoroscopic guidance, navigation bronchoscopy for peripheral lesions, robotic bronchoscopy emerging; 3) Lung cancer staging — EBUS-TBNA revolutionized mediastinal staging with sensitivity 90 percent and specificity 100 percent for malignant lymph node involvement; routine staging includes systematic sampling of N1, N2, and N3 stations; advantages over mediastinoscopy include outpatient procedure, lower morbidity, similar diagnostic yield; 4) Infection evaluation — immunocompromised patients (HIV, transplant, leukemia, chemotherapy, biologic therapy) with new pulmonary infiltrates require bronchoscopy with bronchoalveolar lavage (BAL); BAL fluid analysis includes cell count and differential, Gram stain and culture, fungal stains and culture, AFB stains and culture, viral PCR (CMV, HSV, RSV, influenza), atypical pathogens (PCP via stain or PCR, Legionella, Mycoplasma), Cryptococcus antigen, Aspergillus galactomannan; quantitative cultures with thresholds for pneumonia diagnosis (>10^4 CFU/mL); 5) Interstitial lung disease (ILD) — diagnostic role debated; transbronchial biopsy historically lower yield (30-50 percent) for definitive UIP versus NSIP, but cryobiopsy increases yield; BAL useful for differential cell count (lymphocytic versus neutrophilic versus eosinophilic) suggesting specific disease patterns (sarcoidosis with elevated CD4/CD8 ratio, hypersensitivity pneumonitis with lymphocytosis, eosinophilic pneumonia with high eosinophils, alveolar proteinosis with milky fluid and PAS-positive material); 6) Pediatric foreign body aspiration — rigid bronchoscopy first-line for confirmed cases; 7) Suspected stridor or recurrent pneumonia in same lobe — anatomic abnormality, foreign body, tumor; 8) Persistent atelectasis non-responsive to therapy; 9) Suspected airway tumor; 10) Tracheobronchial trauma and stenosis evaluation.

Therapeutic indications: 1) Hemoptysis control — for moderate to massive bleeding; rigid bronchoscopy for hemodynamic stability and large suctioning, balloon tamponade, electrocautery, argon plasma coagulation, cold saline and epinephrine, plug placement; bronchial artery embolization typically definitive for massive recurrent; 2) Foreign body removal — rigid bronchoscopy first-line in adults and children; flexible bronchoscopy may suffice for soft foreign bodies; cryoextraction useful for organic material like food and aspirated tissue; 3) Tumor debulking and airway tumor management — endobronchial tumor causing obstruction can be debulked with electrocautery, argon plasma coagulation, cryotherapy, neodymium-YAG laser, photodynamic therapy, brachytherapy; goal is restoration of airway patency for symptom relief or radiation therapy/chemotherapy receipt; 4) Airway stent placement — for malignant central airway obstruction (lung cancer compression, esophageal cancer compression, mediastinal masses), benign tracheal or bronchial stenosis (post-intubation, post-tracheostomy, post-radiation, post-transplant), tracheobronchomalacia; stent options include silicone (Y-stents, straight stents — Dumon, Polyflex) requiring rigid bronchoscopy for placement, self-expanding metal stents (Ultraflex, Wallstent) placed flexibly under fluoroscopy; 5) Retained secretion removal — refractory atelectasis with mucus plug; particularly important in ICU patients, post-operative patients, ICU-acquired weakness; 6) Balloon dilation of stenosis — benign tracheal/bronchial stenosis pre-stenting or as definitive therapy; 7) Endobronchial valve placement (Zephyr, Spiration) for severe emphysema causing target-lobe collapse and improved lung function; 8) Bronchial thermoplasty for severe persistent asthma — radiofrequency thermal ablation of airway smooth muscle in three sessions; 9) Foreign body extraction including aspirated tooth fragments after dental procedures, food (peanuts, popcorn, hot dogs in children), broken inhaler parts, pin and needle aspirations; 10) Therapeutic bronchoalveolar lavage for alveolar proteinosis (whole-lung lavage); 11) Endobronchial closure of bronchopleural fistula with sealants, valves; 12) Drug delivery — intra-bronchial chemotherapy (gemcitabine, cisplatin), antimicrobial agents.