Preoperative evaluation including indications and risk factors

Indications for VATS
 A history of guideline's recommended stage 4–5 (GINA) treatment and adherence to this treatment
 Recurrent exacerbations (>2 per year)
 Systemic corticosteroid treatment (at least 10 mg prednisone-equivalent per day over the past 12 months)
 Attendance at an asthma centre or specialist for at least 6 months
 Atypical presentation:
  Parenchymal alterations in the HRCT (e.g. massive air trapping, ground-glass opacities)
  Increased FeNO or eosinophils despite high doses of systemic corticosteroids
  Need for oxygen treatment or low DLCO (<70% of reference)
  Positive autoantibodies (thyroid, ANAs, ANCAs, lupus anticoagulants or rheumatoid factor)
  Coexisting autoimmune disease
  Positive family history for autoimmune disease
  Unclear differential diagnosis (e.g. EGPA or HSP) (see table 2)
Risk factors for diagnostic VATS
DLCO <35% [83]
 FEV1 <55% [83]
 Immunosuppressive treatment
 Current asthma exacerbation
 Systolic PAP >40 mmHg (patients with signs of pulmonary hypertension should be evaluated by   echocardiography) [84]
  • VATS: video-assisted thoracoscopic surgery; GINA: Global Initiative for Asthma; HRCT: high-resolution computed tomography; FeNO: exhaled nitric oxide fraction; DLCO: diffusing capacity of the lung for carbon monoxide; ANA: anti-nuclear antibodies; ANCA: anti-neutrophil cytoplasmic antibodies; EGPA: eosinophilic granulomatosis with polyangiitis; HSP: hypersensitivity pneumonitis; FEV1: forced expiratory volume in 1 s; PAP: pulmonary arterial pressure.