Thoracoplasty

Epidemiology

  • Thoracoplasty is currently indicated only to close a persistent pleural space (used in the past to treat TB)
  • Risk factors for increased mortality post-thoracoplasty: preoperative cavitary disease/ previous artificial pneumothoraces on the opposite side/ older age at operation/ male sex
  • Associated with: COPD

Physiology

  • Pulmonary HTN due to chest wall disease (secondary removal or surgical reversal of ribs, resulting in decreased thoracic volume)
  • Hypoventilation leads to hypoxia/ acidosis (with resultant pulmonary vasoconstriction)

Diagnosis

  • ABG: hypoxemia/hypercapnia
    PFT: restrictive pattern (may worsen over time due to progressive scoliosis/ defect is not correlated with extent of thoracoplasty)
    -FEV1: decreased (typical 60% reduction)
    -VC: decreased (about 50% predicted)
    -TLC: decreased (about 65% predicted)
    -RV: relatively preserved (about 90% predicted)
    -FRC: mildly decreased (about 70% predicted)
    -DLCO: decreased (with normal DLCO/VA)
    -MVV: decreased (about 40% predicted)
    -Lung compliance: decreased (due to lung compression by distorted chest wall/ fibrosis of lung due to underlying TB)

Exercise test: decreased exercise capacity (decreased VO2max) due to ventilatory limitation


Clinical

  • Dyspnea
  • Chronic Hypoventilation (see [[Chronic Hypoventilation]])

-Post-surgical chest wall changes
Complications: cor pulmonale/ hypercapnic respir-atory failure


Treatment

  • Treatment of underlying OSA/ obstructive airway disease
  • Nocturnal assisted ventilation: improves both day/ night ventilation

References

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