How should pulmonary vascular congestion secondary to pectus excavatum be evaluated and managed?

Evaluation and Management of Pulmonary Vascular Congestion Secondary to Pectus Excavatum

Pectus excavatum does not directly cause pulmonary vascular congestion; instead, it causes mechanical cardiac compression and restrictive pulmonary physiology that may mimic or contribute to cardiopulmonary dysfunction requiring systematic evaluation to exclude true cardiac pathology.

Understanding the Pathophysiology

Pectus excavatum creates mechanical effects rather than true pulmonary vascular congestion:

• The deformity causes direct cardiac compression, particularly affecting the right atrium and right ventricle, leading to impaired ventricular strain patterns that improve immediately after surgical correction 1
• Restrictive pulmonary patterns develop with increasing severity of deformity, with patients having a Haller index ≥7 being 4 times more likely to demonstrate FVC ≤80% predicted compared to those with Haller index of 4 2
• Pulmonary perfusion volume is reduced due to cardiac displacement and lung compression, particularly affecting the left lung where cardiac dislocation is most pronounced 3

Initial Evaluation Algorithm

Mandatory Cardiac Assessment

Complete cardiac evaluation is mandatory when genetic syndromes are suspected, particularly connective tissue disorders such as Marfan syndrome or Noonan syndrome 4, 5:

• In Noonan syndrome patients, pectus excavatum may coexist with pulmonary stenosis, requiring evaluation for right ventricular outflow obstruction 6, 5
• In Marfan syndrome patients, thorough aortic assessment is required as pectus excavatum contributes to systemic scoring 4
• Assess for mitral valve prolapse, which can be associated with pectus excavatum, especially in connective tissue syndromes 5

Echocardiographic Evaluation

Transthoracic echocardiography is the primary diagnostic modality for evaluating cardiac function and excluding true pulmonary hypertension 6:

• Measure right ventricular and right atrial size to assess for compression effects 6
• Evaluate pulmonary artery pressure using tricuspid regurgitation velocity to exclude true pulmonary hypertension 6
• Assess for findings consistent with pulmonary hypertension, which would indicate advanced disease with worsened prognosis and suggest pathology beyond mechanical compression 6
• Speckle-tracking strain analysis can detect subclinical ventricular dysfunction, with improvements in RV global longitudinal strain and LV circumferential strain documented immediately after surgical repair 1

Imaging for Severity Assessment

Chest CT with IV contrast provides detailed anatomic assessment when surgical planning requires precise measurements 5:

• Calculate Haller index (transverse diameter divided by anteroposterior diameter) to quantify deformity severity, with values ≥3.25 considered significant 3, 2
• Assess for cardiac migration to the left hemithorax, particularly in patients with kyphoscoliosis, which affects surgical planning 4, 5
• MRI can facilitate surgical planning and is particularly useful for comprehensive evaluation 5

Pulmonary Function Testing

Spirometry and lung volumes are essential to document restrictive physiology 2, 7:

• Expect restrictive patterns (FVC and FEV₁ <80% predicted with FEV₁/FVC >80%) in 14.5% of patients, increasing with deformity severity 2
• Obstructive patterns are rare (<2% of patients), so their presence should prompt evaluation for alternative diagnoses 2
• In osteogenesis imperfecta patients with pectus excavatum, the restrictive pattern may be more severe with ventilatory mechanics altered mainly in the lateral thorax 5

Management Approach

Non-Surgical Management

Low-resistance exercise is recommended to improve chest wall stability by increasing muscle tone 5

Surgical Indications

Surgical correction should be considered when:

• Significant cardiopulmonary dysfunction is documented with Haller index ≥7 and restrictive pulmonary function 2
• Cardiac compression with impaired ventricular strain is demonstrated on echocardiography 1
• Pulmonary perfusion volume is significantly reduced on functional imaging 3

Expected Surgical Outcomes

The Nuss procedure produces immediate improvements in cardiac function 1:

• RV global longitudinal strain improves from -13.5% ± 4.1% to -16.7% ± 4.4% (p < 0.0001) 1
• LV global circumferential strain improves from -18.7% ± 5.7% to -23.5% ± 5.8% (p < 0.0001) 1
• Pulmonary perfusion volume increases by 9-23%, with greatest improvements in the left lung 3
• Improvements in lung function and exercise capacity are reported, along with significant reductions in depression and anxiety 8

Critical Pitfalls to Avoid

• Do not attribute true pulmonary vascular congestion to pectus excavatum alone—findings consistent with pulmonary hypertension indicate advanced cardiac disease requiring separate evaluation 6
• Do not overlook associated genetic syndromes, particularly when planning intervention, as these patients require comprehensive cardiac workup 4, 5
• Do not assume normal echocardiography excludes dysfunction—speckle-tracking strain may reveal subclinical impairment 1
• Be aware that major complications occur in 1-2% of surgical cases, particularly when performed without videothoracoscopy 8