Diagnostic Approach and Management of Elevated Right Hemidiaphragm
The diagnostic workup for an elevated right hemidiaphragm should begin with chest radiography followed by CT scan as the gold standard for diagnosis, with fluoroscopy used to differentiate between paralysis and eventration. 1, 2
Initial Diagnostic Steps
- Chest X-ray (both anteroposterior and lateral views) is the recommended first diagnostic study to identify the elevated hemidiaphragm, though it has limitations in determining the underlying cause 1
- Suspicious chest X-ray findings include abnormal lucency, soft tissue opacity with mediastinal deviation, or hemidiaphragm elevation 1
- CT scan of chest and abdomen is the gold standard for diagnosis with sensitivity and specificity of 14-82% and 87%, respectively 1
- CT findings may include: diaphragmatic discontinuity, segmental non-recognition of the diaphragm, "dangling diaphragm" sign, "dependent viscera" sign, elevated abdominal organs, and thickened diaphragm 1
Differential Diagnosis
The elevated right hemidiaphragm may be due to:
- Diaphragmatic paralysis (with paradoxical motion on fluoroscopy) 2
- Diaphragmatic eventration (congenital defect without paradoxical motion) 3
- Diaphragmatic hernia (traumatic or non-traumatic) 1
- Post-inflammatory changes (e.g., after COVID-19) 4
- Subdiaphragmatic pathology pushing the diaphragm upward 1
- Phrenic nerve injury 5
Specialized Diagnostic Tests
- Fluoroscopic "sniff test" is crucial to differentiate between paralysis (shows paradoxical upward movement during inspiration) and eventration (no paradoxical motion) 2
- Ultrasonography may be useful, especially in pregnant patients with suspected non-traumatic diaphragmatic hernia 1
- MRI can provide additional information in cases where CT findings are inconclusive 1
Management Approach
For Diaphragmatic Hernia:
- Surgery is the treatment of choice for symptomatic diaphragmatic hernia 1
- In stable patients with traumatic diaphragmatic hernia, laparoscopic approach is strongly recommended (1B evidence) 1
- In unstable patients, laparotomy approach is suggested (2C evidence) 1
- Primary repair with non-absorbable sutures should be attempted when possible 1
- For larger defects (>3 cm), mesh reinforcement is suggested to prevent recurrence (2C evidence) 1
- Biosynthetic, biologic or composite meshes are preferred due to lower recurrence rates and higher resistance to infections (2C evidence) 1
For Diaphragmatic Paralysis or Eventration:
- Diaphragmatic plication is indicated for all symptomatic patients with an elevated diaphragm regardless of whether it's paralysis or eventration 2
- Minimally invasive thoracoscopic plication is the preferred approach for most thoracic surgeons 3
- The goal of plication is to improve lung volumes and decrease paradoxic elevation of the hemidiaphragm 2
- Plication has been shown to significantly improve dyspnea and quality of life in properly selected patients 3
Special Considerations
- In patients with previous thoracic surgery or pneumothorax, consider the possibility of diaphragmatic fenestration with abdominal visceral herniation 6
- In post-COVID-19 patients with persistent respiratory symptoms, diaphragmatic paralysis should be considered as a potential cause 4
- When evaluating chest radiographs, be cautious about misinterpreting subpleural fat as pleural thickening, which can be differentiated by HRCT 1
Pitfalls to Avoid
- Don't assume an elevated hemidiaphragm is always benign or due to phrenic nerve palsy; it may represent herniation of abdominal contents requiring surgical intervention 6
- Avoid misdiagnosing diaphragmatic hernia as simple elevation; look for specific signs on imaging such as the "collar sign" (constriction of herniating organ at the rupture level) 1
- Don't overlook the possibility of malignancy as a cause of diaphragmatic elevation, especially in patients with risk factors for lung cancer 1
- Be aware that normal chest radiographs have been reported in 11-62% of cases with diaphragmatic injuries or uncomplicated diaphragmatic hernias 1