What is the frequency of phrenic nerve injury caused by Hypertensive Pulmonary Arterial (HPA) disease?

From the Guidelines

Phrenic nerve injury is a rare complication that is not directly caused by Hypertensive Pulmonary Arterial (HPA) disease, but rather by other factors such as surgical interventions or compression from severely dilated pulmonary arteries in advanced disease. The frequency of phrenic nerve injury specifically caused by HPA disease is not well established in medical literature, as seen in the provided study 1. Phrenic nerve injury is typically related to other factors such as surgical interventions for the disease, catheter-based procedures, or compression from severely dilated pulmonary arteries in advanced disease. Some key points to consider include:

• Phrenic nerve dysfunction can occur in PAH patients due to various factors, but it is not a common direct complication of pulmonary arterial hypertension itself.
• In severe PAH, the main pulmonary artery can become significantly enlarged and potentially compress adjacent structures including the phrenic nerve, but this is considered a rare complication, as noted in the context of coarctation repair complications 1.
• Patients with PAH who develop unexplained dyspnea beyond what would be expected from their PAH severity, or who show diaphragmatic elevation on imaging, should be evaluated for possible phrenic nerve dysfunction.
• Diagnosis typically involves chest radiography, fluoroscopic sniff testing, nerve conduction studies, or diaphragm ultrasound, and management focuses on treating the underlying PAH with appropriate medications while providing supportive care for any respiratory compromise.

From the Research

Frequency of Phrenic Nerve Injury

• The frequency of phrenic nerve injury is not directly related to Hypertensive Pulmonary Arterial (HPA) disease in the provided studies.
• However, the incidence of phrenic nerve injury has been reported in various studies:
  • 2.1% in closed cardiac surgical procedures 2
  • 4% in high mobilization of the right internal mammary artery (RIMA) harvesting 3
• Phrenic nerve injury can result from various causes, including:
  • Iatrogenic injury during surgical procedures 2, 4, 3
  • Trauma 5
  • Neuralgic amyotrophy 6
• The symptoms and treatment of phrenic nerve injury have been discussed in various studies, including:
  • Diagnostic evaluation and treatment options 6
  • Surgical repair and phrenic nerve reconstruction 6
  • Diaphragm plication and other management strategies 2, 4, 3