From the Research
The phrenic nerve runs alongside the pericardiacophrenic vessels, which include the pericardiacophrenic artery and vein, as demonstrated in the most recent and highest quality study 1. The pericardiacophrenic artery is a branch of the internal thoracic artery (also called the internal mammary artery), while the pericardiacophrenic vein drains into the brachiocephalic vein (also known as the innominate vein). These vessels accompany the phrenic nerve as it descends through the thorax between the fibrous pericardium and the mediastinal pleura to reach the diaphragm. This close anatomical relationship is important clinically because surgical procedures or pathological processes affecting these vessels may potentially damage the phrenic nerve, resulting in diaphragmatic paralysis. Additionally, the phrenic nerve receives blood supply from these accompanying vessels, which is crucial for maintaining its function in innervating the diaphragm for respiration. Some studies have also shown that the left phrenic nerve typically courses over the basal region of the anterior interventricular vein, mid region of left marginal veins, and apical region of inferior and middle cardiac veins, with large variation associated with the average angle between nerve and veins 2. However, the most recent study 1 provides the most accurate and detailed description of the blood vessels running alongside the phrenic nerve, making it the most reliable source for clinical decision-making. Key points to consider include:
- The pericardiacophrenic artery is a branch of the internal thoracic artery
- The pericardiacophrenic vein drains into the brachiocephalic vein
- The phrenic nerve receives blood supply from the pericardiacophrenic artery
- Surgical procedures or pathological processes affecting these vessels may potentially damage the phrenic nerve, resulting in diaphragmatic paralysis.