An anatomical study of the full-length phrenic nerve and its blood supply: clinical implications for endoscopic dissection.

For surgeries aimed at the dissection of full-length phrenic nerve, a full appreciation of its trajectory, blood supply and correlation with adjacent anatomical structures is necessary, especially for endoscopic manipulations. A fresh cadaver study was conducted with the purpose of avoiding surgical complications and ensuring further efficacy and efficiency of endoscopic manipulations. Ten fresh adult cadavers were dissected. Special attention was paid to the topography of the origin, the trajectory of the phrenic nerve, and its anatomic communication with the surrounding vessels and organs. In the second side of the cadavers, thoracic endoscopic manipulations and observations were also performed. The full length of the phrenic nerve was 24.6 ± 1.7 and 30.6 ± 1.8 cm on the right and left side, respectively; the blood supply of the phrenic nerve in the thoracic cavity came exclusively from the pericardiacophrenic artery; the distance between the origin of the pericardiacophrenic artery and that of the internal thoracic artery ranged from 0.5 to 5.2 cm on the right side, and from 1.4 to 5.6 cm on the left; most of the pericardiacophrenic veins intermingled with small vessels of pericardium and pleura, forming a venous network and joining the innominate vein. Endoscopic dissection of the thoracic phrenic nerve together with the accompanying pericardiacophrenic artery can be performed. Extreme attention should be paid during surgery to a section of about 6 cm in length of the artery originating from the internal thoracic artery, while the accompanying veins do not require to be spared.