Another important issue to be considered is the risk of serious intraoperative (injury of the supradiaphragmatic IVC, the right phrenic nerve, or the phrenic veins) and postoperative (dysfunction of the diaphragm) complications when these types of access are used.
Thereafter, target evaluation of the topography and size of the identified phrenic veins as well as the right phrenic nerve and its branches was performed.
The insertions of the phrenic veins at the level of the supradiaphragmatic IVC were identified only in 4 (11.4%) of 35 patients.
The insertions of these vessels were mainly localized on the anterior half circle of the IVC, with average diameter 2.6 mm (1.0 to 6.0 mm), and well visualized during diaphragmotomy The inflow of the phrenic veins on the posterior half circle of the IVC was much less frequent.
Despite the distinct advantages of this approach (direct access to the right atrium and intrapericardial segment of the inferior vena cava, the minimum probability of damage to the phrenic veins and right phrenic nerve), there are certain problems associated with its use.
They demonstrate relative safety in terms of possible damage to the phrenic veins for longitudinal approaches to the supradiaphragmatic IVC either with opening of the pericardium or without.
Then the length and width of the supradiaphragmatic IVC as well as the size and topography of the phrenic vein insertions were assessed.