Abstract
Background Additional second vessels may be required to handle multiple flaps used to add breast
volume, boost blood flow for supercharging, or use salvage recipient vessels. In these
situations, retrograde internal mammary vessel flow can be used although this causes
doubts and concerns.
Patients and Methods Forty sides of the chests of 20 fresh cadavers with intact thoracic cages and internal
mammary veins (IMV) were used in the study. IMV valve numbers and locations were checked,
and the bifurcation was confirmed. A retrograde fluorescent angiography and a saline
infusion test were followed to confirm flow direction.
Results Twenty-eight vessels were identified in 40 sides of the chest; of them, 45% had no
valves. A mean 0.7 valves per chest side were identified; 23 (82.1%) of 28 valves
were located above the second intercostal space (ICS). A mean 1.76 communicating veins
were found between the IMV bifurcation. In all cadavers, a crossing vein connecting
the left and right medial IMV was confirmed just below the xiphoid process. Fluorescent
angiography and a saline infusion test proved that the retrograde flow was caudal
through the bifurcated IMV to the communicating, intercostal, and crossing veins.
Conclusion The IMV valve was present in 55% of our subjects and located concentrically above
the second ICS level. It is highly unlikely that the retrograde flow was disturbed
because the retrograde anastomosis level was below the second ICS. Furthermore, the
bifurcation, intercostal, and crossing veins across the xiphoid process enabled valve-less
detour flow. Thus, retrograde IMV flow is considered safe.
Keywords
internal mammary vein - retrograde flow - venous drainage - valve
