Occasionally in breast reconstruction a large portion of the abdominal flap needs to be delivered to the chest either to have significant skin surface area to replace a large defect or a large volume needs to be delivered to re-create the breast.
The stacked DIEP flap has been described to transfer a large portion of the abdominal flap to the chest wall. During my microsurgical study with Dr. Ashjian we have discovered that the venous outflow is a large determinant of flap success with stacked DIEP flaps. There is often more than sufficient arterial blood flow to sustain the volume of fat transferred when using the deep system. This is often evident when the flap is perfusing in situ on the adomen with the deep system connected and the superficial system clamped. Typically, the lateral zones develop congestion when the superficial veins are clipped. When the superficial veins are released there is often blood flow returning from the veins. If there was a lack of arterial blood flow or no connection between the deep and superficial system, then there would be no blood flow from the superficial veins.
Therefore with stacked DIEP flaps, additional venous outflow is needed to accommodate the flap volume. On the left side the venous outflow can be challenging given the traditionally smaller size of the internal mammary vein. The external jugular when mobilized and turned down into the wound can often be short depending on the body habitus of the patient. On occasion the surgeon can be presented with a patient with a short neck and long torso. This makes the reach of the EJ to the flap outflow vein challenging if the flap is already connected to the internal mammary artery. We have used the greater saphenous vein as an extension graft from the EJ to the flap. It is easier to anastomose the greater saphenous vein to the EJ extracorporeally and then pass the graft-EJ anastomosis subcutaneously into the chest.
In some situations, if the superficial epigastric veins have been preserved during flap dissection and are of adequate length, these can be used instead of the greater saphenous vein to lengthen the external jugular vein reach so that venous outflow can be augmented in the flap. This can be very helpful if both SIEVs are preserved during dissection as one can be used to anastomose to the other, offering favorable size match.
When the superficial vein is anastamosed to the external jugular vein, or other adeuate venous drainage system, with the other superficial epigastric vein as an extension graft we have found it possible to maintain almost all of the flap volume for breast reconstrution. We therefore underscore the utility of the superficial venous system in allowing venous egress of the contralateral flap and lateral flap zones.
