Utilizing the Retrograde Flow of Internal Mammary Vessels as a Donor Pedicle.

 The aim of this study is to assess the results of retrograde flow of internal mammary artery and vein (IMA/V) as a donor vessel for free flap microvascular anastomosis (MVA). This need arises with bipedicle deep inferior epigastric perforator (DIEP) flaps, when all four zones with extra fat need to be harvested for unilateral breast reconstruction coupled with poor midline crossover of circulation naturally or because of midline scar. Large anterolateral thigh flaps for chest wall cover, with multiple perforators from separate pedicles, also need supercharging. This needs an additional source of donor vessels, antegrade IMA/V being the first one.  Retrospective study of microvascular breast reconstruction using retrograde internal mammary donor vessels.  Out of 35 cases, 20 cases had distal IMA/V, with retrograde flow, as donor vessel for second set of arterial and venous anastomosis. In two cases, retrograde IMA/V was used for the solitary set of MVA. In remaining 13 cases, either retrograde IMA or V was utilized either as a principal or accessory donor. No flap was lost. Venous and arterial insufficiency happened in one case each, both were salvaged. Two cases developed partial necrosis, needing debridement and suturing. One case developed marginal necrosis. Only one case developed fat necrosis with superadded infection on follow-up.  Distal end of IMA and IMV on retrograde flow is safe for MVA as an additional or sole pedicle. It is convenient to use being in the same field. It enables preservation of other including thoracodorsal pedicle and latissimus dorsi flap for use in case of a complication or recurrence.