When the internal mammary system is not available, laterally based pedicles such as the thoracodorsal system, the lateral thoracic artery and vein, the serratus system, or even the subscapular system can be used.5–8 This sometimes leads to suboptimal flap orientation because of pedicle length issues.
After axilla dissection or radiotherapy, the axillary vessels can be damaged or scarred, complicating dissection. In our experience, microsurgery to the internal mammary system is usually more comfortable than working in the axilla, for both surgeon and assistant. It usually allows for easy positioning of the flap.
Sometimes, a large internal mammary artery perforator is found large enough to perfuse a flap. This is mostly a coincidental intraoperative finding, and we do not recommend relying on preoperative computed tomographic scanning for assessment of their possible use for microsurgical anastomosis. Internal mammary artery perforators have an inconsistent anatomy and run very superficial in the breast skin, meaning they could be damaged during mastectomy.4
A third alternative is performing a flap-to-flap anastomosis, with one DIEP flap pedicle (artery and/or vein) serving as the recipient for the second DIEP flap.5,6 This flap-to-flap anastomosis is a technique we performed quite often for the veins but try to avoid for the arteries, as this relies on a single inflow source for perfusion of both flaps. We believe this is better avoided if alternatives are available.
Internal mammary vessel dissection creates a small window-shaped defect at the upper chest wall. Costal cartilage resection and muscle damage can lead to postoperative pain and sometimes even a visible depression. Although more and more surgeons try to avoid resecting cartilage, it is sometimes necessary for good exposure and comfortable microsurgery. Obviating the need for a bilateral costal cartilage resection in bilateral DIEP flap breast reconstructions might give patients more comfort and less postoperative pain, but we do not yet have data to back this suspicion.
Breast cancer and coronary artery disease are leading causes of mortality in women.17 There is no way of precisely estimating both conditions occurring in the same patient, and reports vary from an incidence of 0.8 percent18 to a number needed to treat to save one internal mammary artery for later coronary artery bypass grafting being 61.19–21 Both diseases are surgically treatable, but the gold standard procedures—DIEP flap breast reconstruction and internal mammary artery–based coronary artery bypass grafting—both rely on the internal mammary artery as an arterial conduit. In our study population, two of the 125 treated patients underwent successful left internal mammary artery coronary bypass surgery during the follow-up period. This is perfectly in line with the number needed to treat reported by Rozen et al.21
Experience with bipedicled DIEP flaps and stacked flaps for unilateral breast reconstruction in large-breasted women has shown the value of the retrograde internal mammary artery.10,12,13,22 Stalder et al. performed intraluminal pressure measurements in 15 retrograde internal mammary arteries and veins and found systolic pressure in the retrograde flow internal mammary artery to be 64.1 percent of systemic systolic pressure. Diastolic blood pressure was 87.3 percent of systemic measurements.13 Although these values are somewhat lower than those measured in the anterograde flow internal mammary artery, our data suggest the blood flow through the retrograde internal mammary artery suffices for autonomous flap perfusion. Studies have shown that arterial flow through a free flap pedicle can increase after anastomosis and adapts to flap requirements.23,24 The pressures measured in the retrograde internal mammary vein were comparable to the central venous pressure.
The technique of performing both flap anastomoses to one side of the sternum might seem complicated or tedious. In practice, both the anterograde and retrograde internal mammary arteries are usually available, and the microsurgical skill required for this procedure is comparable to the conventional technique. Looking over the records of all bilateral DIEP flap patients from the senior authors (K.V.L., S.D.A., and F.S.), we identified four patients with inadequate internal mammary vessels that necessitated conversion to the conventional technique of bilateral internal mammary anastomosis (four or 129). It is imperative that, during flap harvest, the deep inferior epigastric artery and vein are dissected up to their origin in the groin. Several arterial and venous side branches are usually available for flap-to-flap anastomosis and can serve as a lifeboat whenever needed. The flap failure rate reported in this series is nine total failures of 250 free flaps, which is 3.6 percent, and not higher than the reported failure rates for bilateral breast reconstructions.25
It is important to stress that conversion to the conventional technique with flap anastomosis on both sides of the sternum is always possible. Conversion is advised whenever the flow through the retrograde internal mammary artery is deemed insufficient, whenever the veins available are of poor quality, or in cases of revision. To facilitate a possible conversion, the contralateral flap is routinely connected to the retrograde vessels. We do not recommend an arterial flap-to-flap anastomosis to the novice surgeon, as problems with a single inflow source for two flaps will lead to bilateral flap failure.
The bilateral DIEP flap is our first-choice autologous breast reconstruction in most cases. Our data suggest that the retrograde distal internal mammary artery is reliable for autonomous free flap perfusion and that subcutaneous tunneling of a free flap pedicle does not predispose to flap failure. Anastomosing both flaps to one set of mammary vessels might reduce chest morbidity postoperatively; however, more importantly, it safeguards the left internal mammary artery for cardiac surgery, should this be needed later in life.
1. Murphy BD, Kerrebijn I, Farhadi J, Masia J, Hofer SOP. Indications and controversies for abdominally-based complete autologous tissue breast reconstruction. Clin Plast Surg. 2018;45:83–91.
2. Atisha DM, Rushing CN, Samsa GP, et al. A national snapshot of satisfaction with breast cancer procedures. Ann Surg Oncol. 2015;22:361–369.
3. Niddam J, Bosc R, Lange F, et al. DIEP flap for breast reconstruction: Retrospective evaluation of patient satisfaction on abdominal results. J Plast Reconstr Aesthet Surg. 2014;67:789–796.
4. Munhoz AM, Ishida LH, Montag E, et al. Perforator flap breast reconstruction using internal mammary perforator branches as a recipient site: An anatomical and clinical analysis. Plast Reconstr Surg. 2004;114:62–68.
5. Hamdi M, Khuthaila DK, Van Landuyt K, Roche N, Monstrey S. Double-pedicle abdominal perforator free flaps for unilateral breast reconstruction: New horizons in microsurgical tissue transfer to the breast. J Plast Reconstr Aesthet Surg. 2007;60:904–912; discussion 913–914.
6. DellaCroce FJ, Sullivan SK, Trahan C. Stacked deep inferior epigastric perforator flap breast reconstruction: A review of 110 flaps in 55 cases over 3 years. Plast Reconstr Surg. 2011;127:1093–1099.
7. Agarwal JP, Gottlieb LJ. Double pedicle deep inferior epigastric perforator/muscle-sparing TRAM flaps for unilateral breast reconstruction. Ann Plast Surg. 2007;58:359–363.
8. Ali RS, Garrido A, Ramakrishnan V. Stacked free hemi-DIEP flaps: A method of autologous breast reconstruction in a patient with midline abdominal scarring. Br J Plast Surg. 2002;55:351–353.
9. Chan RK, Przylecki W, Guo L, Caterson SA. Case report: The use of both antegrade and retrograde internal mammary vessels in a folded, stacked deep inferior epigastric artery perforator flap. Eplasty 2010;10:e32.
10. Mayo JL, Allen RJ, Sadeghi A. Four-flap breast reconstruction: Bilateral stacked DIEP and PAP flaps. Plast Reconstr Surg Glob Open 2015;3:e383.
11. Nezic D, Antonic Z, Bojovic Z, et al. How to use the left internal thoracic artery which has been damaged during harvesting? Ann Thorac Surg. 2012;94:269–271.
12. Rosa JH, Sherif RD, Torina PJ, Harmaty MA. Use of both antegrade and retrograde internal mammary vessels in the bipedicled deep inferior epigastric perforator flap for unilateral breast reconstruction. J Plast Reconstr Aesthet Surg. 2017;70:47–53.
13. Stalder MW, Lam J, Allen RJ, Sadeghi A. Using the retrograde internal mammary system for stacked perforator flap breast reconstruction: 71 breast reconstructions in 53 consecutive patients. Plast Reconstr Surg. 2016;137:265e–277e.
14. Blechman KM, Broer PN, Tanna N, Ireton JE, Ahn CY, Allen RJ. Stacked profunda artery perforator flaps for unilateral breast reconstruction: A case report. J Reconstr Microsurg. 2013;29:631–634.
15. Salgarello M, Visconti G, Barone-Adesi L, Cina A. The retrograde limb of internal mammary vessels as reliable recipient vessels in DIEP flap breast reconstruction: A clinical and radiological study. Ann Plast Surg. 2015;74:447–453.
16. Al-Dhamin A, Bissell MB, Prasad V, Morris SF. The use of retrograde limb of internal mammary vein in autologous breast reconstruction with DIEAP flap: Anatomical and clinical study. Ann Plast Surg. 2014;72:281–284.
17. World Health Organization. The Global Burden of Disease: 2004 Update. 2008.Geneva: World Health Organization.
18. Nahabedian MY. The internal mammary artery and vein as recipient vessels for microvascular breast reconstruction: Are we burning a future bridge? Ann Plast Surg. 2004;53:311–316.
19. Apostolides JG, Magarakis M, Rosson GD. Preserving the internal mammary artery: End-to-side microvascular arterial anastomosis for DIEP and SIEA flap breast reconstruction. Plast Reconstr Surg. 2011;128:225e–232e.
20. Follmar KE, Prucz RB, Manahan MA, Magarakis M, Rad AN, Rosson GD. Internal mammary intercostal perforators instead of the true internal mammary vessels as the recipient vessels for breast reconstruction. Plast Reconstr Surg. 2011;127:34–40.
21. Rozen WM, Ye X, Guio-Aguilar PL, et al. Autologous microsurgical breast reconstruction and coronary artery bypass grafting: An anatomical study and clinical implications. Breast Cancer Res Treat. 2012;134:181–198.
22. Hernandez Rosa J, Sherif RD, Torina PJ, Harmaty MA. Use of both antegrade and retrograde internal mammary vessels in the bipedicled deep inferior epigastric perforator flap for unilateral breast reconstruction. J Plast Reconstr Aesthet Surg. 2017;70:47–53.
23. Lorenzetti F, Salmi A, Ahovuo J, Tukiainen E, Asko-Seljavaara S. Postoperative changes in blood flow in free muscle flaps: A prospective study. Microsurgery 1999;19:196–199.
24. Lorenzetti F, Suominen S, Tukiainen E, et al. Evaluation of blood flow in free microvascular flaps. J Reconstr Microsurg. 2001;17:163–167.
25. Wade RG, Razzano S, Sassoon EM, Haywood RM, Ali RS, Figus A. Complications in DIEP flap breast reconstruction after mastectomy for breast cancer: A prospective cohort study comparing unilateral versus bilateral reconstructions. Ann Surg Oncol. 2017;24:1465–1474.