Distribution of Flaps
The abdominal flaps were distributed almost equally to the right (50.9%) and left (49.1%) sides. On each side, 38 of these flaps were anastomosed to the IMAP (Table 2). In the TMG-flap group, 18 of the right and left sides were anastomosed to an IMAP, respectively. Fifty (56%) of the TMG flaps were performed on the right side and 41 (44%) on the left side. No difference in IMAP distribution was observed (Table 3).
The mean ischemia time was 35 minutes (14–118) in all abdominal flaps. Using an IMAP took 4 minutes longer (39 minutes [15–75]). The mean time for anastomosis of a TMG flap was 39 minutes (18–57). When an IMAP was used, 2 more minutes were needed (41 minutes [20–63]). Anastomosis to an IMAP took slightly longer; however, no large differences between using the IMA or an IMAP could be observed.
The median diameter of the coupling devices in abdominal flaps for venous anastomosis to the internal mammary vein was 2.5 mm (1.5–3.5). When the perforating vein was used, the median diameter was also 2.5 mm.2,3 The median diameter for venous coupling rings in TMG flaps anastomosed to the internal mammary vein was 2.5 mm (1.5–3) as well. However, when the perforating vein was used, the median size reduced to 2 mm (1.5–2.5).
The mean weight of all abdominal flaps anastomosed to the IMA was 587 g (146–1,838). When the IMAP was used, the mean flap weight was 567 g (180–1,173). The mean size of TMG flaps anastomosed to the IMA was 265 g (163–375). When the IMAP was used, they were slightly heavier (mean, 296 g; 185–921).
After breast reconstruction using the IMA, the median time patients stayed in the hospital was 7 days.4–24 When the IMAP was used, the median stay reduced to only 6 days.4–12 After TMG-flap reconstruction, the median stay for both the IMA and the IMAP was 6 days (IMA, 3–10; IMAP, 4–9).
Thirty-nine (34.8%) of all 112 flaps anastomosed to an IMAP had radiation therapy before reconstructive surgery (Table 6). The mean period between radiation and reconstruction was 3.2 years (3 months to 13 years) in abdominal flaps and 2.9 years (10 months to 7 years) for TMG flaps. Thirty-three of these 39 flaps were abdominal flaps and 6 were TMG flaps.
Revision surgery for vascular problems was necessary in 32 cases (6.2%) of all 515 flaps (Table 7). Twenty-eight cases were DIEP flaps, and 4 were TMG flaps. In 22 cases, the perfusion could be improved, and the flap was saved (68.75%). The most common reason for flap revision was venous congestion. In 2 cases, an additional venous anastomosis was performed in the axilla. In 1 case, an additional arterial in-flap anastomosis was performed. Only 2 of the 32 revisions affected an anastomosis to an IMAP. In these cases, perfusion could be salvaged permanently. All other revisions were done in anastomoses to the IMA.
Flap failure occurred in 1.9% (n = 10; DIEP flaps; survival rate, 98.1%) of all flaps. None of these flaps were anastomosed to a perforating vessel.
Mastectomy skin flap necrosis of more than 2 cm2 occurred in 5 cases (0.97%). In these cases, the mastectomy was combined with an inverted T-reduction pattern. Thus, it is more likely to attribute skin flap necrosis to the incision type. Only 1 of these flaps was anastomosed to an IMAP. In 1 patient, a partial flap necrosis of zone IV according to Holm occurred; in another, flap necrosis of zone III occurred.18 Both flaps were anastomosed to IMA vessels.
Palpable fat necrosis that was detectable by ultrasound was observed in 1.6% (n = 7) of all cases (6 DIEP and 1 TMG). Four of those (only DIEP flaps) were anastomosed to an IMAP. Only 1 of the 7 flaps with fat necrosis had radiation therapy before surgery. In this case, an IMAP was used. The mean weight of abdominal flaps anastomosed to an IMAP and developed fat necrosis was 805 g (611–1,028). Abdominal flaps with fat necrosis anastomosed to the IMA had a mean weight of 819 g (587–1,051). In both cases, the mean flap size was larger than the flaps without fat necrosis (abdominal flaps anastomosed to IMA: mean, 587 g; anastomosed to IMAP: mean, 567 g), which could not be observed in the 1 TMG flap that developed fat necrosis (254 g) and which was smaller than the average TMG size (mean, 265 g).
The reason we began to use the IMAPs as recipient vessels was not only to spare the IMA vessels for a future bypass operation but also to facilitate the anastomoses and the fitting of short pedicled flaps (TMG and SIEA flaps) and to be able to dissect DIEP flaps with shorter pedicles. This limits donor-site exploration and may shorten operation times (Fig. 6).12,14,16,19 Initially, the usage of IMAP vessels was not expected in delayed reconstructions. However, thoracic computed tomographic angiography showed that IMAP vessels were still present in patients who had had previous surgery and after radiation therapy.20 We began, therefore, to look for and to use these vessels in secondary surgery as well. Today, imaging is no longer conducted. A cautious dissection to preserve potential vessels is the only action taken to locate an IMAP. The decision for or against using IMAPs was clinical and depended on the surgeon’s preference.
In a total of 112 of 515 cases (22%), IMAP vessels were used for all flaps of both senior surgeons. If all flaps of S2 are taken into account, it rises to 37%. If all delayed reconstructions are left aside and attention is just paid to immediate reconstructions, it rises further to 46%.
In other studies, these numbers vary between 5.5% and 39%. Hamdi et al13 published a retrospective study in which they used an IMAP in 9% of cases. Saint-Cyr et al15 used IMAP vessels in a total of 5.5% of cases. In a subset, they analyzed 114 cases from just 1 surgeon who always attempted to use the IMAP: the percentage increased to 27%. Munhoz et al16 analyzed 40 immediate reconstructions and used the IMAP in 13 cases (32.5%). Haywood et al12 published 54 reconstructions in which the IMAP was used in 39% of cases. Follmar et al14 used in a retrospective study of 100 abdominal flaps the IMAP in 23%. Over a third of our reconstructions performed to an IMAP had previous radiation therapy, and in 13.4% of all implant exchanges, the perforating vessels could be used despite earlier surgery.
None of the 10 flap failures (1.9%) were anastomosed to an IMAP, which means a survival rate of flaps anastomosed to an IMAP of 100% and of all other flaps anastomosed to the IMA of 97.5%. These rates are comparable with other studies that published flap failure rates between 1% and 3%.12–14 Haywood et al12 reported revision rates of 7.4%, and Follmar et al14 reported revision rates of 2.6%. However, in both studies, complications occurred only when the IMA or TDA was used.12,14 From these data, one can speculate that the IMAP anastomosis seems to be safer than the IMA anastomosis.
We observed palpable and ultrasound detectable fat necrosis in 1.4%. Four (all DIEP flaps) of them were anastomosed to an IMAP. The fact that 4 of 112 flaps (3.6%) anastomosed to the IMAP developed a fat necrosis, but only 3 of the 403 IMA anastomosed flaps indicates a trend toward a slightly increased rate of fat necrosis in IMAP anastomosed flaps. However, the rate is over all very low, and the mean weight of abdominal flaps anastomosed to an IMA and to an IMAP that developed fat necrosis was larger than the average flap weight of their counterparts anastomosed to the IMA/IMAP without fat necrosis. It never occurred in bilateral DIEP flaps, which are always smaller and do not include distant zones. Furthermore, the appearance of fat necrosis is not due only to recipient vessel choice or its caliber. Internal flap perfusion and the quality of included perforators play an important role as well. Saint-Cyr et al15 described a rate for fat necrosis of 8%, which is twice the rate of ours. Hamdi et al13 recorded fat necrosis in 3.3%. and Follmar et al14 recorded fat necrosis in 4.3% if the IMAP was used and 6.5% if the IMA or the thoracodorsal vessels were used. Flap weight was not mentioned in these studies, and all fat necrosis rates published exceeded ours. Despite careful follow-up, not all fat necrosis may have been detected. Small areas of necrotic tissue in larger flaps may remain undiscovered when they do not disturb.
The median length of hospital stay of our patients with DIEP flaps was reduced by 1 day when the IMAP was used as the recipient vessel. Patients with TMG flaps showed no difference in duration of hospital stay in relation to recipient vessel choice, which may be because of more discomfort in the thigh than in the breast.
Today, the IMA is the first choice of most surgeons. However, the IMA vessels themselves are not free of disadvantages. Thoracic contour irregularities, postoperative pain and impaired breathing, pneumonia, and pneumothorax are known complications.13–15,23 The dissection of IMA vessels can be difficult after radiation therapy and especially after chronic inflammation and capsular contracture because of implant reconstruction. Additionally, when used as a recipient vessel in breast cancer patients, the IMA cannot be later used for cardiac bypasses.14
Sparing the IMA for a cardiac bypass may be achieved by an end-to-side-anastomosis.24 However, this technique requires a long pedicle and takes significantly longer time. Another study suggested to use the IMA below the fifth ICS on the right and in the fourth ICS on the left side.10
By using the IMAP, the IMA is not only spared for bypass operations or, more interesting, possible revisions, but limited dissection also reduces operation time.14,16 Using the IMAP as recipient vessels underlines the idea of perforator flaps, which are meant to reduce morbidity in reconstructive surgery.
When adequate IMAP vessels were available, they provided consistent blood supply (100% survival rate) in immediate and delayed breast reconstructions. Even large flaps and previous radiation therapy did not cause increased complication rates. Complication rates were lower when the IMA was used. Patients with DIEP or SIEA flaps went home 1 day earlier after anastomosis to an IMAP. None of these patients had costal cartilage removed, and the superficial position of the IMAP vessels allow shorter pedicles, which reduces exploration when raising the flap and thus decreases donor-site morbidity. Using the IMAPs as recipient vessels is a further step toward simplifying microsurgical breast reconstruction. This technique is a further refinement of perforator-based surgery although it cannot be applied in every patient.
1. Chang EI, Chang EI, Soto-Miranda MA, et al. Comprehensive evaluation of risk factors and management of impending flap loss in 2138 breast free flaps. Ann Plast Surg. 2016;77:6771.
2. Knox AD, Ho AL, Leung L, et al. Comparison of outcomes following autologous breast reconstruction using the DIEP and pedicled TRAM flaps: A 12-year clinical retrospective study and literature review. Plast Reconstr Surg. 2016;138:1628.
3. Nelson JA, Guo Y, Sonnad SS, et al. A comparison between DIEP and muscle-sparing free TRAM flaps in breast reconstruction: a single surgeon’s recent experience. Plast Reconstr Surg. 2010;126:14281435.
4. Koshima I, Inagawa K, Yamamoto M, et al. New microsurgical breast reconstruction using free paraumbilical perforator adiposal flaps. Plast Reconstr Surg. 2000;106:6165.
5. Masia J, Clavero JA, Larrañaga JR, et al. Multidetector-row computed tomography in the planning of abdominal perforator flaps. J Plast Reconstr Aesthet Surg. 2006;59:594599.
6. Fansa H, Schirmer S, Frerichs O, et al. [Significance of abdominal wall CT-angiography in planning DIEA perforator flaps, TRAM flaps and SIEA flaps]. Handchir Mikrochir Plast Chir. 2011;43:8187.
7. Warnecke IC, Kretschmer F, Brüner S, et al. [Hereditary thrombophilia in free microvascular flaps–a case report]. Handchir Mikrochir Plast Chir. 2007;39:220224.
8. Sacks JM, Chang DW. Rib-sparing internal mammary vessel harvest for microvascular breast reconstruction in 100 consecutive cases. Plast Reconstr Surg. 2009;123:14031407.
9. 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;53:311316.
10. Greer-Bayramoglu RJ, Chu MW, Fortin AJ. Feasibility of internal mammary vessel use in breast reconstruction versus coronary artery bypass surgery: an anatomic, cadaveric evaluation. Plast Reconstr Surg. 2011;127:17831789.
11. Guzzetti T, Thione A. Successful breast reconstruction with a perforator to deep inferior epigastric perforator flap. Ann Plast Surg. 2001;46:641643.
12. Haywood RM, Raurell A, Perks AG, et al. Autologous free tissue breast reconstruction using the internal mammary perforators as recipient vessels. Br J Plast Surg. 2003;56:689691.
13. Hamdi M, Blondeel P, Van Landuyt K, et al. Algorithm in choosing recipient vessels for perforator free flap in breast reconstruction: the role of the internal mammary perforators. Br J Plast Surg. 2004;57:258265.
14. Follmar KE, Prucz RB, Manahan MA, et al. Internal mammary intercostal perforators instead of the true internal mammary vessels as the recipient vessels for breast reconstruction. Plast Reconstr Surg. 2011;127:3440.
15. Saint-Cyr M, Chang DW, Robb GL, et al. Internal mammary perforator recipient vessels for breast reconstruction using free TRAM, DIEP, and SIEA flaps. Plast Reconstr Surg. 2007;120:17691773.
16. 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;114:6268.
17. Würinger E, Mader N, Posch E, et al. Nerve and vessel supplying ligamentous suspension of the mammary gland. Plast Reconstr Surg. 1998;101:14861493.
18. Holm C, Mayr M, Höfter E, et al. Perfusion zones of the DIEP flap revisited: a clinical study. Plast Reconstr Surg. 2006;117:3743.
19. Fansa H, Schirmer S, Warnecke IC, et al. The transverse myocutaneous gracilis muscle flap: a fast and reliable method for breast reconstruction. Plast Reconstr Surg. 2008;122:13261333.
20. Fansa H, Schirmer S, Cervelli A, et al. Computed tomographic angiography imaging and clinical implications of internal mammary artery perforator vessels as recipient vessels in autologous breast reconstruction. Ann Plast Surg. 2013;71:533537.
21. Park MC, Lee JH, Chung J, et al. Use of internal mammary vessel perforator as a recipient vessel for free TRAM breast reconstruction. Ann Plast Surg. 2003;50:132137.
22. Wong C, Saint-Cyr M, Arbique G, et al. Three- and four-dimensional computed tomography angiographic studies of commonly used abdominal flaps in breast reconstruction. Plast Reconstr Surg. 2009;124:1827.
23. Rad AN, Flores JI, Rosson GD. Free DIEP and SIEA breast reconstruction to internal mammary intercostal perforating vessels with arterial microanastomosis using a mechanical coupling device. Microsurgery 2008;28:407411.
Copyright © 2016 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of The American Society of Plastic Surgeons. All rights reserved.
24. 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;128:225e232e.