CHAPTER 61 BREAST RECONSTRUCTION: TRAM FLAP TECHNIQUES
JAMES D. NAMNOUM
The transverse rectus abdominis myocutaneous (TRAM) flap was introduced more than 30 years ago for breast reconstruction. Initially described by Holmstrom as a free flap, it was later popularized by Hartrampf, who independently conceived of its use as an abdominal island flap for breast reconstruction.1,2 Drawing on the work of Esser, Hartrampf theorized that the lower abdominal skin and fat could be transferred to the chest to create a breast mound based on circulation provided from the rectus abdominis muscle.3 The successful outcome in a patient with a history of implant failure following radical mastectomy ushered in a new era of breast reconstruction. The TRAM flap is unparalleled in its ability to provide a large volume of skin and fat for breast reconstruction. It is especially valuable in patients presenting for delayed reconstruction following mastectomy with post-mastectomy radiation. In these cases, the requirements for symmetry with the opposite breast often depend on extensive amounts of skin replacement as well as volume (Figure 61.1).
TYPES OF LOWER ABDOMINAL (TRAM) FLAPS
Lower abdominal flaps can be grouped into two main categories, pedicled TRAM and free flaps. The pedicled TRAM relies on perfusion from the superior epigastric system arborizing within the rectus muscle to provide perfusion to the lower abdominal tissues. In contrast, lower abdominal free flaps make use of the deep inferior epigastric system (free TRAM, MS-0, MS-1, MS-2; DIEP [deep inferior epigastric perforator], MS-3) or superficial inferior epigastric system (SIEA [superficial inferior epigastric artery] flap, MS-4); these systems are generally the dominant blood supply to the lower abdominal skin and fat (Chapter 62). With regard to muscle sacrifice and potential for donor-site weakness, bulge, or hernia following free flap harvest, MS-0 flaps make use of the entire rectus muscle while muscle-sparing MS-1 and MS-2 flaps sacrifice decreasing amounts of rectus muscle. MS-3 (DIEP) sacrifices no muscle but involves dissection and concomitant injury of a portion of rectus muscle and its intercostal innervation. MS-4 (SIEA) requires no muscular dissection or sacrifice. Not surprisingly, reduced muscular dissection and sacrifice is associated with decreased abdominal wall complications and improved abdominal wall strength.4-6 However, flap-related complications are higher in DIEP patients as opposed to non–muscle-sparing free TRAM patients (MS-0) owing to the reduced number of perforators supplying the tissues.7
The pedicled TRAM, free TRAM, and DIEP procedures may be indicated for patients who desire immediate or delayed breast reconstruction and are ideal for matching a ptotic opposite breast. Breast reconstruction utilizing tissues of the lower abdomen generally permits a softer, more natural reconstruction and tends to age in a similar fashion with the opposite breast as contrasted with device reconstructions (Chapter 59) (Figure 61.2). This potential improvement in softness and symmetry comes at the expense of a longer operative time and hospital stay, and an abdominal donor site that can result in abdominal weakness, bulge, or hernia. Often the resultant abdominal scar is positioned higher than would be considered aesthetically ideal and is a potential drawback to the procedure that should be discussed with the patient preoperatively (Figure 61.3). Many patients are erroneously led to believe that the TRAM flap is synonymous with an aesthetic abdominoplasty. While both may enhance the appearance of the lower abdomen, they are in fact quite different procedures. The differences should be clearly explained to the patients preoperatively to avoid unrealistic expectations.
While there are few absolute indications for one type of flap over others, several relative indications merit consideration. Selection of one technique over the other as a general rule takes into account the comfort level of the surgeon with the various techniques. For the surgeon who infrequently performs microvascular surgery, the free TRAM or DIEP flap is best avoided. Patients in high-risk categories such as those with a history of heavy cigarette use (greater than 10 pack/years smoking) and those who are overweight or obese are more suitable for free rather than pedicled TRAM reconstruction owing to improved flap perfusion and reduced rectus muscle sacrifice.8 This is particularly true for those undergoing bilateral reconstruction. In contrast, patients without significant comorbidity, elevated BMI, or heavy smoking history show no difference in incidence of flap or abdominal complications whether one (unipedicle) or two (bilateral single pedicle or double pedicle) pedicles are used, or whether a free TRAM flap is performed.9 Nahabedian has suggested an excellent algorithm for decision making regarding DIEP versus free TRAM selection. For patients requiring flaps less than 750 cc in volume in which a perforator of at least 1.5 mm can be identified, a DIEP flap can be safely selected; patients requiring larger flaps or having inadequate perforators (less than 1.5 mm perforators) are better candidates for muscle-sparing free TRAM flaps.
The pedicled TRAM is still the preferred technique for breast reconstruction by most surgeons who perform the TRAM flap. However, microvascular procedures, particularly the DIEP flap, have gained significant popularity over the past 10 years.10 Advocates for the pedicled TRAM cite its reliability, predictable blood supply, ease and speed of harvest, safety in appropriately selected patients, and avoidance of a requirement for microvascular skills and instrumentation. The relative simplicity of flap harvest may afford more time for insetting and shaping, leading to superior aesthetic outcomes. The popularity of skin-sparing mastectomies has made this task considerably easier. TRAM flap procedures are somewhat more complex than the other options for breast reconstruction. As with other complex procedures, declining reimbursement has likely played a role in the popularity of simpler procedures for breast reconstruction such as expander/ implant reconstruction. It is interesting to note, though, that many surgeons who prefer autologous reconstruction are increasingly opting for more technically sophisticated procedures such as the DIEP flap for their patients. An analysis of the reasons behind this change is of great interest but beyond the scope of this chapter.
FIGURE 61.1. Preoperative and postoperative appearance of a 44-year-old woman who underwent delayed breast reconstruction after radiation with TRAM flaps and Tissue expanders. At a second stage the expanders were exchanged for permanent breast implants and fat grafting was performed. Under certain circumstances one needs large amounts of skin in conjunction with breast implants to achieve an aesthetically pleasing result.
FIGURE 61.2. Muscle-sparing free TRAM reconstruction in the right breast of a 54-year-old with ptotic opposite breast. A. Preoparative appearance. B. Postoperative appearance. The large volume of soft tissue permits symmetrical reconstruction in a patient who refuses balancing of the opposite breast.
Technical Details (Figure 61.4)
The pedicled TRAM is based on the superior epigastric vessels. A split muscle technique is used for flap harvest. Controversy exists whether a whole muscle approach is superior, as the muscle-sparing approach may exclude some of the normal connections between the superior and inferior epigastric systems potentially affecting flap perfusion.11 This reduces the incidence of abdominal contour deformities and permits a more secure immediate abdominal closure.12 Mesh is used as an onlay only after the best possible primary fascial closure. The indications for mesh include excessive tension on the repair and fascia that tears at closure or appears thin and weak. Mesh is rarely required following single-pedicle TRAM flaps but is required more frequently in patients undergoing bilateral or double-pedicle TRAM flaps. A continuous nonabsorbable suture is used for the fascial repair. Care is taken to ensure that the internal oblique fascia is included in the repair. This is especially important in the lower abdomen where it may retract underneath the external oblique fascia and be inadvertently excluded, with postoperative abdominal bulging or hernia as a result. The pedicled TRAM can be based on an ipsilateral (relative to mastectomy) or contralateral pedicle; an ipsilateral pedicle is chosen most often due to reduced bulk in the epigastrium. Flap orientation, either vertical or horizontal, is at the discretion of the surgeon. Adherence to Hartrampf’s criteria for flap selection is associated with a low incidence of fat necrosis and partial and total flap loss; abdominal bulge and hernia are rarely encountered with the muscle-sparing technique in normal-risk patients.13
FIGURE 61.3. A 34-year-old following muscle-sparing free TRAM reconstruction of left breast. Abdominal scar somewhat higher than ideal from an aesthetic perspective although breast symmetry is achieved.
The free TRAM represents an evolution of technique from the pedicle TRAM. First described by Holmstrom and later popularized by Grotting and others,14-16 it has undergone further refinement as surgeons have sought to optimize flap viability while minimizing donor-site morbidity. This has led to the popularity of highly muscle-sparing free flaps such as the MS-1/MS-2 free TRAM and the DIEP (MS-3).17,18 Advocates for the free TRAM in its various degrees of muscle sparing cite its advantages of reduced abdominal dissection, muscle sacrifice and attendant weakness, enhanced flap vascularity, ease of flap inset, and avoidance of disturbance of the inframammary fold. Patients undergoing free TRAM appear to have less immediate postoperative pain and a quicker initial abdominal recovery (Chapter 62).
In contrast to the pedicled TRAM, patients with elevated BMI or history of heavy tobacco use undergoing free TRAM did not differ in the incidence of flap or abdominal complications, such as total flap loss, fat necrosis, hernia, and bulge. Thus, the free TRAM is more appropriate for use in these high-risk patients. Patients in high-risk categories are at risk for abdominal or mastectomy skin loss, umbilical loss, seroma, and infection, indicating that TRAM flap surgery in general is not without increased morbidity in these patient populations regardless of the technique utilized.19,20 Besides requiring microvascular skills and longer operative times, the main disadvantage of the free TRAM is the significantly higher incidence of total flap failure when compared with pedicle TRAM, where it is virtually nonexistent. Decision making when selecting a technique should therefore take into consideration a surgeon’s personal success rate with the free flap breast reconstruction before committing a patient to a procedure with a potentially higher rate of failure.
FIGURE 61.4. Pedicle TRAM flap technique—muscle-sparing flap is harvested preserving medial and lateral rectus muscle. Circulation is based on superior epigastric vessels. Flap is tunneled to mastectomy defect. Fascia closed with a running nonabsorbable suture. Inset completed at mastectomy defect.
Technical Details (Figure 61.5)
A small segment of muscle and fascia from the lower abdomen is utilized for the harvest of the free TRAM flap, simplifying the abdominal closure. In contrast, the DIEP flap spares both the fascia and muscle though the dissection causes both intramuscular scarring and denervation. The flap is based on deep inferior epigastric vessels. The thoracodorsal vessels or internal mammary vessels may be used as recipients, depending on the ease of harvest. As more surgeons shift from formal axillary dissections to sentinel node biopsies or limited axillary dissections, the internal mammary vessels have gained in popularity. Use of these vessels permits more central positioning of the flap, avoids the need for an axillary extension of the skin-sparing incision, and avoids disturbance of the axilla. This is balanced against the potential disadvantage of sacrificing the left internal mammary artery, which may later be necessary for coronary artery revascularization. The increased flap vascularity permits a more flexible approach to shaping.
FIGURE 61.5. Free TRAM flap technique—muscle-sparing flap removes small central segment of rectus muscle and fascia from lower abdomen. Circulation is based on inferior epigastric vessels. Flap is transferred to the chest. Microvascular anastomoses are completed end to end to the thoracodorsal or internal mammary vessels. Fascia is closed with running nonabsorbable suture. Flap is inset at the mastectomy defect.
Both the pedicled and free TRAM techniques can be used to create an attractive breast mound (Figure 61.6). Disturbance of the inframammary fold due to tunneling may give the free flap technique an advantage in the short term. In most cases, the crease disturbance settles down after several months. As long as all the intercostal nerves to the rectus muscle have been divided, the muscle around the pedicle atrophies and does not distort the inframammary fold. Abdominal contour disturbances may be minimized by the use of a muscle-sparing technique but are seen from time to time whether a free or pedicle technique is utilized.
Selection of a mastectomy skin pattern may generally be made without regard for the type of flap utilized. For free flap reconstruction, a skin-sparing pattern requires use of the internal mammary vessels as recipients unless a short axillary extension or vertical incision is added. For surgeons preferring the pedicled TRAM, the skin-sparing incision offers a great opportunity for near anatomic breast reconstruction. Reduction patterns for mastectomy are plagued by problems with mastectomy skin flap compromise particularly when coupled with pedicled TRAMs and may be best reserved for patients undergoing free TRAM reconstruction where tunneling is not required. In such instances, use of a vertical skin pattern may reduce the risk of mastectomy skin loss; a transverse incision may be added at the second stage of reconstruction if needed. Intraoperative imaging with conventional fluorescein or laser-assisted indocyanine green fluorescent dye can help determine compromise of mastectomy skin flaps but may overcall flap ischemia and lead to excessive debridement.
FIGURE 61.6. A 39-year-old 2 years following muscle-sparing free TRAM flap, right, and left breast reduction for balancing.
Donor-site issues such as abdominal bulge and hernia, weakness, and interference with activities of daily living have been debated over the decades since the introduction of the TRAM. This debate continues today. There is a direct relationship between increased muscle sacrifice and improved flap perfusion in pedicle and free flaps owing to the inclusion of additional perforators. On the other hand, in a comparison of free TRAM and DIEP flaps, additional muscle sacrifice is associated with increased abdominal bulge, hernia, and diminished functional strength.5 The ability to perform sit-ups postoperatively is dependent on the amount of muscle harvested and is more likely to be preserved in patients undergoing free TRAM compared with pedicled TRAM. Despite this finding, pedicled TRAM harvest rarely affects the activities of daily living and most patients return to preoperative athletic pursuits.21 A recent study directly comparing patients undergoing bilateral pedicle TRAM with bilateral DIEP flaps showed no difference in abdominal hernia and bulge in these two groups attesting to its continued value in appropriately selected patients.22
Fat necrosis and partial and total flap loss can occur with either pedicled or free TRAM techniques. Patients who are heavy past smokers, actively smoking at the time of surgery, and obese or overweight may be at increased risk for flap complications. Direct comparisons between pedicle and free TRAM flaps have not yielded consistent results regarding the incidence of fat necrosis. In general, increasing the numbers of perforators included with the flaps reduces the incidence of fat necrosis and partial and complete flap loss. Patients requiring larger flaps, who smoke, and are obese are better candidates for less muscle conservation.
For patients in high-risk categories, surgical delay has been suggested as a method to improve flap vascularity. To date, no study has shown a consistent reduction in the incidence of flap complications in patients undergoing surgical delay of TRAM but experimental data suggest that flow is enhanced in the superior epigastric vessels after surgical delay.
1. Holmstrom H. The free abdominoplasty flap and its use in breast reconstruction: an experimental study and clinical case report. Scand J Plast Reconstr Surg.1979;13:423.
2. Hartrampf CR, Scheflan M, Black P. Breast reconstruction with a transverse abdominal island flap. Plast Reconstr Surg. 1982;96:216.
3. Esser JFS. Island flaps. N Y Med J. August 1917;264.
4. Nahabedian MY, Momen B, Galdino G, et al. Breast reconstruction with the free TRAM or DIEP flap: patient selection, choice of flap, and outcome. Plast Reconstr Surg. 2002;110(2):466-475.
5. Selber JC, Nelson J, Fosnot J, et al. A prospective study comparing the functional impact of SIEA, DIEP, and muscle-sparing free TRAM flaps on the abdominal wall: part I. Unilateral reconstruction. Plast Reconstr Surg. 2010;126(4):1142-1153.
6. Selber JC, Fosnot J, Nelson J, et al. A prospective study comparing the functional impact of SIEA, DIEP, and muscle-sparing free TRAM flaps on the abdominal wall: part II bilateral reconstruction. Plast Reconstr Surg. 2010;126(5):1438-1453.
7. Man LX, Selber JC, Serletti JM. Abdominal wall following free TRAM or DIEP flap reconstruction: a meta-analysis and critical review. Plast Reconstr Surg. 2009;124(3):752-764.
8. Serletti JM. Breast reconstruction with the TRAM flap: pedicled and free. Journal of. 2006;94:532-537.
9. Namnoum JD. An analysis of 920 pedicled and 286 free TRAM flap breast reconstructions. Presented at the Annual Meeting of the American Society of Plastic Surgery, Orlando, Florida; November 2001.
10. Report of the 2010 Plastic Surgery Statistics: 2010 Reconstructive Breast Procedures. American Society of Plastic Surgeons.
11. Moon HK, Taylor GI. The vascular anatomy of rectus abdominis musculocutaneous flaps based on the deep superior epigastric system. Plast Reconstr Surg. 1988;82(5):815-832.
12. Nahabedian MY, Dooley W, Singh N, et al. Contour abnormalities of the abdomen after breast reconstruction with abdominal flaps: the role of muscle preservation. Plast Reconstr Surg. 2002;109(1):91-101.
13. Hartrampf CR Jr, Bennett GK. Autogenous tissue reconstruction in the mastectomy patient. A critical review of 300 patients. Ann Surg. 1987;205:508.
14. Grotting JC, Urist MM, Maddox WA, et al. Conventional TRAM flap versus free microsurgical TRAM flap for immediate breast reconstruction. Plast Reconstr Surg. 1989;83:828.
15. Elliott LF, Eskenazi L, Beegle PH, et al. Immediate TRAM flap breast reconstruction: 128 consecutive cases. Plast Reconstr Surg. 1993;92:217.
16. Schusterman MA, Kroll SS, Weldon ME. Immediate breast reconstruction: why the free TRAM over the conventional TRAM? Plast Reconstr Surg. 1992;90:255.
17. Koshima I, Soda S. Inferior epigastric artery skin flaps without rectus muscle. Br J Plast Surg. 1989;42:645.
18. Allen RJ, Treece P. Deep inferior epigastric perforator flap for breast reconstruction. Ann Plast Surg. 1994;32:32.
19. Chang DW, Wang B, Robb GL, et al. Effect of obesity on flap and donor-site complications in free transverse rectus abdominis myocutaneous flap breast reconstruction. Plast Reconstr Surg. 2000;105:1640-1648.
20. Chang DW, Reece GP, Wang B, et al. Effect of smoking on complications in patients undergoing free TRAM flap breast reconstruction. Plast Reconstr Surg. 2000;105:2374.
21. Mizgala CL, Hartrampf CR, Bennett GK. Assessment of the abdominal wall after pedicled TRAM flap surgery: 5- to 7-year follow-up of 150 consecutive patients. Plast Reconstr Surg. 1994;93:988.
22. Chun Y, Sinha I, Turko A, et al. Comparison of morbidity, functional outcome, and satisfaction following bilateral TRAM versus bilateral DIEP flap breast reconstruction. Plast Reconstr Surg. 2010;126(4):1133-1141.
23. Restifo RJ, Ward BA, Scoutt LM, et al. Timing, magnitude, and utility of surgical delay in the TRAM flap: II. Clinical studies. Plast Reconstr Surg. 1997;99:1217.
24. Atisha D, Alderman AK, Janiga T, et al. The efficacy of the surgical delay procedure in pedicle TRAM breast reconstruction. Ann Plast Surg. 2009;63:383-388.