The unipedicle transverse rectus abdominis myocutaneous flap (TRAM) described by Carl Hartrampf still remains the gold standard for autologous breast reconstruction more than 20 years after its first description. Yet, certain things have been learned over the years that have improved the safety and outcomes of the procedure. We have a better understanding of proper patient selection, the delay procedure in higher-risk patients, microvascular free tissue transfer, muscle-splitting techniques, means of insetting the flap along aesthetic units, and preoperative and postoperative care.

Although some plastic surgeons prefer the option of a free TRAM flap, we prefer the pedicle TRAM flap in properly selected patients for its predictability, low serious complication rate, technical ease, reliability of results, decreased operative time, and patient satisfaction. We prefer the deep inferior epigastric artery perforator (DIEP) or free TRAM flap for those patients who we believe are not good candidates for the unipedicle TRAM procedure, including patients with transverse upper abdominal scars that have compromised the superior epigastric system and obese patients. We will also perform a free TRAM or DIEP in patients who choose a free flap procedure electively. Although the free TRAM flap plays the dominant role in breast reconstruction in some centers, the pedicle TRAM, in most cases, can obtain equally good results without the lengthy time, special risks, and needs for microsurgical skills of a free flap.

Proper patient selection is the key to success with a unipedicle TRAM flap. This begins with an appropriate medical history, including a history of breast cancer, family and genetic history, a history of familial or genetically linked breast cancer, previous radiation or chemotherapy, previous breast surgery and nodal status, health history such as smoking and diabetes, lifestyle, relevant previous abdominal or chest surgery, and patient preference. With regard to safety and risk factors, we have found that obesity, smoking, and radiation history have the most significant impact on outcomes with the unipedicle muscle-splitting TRAM flap.

The patient should be weighed and body mass index (BMI) calculated. Obese patients (BMI of 30 and greater) are not good candidates for the standard unipedicle flap. We have found that these patients have a significantly higher incidence of multiple flap complications, including fat necrosis, seroma, hematoma, infection, and delayed wound healing. In addition, patients with a BMI above 30 are at an increased risk for partial flap necrosis and donor-site complications, including seroma and delayed wound healing.

The patient should be counseled and evaluated regarding smoking status. Smoking is a significant risk factor for developing multiple flap complications, including infection. In addition, former smokers (defined as patients who stopped smoking at least 4 weeks prior to reconstruction) have been found to also be at increased risk for multiple flap complications, including delayed TRAM healing. This highlights the detrimental effect that smoking can have on TRAM reconstruction, and therefore we recommend that smoking be considered a contraindication to pedicle TRAM reconstruction unless the patient has stopped smoking for more than 1 month.

The harmful effects of radiation with regard to wound healing and aesthetic outcome have been well established, and this holds true in the unipedicle TRAM as well. When examining prereconstruction versus postreconstruction radiation, patients who have TRAM reconstruction following radiation have significantly improved aesthetic outcomes. Therefore, in patients who are known or expected to receive postmastectomy radiation, unipedicle TRAM reconstruction should be delayed until after completion of radiation therapy.

Equally important is the physical examination. If the patient has already had a mastectomy, the defect should be evaluated. The mastectomy scar length and direction are noted, along with the quality and thickness of the overlying skin, particularly in the radiated patient. The axilla is assessed for evidence of disease. The contralateral breast is then assessed for scars, size, shape, base dimensions, ptosis, approximate weight, nipple to inframammary fold length, and overall attractiveness. Evaluation of the contralateral breast will help in the preoperative decision regarding possible augmentation, mastopexy, or reduction procedures to improve symmetry. Patients with a C breast cup size or smaller with relatively little ptosis and good projection often have the option of being reconstructed with an expander or implant, whereas the patient with a larger breast or significant ptosis may benefit preferentially from autologous tissue reconstruction.

The abdominal wall must also be carefully examined to evaluate any scars from previous surgery. For whatever reason, some patients may fail to mention previous abdominal procedures such as liposuction. Upper transverse abdominal scars may have transected the superior epigastric vessels and would be a contraindication to a pedicle TRAM flap on the affected side. Vertical midline scars that extend significantly below the umbilicus should not disrupt blood flow to the ipsilateral
TRAM flap, but blood flow to zones II and IV will obviously be reduced and may need to be discarded. A previous abdominoplasty almost certainly divided the important flap perforators and may preclude any type of TRAM. A Pfannenstiel incision or other lower transverse abdominal incision is not a contraindication to a TRAM flap, although the location of the incision may make the planning of the incision and the donor-site closure more complex. Finally, the patient’s abdomen should be examined for hernias or other defects that might need to be repaired during the primary procedure.

The ideal patient for a TRAM operation is the patient who would otherwise benefit from an abdominoplasty with a BMI less than 30 and who has sufficient lower abdominal “fullness” and skin to reconstruct the breast. An excess of abdominal fat only increases the risk of flap loss or fat necrosis by exceeding the available blood supply. More-obese patients (BMI of 30 and greater) are at significantly greater risk of complications both of the flap and the donor site. Such patients are better suited for the latissimus or free TRAM flap option. Patients with significant pulmonary disease and vascular disorders are also at a higher risk of complications.

Patients should be informed of the relevant risks and complications of the unipedicle TRAM procedure, including bleeding, infection, partial and total flap loss, abdominal seromas and hematomas, abdominal dehiscence and hernias, scarring, and the length of time for recovery when compared with expander/implant reconstruction. Patients who smoke are advised to stop prior to surgery. Patients who smoke may benefit from a delay procedure or a free TRAM flap, both of which should improve the blood supply. It is particularly helpful to mark these patients for TRAM flap reconstruction in a comfortable, unhurried setting. On occasion, we may see the patient in the office on the day prior to surgery to plan and photograph the preoperative markings on the chest and abdomen. The marks can be reinforced by the patient at home with a permanent marker. Just prior to surgery, the plan is again reviewed with the patient, and the marks are revised and reinforced. The patient is also placed on a clear liquid diet the day prior to surgery and given a mild laxative. Lower-extremity pneumatic compression devices are used for antiembolic prophylaxis. The surgery is carried out under general anesthesia without the use of nitrous oxide in order to reduce the volume of gas in the intestine.

Preoperative planning is a critical part of breast reconstruction. The abdomen is marked as if doing an abdominoplasty procedure with the upper limb reaching the superior border of the umbilicus or higher if sufficient tissue is available and the lower limb at the level of the superior pubic escutcheon. At no time is the upper limb placed below the level of the umbilicus because of the strict necessity to incorporate the highest infraumbilical perforator in the flap. After the abdominoplasty ellipse is marked, the side of the pedicle and the orientation of the flap must be determined. Although we prefer to use an ipsilateral rectus muscle flap for unilateral reconstruction because it rotates more facilely, we do not hesitate to use a contralateral pedicle. The exact flap pattern and inset orientation are ultimately highly variable and depend on the desired breast shape, the defect, and the nature of the donor tissues. Finally, the full extent of abdominal undermining is estimated. The xiphisternal junction is palpated and the upper limit of dissection set just above it. The flap dissection will be continued laterally only as required up to the costal margin and along the lateral abdominal border.

The vertical midline is marked from the suprasternal notch to the pubis, passing through the umbilicus. The inframammary fold of the remaining breast is marked and transferred as a mirror image to the side of the defect. A line is then drawn parallel to and 1 or 2 cm above the transferred fold as the expected position of the final inframammary fold on the reconstructed side. This upward shift is performed to compensate for greater descent of the released low thoracic tissues on the reconstructed side as the abdominal wall is closed. The exact amount varies but is usually one to two finger breadths above the fold line. It is now necessary to determine how much abdominal skin will be required to match the shape and ptosis of the opposite breast. In the case of delayed reconstruction, a mirror image of the mastectomy scar is transferred to the opposite breast and marked. Now, the exact skin requirement for matching the existing breast ptosis can be measured along the vertical axis of the breast from the scar to the inframammary line. This can be performed with a soft tape measure that follows the contour of the breast exactly. Three measurements are usually taken: one at the nipple position and one each on either side. This total height of skin must be matched on the new breast from its existing scar to its adjusted inframammary fold. These vertical measurements are now transferred to the abdominal ellipse to determine the best alignment. As mentioned, the ipsilateral flap will invariably be rotated 90 to 270 degrees in the unipedicle setting. The desired transverse dimension of the skin requirement is measured and fit to the abdominal flap. A preliminary plan for the required skin island is thus laid out on the abdominal flap according to the measurements of exact skin requirement. Final planning is done to address the contour deficiencies and volume requirements that are or may be present. In planning an immediate reconstruction, the mastectomy markings are placed in coordination with the general surgery team.

A final decision in terms of skin planning should be left until after the mastectomy is completed when the mastectomy flaps can be reexamined to ensure that more abdominal skin is not required. When possible, we prefer to deepithelialize appropriate portions of the flap while it still sits on the abdomen because this facilitates the deepithelializing process. The umbilicus is dissected out, leaving a modest amount of fat along the stalk to ensure its blood supply. The upper abdominal skin and subcutaneous fat are undermined off the fascia up to the costal margins, and a tunnel is made into the mastectomy defect along the meridian of the breast. On average, this tunnel should accommodate four of the surgeon’s fingers, although this may vary based on flap volume. In a delayed reconstruction, the mastectomy scar would now be excised and a subcutaneous pocket developed to recreate the original
defect. The dissection superiorly is maintained in the subcutaneous plane above the pectoralis major muscle. As the dissection is continued inferiorly, a small cuff of subcutaneous fat is left on the skin flap along the inframammary fold. A tunnel is then created between the mastectomy defect and abdominal dissection superficial to the chest wall fascia.