Unipedicled Transverse Rectus Abdominis Myocutaneous (TRAM) Flap Breast Reconstruction

Anatomy and Physiology

The critical anatomy to focus on is the vascular supply to the abdomen and the flap. The abdominal vascular supply can be divided into 3 zones based on the regional anatomy:

• Zone I
  • This zone is in the central abdomen. The branches of the deep and superficial superior epigastric arteries supply it.
• Zone II
  • Four main arteries supply the inferior abdomen in this zone: the deep inferior epigastric artery, the deep circumflex iliac artery, the superficial circumflex iliac artery, and the superficial external pudendal artery.
• Zone III
  • This zone is the lateral or peripheral area of the abdomen. The intercostal arteries, subcostal arteries, and lumbar arteries supply this zone.

The vascular supply of the abdominal flap is based on Hartrampf perfusion zones. There are 4 different but equally sized zones, each with a different perfusion. The idea is that the zones immediately adjacent to the vascular pedicle have better perfusion than the lateral zones. The medial zones are I and II, while the lateral zones are III and IV. Therefore, surgeons first resect the higher zones and leave the lower zones for reconstruction, depending on the required volume.[10][11][12]

The ms-TRAM is an alternative option to TRAM, in which case as much muscle as possible is spared, and a vascular anastomosis is often performed. In contrast, the benefit of a TRAM is that no anastomosis is needed. In addition to an ms-TRAM, a deep inferior epigastric perforator (DIEP) can also be performed. A DIEP flap is a complete muscle-preserving flap composed of the lower abdomen's skin, fat, and blood vessels. Studies have assessed the superiority of 1 flap over the other. Study results have shown that ms-TRAM flaps had higher blood flow and lower vascular resistance than DIEP flaps. This was likely because the ms-TRAM flaps consisted of a small segment of rectus muscle, thus resulting in more perforators, which increase blood flow and decrease vascular resistance. Regardless of this finding, the superiority between DIEP and ms-TRAM could not be determined.[13]

Indications

Breast reconstruction is indicated for women undergoing mastectomy or other breast surgeries for oncologic reasons, including breast-conserving surgery with poor cosmetic outcome or prophylactic mastectomy in high-risk individuals (eg, BRCA mutation carriers). While some women may initially choose external prostheses, these are often reported to interfere with physical activity, clothing options, and body image, leading many to pursue more permanent reconstructive options. Autologous reconstruction using a TRAM flap is an excellent choice for women who are in good health and prefer to avoid breast implants. Ideal candidates are those who are willing to accept a more complex operative and postoperative course, including the possibility of donor-site morbidity and the need for future revision surgeries. This approach offers a more natural look and feel compared to implants and can be particularly appealing to women who prioritize the tactile authenticity of the reconstructed breast.

Patients who have undergone prior radiation therapy to the chest wall are excellent candidates for autologous reconstruction. Radiation increases the risk of complications with implant-based reconstruction, including capsular contracture, skin fibrosis, and poor aesthetic outcomes. In contrast, autologous flaps such as the TRAM provide vascularized tissue that can better withstand the effects of prior irradiation. In addition, patients with sufficient lower abdominal tissue, especially those who desire the aesthetic benefits of an abdominoplasty, may find the TRAM flap a favorable option.[14] Preoperative counseling should address the nature and extent of the abdominal scar, the potential for abdominal wall weakness or hernia, and the need for compliance during postoperative recovery to optimize both breast and abdominal outcomes.[15][16]

Contraindications

Due to the technical complexity and extended operative time involved in TRAM flap breast reconstruction, contraindications are primarily related to the integrity of the flap’s vascular supply and patient-specific medical comorbidities that increase surgical risk or reduce the likelihood of flap survival. The most critical anatomic consideration is the blood supply to the rectus abdominis muscle and overlying skin, which determines the viability and volume of tissue that can be harvested. Any factor compromising this blood flow, particularly from prior abdominal surgeries, must be evaluated cautiously.

Patients with upper abdominal incisions are at increased risk for compromised flap perfusion. Specifically, ipsilateral subcostal or paramedian incisions, or a chevron incision, can disrupt 1 or both of the rectus pedicles and render the flap nonviable. Vertical midline incisions, by contrast, typically only compromise perfusion from the contralateral side, and reconstruction may still be possible depending on intraoperative assessment of vascularity. However, TRAM flaps after previous abdominoplasty are strongly contraindicated because the subdermal vascular network and perforators are divided during the cosmetic procedure, dramatically increasing the risk of flap necrosis.

Similarly, prior abdominal liposuction, particularly if performed in the lower abdomen, may disrupt critical perforators to the skin and subcutaneous tissues, increasing the risk of ischemic complications. Scars that cross horizontally or vertically through the planned TRAM flap can reduce the usable soft tissue for breast mound creation and adversely affect the final aesthetic outcome, an especially important issue for large-breasted patients. Excluding previously scarred areas from the flap design improves perfusion and cosmetic results.

Medical contraindications include systemic conditions that impair wound healing or increase the likelihood of perioperative complications. Hartrampf emphasized that patients with poorly controlled cardiovascular disease, chronic obstructive pulmonary disease, insulin-dependent diabetes, or uncontrolled hypertension are generally poor candidates for this extensive procedure. Smoking and autoimmune diseases further impair tissue healing and microvascular integrity, increasing the risk of total or partial flap loss. Obesity also contributes to adverse outcomes; several studies' results suggest avoiding autologous flap procedures in patients with a body mass index (BMI) over 39.9 due to significantly elevated complication rates at both the donor and recipient sites, independent of other risk factors such as age, radiation, or smoking.[4][11][17] In such patients, alternative reconstructive strategies—such as implant-based approaches or flaps harvested from other donor sites—should be considered to minimize morbidity.

Preparation

Patient Selection and Risk Stratification

Ideal candidates are in good general health with adequate lower abdominal tissue and no significant comorbidities that impair wound healing. Key considerations include:

• Obesity and comorbidities
  • Obesity (BMI >30), insulin-dependent diabetes, uncontrolled hypertension, severe cardiovascular or pulmonary disease, and autoimmune conditions are associated with significantly higher complication rates. Some advocate avoiding flap reconstruction in patients with a BMI >39.9 due to poor donor and recipient site outcomes.
• Smoking
  • Smoking impairs flap perfusion and increases wound complications. Cessation is required for at least 4 to 6 weeks preoperatively.
• Previous abdominal surgery
  • Prior procedures such as abdominoplasty, liposuction, or abdominal incisions (particularly ipsilateral subcostal, paramedian, or chevron incisions) may disrupt the flap’s blood supply and pose a contraindication. Vertical midline scars are less concerning but may reduce available tissue and affect aesthetics.
• Radiation history
  • Patients with prior chest wall radiation benefit from autologous reconstruction, as implant-based options are associated with capsular contracture and poor aesthetic outcomes.

Oncologic Coordination and Timing

Timing (immediate vs delayed reconstruction) is tailored to the oncologic plan and patient preference. For patients expected to receive adjuvant radiation, options include:

• Immediate reconstruction with a larger flap to accommodate anticipated radiation-induced volume loss.
• Delayed reconstruction after radiation therapy to optimize flap quality and reduce complication risks.

Close collaboration with breast surgeons helps determine the mastectomy type (eg, skin-sparing vs nipple-sparing) and guides flap planning accordingly.

Preoperative Imaging and Planning

Preoperative imaging such as computed tomography angiography or handheld Doppler ultrasound may be used to map perforators and assess the integrity of the rectus abdominis blood supply, particularly in patients with previous abdominal operations. This step helps minimize the risk of flap necrosis and guides flap design.

Surgical Marking and Flap Design

Preoperative markings are typically performed with the patient in a standing position and resemble markings used for an abdominoplasty:

• A superior line is drawn from the upper border of the umbilicus to each anterior superior iliac spine, guided by the abdominal pannus.
• An inferior line is drawn along the suprapubic crease and curves upward to meet the superior line at the iliac spines, forming an elliptical flap outline.
• The midline from the suprasternal notch to the pubis is marked for symmetry.
• The inframammary fold of the contralateral, noncancerous breast is transposed to the mastectomy side, placed 1 to 2 cm above its mirror point.
• The volume of the contralateral breast is estimated to guide how much abdominal tissue is required for symmetry.

The flap can be ipsilateral or contralateral, with contralateral designs more commonly used to optimize pedicle length and arc of rotation. Ipsilateral designs are considered when about 60% to 70% of the abdominal ellipse is needed or when microvascular integrity is not in question.

Patient Education and Informed Consent

Patients should understand:

• Surgical complexity and duration, often >6 hours
• Postoperative recovery expectations, including a hospital stay of 3 to 5 days and a recovery time of 6 to 8 weeks
• Potential complications such as flap necrosis, wound dehiscence, infection, or abdominal wall weakness
• Aesthetic outcomes, scar placement, and potential need for revision
• Donor site morbidity, including risk for bulge or hernia formation

Perioperative Optimization

• Nutrition and protein status should be optimized preoperatively.
• Glycemic control is critical in diabetic patients.
• Venous thromboembolism prophylaxis is initiated due to the long operative time.
• Preoperative photographs and breast volume assessments are often taken for documentation and surgical planning.

Technique or Treatment

The goal is to perform a safe and reliable TRAM flap while minimizing harm to the abdominal wall. In the operating room, the TRAM flap is mobilized with its vascular pedicle intact. A tunnel is created in the medial inframammary fold and onto the xiphoid process. The flap is rotated and tunneled to be placed on the chest wall. Once the flap is positioned in the breast pocket, it is tacked in place and further shaped, eg, circumferentially, and examined upright to confirm symmetry. The flap is trimmed to conform to the mastectomy flaps and breast shape. The abdominal wall defect is closed primarily unless the abdominal muscles appear weak; an interposition mesh is used to decrease the risk of future hernias. The fascia is closed in 2 layers and imbricated in the epigastric and lower suprapubic area to prevent a bulge. The rest of the abdominal closure is performed in multiple layers with careful attention to the superficial fascial system, deep dermis, and intradermal layers. These are the layers that contain collagen and prevent wound dehiscence. Drains are placed before closure of the abdominal wound and within the breast pocket. The procedure is completed with skin closure and the application of a dressing.[14][18]

Postoperatively, multimodal pain management is used for adequate pain management while reducing opioid use. The patient is maintained in the flexed position, and an abdominal binder is applied to support and decrease seroma formation. A bra is not worn during this time to avoid pedicle compression, allowing optimal blood flow to the flap.[9]

Complications

The most significant and potentially devastating postoperative complication in TRAM flap reconstruction is vascular compromise of the flap. Inadequate arterial inflow or impaired venous outflow can result in ischemia or venous congestion, respectively. The flap must be closely monitored in the immediate postoperative period, particularly within the first 6 to 8 hours, as early recognition and intervention are critical to flap salvage. Clinical signs of healthy perfusion include appropriate color, warmth, softness, brisk capillary refill, and adequate bleeding from pinprick testing. Conversely, signs of compromised perfusion may include pallor, duskiness, firmness, or delayed capillary refill.

If identified early, venous congestion may be addressed with nonsurgical measures such as patient repositioning, removing or loosening tight dressings, and increasing ambient room temperature. However, persistent signs of ischemia or congestion require prompt surgical reexploration. Most salvageable cases are identified within the first postoperative day. If nonviable tissue becomes evident over the following 3 to 4 days, flap debridement and local wound care are indicated. Other recipient site complications include hematoma, seroma, wound infection, wound dehiscence, fat necrosis, and palpable nodularity within the reconstructed breast mound.[11][16] Fat necrosis, which may present as firm lumps, results from poor adipose tissue perfusion and is more common in patients with risk factors such as smoking, diabetes, obesity, or large flap volumes.

Donor site complications are also a significant concern in TRAM flap reconstruction due to the sacrifice of the rectus abdominis muscle. The most frequently reported donor site complications include wound infection (up to 17%) and wound dehiscence (13.8%). Abdominal wall morbidity, including hernia or bulge formation, occurs in 3.5% to 9.9% of cases, as reported in results from recent large-scale studies over the past decade. These complications are more likely in patients with high BMI, poor nutritional status, prior abdominal surgery, or increased intra-abdominal pressure postoperatively.

Abdominal bulges occur more commonly with traditional pedicled TRAM flaps compared to muscle-sparing free-TRAM or DIEP flaps due to the extent of muscle sacrifice. Use of mesh reinforcement at the donor site and careful patient selection can help reduce the risk of these complications. Overall, the most significant risk factors for both donor and recipient site complications include obesity, active smoking, and poorly controlled diabetes.[9] These patient-related variables should be addressed preoperatively through smoking cessation programs, glycemic control, and weight optimization whenever possible to improve outcomes and reduce the risk of surgical failure.

Clinical Significance

The unipedicled TRAM flap is a significant and time-tested option in autologous breast reconstruction, offering a reliable method for recreating the breast mound using the patient’s tissue. One of its key advantages is that it does not require microvascular anastomoses, which reduces operative time and decreases the procedure's complexity and the risks associated with microsurgical techniques. This makes it particularly useful in centers without microsurgical expertise or for patients with comorbidities that preclude longer surgeries. Furthermore, the TRAM flap avoids using implants, which carry potential complications such as capsular contracture, rupture, or infection.

Clinically, the unipedicled TRAM flap uses the superior epigastric vascular pedicle, with flap perfusion strongest in the medial (zone I) tissues and progressively less reliable in lateral zones (especially zone IV). Consequently, the surgeon may need to trim or discard poorly perfused areas to reduce the risk of ischemia or fat necrosis, which remains one of the most significant postoperative complications. Nevertheless, when properly executed, the flap produces a breast mound that closely mimics natural breast tissue, contributing to high patient satisfaction.

However, not all patients are suitable candidates for this procedure. A TRAM flap is contraindicated or less favorable in thin women with insufficient abdominal tissue, patients with multiple prior abdominal surgeries that may compromise flap vascularity, and those who plan future pregnancies or are concerned about postoperative abdominal wall weakness. Since the unipedicled TRAM flap involves complete sacrifice of the rectus abdominis muscle, it carries a higher risk of abdominal bulge or hernia than muscle-sparing alternatives like free TRAM or DIEP flaps. In carefully selected patients, the unipedicled TRAM flap achieves excellent long-term results, particularly when part of a coordinated, interprofessional approach involving surgical oncology, plastic surgery, nursing, and physical therapy.[1][19][20] The technique continues to offer a durable, natural-feeling reconstruction, especially in patients for whom implant-based reconstruction is not desirable or feasible.

Enhancing Healthcare Team Outcomes

Effective TRAM flap breast reconstruction requires a highly coordinated, multidisciplinary approach to optimize outcomes and ensure patient safety. Surgeons must possess advanced flap design, dissection, and vascular preservation skills while considering patient-specific anatomical factors and comorbidities. Advanced clinicians and nurses play a vital role in preoperative education, surgical preparation, and postoperative monitoring, particularly in assessing flap viability, drain output, and signs of infection or ischemia. Pharmacists contribute by managing perioperative medications, including anticoagulation, pain control, and antibiotics, ensuring appropriate dosing and minimizing drug interactions. Each member must be skilled and aware of the surgical goals to reduce complications and maximize reconstructive success.

Interprofessional communication is essential from the initial consultation through postoperative recovery. Preoperative planning conferences between surgical oncology, plastic surgery, anesthesia, and nursing staff ensure a clear understanding of operative plans and contingency strategies. Postoperatively, regular team huddles and shared documentation facilitate timely recognition of complications such as flap congestion or abdominal wound issues. Coordination with physical therapy, nutrition, and social work supports holistic recovery. A patient-centered strategy—built on transparency, empathy, and collaborative decision-making—enhances satisfaction, reduces readmissions, and drives better functional and aesthetic outcomes.

Nursing, Allied Health, and Interprofessional Team Monitoring

Nurses should assist with monitoring patients after they wake up from anesthesia. They should evaluate the incision sites to ensure the sutures are holding and the wound is healing properly. The nurse may also identify potential infections and relay concerns to the surgical team if antibiotics are needed. Nurses will assess the patient and administer pain medication as necessary.

Patients are more susceptible to illness after surgery; nurses watch for signs of pneumonia or easily transmitted infections, such as staph. The nurses regularly check the patient’s vital signs, including heart rate, pulse, respiration, and temperature. If present, they also monitor the patient’s intravenous line and urinary catheter. If complications occur, nurses will communicate their concerns with the surgical team. Effective outcomes depend on coordination between the nurse and the surgeon.