Breast, Reconstruction, Unipedicled Tram

Article Author:
Darren Sachs
Article Editor:
Steve Bhimji
Updated:
10/27/2018 12:31:26 PM
PubMed Link:
Breast, Reconstruction, Unipedicled Tram

Introduction

Breast reconstruction with a transverse rectus abdominis myocutaneous flap is a specific type of breast construction that allows women a delayed or immediate breast restoration. Since the tissue that is being used is part of the patient's body, this has many benefits for the patient. First, it is not a foreign body so the common complications associated with breast implants, inflammatory reaction, or capsular contracture, are avoided. Second, the scar from the abdominal donor site can be hidden under most clothing styles. 

The first step in deciding if a patient is a candidate for this procedure is to assess the patient. The practitioner should focus on the breast defect and the volume needed to correct it. For immediate reconstruction of the breast, both oncologic and reconstructive surgeons can operate simultaneously and communicate about the incisions and mastectomy defect. If doctor and patient decide on a delayed repair, a transverse rectus abdominis (TRAM) flap can provide additional skin and fatty tissue for breast volume and closure. A transverse rectus abdominis (TRAM) flap is a better option for patients with larger breasts or significant ptosis. The most important factor for aesthetic success is the match between the tissue volume of the transverse rectus abdominis (TRAM) flap and the other breast. The abdominal pannus is used to reconstruct the breast. Therefore, thicker abdominal pannus for a smaller breast reconstruction often requires a secondary revision for symmetry, while a thin patient with larger breasts would not be an ideal candidate. They may need implant augmentation of the transverse rectus abdominis (TRAM) flap or reduction of the opposite breast. The main advantage of the procedure for the patient is the similarity to a natural breast. This includes the softness and the way the tissue appears on the chest.

Anatomy

The important anatomy to focus on is the vascular supply to the abdomen and the flap. The abdominal vascular supply can be divided into three zones based upon the regional anatomy. Zone I is the central abdomen. The branches of the deep and superficial superior epigastric arteries supply this zone. In zone II, the four main arteries supply the inferior abdomen. These include the deep inferior epigastric artery, deep circumflex iliac artery, the superficial circumflex iliac artery, and the superficial external pudendal artery. Zone III is the lateral or peripheral abdomen. The intercostal arteries, subcostal arteries, and lumbar arteries supply this zone.

Vascular supply of the abdominal flap is based upon Hartrampf perfusion zones. There are four different but equal sized zones, each with a different perfusion. The idea is that the zones immediately adjacent to the vascular pedicle have better perfusion compared to the lateral zones. The medial zones are I and II, while the lateral zones are III and IV. Therefore, surgeons resect the higher zones first and leave the lower zones for reconstruction.

Indications

Breast reconstruction is indicated for any women who undergoes a breast surgery for oncological reasons. Some women try external prosthesis, but often they feel this restricts their lifestyle and can negatively affect their self-image. A transverse rectus abdominis (TRAM) flap provides an excellent breast reconstruction for women in good health who want to avoid breast implants. Discussion about the compliance with the postoperative recovery and an understanding of the abdominal scars are important. The procedure is particularly attractive for women with previous radiation to the chest wall. Radiation is associated with scaring and capsular contracture when a patient chooses implant reconstruction. Patients with excess lower abdominal tissue and desire abdominoplasty might be in favor of this procedure as well.

Contraindications

Due to the complexity and length of the procedure, contraindications for this procedure are usually based on the blood supply to the flap and the overall health of the patient. The most important factor to a reconstructive surgeon is the blood supply since it sets the limit for the amount of tissue available. Patients must be assessed for upper abdominal scars because postoperative scars can interfere with blood supply of the flap. The transverse rectus abdominis (TRAM) flap relies on one specific blood supply which if incised previously would make the procedure extremely risky for the patient. Ipsilateral subcostal and paramedian incisions or a chevron incision are specific contraindications because there is disruption of the blood supply to both rectus pedicles. Vertical midline scars should only disrupt flow to the contralateral side. Transverse rectus abdominis (TRAM) flaps used after abdominoplasty procedures are risky because the perforators to skin and subcutaneous tissue from the pedicle have been surgically divided. Previous abdominal liposuction may also disrupt major perforators putting the skin and subcutaneous tissue at risk of necrosis as well. Another issue with vertically or horizontally scars across the transverse rectus abdominis (TRAM) flap is they reduce the breast mound, which is important for large breasted patients. The scar is not aesthetically pleasing and should not be included in the flap. Hartrampf believes medical conditions including severe cardiovascular disease, chronic obstructive pulmonary disease, uncontrolled hypertension, morbid obesity, and insulin dependent diabetes are contraindications to a successful reconstruction as well. Smoking, moderate obesity, autoimmune disease, and non-insulin dependent diabetes increase the complication risk.

Preparation

Preoperatively, the surgeon will mark the abdomen as if doing an abdominoplasty procedure. For the unipedicle transverse rectus abdominis (TRAM) flap, a contralaterally or ipsilaterally based flap can be designed. This is preferred when less than 60% to 70% of the lower abdominal ellipse is needed, or the patient has no history of impaired microvascular circulation. First, a superior line is drawn from the superior border of the umbilicus to each anterior superior iliac spine. This line is based on the size of the abdominal pannus. Then an inferior skin line is drawn from the suprapubic crease laterally upward to meet the upper line at the iliac spine creating an ellipse. This is the margins of your flap. Next, the midline from the suprasternal notch to the pubis is marked. The inframammary fold of the remaining breast is marked and transferred as a mirror image to the reconstructed side 1 cm to 2 cm above. Lastly, the remaining breast is measured to determine how much abdominal issue is needed to obtain symmetry between the breasts. These measurements are marked on the flap.

Technique

The goal is to perform a safe and reliable transverse rectus abdominis (TRAM) flap while minimizing harm to the abdominal wall. In the operating room, the transverse rectus abdominis (TRAM) flap is mobilized off the abdominal wall 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 through to be placed on the chest wall. Once the flap is positioned in the breast pocket, it is tacked in place and further shaped. The flap is tacked down circumferentially and examined in an upright position to confirm symmetry. The flap is trimmed to conform to the mastectomy flaps and breast shape. The abdominal wall defect is closed primarily, but if the abdominal muscles appear weak, an interposition piece of mesh is necessary to prevent future hernias. The fascia is closed in two layers and imbricated in the epigastric and lower suprapubic area to prevent a bulge. The rest of the abdominal closure is performed in a multiple layer form 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 under the abdominal flap and inside the breast pocket. The procedure is completed with skin closure and applying a dressing.

Complications

The most significant post-operative complication is the lack of blood supply to the flap. This lack of blood causes ischemia. After the procedure is complete, the flap is monitored extremely closely for any signs of malperfusion. It is important to monitor the flap for warmth, capillary refill, softness, and color. It is also important to monitor the output of the drains. If the flap becomes congested, observation is the usual treatment. If ischemia or congestion is recognized within the first six to eight hours, the patient can be taken back to the operating room for immediate repair. If congestion and demarcation occur in the first three or four days, the flap can be debrided and local wound care performed. Other complications include wound infection, wound dehiscence, bleeding, abdominal hernias, and lumps in the new breast mound.

Clinical Significance

The Unipedicle Tram Flap is an important alternative in breast reconstruction. This procedure does not require microvascular anastomosing techniques, which allows shorter operative time and fewer complications. A transverse rectus abdominis flap also avoids the use of foreign bodies which carry their own risks of complications. There is a high degree of patient satisfaction because of the similarity to breast tissue, but not every patient is a candidate for this procedure. If the patient is a thin woman with minimal extra abdominal tissue, has multiple abdominal surgeries, plans on getting pregnant, or is concerned about the strength of her lower abdomen, then alternative procedures would be ideal.