CHAPTER 7 TRAM Flap Variations in Breast Reconstruction

Summary/Key Points

1. The pedicled transverse rectus abdominis myocutaneous (TRAM) flap still remains a very useful and the most popular method of autogenous breast reconstruction throughout the world.¹

2. Like any operation, careful planning and preoperative preparation is necessary in order to assure a successful outcome. In the TRAM flap this should include careful mapping of the perforators that will supply the flap.

3. In cases of patients with significant metabolic risk factors, TRAM flap variations such as a double-pedicled TRAM flap, a mid or upper abdominal TRAM flap, or a vascular delay of the TRAM flap should be considered. A free or perforator flap should be strongly considered in these patients if the expertise and facilities are available.

4. The choice of breast reconstruction depends on the characteristics of the mastectomy defect, the size and shape of the contralateral breast, and the condition and desires of the patient. Equally important is the experience of the surgeon.

5. In choosing autogenous reconstruction of the breast, a single-pedicled TRAM flap still remains an excellent choice in a healthy patient.

6. The increasing use of adjuvant radiation therapy has changed the trend from immediate breast reconstruction to a delayed form of breast reconstruction.

Patient Selection

Patient selection as in other surgical procedures is of critical importance in the success of breast reconstruction and in particular in the area of autologous breast reconstruction. Carl R. Hartrampf who developed and popularized the TRAM flap (originally termed by him as the transverse abdominal island flap) developed a strict criteria for patient selection that included patient risk factors as well as surgeon experience.²

Once it has been determined that the patient is a candidate for breast reconstruction and has the desire and realistic expectations of what this involves, a more thorough evaluation of the patient can proceed for surgical repair.³^,⁴ The risk factors that keep coming up in studies as most significant include obesity, a strong smoking history, significant metabolic or cardiovascular compromise and a history or intention of using radiation therapy to the breast cancer site. These risk factors need to be considered individually and in combination in order to make a final decision whether breast reconstruction should be performed and what type is most appropriate. This chapter will concentrate on variations of the traditional TRAM flap that can in certain situations improve the chance of a successful outcome.

Indications

TRAM flap reconstruction can give a very satisfying outcome to the patient who has recently experienced the shock and hardship of a diagnosis of breast cancer. It does however require a considerable investment of time and effort on the part of the patient and the surgeon in order to achieve optimal results. The TRAM flap can also be used for other forms of chest reconstruction resulting from tumor excision or congenital problems such as Poland’s syndrome. It has been used very effectively based on the more robust inferior epigastric pedicle for pelvic and perineal reconstruction due to tumors, trauma, and other causes requiring a large volume of well vascularized tissue. The algorithmic flow charts in Figures 7.1, 7.2, 7.3 and 7.4 show the indications for the TRAM flap and its variations based on morphologic and treatment characteristics.

Fig. 7.1 Single-pedicled TRAM flap algorithm.

Fig. 7.2 Bipedicled TRAM flap algorithm.

Fig. 7.3 Delayed TRAM flap indications.

Fig. 7.4 Midabdominal TRAM flap indications.

The most common indication for TRAM flap reconstruction is for a patient with breast cancer who will undergo or has undergone some form of mastectomy. This brings up the issues of immediate or delayed reconstruction which has again become a timely concern with the increasing use of adjuvant radiation therapy for breast cancer. Many studies over the years have shown that immediate reconstruction is a very good option.⁵ It does not add to the oncologic risks to the patient whether a traditional mastectomy or the increasingly popular skin-sparing mastectomy is performed.⁶^,⁷ It also permits the surgeon to perform an excellent reconstruction knowing how much breast tissue and volume have been removed, working with native tissues unaffected by scar and contracture, and having a three-dimensional image of the needs for reconstruction. It also permits the patient to recover more quickly overall from the ablative and reconstructive procedures. A psychological benefit in not experiencing a loss of the breast has also been noted, although there are recent counter-arguments in this regard.⁷ However if post-mastectomy radiation therapy is indicated this will adversely affect the aesthetic outcome of the reconstructive procedure. This has been shown in cases of immediate and even delayed reconstruction.⁸ The major problem arises when the decision for radiation therapy is determined after the operation when the final pathology of the specimen is determined. This usually occurs about one week after the mastectomy procedure. Several centers will prescribe delayed reconstruction in the patients with a high risk or a high potential for post-mastectomy radiation therapy. At times, reconstruction is temporized by placing a tissue expander in the mastectomy pocket that will be removed after radiation therapy or at the time of the delayed TRAM flap reconstruction.⁹

The size and extent of the mastectomy defect will also determine the type of breast reconstruction to be performed. The size and shape of the contralateral breast is also important in the decision making process. A single-pedicled TRAM flap is appropriate for a small to moderate size defect along with a small to moderate contralateral breast. Increased size and volume may require a double-pedicled TRAM flap or a delay procedure or even free tissue transfer. The anatomy of the patient is also important in deciding what procedure to perform. We do not see many subcostal (Kocher) incisions for cholecystectomy any more that would require a left-sided single-pedicled TRAM flap. An infraumbilical midline incision is not uncommon, however. In these situations we would consider a single-pedicled hemi-flap, or if more volume is required a double-pedicled TRAM flap in order to use all of the lower abdominal tissue.

The pedicled TRAM flap is not indicated in a woman who does not want to lose a significant amount of their rectus abdominis musculature. Although studies have gone back and forth as to the significance of abdominal wall continence and strength with the removal of one or two rectus muscles, some form of donor deformity is to be expected. Athletic patients that routinely use their abdominal muscles should be offered other options such as perforator flaps of the deep inferior epigastric (DIE) vessels or superficial inferior epigastric (SIE) flaps or other methods.

Other contraindications for TRAM flap reconstruction are significant systemic disease such as cardiovascular and respiratory problems as well as insulin-dependent diabetes. Hartrampf included insulin-dependent diabetes as one of his significant risk factors. Other groups have not placed as much importance with this.¹⁰ I personally have experienced some significant infectious complications in patients with insulin-dependent diabetes and so I am particularly cautious in these patients.

Morbid obesity and smoking have been shown in several studies to be significant risk factors in all forms of breast reconstructions including the TRAM flap.¹¹^,¹² Variations of the TRAM flap need to be considered in these cases. In the morbidly obese, a midabdominal TRAM flap, a delayed or a double-pedicled TRAM flap may be indicated if it is decided to do any surgery at all. Similarly, in a chronic smoker or one that has recently quit, these TRAM flap variations may also be useful. All attempts, of course, should be made for weight reduction and cessation of smoking prior to performing autologous breast reconstruction.

The experience and comfort level of the surgeon and the surgical team is an important factor in the final indication and decision for a particular type of breast reconstruction. The relative ease and decreased time of performing a TRAM flap makes it a most desirable method of reconstruction. However the surgeon should discuss the various options available in an honest and humble manner with the patient prior to making the final decision. Our understanding of the vascular supply of the TRAM flap is based on a great number of anatomical studies. The more recent classification of Ninkovic et al has refined our understanding of the zones of perfusion. This classification places more importance on the ipsilateral perfusion than the older Hartrampf classification that assigned greater importance across the midline (see Fig. 7.5).

Fig. 7.5 Newer classification of blood perfusion of the pedicled TRAM and free TRAM flaps according to Ninkovic et al.²⁴

Operative Technique

Preoperative preparation

The preoperative preparation of the patient should be well structured and thorough. The amount of time and effort that goes into this preparation will reap benefits intraoperatively as well as in the postoperative period. Any imaging or non-invasive vascular studies, such as laser Doppler flow studies, or computerized tomography (CT) angiogram ¹³ can be conducted preoperatively in order to get a good assessment of the vasculature of the lower abdomen and chest. This is not a substitute for careful operative dissection but can be useful in patients with risk factors that may also include previous scars on the abdomen. Preoperative marking is very important and should be done with the patient in a standing position. Scars of the abdomen are noted; they may include an upper or lower midline scar, appendectomy scar, paramedian scar, or a Pfannenstiel incision. All of these will impact on the type of TRAM flap that will be proposed as well as the incision of the flap. For instance, a lower midline incision may dictate a double-pedicled TRAM flap if a large volume of tissue is needed for reconstruction. The size of the contralateral breast is also taken into consideration. If any modifications are going to be made during the procedure or in a subsequent operation, this also needs to be taken into account. If it is an immediate reconstruction, the size and weight of the mastectomy specimen will be readily available. If it is a delayed reconstruction, it is useful to ascertain the size and weight of the prior mastectomy specimen. This was a very important piece of information to Hartrampf in deciding and predicting the amount of tissue needed for reconstruction. The midline of the abdomen from the xiphoid to the pubis is drawn. A lenticular or transverse elliptical pattern is then drawn on the lower abdomen. An attempt to establish symmetry on both sides is made. The anterior–superior iliac spines are delineated and used in the markings. A pinching of the lower abdominal tissue in order to get an idea for closure is then performed. Adjustments are made according to the ability to be able to close the abdominal wound once the flap has been raised.

Attention is then directed to the chest. In cases of immediate reconstruction, the marks for the resection are drawn jointly with the surgical oncologist. If possible a skin-sparing mastectomy technique should be used since it gives a better result overall. In situations of delayed reconstruction, the outline of the breast for reconstruction on the mastectomy site is drawn. The width and height of the breast is taken from the contralateral breast, if this is being used as a reference. Projection of the breast will be obtained by appropriate positioning and infolding of the excess pedicle tissue.

The patient is placed in a supine position and general endotracheal anesthesia is induced. A Foley catheter is placed and checked to be in good working condition. Sequential compression devices are now applied to both lower extremities. If the patient is at high risk for DVT or pulmonary embolus, prophylaxis with low molecular weight heparin or other indicated prophylactic drugs are given. Guidelines that include a list of risk factors should be followed to help in preventing thromboembolic disease.¹⁴ Blood is screened but not cross-matched for possible transfusion which has become rare in ablative and reconstructive breast procedures.

Prior to prepping and draping the patient, the surgeon is advised to perform a careful Doppler examination of the abdomen and chest to look for appropriate perforators. This will serve as a good road map to follow during the dissection and will also confirm the type of TRAM flap or variation to be performed. The perforators are marked in ink that should not be washed off.

Surgical technique

Variation I: double-pedicled TRAM flap

The operative technique for a single-pedicled and double-pedicled TRAM flap (DPTF)¹⁵ reconstruction initially is similar. Since the DPTF is much better vascularized, a larger flap can be drawn on the abdomen as both rectus muscle pedicles will be used (see Fig. 7.6

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