(Radiographics. 1999;19:1593-1603.)
© RSNA, 1999
Breast Reconstruction with TRAM Flaps: Normal and Abnormal Appearances at CT1
Mark A. LePage, MD,
Ella A. Kazerooni, MD,
Mark A. Helvie, MD and
Edwin G. Wilkins, MD
1 From the Department of Radiology (M.A.L., E.A.K., M.A.H.) and the Department of Surgery, Section of Plastic and Reconstructive Surgery (E.G.W.), University of Michigan Health System, 1500 E Medical Center Dr, Ann Arbor, MI 48109-0326. Recipient of a Certificate of Merit award for a scientific exhibit at the 1998 RSNA scientific assembly. Received February 9, 1999; revision requested March 3 and received March 17; accepted March 24. Address reprint requests to E.A.K.
 |
Abstract
|
|---|
In the transverse rectus abdominis musculocutaneous (TRAM) flap procedure, a portion of the abdominal wall is transposed to the chest as a pedicle or free flap. Patients who have undergone this procedure often subsequently undergo computed tomography (CT) for assessment of metastatic disease or unrelated pathologic conditions. CT scans obtained in patients who had undergone the TRAM flap procedure were reviewed to facilitate recognition of both the normal and abnormal postoperative CT appearances of the TRAM flap. In 28 reconstructed breasts in 21 patients, three general appearances were identified: type 1 (homogeneous fat attenuation) (n = 4), type 2 (fat attenuation with a thin, curvilinear soft-tissue band parallel to the skin surface) (n = 19), and type 3 (thick soft-tissue band parallel to the skin surface) (n = 5). A mass that arose in a type 2 breast 21 months after surgery represented recurrent cancer. A markedly thickened soft-tissue band in another patient represented a dry eschar with inflammation and fat necrosis. The rectus abdominis muscle was partially absent in eight cases and completely absent in 20 cases. Recognition of the normal postoperative appearance of the body wall helps avoid confusion with disease states and allows identification of abnormal conditions such as inflammation, infection, and recurrent breast cancer.
Index Terms: Breast, CT, 00.1211 • Breast, postoperative, 00.4545, 00.458 • Breast, surgery, 00.4545 • Muscles, denervation, 00.458
|
INTRODUCTION
|
|---|
The transverse rectus abdominis musculocutaneous (TRAM) flap procedure is a commonly performed breast reconstruction technique after mastectomy for breast cancer (1). Subcutaneous fat from the abdominal wall and all or part of one or both rectus abdominis muscles is transferred to the chest wall to reconstruct the breast (2). The TRAM flap technique was described by Hartrampf et al (3) in 1982 and can be performed either at the time of mastectomy or at a later date. It is the most commonly used procedure for autogenous or natural-tissue breast reconstruction and allows creation of a realistic-looking breast (1). Nipple reconstruction is also performed. There are two major variants of the TRAM flap procedure: pedicle TRAM flap reconstruction (Figs 1, 2) and free or microsurgical TRAM flap reconstruction (Fig 3). The latter is generally preferred when improved vascularity of the flap is required (4). Bilateral procedures can be performed at the same time (Fig 2).
With the pedicle TRAM flap procedure, a large ellipse of lower abdominal fat and skin is obtained with a transverse abdominal incision made either ipsilateral or contralateral to the breast to be reconstructed (Fig 4a, 4b). The flap remains attached to the underlying rectus muscle, which carries the blood supply to the flap (Fig 4c). The flap is then tunneled into the mastectomy
site, where it is used to form the reconstructed breast (Fig 4d– 4f) (2,5,6). A small portion of the epidermis is left intact and forms part of the skin surface of the new breast. The remainder of the TRAM flap surface is de-epithelialized and tunneled under the native skin of the chest wall and subcutaneous tissue. This tunneling helps prevent the formation of sebaceous cysts under the native chest wall skin.
View larger version (111K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4a. Unilateral breast reconstruction with a pedicle TRAM flap. (a) Photograph shows lines drawn on the abdominal wall indicating the borders of the right rectus muscle (cross-hatching) and the blood supply of the abdominal wall (I-IV). Region I indicates the area of best blood supply and region IV the area of poorest blood supply for the flap that will be taken from the muscle. (b) Photograph shows transverse abdominal incisions that create an ellipse of abdominal fat and skin. (c) Photograph shows the raised flap, which includes the rectus muscle. (d) Photograph shows the tunnel through which the flap will be pulled. (e) Photograph shows the abdominal wall flap pulled through the tunnel. Portions of the flap are visible at both the abdominal and breast incisions (arrows). (f) Photograph shows perioperative results before final suturing of the flap.
|
|
View larger version (103K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4b. Unilateral breast reconstruction with a pedicle TRAM flap. (a) Photograph shows lines drawn on the abdominal wall indicating the borders of the right rectus muscle (cross-hatching) and the blood supply of the abdominal wall (I-IV). Region I indicates the area of best blood supply and region IV the area of poorest blood supply for the flap that will be taken from the muscle. (b) Photograph shows transverse abdominal incisions that create an ellipse of abdominal fat and skin. (c) Photograph shows the raised flap, which includes the rectus muscle. (d) Photograph shows the tunnel through which the flap will be pulled. (e) Photograph shows the abdominal wall flap pulled through the tunnel. Portions of the flap are visible at both the abdominal and breast incisions (arrows). (f) Photograph shows perioperative results before final suturing of the flap.
|
|
View larger version (122K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4c. Unilateral breast reconstruction with a pedicle TRAM flap. (a) Photograph shows lines drawn on the abdominal wall indicating the borders of the right rectus muscle (cross-hatching) and the blood supply of the abdominal wall (I-IV). Region I indicates the area of best blood supply and region IV the area of poorest blood supply for the flap that will be taken from the muscle. (b) Photograph shows transverse abdominal incisions that create an ellipse of abdominal fat and skin. (c) Photograph shows the raised flap, which includes the rectus muscle. (d) Photograph shows the tunnel through which the flap will be pulled. (e) Photograph shows the abdominal wall flap pulled through the tunnel. Portions of the flap are visible at both the abdominal and breast incisions (arrows). (f) Photograph shows perioperative results before final suturing of the flap.
|
|
View larger version (105K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4d. Unilateral breast reconstruction with a pedicle TRAM flap. (a) Photograph shows lines drawn on the abdominal wall indicating the borders of the right rectus muscle (cross-hatching) and the blood supply of the abdominal wall (I-IV). Region I indicates the area of best blood supply and region IV the area of poorest blood supply for the flap that will be taken from the muscle. (b) Photograph shows transverse abdominal incisions that create an ellipse of abdominal fat and skin. (c) Photograph shows the raised flap, which includes the rectus muscle. (d) Photograph shows the tunnel through which the flap will be pulled. (e) Photograph shows the abdominal wall flap pulled through the tunnel. Portions of the flap are visible at both the abdominal and breast incisions (arrows). (f) Photograph shows perioperative results before final suturing of the flap.
|
|
View larger version (119K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4e. Unilateral breast reconstruction with a pedicle TRAM flap. (a) Photograph shows lines drawn on the abdominal wall indicating the borders of the right rectus muscle (cross-hatching) and the blood supply of the abdominal wall (I-IV). Region I indicates the area of best blood supply and region IV the area of poorest blood supply for the flap that will be taken from the muscle. (b) Photograph shows transverse abdominal incisions that create an ellipse of abdominal fat and skin. (c) Photograph shows the raised flap, which includes the rectus muscle. (d) Photograph shows the tunnel through which the flap will be pulled. (e) Photograph shows the abdominal wall flap pulled through the tunnel. Portions of the flap are visible at both the abdominal and breast incisions (arrows). (f) Photograph shows perioperative results before final suturing of the flap.
|
|
View larger version (108K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 4f. Unilateral breast reconstruction with a pedicle TRAM flap. (a) Photograph shows lines drawn on the abdominal wall indicating the borders of the right rectus muscle (cross-hatching) and the blood supply of the abdominal wall (I-IV). Region I indicates the area of best blood supply and region IV the area of poorest blood supply for the flap that will be taken from the muscle. (b) Photograph shows transverse abdominal incisions that create an ellipse of abdominal fat and skin. (c) Photograph shows the raised flap, which includes the rectus muscle. (d) Photograph shows the tunnel through which the flap will be pulled. (e) Photograph shows the abdominal wall flap pulled through the tunnel. Portions of the flap are visible at both the abdominal and breast incisions (arrows). (f) Photograph shows perioperative results before final suturing of the flap.
|
|
With the free TRAM flap procedure, an ellipse of abdominal fat and skin is obtained with a transverse abdominal incision as with the pedicle procedure. However, the ellipse of tissue including the underlying rectus muscle is separated completely from the anterior abdominal wall and transposed to the chest wall, where it is used to reconstruct the breast (Fig 5). The vessels that supply the ellipse of tissue are anastomosed to the thoracodorsal vessels of the chest wall with the use of microsurgical techniques (1,4,7). As with the pedicle TRAM flap procedure, a small portion of the epidermis is left intact and forms part of the skin surface of the new breast, and the remainder of the TRAM flap surface is de-epithelialized and tunneled under the native chest wall skin and subcutaneous tissue. With both free and pedicle TRAM flap procedures, the rectus muscle flap is denervated and atrophies over time. This atrophy is desired to avoid a masslike appearance caused by the contracted muscle in the chest wall after surgery.
View larger version (121K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5a. Bilateral breast reconstructions with free TRAM flaps. (a) Photograph shows transverse abdominal incisions that create an ellipse of abdominal fat and skin. (b) Photograph shows bilateral breast incisions with the free flaps lying next to the incisions (arrows). (c) Photograph shows postoperative results after healing.
|
|
View larger version (110K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5b. Bilateral breast reconstructions with free TRAM flaps. (a) Photograph shows transverse abdominal incisions that create an ellipse of abdominal fat and skin. (b) Photograph shows bilateral breast incisions with the free flaps lying next to the incisions (arrows). (c) Photograph shows postoperative results after healing.
|
|
View larger version (137K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 5c. Bilateral breast reconstructions with free TRAM flaps. (a) Photograph shows transverse abdominal incisions that create an ellipse of abdominal fat and skin. (b) Photograph shows bilateral breast incisions with the free flaps lying next to the incisions (arrows). (c) Photograph shows postoperative results after healing.
|
|
Descriptions of the radiologic appearance of this increasingly utilized procedure are sparse in the literature; they include the mammographic findings of recurrent cancer in the TRAM flap (8) and a few published images demonstrating the normal appearance of the TRAM flap at computed tomography (CT) (9). The use of TRAM flaps has increased since controversy arose over the use of silicone gel–filled implants and the implants were taken off the market. In addition, CT is frequently used for evaluation of disease in implant recipients with known or suspected breast cancer. Consequently, normal and abnormal morphologic changes associated with the TRAM flap procedure will be encountered and should be recognized as such. In this article, we discuss and illustrate the normal and abnormal CT appearances of TRAM flaps in breast reconstruction.
|
MATERIALS AND METHODS
|
|---|
All CT scans obtained in patients who underwent a TRAM flap procedure at our institution between 1990 and 1997 (n = 21) were reviewed for the morphology of the reconstructed breast and abdominal wall. The mean age of patients at the time of surgery was 48.7 years. CT was performed 1–143 months (mean, 39.5 ± 37.1 months) after surgery. Nine of 21 patients underwent one CT examination, five underwent two, four underwent three, and one patient each underwent four, five, and six CT examinations (46 examinations in all). The images obtained at CT included 35 chest scans, 34 abdominal scans, and 18 pelvic scans, with combined CT scans of the chest, abdomen, or pelvis obtained in many patients. A total of 28 reconstructed breasts were evaluated. Each reconstructed breast was categorized as type 1, 2, or 3 on the basis of its CT appearance (Figs 6–8) (Table 1). CT scans were evaluated for type of breast reconstruction (Table 2), presence of abdominal and chest wall surgical clips, and presence of the rectus abdominis musculature. For pedicle TRAM flaps, we noted the level at which the belly of the rectus muscle used for reconstruction crossed the midline relative to the anterior costal cartilage and measured the thickness of the contralateral native rectus muscle for comparison. The clinical indications for which CT was performed were also noted (Table 3). The most common clinical indication was the need for evaluation of known or suspected breast cancer metastases.
View larger version (123K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 6. Type 1 appearance of a reconstructed left breast in a 66-year-old woman 7 months after chest wall reconstruction with a unilateral pedicle TRAM flap for breast cancer. CT scan shows homogeneous fat attenuation of the reconstructed breast (arrowheads). Methyl methacrylate (arrows) was used in this procedure, in which partial resection of the chest wall was performed.
|
|
View larger version (119K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7a. Type 2 appearance of reconstructed breasts in a 47-year-old woman 34 months after bilateral reconstruction with pedicle TRAM flaps. (a) CT scan shows fat-attenuation breasts with a thin, curvilinear soft-tissue band (arrows) representing the skin from the abdominal wall flaps. (b) CT scan shows complete absence of the rectus abdominis muscles (arrowheads). A hepatic cyst is incidentally noted.
|
|
View larger version (139K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 7b. Type 2 appearance of reconstructed breasts in a 47-year-old woman 34 months after bilateral reconstruction with pedicle TRAM flaps. (a) CT scan shows fat-attenuation breasts with a thin, curvilinear soft-tissue band (arrows) representing the skin from the abdominal wall flaps. (b) CT scan shows complete absence of the rectus abdominis muscles (arrowheads). A hepatic cyst is incidentally noted.
|
|
View larger version (134K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 8. Type 3 appearance of reconstructed breasts in a 60-year-old woman with adult respiratory distress syndrome 12 days after bilateral reconstruction with ipsilateral pedicle TRAM flaps. CT scan shows thick soft-tissue bands parallel to the skin surface within the breasts.
|
|
|
RESULTS
|
|---|
Unilateral Pedicle TRAM Flap
CT features of the 13 unilateral pedicle TRAM flaps are summarized in Table 4. Most of the reconstructed breasts (nine of 13 [69%]) had a type 2 appearance consisting of a thin, curvilinear band of soft tissue that paralleled the skin contour of the breast (Fig 7a). In all 13 cases, the corresponding rectus muscle was completely absent from the anterior abdominal wall (Fig 7b). Three of the reconstructed breasts had type 1 homogeneous fat attenuation and one had a type 3 appearance. Surgical clips were present in the chest wall in eight cases (62%) and in the corresponding rectus muscle sheath in 10 cases (77%). In all cases, the rectus muscle crossed the midline at the level of the fifth, sixth, or seventh costal cartilage.
The thickness of the rectus abdominis muscle used in breast reconstruction was compared with that of the contralateral native rectus muscle. Postsurgical changes over time in the thickness of the former were evaluated (Fig 9). Figure 10 demonstrates the appearance of the abdominal wall before and after TRAM flap reconstruction. In general, the rectus muscle used in reconstruction decreased in thickness over time following surgery, and, except during the immediate postsurgical period, it was less thick than the contralateral native rectus muscle, a finding that reflects denervation atrophy (Figs 11, 12). In the one reconstructed breast with a type 3 appearance, CT demonstrated an abnormally thickened abdominal wall flap representing an eschar with chronic inflammation and fat necrosis (Fig 13).
View larger version (13K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 9. Graph shows postsurgical atrophy of the transposed rectus muscle over time for each patient individually and for the patient population as a whole. Each symbol represents a different patient.
|
|
View larger version (130K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 10a. Resection of the right rectus muscle after unilateral breast reconstruction with a pedicle TRAM flap. (a) CT scan obtained 1 month before surgery shows normal bilateral rectus muscles (arrowheads). (b) CT scan obtained 10 years after surgery shows complete absence of the right rectus muscle (arrowheads).
|
|
View larger version (135K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 10b. Resection of the right rectus muscle after unilateral breast reconstruction with a pedicle TRAM flap. (a) CT scan obtained 1 month before surgery shows normal bilateral rectus muscles (arrowheads). (b) CT scan obtained 10 years after surgery shows complete absence of the right rectus muscle (arrowheads).
|
|
View larger version (106K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11a. Rectus muscle atrophy after breast reconstruction with a pedicle TRAM flap. (a) CT scan obtained 1 month after surgery shows the reconstructed right breast with a type 2 appearance. (b) CT scan obtained at the same time as a shows a 12-mm-thick rectus muscle from the left abdominal wall (arrowheads) crossing from left to right at the level of the sixth costal cartilage with adjacent surgical clips. (c) CT scan obtained at the same level 6 months later shows atrophy of the rectus muscle (arrowheads), which is now only 4 mm thick. (d, e) Mediolateral oblique (d) and craniocaudal (e) mammograms show fat density of the reconstructed right breast in contrast to the fibroglandular tissue of the left breast. Note also the soft tissue of the muscle flap against the chest wall with adjacent surgical clips on the oblique view (arrows in d) and the curvilinear soft-tissue band on the craniocaudal view (arrowheads in e).
|
|
View larger version (130K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11b. Rectus muscle atrophy after breast reconstruction with a pedicle TRAM flap. (a) CT scan obtained 1 month after surgery shows the reconstructed right breast with a type 2 appearance. (b) CT scan obtained at the same time as a shows a 12-mm-thick rectus muscle from the left abdominal wall (arrowheads) crossing from left to right at the level of the sixth costal cartilage with adjacent surgical clips. (c) CT scan obtained at the same level 6 months later shows atrophy of the rectus muscle (arrowheads), which is now only 4 mm thick. (d, e) Mediolateral oblique (d) and craniocaudal (e) mammograms show fat density of the reconstructed right breast in contrast to the fibroglandular tissue of the left breast. Note also the soft tissue of the muscle flap against the chest wall with adjacent surgical clips on the oblique view (arrows in d) and the curvilinear soft-tissue band on the craniocaudal view (arrowheads in e).
|
|
View larger version (123K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11c. Rectus muscle atrophy after breast reconstruction with a pedicle TRAM flap. (a) CT scan obtained 1 month after surgery shows the reconstructed right breast with a type 2 appearance. (b) CT scan obtained at the same time as a shows a 12-mm-thick rectus muscle from the left abdominal wall (arrowheads) crossing from left to right at the level of the sixth costal cartilage with adjacent surgical clips. (c) CT scan obtained at the same level 6 months later shows atrophy of the rectus muscle (arrowheads), which is now only 4 mm thick. (d, e) Mediolateral oblique (d) and craniocaudal (e) mammograms show fat density of the reconstructed right breast in contrast to the fibroglandular tissue of the left breast. Note also the soft tissue of the muscle flap against the chest wall with adjacent surgical clips on the oblique view (arrows in d) and the curvilinear soft-tissue band on the craniocaudal view (arrowheads in e).
|
|
View larger version (132K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11d. Rectus muscle atrophy after breast reconstruction with a pedicle TRAM flap. (a) CT scan obtained 1 month after surgery shows the reconstructed right breast with a type 2 appearance. (b) CT scan obtained at the same time as a shows a 12-mm-thick rectus muscle from the left abdominal wall (arrowheads) crossing from left to right at the level of the sixth costal cartilage with adjacent surgical clips. (c) CT scan obtained at the same level 6 months later shows atrophy of the rectus muscle (arrowheads), which is now only 4 mm thick. (d, e) Mediolateral oblique (d) and craniocaudal (e) mammograms show fat density of the reconstructed right breast in contrast to the fibroglandular tissue of the left breast. Note also the soft tissue of the muscle flap against the chest wall with adjacent surgical clips on the oblique view (arrows in d) and the curvilinear soft-tissue band on the craniocaudal view (arrowheads in e).
|
|
View larger version (123K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 11e. Rectus muscle atrophy after breast reconstruction with a pedicle TRAM flap. (a) CT scan obtained 1 month after surgery shows the reconstructed right breast with a type 2 appearance. (b) CT scan obtained at the same time as a shows a 12-mm-thick rectus muscle from the left abdominal wall (arrowheads) crossing from left to right at the level of the sixth costal cartilage with adjacent surgical clips. (c) CT scan obtained at the same level 6 months later shows atrophy of the rectus muscle (arrowheads), which is now only 4 mm thick. (d, e) Mediolateral oblique (d) and craniocaudal (e) mammograms show fat density of the reconstructed right breast in contrast to the fibroglandular tissue of the left breast. Note also the soft tissue of the muscle flap against the chest wall with adjacent surgical clips on the oblique view (arrows in d) and the curvilinear soft-tissue band on the craniocaudal view (arrowheads in e).
|
|
View larger version (129K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 12a. Rectus muscle atrophy after unilateral breast reconstruction (type 1) with a pedicle TRAM flap. (a) CT scan obtained 1 month after surgery shows the rectus muscle in the chest wall (arrow). (b) CT scan obtained at the same level 6 months later shows muscle flap atrophy (arrow).
|
|
View larger version (128K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 12b. Rectus muscle atrophy after unilateral breast reconstruction (type 1) with a pedicle TRAM flap. (a) CT scan obtained 1 month after surgery shows the rectus muscle in the chest wall (arrow). (b) CT scan obtained at the same level 6 months later shows muscle flap atrophy (arrow).
|
|
View larger version (140K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 13. Abnormal abdominal wall flap thickening after unilateral breast reconstruction with a pedicle TRAM flap. CT scan obtained 1 month after surgery shows a soft-tissue band (arrows) representing a dry eschar with inflammation and fat necrosis.
|
|
Bilateral Pedicle TRAM Flap
CT features of the six bilateral pedicle TRAM flaps are summarized in Table 5. In all cases, surgical clips were present in the reconstructed breast and the corresponding rectus muscle sheath and the rectus muscle was completely absent from the anterior abdominal wall. Four of the reconstructed breasts were consistently categorized as type 2 between 14 and 60 months after surgery, and two were consistently categorized as type 3 up to 3 months after surgery. Both breasts were of the same type in all three patients. In one type 2 breast, a mass was discovered 21 months after surgery. The mass proved to represent recurrent breast carcinoma at biopsy (Fig 14).
View larger version (128K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 14. Recurrent breast cancer in a patient who had undergone bilateral breast reconstruction with pedicle TRAM flaps 21 months earlier. CT scan demonstrates a mass (arrowhead), which proved to be recurrent breast carcinoma at biopsy.
|
|
Bilateral Free TRAM Flap
CT features of the six bilateral free TRAM flaps are summarized in Table 6. In all cases, surgical clips were present in the reconstructed breast and the corresponding rectus muscle sheath and the portion of rectus muscle inferior to the umbilicus was absent. Four of the reconstructed breasts were consistently categorized as type 2 at 7 and 47 months after reconstructive surgery, whereas two of the reconstructed breasts had changed from type 3 to type 2 38 months after surgery. In one patient, CT performed 12 days after surgery showed fluid in the axillary portion of both breasts, air in the chest wall, and fluid in the anterior abdominal wall (Fig 15).
View larger version (121K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 15a. Edema and air in a patient who had undergone bilateral breast reconstruction with free TRAM flaps 12 days earlier. (a) CT scan shows fluid in the axillary portion of each breast (large arrows) and in the medial aspect of the right breast (arrowheads). Small arrows indicate air in the left side of the chest wall. (b) CT scan shows fluid in the anterior abdominal wall (arrowheads).
|
|
View larger version (148K):
[in this window]
[in a new window]
[Download PPT slide]
|
Figure 15b. Edema and air in a patient who had undergone bilateral breast reconstruction with free TRAM flaps 12 days earlier. (a) CT scan shows fluid in the axillary portion of each breast (large arrows) and in the medial aspect of the right breast (arrowheads). Small arrows indicate air in the left side of the chest wall. (b) CT scan shows fluid in the anterior abdominal wall (arrowheads).
|
|
|
DISCUSSION
|
|---|
The TRAM flap technique has become a popular method of breast reconstruction in cancer patients following mastectomy, particularly as the popularity of reconstruction with silicone gel implants has waned. These patients often undergo CT of the chest, abdomen, and pelvis for evaluation of known or suspected breast cancer metastases. The normal and pathologic changes that occur in the chest and abdomen as a result of the surgical procedure are seen at CT and must be recognized to avoid confusion of the normal appearance with active disease and to identify pathologic conditions within the flap.
The normal changes that occur after the TRAM flap procedure are fairly uniform, allowing recognition of pathologic changes postoperatively. The shape of the TRAM flap is the same as that of the native breast. However, fat attenuation is predominant in the TRAM flap at CT, as opposed to the irregular soft-tissue attenuation of fibroglandular tissue mixed with fat seen in the native breast. The thin, curvilinear soft-tissue band seen within the reconstructed breast represents the de-epithelialized skin from the abdominal wall. The fat-attenuation tissue superficial to this band represents adipose tissue of the native chest wall, and the fat-attenuation tissue deep to the band represents the adipose tissue transposed from the abdominal wall.
The thin band that extends to the skin surface represents the transition from full-thickness TRAM flap skin to the de-epithelialized skin that is tunneled under the native chest wall skin and subcutaneous tissue. Although this band may appear thick within a month of surgery, persistent thickening or the development of new thickening should raise suspicion for infection, inflammation, or recurrent breast cancer (Fig 13).
In our study, the appearance and degree of thickness of the curvilinear band was bilaterally symmetric in patients in whom bilateral TRAM flap procedures were performed; the appearance of asymmetry in the curvilinear band in such patients should also raise suspicion for infection, inflammation, or recurrent cancer. Similarly, when a soft-tissue mass is identified within the TRAM flap, recurrent breast cancer should be strongly suspected, and mammography and possibly ultrasonography should be recommended (Fig 14). In our study, two reconstructed breasts in one patient changed over time from type 3 to type 2, a finding that probably reflects resolution of postoperative edema and hemorrhage within the flap. However, in no case did a reconstructed breast change from type 1 to type 2 or from type 2 to type 3. Such a change should raise suspicion for recurrent cancer, inflammation, or infection.
Absence of all or part of the rectus muscle from the abdominal wall is to be expected in the TRAM flap procedure. The body of the muscle can be seen to cross the midline in the epigastric region in a contralateral pedicle TRAM flap and should not be confused with a pathologic condition. Normally, the muscle body will atrophy over time. Soft tissue that abuts the ribs represents the transposed rectus muscle and is also an expected finding.
|
Footnotes
|
|---|
Abbreviation: TRAM = transverse rectus abdominis musculocutaneous
|
References
|
|---|
-
Bostwick J. Breast reconstruction following mastectomy. CA Cancer J Clin 1995; 45:289-304.[Abstract]
-
Slavin S, Goldwyn R. The midabdominal rectus abdominis myocutaneous flap: review of 236 flaps. Plast Reconstr Surg 1988; 81:189-197.[Medline]
-
Hartrampf C, Scheflan M, Black P. Breast reconstruction with a transverse abdominal island flap. Plast Reconstr Surg 1982; 69:216-225.[Medline]
-
Carlson G. Breast reconstruction: surgical options and patient selection. Cancer 1994; 74(suppl):436-439.[Medline]
-
Beasley M. The pedicled TRAM as preference for immediate autogenous tissue breast reconstruction. Clin Plast Surg 1994; 21:191-205.[Medline]
-
Mendelson E. Evaluation of the postoperative breast. Radiol Clin North Am 1992; 30:107-138.[Medline]
-
Grotting J. Immediate breast reconstruction using the free TRAM flap. Clin Plast Surg 1994; 21:207-221.[Medline]
-
Helvie M, Wilson T, Roubidoux M, Wilkins E, Chang A. Mammographic appearance of recurrent breast carcinoma in six patients with TRAM flap breast reconstruction. Radiology 1998; 209:711-715.[Abstract/Free Full Text]
-
Loyer E, Kroll S, David C. Mammographic and CT findings after breast reconstruction with a rectus abdominis musculocutaneous flap. AJR 1991; 156:1159-1162.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
J. I. Jung, H. H. Kim, S. H. Park, S. W. Song, M. H. Chung, H. S. Kim, K. J. Kim, M. I. Ahn, S. B. Seo, and S. T. Hahn
Thoracic Manifestations of Breast Cancer and Its Therapy
RadioGraphics,
September 1, 2004;
24(5):
1269 - 1285.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. K. Devon, M. A. Rosen, C. Mies, and S. G. Orel
Breast Reconstruction with a Transverse Rectus Abdominis Myocutaneous Flap: Spectrum of Normal and Abnormal MR Imaging Findings
RadioGraphics,
September 1, 2004;
24(5):
1287 - 1299.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. A. Helvie, J. E. Bailey, M. A. Roubidoux, H. A. Pass, A. E. Chang, L. J. Pierce, and E. G. Wilkins
Mammographic Screening of TRAM Flap Breast Reconstructions for Detection of Nonpalpable Recurrent Cancer
Radiology,
July 1, 2002;
224(1):
211 - 216.
[Abstract]
[Full Text]
|
|
|
Top
Abstract
INTRODUCTION
