Flap revascularization in patients following immediate reconstruction using an autologous free dermal fat graft for breast cancer: a report of two cases

Case 2

A 37-year-old premenopausal woman with a localized mass in the inner-upper quadrant of her left breast was diagnosed as having T1N0M0 clinical stage I breast cancer. Her BMI was 20.9 kg/m², less than case 1. The tumor was seen as a circumscribed equal-density mass on mammography, a 1.2-cm, hypoechoic, microlobulated mass on US, which was visualized as an enhanced localized mass in the upper region of her left breast in the early period on MRI, as shown in the left and center panels of Fig. 1b. No metastases were found in two SNs. She underwent surgery with an FDFG (4.2 cm?×?6.5 cm) in the same manner as previously described. On pathological examination, the tumor was a 1.4-cm IDC and surgical margins were negative (Fig. 1b, right panel), positive for ER and negative for PgR, HER2, and lymphatic vessel invasion, with an NG score of 1 and Ki67 of 30 %. After surgery, RT (50 Gy in 25 fractions with a boost of 12.5 Gy in five fractions) and tamoxifen were administered. She has been free from recurrence for 45 months following surgery, and her appearance is shown in Fig. 6. On the questionnaire, a “good” score (10 of 12 points) was obtained both 6 months and 3 years after operation. As in case 1, 2 points were lost because of wound scarring and softness of the breast, but she commented that she felt the graft region softening somewhat, slowly over the years. FDFG thickness on CT changed from 22 to 19 mm, and FDFG width decreased from 42 to 37 mm (dimension decrease rate 25.2 %) 32 months after surgery, as shown in Fig. 4b. The FDFG was detected as a circumscribed oval and heterogeneously hypo-echoic mass on US 45 months after operation. This mass was coated by a smooth capsule with an iso- or hyperechoic structure, the findings of which were very similar to those of case 1 (Fig. 5b, left panel). CEUS showed blood flow into the graft mainly from the retro-mammary fat side, which began approximately 10 s after intravenous administration of contrast agent (Fig. 5b, center panel). In the mass, several blood flows were observed with persistent enhancement without attenuation once the vessels were enhanced for 30 s after administration (Fig. 5b, right panel).

Postoperative appearance of case 2. A 37-year-old woman with a localized 1.2-cm tumor in the upper region of the left breast 44 months after surgery

From 2011 to 2012, several patients with localized early-stage breast cancer in the upper quadrant of the breast underwent successful BCS with immediate reconstruction using autologous FDFGs in our hospital. The two basic criteria for the FDFG technique were as follows: the patients had a localized malignant neoplasm; and the cancer lesion was restricted to the upper-inner or upper-outer quadrant, with adjoining pectoralis major muscle, as described by Kijima et al. [7]. In our hospital, patients who underwent BCS, even with the FDFG technique, routinely underwent adjuvant RT to prevent local recurrence. However, as in the present two cases, no severe adverse events related to the technique were seen, though radiotherapy might cause the breast tissue to be firmer; the breast tissue becomes more fibrous, hard, and less stretchy due to radiation fibrosis [10].

To assess the benefit of this FDFG technique, the degree of cosmetic satisfaction (using a questionnaire), graft shrinkage (measured by CT), and blood flow (using CEUS) were evaluated to assess the graft 3 years after surgery and postoperative radiotherapy. Two cases that underwent these assessments were described in this report, providing important information given the few previous series.

The questionnaire has been commonly used to assess cosmetic statements by patients, as reported by Sawai’s group and supported by the JBCS [11]. In the present two cases, the patients’ self-reported questionnaire results suggested that this technique might be relatively satisfactory, but the graft appeared to be relatively hard, both subjectively and objectively. It is likely that one reason for the slight decrease in satisfaction might have been graft hardness. Mild resorption of the graft was seen to a similar extent on CT in both cases after 2 years; this is consistent with previous reports of FDFG [7].

Both of the present cases had very similar clinical courses, but there was a slight difference in the patients’ comments about “hardness” and in the CEUS findings. While the graft was continuously hard in case 1, it became slightly softer than immediately after the operation and RT in case 2. On the other hand, CEUS was performed to assess the blood flow in the FDFG at over 3 years after the operation in the present two cases. It is noteworthy that CEUS showed two different patterns: blood flow into the graft mainly from the pectoralis major muscle side was observed with persistent enhancement in case 2, while case 1 showed no enhancement. CEUS can detect blood flow more accurately than CT or MRI, because ultrasound contrast media remain within the vasculature [9]. Thus, CEUS objectively demonstrated vascularization in the graft after approximately 3 years after operation in case 2. This finding is consistent with the hypothesis that engraftment might require revascularization from the pectoralis major muscle to the vascular network in the subcutaneous tissue, because an FDFG is not a pedicle flap [4, 12].

It has been reported that the graft might change to fibrotic tissue and finally shrink due to decreased graft perfusion, and there might be no blood flow in the center, but resumption of blood flow might be seen only in the periphery of the graft [12, 13]. The FDFG may have had a pathologically necrotic background, such as graft resorption and epithelial cyst formation [12], which might result in “hardness.” From the questionnaire results, this technique was relatively acceptable for 3 years, except for this particular point. Despite mild shrinkage of the graft, the volume balance of the breasts might not be lost enough to decrease the patients’ satisfaction. In addition to relatively good cosmetic outcomes in both cases despite RT, case 2 was striking because the graft achieved at least partial blood flow from the pectoralis major muscle, which may be a meaningful clue to investigating such grafts in detail in the near future. However, careful attention is required to use this technique because the abdominal region is well known as a good donor site for free tissue transplantation with blood vessels. This technique appears to be an optional surgical procedure for use in limited cases.