Introduction
Breast reconstruction after total mastectomy provides important psychosocial and quality of life benefits (1). The incidence of breast reconstruction is gradually increasing in most developed countries and there are many types of reconstruction methods. Among them, latissimus dorsi (LD) flap reconstruction without a prosthetic implant is very popular in Japan and at our institution. Since Asian breast cancer patients generally have small to moderately-sized breasts, the LD flap provides a natural feel and appearance postoperatively. The LD flap is rotated anteriorly through the axillary cavity while preserving the thoracodorsal bundle. It is a relatively easy procedure because it does not require vascular anastomosis. Additionally, LD flap reconstruction reportedly tends to have fewer complications than other autologous tissue reconstructions (2). However, because the reconstruction involves anatomical changes, future locoregional recurrence requiring radical surgery can be challenging. Especially in the case of axillary recurrence in patients with an LD flap, passage of the flap through the axilla might interfere with the operation, since it requires careful dissection to preserve the axillary vein, thoracodorsal bundle and long thoracic nerve, in a limited surgical field. Because cases of axillary lymph node recurrence alone are rare, no paper has ever reported in detail on the technique and course about lymph node recurrence after LD flap reconstruction. Since we experienced two cases of axillary lymph node recurrence in breast cancer patients after LD flap reconstruction, we report these cases along with a brief summary of patients who underwent immediate LD flap reconstruction at our institution.
Discussion
Many patients who undergo mastectomy are interested in breast reconstruction after the initial treatment (4). Reconstruction has been shown to improve the patient's ability to overcome the psychological trauma in the wake of the primary diagnosis and treatment (5).
Our institution promotes autologous reconstruction because of the very good aesthetic results obtained, while offering a better tolerance to radiotherapy than prosthetic reconstruction (6,7). However, autologous reconstruction has the disadvantage that the procedure is more complicated than prosthetic reconstruction. In several types of autologous reconstructions, creation of an LD flap is regarded as a relatively safe procedure, because it requires no microsurgical skills (2). Since this procedure is particularly suitable for Asians with low breast volume, the number of such procedures being performed is increasing year by year. However, since the LD flap usually passes through the axillary cavity, the concern is that if regional lymph node recurrence occurs, it will make subsequent surgery more difficult than usual. It is necessary to preserve the thoracodorsal bundle and pedicle to avoid atrophy of the LD flap, which requires careful dissection in a narrow surgical field. We experienced two such cases, both of which had a good postoperative course. In these two cases, the enlarged lymph node was behind the LD muscle passing through the axilla. Axillary dissection could be performed by retracting the flap caudally. Although the dissection proceeded as normal, it was noted that the thoracic neurovascular bundle was more anteriorly shifted than normal in both cases.
The humeral attachment is not resected during LD flap reconstruction at our institution. If the humeral attachment is resected at the time of reconstruction, the axillary field of view is no longer an issue. If it is difficult to secure the visual field at the time of dissection, as in this case, the LD flap can be resected, but considering the possibility of muscle atrophy, we believe it is better to preserve the flap as far as possible.
In both our cases, only one lymph node was enlarged, without involvement of the surrounding blood vessels or nerves. Since resection of the flap is likely to be necessary in cases with many metastatic lymph nodes adherent to one another or to other structures, breast cancer patients with LD flap reconstruction should be carefully followed to detect local recurrence at an early stage.
In the review of previous cases of immediate LD reconstruction following breast cancer surgery performed at our hospital, the two cases (2.8%) that had axillary recurrence were SNB-negative at the time of the first surgery. Distant recurrence occurred in 6 patients (8%). The 5-year and the 7-year recurrence-free survival rate was 94.0 and 89.5% each. Previous reports have reported a 5-year DFS of 85-92% in cases of mastectomy alone without reconstruction, 90-95% in cases of reconstruction (8-12). This is largely consistent with our study. The incidence of axillary recurrence in SNB-negative breast cancer patients is reportedly 0.5-1% (13-16). This data is almost the same as our own, although, since the number of our cases was small, we need to accumulate more cases in the future. Due to the low rate of axillary recurrence in patients with negative sentinel lymph nodes, there are not many reports on predictive factors for axillary recurrence. Previously reported cases have pointed to young age and omission of irradiation as predictors of axillary lymph node recurrence in sentinel node-negative breast cancers (17,18). Neither of these factors were present in our two cases. However, even with SNB with dye and radioisotope injection, as in our institution, axillary recurrence is sometimes unavoidable. If axillary lymph node recurrence is detected early, as in our cases, the foci of recurrence can be resected early, while preserving the LD flap. Hence, it is important to keep in mind the possibility of axillary lymph node recurrence during surveillance after LD flap reconstruction following breast cancer surgery.
In conclusion, we experienced two cases of axillary lymph node dissection in LD flap reconstruction patients. It should be noted that if a second surgery is required after LD flap reconstruction following breast cancer surgery, the field of view is significantly narrowed by the LD flap, and the thoracodorsal bundle is anteriorly displaced as compared to normal. In patients who undergo LD flap reconstruction, careful postoperative follow-up is necessary to detect axillary lymph node recurrence at an early stage, to minimize surgical difficulty.