The MALND technique provides an excellent view of the various important anatomic structures that can be easily preserved during the intervention. Bleeding can be stopped precisely, incisions are smaller, and thus trauma to the tissue is reduced.34-38
Our study found that bleeding during MALND was minimal (12.82±5.46 mL) compared with bleeding during CALND (128.29±52.82 mL; P
<.001). Our previous study19
concluded the bleeding occurred readily in 5 key operative points during MALND: (1) injecting lipolysis solution, (2) liposuctioning, (3) dissecting the axillary vein, (4) dissecting the thoracodorsal vessels, and (5) dissecting the lateral thoracic vessel. However, if MALND is performed carefully, it does not increase the bleeding risk.
Some investigators have stated that the operative time for MALND is longer (approximately 60-150 minutes) compared with CALND. Although in our study MALND initially required more time to perform, the operative time shortened gradually to less than 1 hour after we had performed approximately 10 operations. If the surgeon and the camera operator are experienced, the operation can be accomplished in a half hour, which is even shorter than the time required for CALND. Of course, an efficient operation depends on the selection of an appropriate endoscope, complete liposuction, accurate operative procedures, the surgeon's familiarity with the axillary anatomy, and an understanding of the complex operative technique. If the lipolysis and aspiration of the fat are accurately performed during the resection of the breast tissue before dissecting the axillary lymph nodes, time can be saved during the procedure. In this multicenter trial, the operative times were 40.63±14.27 minutes and 31.18±10.78 minutes in the MALND and CALND groups, respectively (no statistically significant difference between the 2 groups).
The number of lymph nodes harvested was repeatedly reported to be equal to the number harvested during traditional CALND and could provide adequate information on the lymph node status. In this study, the number of lymph nodes harvested during MALND was 17.65±5.38, which is statistically comparable to the number harvested during CALND (16.18±4.38, P=
.35). This finding is similar to those in other reports.21,23,25
Suzanne et al39
described a daily postoperative lymph flow of only 23.4 mL, leading them to reject wound drainage. An overall mean drainage flow of 372 mL was observed in another series, over a period of 5 to 6 days. Other groups have reported similar results, and most surgeons will not omit axillary drainage after MALND.5,7
The drainage flow of CALND is reported to be 322 to 447 mL (range, 23-1100 mL).40,41
In the present study, the overall flow in the MALND group was 120.91±39.22 mL over 4.04±1.29 days, slightly lower than that in the CALND group (150.29±66.92 mL over 5.29±2.01 days; P=
.08 for drainage and P
=.23 for duration).
Some reports have described seroma rates of 2.8% to 25% for the endoscopic technique. After CALND, seromas are reported in 2% to 59% of patients.35,39,42
In the current literature, subcutaneous seroma occurs in 4.8% of patients during MALND and 6.2% during CALND (P=
.11) (). Therefore, there is no clear advantage of MALND over CALND in terms of reducing postoperative lymphorrhea.
Our study corroborates previous findings from smaller studies13,15,19,36
that report excellent arm function results after MALND (). The patients who underwent MALND had less axillary pain, numbness or paresthesias, and arm swelling on the treated side (P
<.001). Although arm mobility was a little worse in the CALND group than in the MALND group at 6 months after surgery (P
14), mobility was the same 24 months after the operation. The aesthetic appearance of the axilla in the MALND group was much better than that in the CALND group. Mastoscopic axillary lymph node dissection reduces the arm morbidities associated with ALND, an unsurprising finding given that MALND results in less arm swelling (lymphedema) than CALND. This finding is partly because the operation is minimally invasive but is also because of the procedure's functional conservation and cosmetic effects. A major potential benefit of reducing morbidities of axillary surgery will have both societal and patient economic effects. These advantages of MALND will result in fewer clinic visits, increased patient satisfaction, faster return to normal social and domestic activity, and greatly reduced costs.
The most tedious procedure in CALND is the isolation and dissection of fat tissues in the axilla. The fat tissues must be dissected from the axillary wall, blood vessels, and nerves. If the fat tissues first undergo liposuction and inflation, the parenchymatous axilla becomes the reticular structure, just like a spider web, and the swollen lymph nodes hang to the “web.” Therefore, the operation gets simpler. The use of liposuction during MALND has been approved. Nevertheless, whether the liposuction affects the pathologic characteristics of the lymph node and interferes with the pathoanatomic study of the lymph node, whether it increases the risk of exfoliation and implantation of tumor cells from the lymph node with metastasis, and whether it raises the risk of hematogenous dissemination or metastasis have worried surgeons. For this reason, the operative safety of MALND has been investigated in several studies. As early as 1997, Brun et al15
performed a prospective study of 34 axillary dissections performed from July 1995 to September 1996 in patients with breast cancer to determine the pathologic features of lymph nodes removed by axillary liposuction. After lipolysis, the fat was drained from the axillary cavity by liposuction. A mean of 15 lymph nodes (range, 8-31) were removed. A total of 502 lymph nodes were examined: 458 (91%) were not involved and 44 (9%) were involved, including 21 (4%) with rupture of the capsule. No pathologic trauma was seen. The authors concluded that axillary liposuction did not alter the pathologic features of lymph nodes and did not affect the quality of lymph node dissection. Jun et al43
also designed a clinical control study of the histologic alterations seen in lymph nodes damaged by MALND after liposuction and CALND. In 931 nodes harvested by endoscopic dissection after liposuction, 37 metastatic nodes and 58 damaged nodes were found; 8 nodes without carcinomatous metastasis and 2 nodes with metastasis were crushed. In 642 nodes obtained by traditional dissection, 31 metastatic nodes and 41 damaged nodes were found; 2 nodes without carcinomatous metastasis and 2 nodes with metastasis were crushed. Crushing and bleeding in the node were found more frequently in those removed by MALND than those removed by CALND. The percentage of damaged lymph nodes, with or without metastasis, was approximately the same with both techniques. No statistically significant differences in lymph node damage were found between the 2 groups. Compared with CALND, the use of MALND after liposuction did not produce more damage to lymph nodes and did not introduce more exfoliated cancer cells into the surgical field. In addition, MALND did not enhance tumor spread during the operation.44
Other related studies have also found MALND to be a safe technique.24,36,37
Four axillary recurrences and 2 port-site metastases have been reported after MALND in a small series. The 2 failed operations described in the article by Salvat et al16
occurred in patients with primarily extensive lymph node involvement. One patient was a 33-year-old woman with T2pN1 disease, with 22 of 23 nodes negative for hormonal receptor expression, in whom disease recurred in the axilla and the breast. The other patient had T2pN1 disease, with 3 of 14 nodes negative for hormonal receptor expression, in whom disease recurred in the posterior axillary line and in the pectoralis major muscle. Hussein et al23
described a 38-year-old patient with stage II, grade II infiltrating duct carcinoma who experienced local and axillary recurrence 2 years after endoscopic dissection of 11 lymph nodes. Notably, in this patient the operation was performed without liposuction. In a smaller randomized study by Langer et al,22
MALND had a low axillary recurrence rate, but the authors reported 2 port-site metastases after MALND. In 2 patients, histologically confirmed port-site metastases were detected at 24 and 49 months after endoscopic ALND. One of these postmenopausal women was node positive at the time of the initial operation (9 of 17 positive lymph nodes) with disease staged as pT2G2 invasive ductal carcinoma. After excision of the port-site metastasis at 24 months, distant metastasis disease to the liver occurred. The patient died 1 year later. In the other patient with pT2G3 invasive lobular carcinoma, all 11 endoscopically removed lymph nodes were free of metastases. Concurrently with a surprising port-site metastasis, this patient experienced the only axillary recurrence. The metastatic lesion was surgically removed. Three years later, the patient is still alive and without evidence of recurrent local or metastatic disease. Nevertheless, with the improvement in the MALND technique, including the endoscope reselection, operation standardization, and management of the operative field, no axillary relapse or trocar implantation has been reported in larger series and nonrandomized studies in recent years.9,18,34,39
Our trial found no port-site metastasis in the MALND group. In addition, the axillary recurrence rate is smaller in both our study groups (1.0% [5/500] in the CALND group and 1.2% [6/496] in the MALND group).
Certainly, preventing the occurrence and spread of metastasis during an operation is a systematic undertaking. It includes improving the operating technique of MALND, standardizing the operative procedures, paying great attention during the operation, and washing the axillary cavity with warm distilled water just before the end of the operation (similar to lavage of the peritoneal cavity after removal of malignant tumors of the gastrointestinal tract and other quality control measures).
The conventional procedure for breast cancer surgery is that breast or tumor is operated on first and the axillary lymph node is then dissected. During this procedure, it is difficult to avoid squeezing and pulling the breast. In addition, the blood vessels and tumor-draining lymphatic ducts are still open and the operative exposure is not optimal. Undoubtedly, these factors can increase the risk for tumor metastases.45
The most important finding of our study is the significantly lower rate of distant metastases occurring during MALND (22.8% [113/496]) compared with CALND (28.2% [141/500]) (P=.04). Moreover, the obvious reduction in distant metastases found in our study may have affected breast cancer–related death rates (16.4% [82/500] in the CALND group vs 12.9% [64/496] in the MALND group) and disease-free survival rates (60.8% after CALND vs 64.5% after MALND), although this difference is not statistically significant. Longer-term follow-up (ie, 10 and 20 years) is still needed before a definite conclusion can be made. The findings of our study raise the question of whether the axillary operation should be performed before the breast operation even in the conventional open procedure, which may further change the surgical treatment of lymphatic metastasis of the breast.
The special operative view afforded by MALND creates an ideal and convenient preservation of some anatomic structures. As a result, it achieves a 3-fold effect on the minimally invasive, function-preserving, and appearance-enhancing aspects of the operation, with the benefits of improved safety and tumor dissection. Some complications and functional injuries that occurred during CALND decreased during MALND.46,47
The MALND technique achieves the double aims of creating physiologically and psychologically minimal invasions. In conclusion, MALND has advantages in operative outcomes, complication reduction, function conservation, and cosmetics. Therefore, MALND should be the preferred approach for breast cancer surgery.