Direct-to-Implant Breast Reconstruction Method: Muscle Anchoring Technique Using Absorbable Strings and Its Safety

Abstract

In prosthesis-based breast reconstruction, surgeons select the sub-muscle layer for implant placement, but the pectoralis major muscle is not sufficient to cover the implant. The pectoralis major muscle does not reach the inframammary sulcus line, so the muscle pockets for implant inevitably have defects. From 2016 to 2019, we performed direct-to-implant (DTI) breast reconstruction for 123 patients, during which the implant was placed partially under the muscle plane and the inferior-lateral portion was placed directly underneath the skin flap. We divided the pectoralis major muscle and serratus anterior muscle in their origin partially and arranged their shape and position. To maintain their intended placement, we used the absorbable mesh sling. From 2020, we had arranged this method and performed DTI in 35 patients using absorbable strings simply as a substitute for mesh. The DTI reconstruction using mesh or using absorbable strings could show the acceptable safety and feasibility. Both techniques were associated with a low risk of surgical complications, reoperation (with mesh 4.1%, and without mesh 0%), and removal of implant (with mesh 2.4%, and without mesh 0%).

1. Introduction

In Japan, allograft skin is not covered by public health insurance and cannot be used for breast reconstruction in practice. In such a situation, we have pursued the optimal methodology of direct-to-implant (DTI) breast reconstruction with various ideas [1, 2]. Since 2019, we have started a new method and have obtained good outcomes, so I would like to report it here.

2. Muscle anchoring technique using absorbable strings

2.1 Anatomical constraints in breast reconstruction using implant

Of the prosthesis-based reconstructive surgeries that are performed at the same time as radical surgery for breast cancer, the process can be classified into two.

One is direct-to-implant (DTI) reconstruction, in which the space created by resection of mammary tissue is replaced immediately with an implant as it is. Then the reconstruction process is completed at the same time as breast cancer surgery. This procedure does not force the patient to experience breast loss. The other is to temporarily place a tissue expander in the space after resection, and gradually expand it after the wound heal. It is to stretch the chest skin and the surrounding muscles that cover the tissue expander. After obtaining sufficient space for the implant, the tissue expander is replaced with an appropriate implant at the right time. The patients will have to undergo two surgeries (two-stage reconstruction).

The mammary gland is completely removed by nipple-sparing mastectomy (NSM) or skin-sparing mastectomy (SSM), and almost all of the breast skin is preserved in both surgeries. Therefore, it is not necessary to stretch the mammary gland skin primarily. Then why is two-stage process needed after NSM and SSM?

This is because the pectoralis major muscle does not have sufficient area to cover the implant. Both length and width are insufficient (Figure 1 left). The skin-flap in the lower half area of the breast mound bears the weight of the implant. Because the pectoralis major muscle does not reach that far, the skin bears the implant independently. Certainly, if the surrounding muscles such as the serratus anterior, rectus abdominis, transversus abdominis, and anterior oblique muscles are all mobilized, we could make a complete pocket with the muscles (Figure 1 right). If you go that far, however, it would be wiser to reconstruct the mammary glands with only muscles. Therefore, in two-stage breast reconstruction, a tissue expander was once inserted, a capsule was created with the pectoralis major muscle and, in some cases, a part of the serratus anterior muscle, and the muscle was stretched over time.

Figure 1.

The pectoralis major muscle does not have a sufficient area to anatomically cover the surface of the implant, and a sizable portion of the surrounding muscles would need to be sacrificed to adequately conceal the entire implant.

To solve this anatomical problem, in the United States, Alloderm® (Allergan U.S.A. K.K.) is applied as a patch to reinforce the areas that cannot be covered with the pectoralis major muscle. Alloderm® is a commercially available medical material that can be applied to anyone by treating the dermis of the skin collected from a donor’s body to inactivate antigenicity. Alloderm® is sure that it could patch and reinforce the lower area of breast mound, but it has no blood flow and no immune function that protects from bacterial infection. Since Alloderm® is premised on a body donation so it is not covered by public health insurance in Japan.

2.2 Direct-to-implant reconstruction that can be implemented in Japan

In 2016, Tessler et al. first reported a method of using VICRYL mesh® (Ethicon, Johnson & Johnson K.K., JAPAN) instead of Alloderm® to connect the pectoralis major muscle and the chest wall to cover the inferior area that cannot be patched by the pectoralis major muscle alone [3]. Unlike Alloderm®, VICRYL mesh® is an absorbable material. It has a temporary reinforcing effect on the flap in the inferior area, but it will continue for 2 weeks, just like VICRYL PLUS® absorbable strings. After absorption, it lost its function. However, they reported the excellent outcomes of their absorbable mesh-sling procedure; 2.6% of cases had flap necrosis, 1.3% had infection, 1.3% required revision surgery due to implant displacement, and only 1.3% had implant removal. We have adopted this procedure since 2016 and have performed it in 123 cases to date.

Faulkner et al. used this technique to perform 227 reconstructions in 227 cases and reported the results of 7 years of observation [4]. As a matter to be noticed, they performed postoperative radiotherapy in 20.5% of cases. As a result, they also showed good results; flap necrosis (requiring invasive procedure) was 3.5%, infection was 2.1%, and implant removal was 4.5%.

Tessler does not use the serratus anterior muscle, only the pectoralis major muscle serves its purpose. Therefore, the only role of the absorbable VICRYL Mesh® is to place the pectoralis major muscle in a caudal stretched state as much as possible and to wait for the adhesion between the pectralis major muscle and the skin flap at the appropriate position intended by the surgeon. Using this absorbable mesh-sling method, then we could perform DTI reconstruction surgery even in Japan, where Alloderm® cannot be used.

2.3 Arrange and place the muscle body and implants appropriately

Figure 2 shows our method, which is a modification of Tessler’s one, currently in use. The pectoralis major muscle and the serratus anterior muscle are arranged and placed properly to cover the implant, by using absorbable strings like shoelaces. Unlike Tessler, our new method does not use mesh on the purpose. In practice, VICRYL PLUS 4–0® (“4–0” is a USP size and the diameter of the string is 0.2 mm.) is used, but these “shoelaces” are used to make tension and anchor between the muscle and the subcutaneous area of the inframammary sulcus. The pectoralis major muscle is partially dissected at its origin and is separated as needed. The top of the mammary gland mound, around the areola, has the least blood flow. There should be support from underneath with the pectoralis major muscle as much as possible. The serratus anterior can also be mobilized as needed simultaneously. In this case, it is not necessary to dissect the origin of the muscle body in its entire length. It is possible for the fascia of serratus anterior muscle alone to serve its purpose (Figure 3).

Figure 2.

The pectoralis major muscle and the serratus anterior muscle are arranged and placed properly to cover the implant, by using absorbable strings as if like shoelaces. VICRYL PLUS 4–0® is used to make tension and anchor between the muscle and the subcutaneous area of the inframammary sulcus.

Figure 3.

Even minimal ischemic necrosis at the wound edge can also cause infection. The underlayer of the incision is completely covered by the muscle tissue.

With this method, the pectoralis major muscle can be moved to the desired position. Whether the surgery is SSM or NSM with a peri-areolar incision, around the incision is with the highest risk of ischemic skin necrosis. With the mobilization of the pectoralis major muscle, it is possible to support the suture directly from underneath by the muscle body with rich blood microcirculation (Figure 3). The papilla, which is prone to ischemia, can also be supported. In a case, if the sub-mammary sulcus is incised, it can be supported from underneath with part of the serratus anterior muscle. Even if the required implant weight is heavy, it can be supported from below by not only skin flap but the serratus anterior muscle. If the surgeon needs the appearance of breast ptosis, surgeons should also consider not using the serratus anterior.

Since 2020, at our facility, we have performed DTI reconstruction in 35 cases using this anchoring technique with absorbable strings. We will retrospectively examine the results and the risk of complications in a group of patients who underwent DTI reconstruction using this technique (without Mesh) and compare them with 123 patients who underwent DTI using the Tessler method (with Mesh).

2.4 Surgical technique

The operations are performed under general anesthesia. At the start, we perform ultrasonography to confirm the location of tumor. To avoid the tumor contamination in the flap, we put a mark at the point where the tumor should edge up to the skin by injecting the pigment. During the operation, we harvested the subcutaneous tissue from the flap side and submitted to the immediate pathological examination.

On a case-by-case basis, sentinel lymph node biopsy or axillary lymph node dissection will be performed. Surgery to the axilla should not influent the indication for, or the procedure of breast reconstruction, aside from skin incision. The surgeon has to choose whether skin incision the inframammary line or the line around the nipple-areolar circle and extending to the axilla. In the case requiring the axillar dissection, we routinely select the later incision.

First, it is important to find the superficial layer of superficial fascia in the incision, then we start exfoliation of mammary glands from the skin in appropriate layers. After reaching underneath the nipple, we get the sample of the specimen and provide to the intraoperative pathological examination by frozen section. If the malignant involvement was recognized, we convert the NSM, even if you planned, into SSM with the nipple-areolar complex resection. Similarly, the malignant involvement at the site above the tumor should be coped with widening the skin resection enough and properly. If the area of flap got too tighter to cover the desired implant, we should convert DTI into two-stage using the proper tissue expander.

After completion of skin-preserving mastectomy, we start reconstruction by creating appropriate subpectoral pocket. We release the pectoralis major muscle at its origin on the sternum, if it was right breast, proceeded to the 3- and 9- o’clock levels. Occasionally, we add the slitting the pectoralis along the muscle bundles and adjusted its position (Figure 4).

Figure 4.

The pectoralis major muscle was partially released from its origin on the sternum. If it was the right breast, the release extended to the 3- and 9-o’clock levels. Occasionally, we also make a slit in the pectoralis along the muscle bundle.

A saline sizer was placed in the subpectoral pocket and inflated to the desired volume. While checking the appearance of the mammary gland, we select the best cohesive according to the size of the sizer and the weight of the removed breast weight.

We decide whether to use the serratus anterior fascia at this time. If the width of the pectoralis major muscle defect covering the implant is likely to exceed 4 cm, it should be used in combination. There are demerits due to detachment and use of the serratus anterior fascia; increased postoperative pain, and loss of breast ptotic appearance.

After placement of the appropriate implant in the pocket, we start suturing between the pectoralis major muscle and lateral and inferior fold, or between the pectoralis major muscle and the fascia of serratus anterior muscle, using the absorbable string (VICRYL PLUS® 4–0). The important thing here is not to overtighten the string to the end (Figure 5). We believe that we should not tighten the thread, just like we do with shoelaces. We just keep in mind that it is enough if there is a muscle body under the incision.

Figure 5.

After placement of the implant, we start suturing between the pectoralis major muscle and lateral and inferior fold, or between the pectoralis major muscle and the fascia of serratus anterior muscle, using the absorbable string (VICRYL PLUS® 4–0). We refrain from using mesh to anchor the muscle body to the needed site.

Then, suction drains were placed. Adjustments were made as necessary, hemostasis was ensured, and the wound was then closed (Figure 6).

Figure 6.

The photograph depicts a stage where the surgery is nearly finished, and only the skin remains to be sutured.

3. Assessment of complications

In the Tessler method, between the pectoralis major muscle and a part of the serratus anterior muscle or inframammary sulcus line are slung using an absorbable mesh (VICRYL Mesh®). From 2016 to the present, we performed the DTI breast reconstruction in 123 patients (with mesh). In December 2019, we started to apply our modified method in which the pectoralis major muscle and inframammary sulcus are anchored using only absorbable strings (VICRYL PLUS® 4–0) like shoelaces without using absorbable mesh. Thirty-five patients underwent DTI reconstruction with this method (Without Mesh).

Although both VICRYL Mesh® and VICRYL PLUS® 4–0 are absorbable substances, it is a foreign substance. If the amount of the use is reduced, it is expected that surgical site infections will also decrease.

We retrospectively compared the outcome, especially from the viewpoint of complication due to ischemia in 35 patients who underwent DTI without Mesh and 123 patients with Mesh.

To check for surgical complications, we checked ischemic changes and surgical site infections for all patients during hospitalization, and in visiting the hospital as an outpatient about 1 and 2 weeks after surgery. Since 2010, we have been prospectively investigating complications in breast reconstruction cases at our institution. We checked and made an independent database for the occurrence and time of occurrence (days after surgery) about the following items; presence of seroma, wound edge necrosis, nipple ischemia or necrosis, surgical site infection (SSI), hematoma formation, hospitalization due to complications, request of reoperation due to complications, and implant removal. Other complications are described and evaluated.

In this study, we did the assessment in using this database, but hence, we did not consider implant displacement, the presence or absence of capsular contracture, deformation, which should be accessed in long-term observation. The grade classification of complications was based on Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0 Published: Nov 27, 2017 and Japanese translation by JCOG [5].

Because we examined perioperative complications observed within 2 months after surgery, postoperative adjuvant treatments such as chemotherapy, radiotherapy, and hormone agents are, if any, almost negligible. We have never performed bilateral simultaneous DTI breast reconstruction.

For statistical analysis, the computer software EZR was used [6]. The analysis method was described for each.

3.1 Result

Since this study is a retrospective analysis, it is not appropriate to compare significant differences in complication rates in two methods (with or without Mesh).

First, the time when the surgery was performed was different, so the learning curve of the operator affected against the group without mesh (Table 1). Second, some significant differences are shown in the patient background; in the presence or absence of hypertension as a medical history, T factor, and stage in the TNM classification. With mesh group, which includes more advanced cases, is at a disadvantage. On the other side, without mesh group underwent a larger mastectomy and was reconstructed using a larger implant. In this regard, without mesh group is at a significant disadvantage (Table 1).

	With Mesh (n = 123)	Without Mesh (n = 35)
Age (years)	45.8 ± 6.1 (22–63)	45.3 ± 4.2 (35–56)	p = 0.677¶
Body-mass index (kg/m^2)	21.5 ± 3.0 (16.83–32.7)	22.3 ± 2.6 (18.03–27.61)	p = 0.166¶
DM(−/+)	119/1 Uncertain 3	35/0	p = 1.0§
HT(−/+)	120/3	34/1	P<0.001§
Smoking (Never/ Quit^*1)	110/11 Uncertain 2	30/5	p = 0.357§
Neoadjuvant chemotherapy (−/+)	110/13	31/4	p = 0.519§
T^*2 (is/ 1/ 2/ 3/ 4)	(50/ 50/ 15/ 7/ 1)	(19/ 11 /5 /0 /0)	p = 0.00052
Stage^*3 (0 /1 /2 /3 /4)	(51/ 46/ 18/ 7/ 0)	(19 /6 /5 /1 /1)	P < 0.001
Surgery
Operation time (min)	125.5 ± 22.9 (78.0–186.0)	128.4 ± 23.4 (60.0–175.0)	p = 0.520¶
Bleeding (ml)	91.9 ± 65.5 (nearly 0–410)	86.7 ± 59.3 (nearly 0–260)	p = 0.680¶
Mastectomy weight (g)^*4	211.2 ± 119.9 (130–567)	277.0 ± 114.4 (54–552)	p = 0.00493¶
Implant Volume (ml)	229.0 ± 89.9 (170–595)	294.1 ± 65.6 (190–415)	p = 0.00463¶
NSM/SSM	117/6	32/3	p = 0.416§
Ax (0-SLNB/ I-II)	103/20	28/7	p = 0.615§

Table 1.

Baseline characteristics.

¶

Student-t.

§

Fisher’s Exact Test χ² test.

*1 Smokers were instructed to abstain from smoking for at least 28 days before surgery.

*2 We took the value of cT at admission as the value of pT, in the case of requiring neoadjuvant chemotherapy.

*3 We took the value of cStage at admission as the value of pStage, in the case of requiring neoadjuvant chemotherapy.

*4 Including cases in which margins were positive in the first surgery and subcutaneous mastectomy was performed in reoperation.

Complications occurred from the day of surgery to 43 days. We experienced cases of surgical site infection (SSI) on the 137th day and the 202nd day in the with mesh group. These were not perioperative complications, but due to a local trauma. Excluding these, the mean time to SSI was 12.5 days.

Overall complications were not affected by the presence or absence of Mesh, and indeed no significant difference was observed. We expected a decrease in SSI by not using mesh, but this was not observed. Concerning about any ischemic changes around the wound, we checked even small ones, which patients do not seem to notice, and converted them into data according to the grade. However, no increase was observed even after stopping the use of Mesh (Table 2).

	With Mesh (n = 123)		Without Mesh (n = 35)
	Grade 1–2	Grade 3	Grade 1–2	Grade 3
Seroma	4 (3.3%)	0	0	0	p = 0.576§
Ischemic change (in nipple, areola, wound area)	19 (15.4%)	0	4 (11.4%)	1 (2.9%)	p = 0.786§
Surgical site infection	5 (4.1%)	5 (4.1%)	1 (2.6%)	0	P = 1§
Hematoma	4 (3.3%)	0	3 (8.6%)	0	p = 0.183§
Hospitalization due to complications	7 (5.7%)		1 (2.9%)		p = 0.686§
Request of reoperation due to complications,	5 (4.1%)		0		p = 0.588§
Implant removal	3 (2.4%)		0		p = 1§

Table 2.

Adverse events per breast.

§

Fisher’s Exact Test χ² test.

Through the recruitment period, only three cases in the with mesh group resulted in discontinuation of reconstruction with IMP removal.

4. Discussion

4.1 Anchoring with absorbable materials

Our series with absorbable mesh sling or with absorbable anchor strings for DTI breast reconstruction confirmed Tessler’s excellent results with a low complication profile [3]. As well as their experience, the complications in our series were more favorable than that reported complication profiles of up to 14.8–18% for DTI with using Allodermnew® [7, 8] and 33.9% of reoperation incidence, and 10.9% of explantation and replacement in the Mentor [9] study. Our results are encouraging for Japanese surgeons, who cannot access Alloderm® at present. Both Vicryl mesh® and Vicryl PLUS® are widely available and relatively inexpensive materials, which have been used in numerous surgical procedures for many years.

We experienced surgical site infection (Grade 1–2) in this series (4.1% in group with mesh, 2.6% in group without mesh). In one case of them, we had misled the inadequate candidate who was with atopic active dermatitis to the implant-based reconstruction. Through these experiences, we found thought-provoking facts concerning about the infectious complication in using the implant that surgical site infection could develop in outpatients even more than 6 weeks after the surgery. From these findings, we made a hypothesis that these infections were not usual surgical site infections, and might be caused by the lymphogenous dissemination of “hand or finger contamination” from the patients’ everyday affairs. We now routinely give the patients specific guidance on hand hygiene; occasionally glove use to steer clear of injury, daily skin care, and avoidance of gardening or handling of kitchen garbage. We keep them strictly in order, especially during the three months after the surgery. SSI complications were obviously reduced since we started this guidance.

As this fact shows, patient cooperation is essential for successful reconstructive surgery. Smoking cessation in the perioperative period would be an almost absolute requirement.

Implant exposure is the major complication requiring the explantation. To prevent this tragedy, it is important to cover of the implant with the healthy muscle to the extent possible. Although complete muscle coverage using both the pectralis major and serratus anterior muscle would decrease the risk of infection, this technique may prevent smooth expansion, especially in the lower pole of the breast, thereby resulting in a high-riding device placement [10]. In the case of the breast with ptosis, the pectoralis major muscle alone is insufficient to cover the lower pole of the implant. Thus, the implant comes into direct contact with the skin, and that potentially causes ischemia of the skin. Breast surgeons in the USA are trying to overcome this anatomical limit by using Alloderm® [11, 12]. Absorbable materials should be resorbed at 3 to 4 weeks. If this happens, the implant will always come into direct contact with the skin. Using mesh sling or anchoring strings cannot improve the blood flow in the flap. But it is the same with Alloderm®. Then why does a sling with Alloderm® prevent capsular contracture [8, 13]? Iwahira said that the muscle envelope of the implant at the inferolateral site is not indispensable if the skin flap in there is sufficiently thick [14]. She also advocated that applying the serratus anterior muscle for the implant envelope would cause not only insufficient projection by the shortening of the lower part, but postoperative pain, or implant displacement. It is important that the implant is covered by a solid capsule with good blood flow. It does not matter if the muscle is there or not. The results of our present study seem to support this.

For studies of prosthesis-based breast reconstruction, extended follow-up is mandatory, as many complications, especially capsular contracture, develop long after the initial operation. We will continue to follow up with the patients of this study from this perspective. Nonetheless, once esthetics are compromised during the primary surgery, it will not improve spontaneously thereafter. Since DTI should be performed only in one operation, there is no opportunity for revision. For this decade, we performed the 158 DTI reconstruction with using absorbable materials and have never suffered from capsular contracture from early perioperative period. While performing DTI reconstruction using absorbable mesh sling technique and absorbable strings anchoring technique, we have got satisfaction about the results, both cosmetically and safely.

4.2 Direct-to-implant or taking two steps reconstruction

In this work, we introduced a unique DTI breast reconstruction technique that we developed with reference to Tessler’s procedure. As a matter of fact, only these techniques can be practiced in our country where Alloderm® cannot be used. Long-term outcomes are yet to be accessed, but from the viewpoint of perioperative complications, safety appears acceptable in clinical practice.

In June 2013, the Japanese Central Social Insurance Medical Council of the Ministry of Health, Labor and Welfare approved insurance coverage for implants (prosthesis) used in breast reconstruction surgery, and insurance coverage began on July 1. The Japanese Society of Breast Oncoplastic Surgery began to collect data [15] from 2013, and then, there were 1281 cases undergone the breast reconstruction. With the exception of 2019, when breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) gained public attention, the number of prosthesis breast reconstruction surgeries has continued to augment every year.

As described in “introduction”, prosthesis-based breast reconstructive surgeries covered by insurance are classified into DTI and two-stage reconstruction. In the social burden of hospital visits, duration of hospitalization, and the medical costs associated with surgery, DTI reconstruction is superior. However, not only in Japan but also in the rest of the world, breast reconstruction is performed in two-stage.

According to aggregate results enforced by the Japanese Society of Breast Oncoplastic Surgery, the latest statistics in 2021 show that 388 cases were reconstructed in DTI manner, while 3667 cases were reconstructed in two-stage. The difference between the DTI and two-stage is almost ten times, and it can be said that two-stage reconstruction is the standard surgical procedure in Japan, de facto.

Japanese public insurance covered both DTI and two-stage breast reconstruction. In addition, two-stage reconstruction is clearly inferior in terms of patient burden than DTI manner. Why does as many as 90% of the surgeon select two-stage manner and DTI manner only 10%?

There are two notable papers.

The first is a big data study of 941,191 breast reconstruction cases after total mastectomy in the United States published by Kamali et al. in 2016 [16]. Using the Nationwide Inpatient Sample Database in the United States, they analyzed almost all patients who underwent DTI and two-stage reconstructive surgery, and investigated the basis for the selection of the two surgical procedures investigated. In the United States, 13.6% patients underwent DTI and 86.4%, two-stage reconstruction. As a result, DTI reconstruction is more likely to be selected for in the case of bilateral breast surgery. This reason is a patient factor. However, the patients, being nonwhite, being on Medicare, and living in a relatively western region, underwent DTI manner more often significantly. These factors could not be understood as a patient factor but should be accepted as rather a social factor. Two-stage reconstruction is more likely to be selected for patients aged 60 or over, which is a patient factor. However, two-stage reconstruction is more likely to be selected for patients; black, Hispanic, the person live in urban, undergoing surgery at the facility of the educational institution such as a university hospital, and are on Medicaid. Kamali said that the rationale for deciding the surgical manner, which was found to be highly significant by statistical processing, was not any patients’ physical or disease-related factors, but more social reasons such as race and household income.

University hospitals and large facilities in urban areas are the centers of dissemination of information that determines a trend of the times. In these facilities, young doctors receive training of two-stage reconstruction manner as a standard. The ratio of doctors accustomed to two-stage manner and those accustomed to the DTI manner is 9:1, therefore the ratio of the patients underwent two-stage reconstruction and those underwent DTI reconstruction come down to 9:1. Most surgeons simply follow and perform the familiar procedure because the trend of the surgical manner of reconstruction in the past was so. As my interpretation of Kamali’s work, that is thought to be the real reason why two-stage manner continues to be mainstream up to now.

The second important paper was published by Dikmans et al. in Lancet Oncology in 2017 [17]. This study was a prospective, randomized, multicenter, Phase IV trial designed to conclude the superiority of DTI versus two-stage reconstruction. As a result, it was revealed that DTI reconstruction was associated with a three-fold risk of perioperative complications (Odds 3.81, 95% CI 2.67–5.43, p < 0.001) and a risk of implant removal. Was eight times higher (8.80, 8.24–9.40, p < 0 001). By this work, this dispute which is a better manner between DTI and two-stage seems to have settled. Compared to two-stage reconstruction, DTI reconstruction has more complications and a higher risk of failure. We should select two-stage manner even if the disadvantages such as hospitalization and cost related to surgery are considered.

However, after considering this chapter in detail, it is unreasonable to apply this conclusion to clinical practice. The first point is breast size undergoing the reconstruction. Indeed, women’s breasts in Japan may be relatively small compared to those in the United States. The average size of implants used in our hospital for breast reconstruction was 233.4 (80–595) ml (out of 205 cases). On the other hand, the average implant size used in Dikmans study was 392.1 or 416.2 ml in each group, and then, these averages were almost double the size of ours. The larger and heavier size of implant should cause the greater weight-bearing stress, especially in the lower half of the breast where the pectoralis major muscle defect. This condition compromises flap blood flow and increases complications. DTI is not suitable for reconstructing large mammary glands. Randomizing surgical procedures without considering breast size becomes disadvantageous to DTI.

Being with an incomplete muscle capsule is disadvantageous of DTI manner. Dikmans study also included currently smokers in 20% of DTI group and 13% of two-stage group. A decrease in skin flap blood flow due to smoking habit should increase ischemic complications, especially in DTI cases. Smoking cessation should be strictly enforced before surgery. Smoking cessation failures suggest that the patient’s cooperation was not obtained in postoperative wound management, which is very important in reconstructive surgery with implants. This is especially true if the ratio of the smoker is higher in the DTI reconstruction group.

In this chapter, implant removal in the DTI group reached 11% of the total, but the expander removal rate in Two-stage was only 3%. However, 11% result is too high. The tabulated results of the Japanese Society of Breast Oncoplastic Surgery in Japan showed that the rate of implant removal in DTI group is 4.1% and in Two-stage is 3.8%, respectively [15]. In our result, the rate of implant removal in DTI was 3/158 cases (1.9%). Compared to these data, the outcomes of DTI reconstruction in Dikmans study was unnaturally bad. Again, the following factors may have contributed that the ratio of doctors accustomed to two-stage manner are nine-folds high to that accustomed to DTI manner. However, if you do not take any factors (breast size, smoker, surgeon proficiency) into consideration and choose a procedure at random, there is no doubt that you should definitely choose two-stage.

In Japan, where Alloderm® is not practical, the technology for DTI reconstruction has not been developed and never been trained. However, Tessler’s method, our anchoring method using absorbable strings, can be practiced. Compared to the Tessler method, our method succeeded in lowering the possibility of SSI while retrospectively and with fewer observations.

Regarding the superiority of DTI reconstruction and two-stage reconstruction, a conclusion may eventually be drawn from the accumulation of big data in Japan. However, as Dikmans indicated, we must carefully select suitable patients for DTI reconstruction, and otherwise, we must be prepared for serious and highly frequent complications. In the current situation, patient selection criteria for DTI have not yet been established. From the patient’s point of view, the DTI manner is clearly attractive because at the time when breast cancer surgery is over, and when she waked up from general anesthesia, the breast has already been reconstructed. No conclusions can be drawn until a situation arises in which a randomized trial is conducted at a facility with operators who are sufficiently familiar with both DTI and two-stage reconstruction. Until then, we must not abandon the pursuit and training of DTI reconstruction techniques just because we are unfamiliar with them.