Reverse Submammary Adipofascial Perforator Flap: Preliminary Results of a Dual-plane, Acellular Dermal Matrix–free, Direct-to-implant Hybrid Reconstruction

Abstract

Background:

Single-stage direct-to-implant (DTI) reconstruction, particularly the prepectoral technique, has become prominent due to its reliable outcomes and shorter operative time. This approach spares the pectoralis major muscle, reducing postoperative pain and morbidity, and ensuring quicker recovery. However, limitations such as patient comorbidities and tumor characteristics can limit feasibility, leading to complications and high reconstructive failure rates. In such cases, switching to autologous or 2-stage approaches becomes necessary. This study introduced an innovative acellular dermal matrix–free dual-plane DTI hybrid reconstruction using a reverse submammary adipofascial perforator flap for small-volume breasts.

Methods:

A prospective noncontrolled cohort study was conducted from January to April 2024, enrolling 10 breast cancer patients eligible for DTI reconstruction. Data collected included preoperative clinical characteristics, intraoperative surgical data, and postoperative outcomes, including complications and patient satisfaction measured using BREAST-Q version 2.0. Breast aesthetics was also evaluated by 12 independent observers at minimum 3 months follow-up.

Results:

The surgical technique involved a dual-plane pocket with a reverse submammary adipofascial perforator flap, harvested from the inframammary fold, anchored to the pectoralis major muscle for inferolateral pole coverage of the breast implant. Results showed 1 major complication requiring surgical revision and 1 minor skin flap necrosis managed conservatively. All patients reported good satisfaction with their reconstruction results, supported by positive aesthetic evaluations from observers.

Conclusions:

This acellular dermal matrix–free, dual-plane DTI hybrid technique seems safe and effective for small-volume breasts. It offers a viable alternative for selected cases, warranting further investigation with larger cohorts and longer follow-ups.

Takeaways

Question: Is it possible to offer a direct-to-implant breast reconstruction without acellular dermal matrix (ADM) in thin patients, while avoiding both the prepectoral and submuscular planes?

Findings: Yes, our study demonstrates that an adipofascial flap based on inframammary intercostal perforators can provide coverage in a partially submuscular prosthetic pocket, enabling immediate reconstruction in slim patients while avoiding the use of ADM and reducing implant visibility and palpability.

Meaning: Partially submuscular breast reconstruction without ADM is feasible in thin patients with small breasts.

INTRODUCTION

Over the past decades, breast reconstruction has evolved considerably, leading to the development of a range of surgical techniques.¹ Single-stage reconstruction has become a primary goal following oncological breast surgery, and today, multiple methods are available for direct-to-implant (DTI) reconstruction. The most recent and widely adopted heterologous strategies involve using the “prepectoral” plane, which offers reliable outcomes within a shorter operative time frame.^2,3 This approach spares the pectoralis major muscle entirely, reducing postoperative pain and upper limb morbidity, and ensuring quicker recovery times. However, candidates for prepectoral DTI breast reconstruction must be carefully evaluated, as certain limitations can affect the feasibility of this technique.⁴

Specific contraindications, such as patient comorbidities, tumor characteristics, and the need for radiation therapy, can lead to higher rates of complications such as breast envelope disruption, inadequate mastectomy flaps causing skin flap necrosis, wound breakdown, implant exposure, and the need for revision procedures.⁵ In these cases, the likelihood of reconstructive failure is high, reaching up to 19%.⁶ Therefore, switching to an autologous or a 2-stage approach becomes necessary.⁷ Various methods have been described to provide additional soft tissue coverage under mastectomy skin flaps to protect breast implants while sparing the pectoralis major muscle. These methods include the implant-enhanced latissimus dorsi flap, inferior pole dermal flaps, and locoregional flaps.^3,8–11 However, dermal flaps are not suitable in all cases due to breast size and tumor characteristics, and the other techniques can cause significant donor site morbidity, potentially limiting their use.¹² In a subset of breast reconstruction patients who are not candidates for either a prepectoral strategy or a standard 2-stage procedure with a tissue expander, we have adopted a dual-plane DTI technique combined with a reverse submammary adipofascial perforator flap (Re-SAP flap) based on the perforator vessels at the inframammary fold (IMF) for the coverage of the inferolateral pole. In this study, we present the preliminary outcomes, demonstrating the safety and reliability of an innovative acellular dermal matrix (ADM)–free, dual-plane, DTI hybrid reconstruction in small-volume breast patients.

MATERIALS AND METHODS

A prospective noncontrolled (cohort) multicenter study was designed. From January 2024 to April 2024, a total of 10 patients (11 breast reconstruction) diagnosed with breast cancer were enrolled in this study, in accordance with the Declaration of Helsinki of 1964 (revised 2008) and with the approval of the local ethics committee. Specific informed consent was obtained from each patient.

Patient Selection

Inclusion criteria for participation in the study were eligibility for immediate DTI breast reconstruction according to tumor characteristics and patient status, including an American Society of Anesthesiologists score ranging from 1 to 3, age lower than 80 years at the time of surgery, a breast size cup of A, and mastectomy flap thickness less than 1 cm. Risk-reducing mastectomies were also included. A history of preoperative radiation or previous breast surgery was not considered an exclusion criterion, and patients expected to receive postoperative radiotherapy were not excluded from the study. Each case was managed with a 2-team approach: a breast surgery team for the cancer extirpation procedure and a plastic surgery team for the reconstruction. All patients received antibiotic prophylaxis during surgery. Thromboembolism prophylactic therapy was administered according to our modified Caprini score tool.¹³ After discharge, a comprehensive follow-up regimen was instituted, with scheduled visits at 1 week and 1, 3, 6, and 10 months postsurgery.

Collected Data

Patients’ clinical characteristics are summarized in Table 1. Surgical data, including type of mastectomy, axillary surgery, type and size of implant, were collected for each patient (Table 2).

Table 1.

Demographic Characteristics of Patients

Variable	N	%
Age, y
0–40	3	30
41–69	7	70
>70	—	—
BMI, kg/m2
<18	2	20
18 to <25	7	70
25 to <30	1	10
≥30	—	—
BRCA mutation
Positive	1	10
Negative	9	90
Comorbidity
Diabetes	1	10
Hypertension	3	30
Active smoker	3	30
Previous RT	—	—
Previous breast surgery	1	10

BMI, body mass index; RT, radiotherapy.

Table 2.

Surgical Data

Patients	Histology	Operation	Breast Implant
1	IBC-NST	NSM + SNB	CPG 311—160 mL
2	ILC	NSM + ALND	CPG 311—210 mL
3	IBC-NST	NSM + SNB	CPG 311—210 mL
4	IBC-NST	NSM +ALND	CPG 311—210 mL
5	DCIS G2	SSM + SNB	CPG 311—300 mL
6	IBC-NST	NSM + SNB	CPG 311—140 mL
7	IBC-NST	NSM + SNB	CPG 311—180 mL
8	IBC-NST	SSM + SNB	CPG 311—210 mL
9	DCIS G2	NSM + SNB	CPG 311—180 mL
10	ILC	SSM + SNB	CPG 311—210 mL

ALND, axillary lymph node dissection; DCIS, ductal carcinoma in situ; IBC-NST, invasive breast carcinoma of no special type; ILC, invasive lobular carcinoma; NSM, nipple-sparing mastectomy; SNB, sentinel node biopsy; SSM, skin-sparing mastectomy.

Postoperative outcomes, including complications, necessity to perform other interventions, and patient’s satisfaction were meticulously recorded and are presented in Tables 3 and 4.

Table 3.

Complications

Complications	N	%	Treatment
Minor
Seroma	—	—	—
Wound dehiscence	—	—	—
Skin necrosis (partial thickness)	1	10	Dressing
Major
Skin necrosis (full thickness)	—	—	—
Infection	—	—	—
Postoperative bleeding	1	10	Surgical revision

Table 4.

BREAST-Q Scores Recorded Preoperatively and 3 Months Postoperatively, Expressed as Mean ± SD

Domain	Preoperative Mean (±SD)	Postoperative Mean (±SD)	Delta Mean	P
Satisfaction with breasts	60.3 (±21.2)	61 (±9.3)	0.7	0.9
Satisfaction with implants	—	6.1 (±2.4)	—	—
Psychosocial well-being	73.8 (±17.6)	72.8 (±21)	1	0.9
Sexual well-being	66.9 (±24.9)	62.7 (±24.5)	4.2	0.7
Physical well-being: chest	23.5 (±21.9)	25.2 (±15.5)	1.7	0.7
Overall satisfaction with outcome	—	55 (±)	—	—

Changes in scores are expressed as delta (postoperative score minus preoperative score).

Patient satisfaction and cosmetic outcome evaluation were registered using the preoperative and postoperative BREAST-Q version 2.0 modules for breast reconstruction (Copyright ©2017, Memorial Sloan Kettering Cancer Center and the University of British Columbia).¹⁴ Patients were invited to answer the preoperative form questionnaire before surgery and the postoperative questionnaire during follow-up visits (Table 4). The raw data from patients’ answers were converted into the equivalent Rasch-transformed score (0–100) using the specific module conversion table. Analysis of variance and chi-square was used to analyze differences before and after treatment.

Higher scores indicate greater satisfaction and residual function. A P value less than 0.05 was considered statistically significant. Furthermore, to assess breast shape aesthetics, multiple views of patients’ photographs were judged by 12 different observers (6 plastic surgeons, 4 residents in plastic surgery, and 2 nurses) at a minimum 3-month follow-up. The evaluators scored the breast aesthetics using a 5-item Likert scale (scores from “poor result”¹ to “excellent result”⁵).¹⁵ An average score greater than 4 was considered a satisfactory result.

Surgical Technique

The flap was preoperatively planned, with the patient in the standing position; the IMF and the space corresponding to the lateral two-thirds of the submammary area were marked to cover the inferolateral pole of the breast implant (Figs. 1, 2). The proportions of the flap were established according to the width and arc of the breast implant as well. Perforator vessels were preoperatively mapped with a handheld Doppler. (See Video 1 [online], which demonstrates the localization of perforators in the inframammary region using a handheld Doppler.) Following breast surgery, the mastectomy flaps were clinically assessed. A submuscular pocket was planned, and the pectoralis major muscle was elevated with all inferior costal insertions resected up to the sternal portion. For each case, an Re-SAP flap was harvested. Using the same access localized at the IMF as for the mastectomy, a subdermal dissection was carried out downward, carefully respecting the sulcus ligament and proceeding caudally until the flap reached the appropriate size. Distally, the flap was harvested by deepening the dissection until reaching the rectus fascia. Subsequently, it was elevated in a distal-to-proximal manner until it reached sufficient length for easy suturing to the pectoralis muscle or until the previously identified perforating vessels became clearly visible. The flap was left anchored at the level of the IMF, with a variable thickness at the base, depending on the position of the perforating vessels in relation to the overlying breast pocket. The flap viability was assessed using indocyanine green fluorescence. (See Video 2 [online], which illustrates the previously harvested Re-SAP flap, which completes its entire range of movement toward the prosthetic pocket.) (See Video 3 [online], which demonstrates the indocyanine green angiography at the end of flap harvesting.) The breast implant was placed into the subpectoral pocket, and the Re-SAP flap was cranially rotated and sutured to the pectoralis major muscle to complete the pocket (Fig. 3). (See Video 4 [online], which demonstrates the final flap inset during the suturing phase, securing the flap to the pectoralis major muscle to create the breast implant pocket.) Two drains were placed, in the submuscular and the subcutaneous plane.

Fig. 1.

Preoperative planning: the IMF and the space corresponding to the lateral two-thirds of the submammary area were marked, and perforator vessels were mapped with a handheld Doppler.

Fig. 2.

Drawings illustrating the rotating upward Re-SAP flap, creating the pocket together with the pectoralis major muscle.

Fig. 3.

Surgical details of the Re-SAP flap preparation technique. Intraoperative view of Re-SAP flap during the suturing phase to the pectoralis major muscle, creating the pocket for the underlying breast implant (A and B).

Video 1. This is a video displays perforator markings in the inframammary fold.

Download video file ^{(35.5MB, mp4)}

Video 2. This video displays the previously harvested Re-SAP Flap which completes its entire range of movement towards the prosthetic pocket.

Download video file ^{(5.8MB, mp4)}

Video 3. This is a video demonstrating the indocyanine green angiography at the end of flap harvesting.

Download video file ^{(12.4MB, mp4)}

Video 4. This is a video demonstrating the final flap inset during the suturing phase, securing the flap to the pectoralis major muscle to create the breast implant pocket.

Download video file ^{(31MB, mp4)}

RESULTS

Preoperative

A total of 11 breast reconstructions using implants in a dual-plane pocket with an Re-SAP flap were included in the study. The follow-up time ranged from 3 to 10 months.

Intraoperative

Seven patients underwent unilateral nipple-sparing mastectomy, all for primary breast cancer. Axillary surgery was combined in all cases, except for 1 prophylactic mastectomy (8 sentinel lymph node biopsies and 2 axillary dissections). In 1 case, a unilateral breast tumor benefited from a bilateral nipple-sparing mastectomy as a BRCA 1 mutation carrier. Three patients underwent unilateral skin-sparing mastectomy, for nipple–areola complex tumor involvement. The average surgical time was 3 hours. Once submuscular pocket was prepared, the mean surgical time for implant positioning and flap harvesting was 20 minutes. Anatomical microtextured implants (Mentor MemoryShape Johnson & Johnson Medical S.P.A) were used in all cases, with low projection and an average volume of 200 mL (range: 140–300 mL).

Postoperative

The mean hospital stay was 2 days. Among all patients, only 1 experienced a major complication: acute bleeding that required a surgical revision procedure for hemostasis. One patient had minimal necrosis of the mastectomy skin flap, which did not require a revision procedure and was managed conservatively. Throughout the follow-up period, no instances of implant displacement were detected across the entire series, and there were no occurrences of bottoming-out deformity. The drains were removed on average on the fourth postoperative day. No cases of infection or seroma were observed in any of the patients. All 10 patients were generally satisfied with their reconstruction result, as expressed by BREAST-Q scores. At 3-month follow-up, the score demonstrates satisfactory results, with most domains above the average of 50 (scores 0–100) (Table 4). With respect to breast shape aesthetic results evaluated by 12 external observers using the 5-point Likert scale, the mean score was 4.18 (range: 4.02–4.29). Figures 4–6 show preoperative and postoperative results at a minimum 1-month follow-up.

Fig. 4.

Patient with left breast carcinoma who underwent left nipple-sparing mastectomy and immediate reconstruction with a submuscular implant and Re-SAP flap (anatomical microtextured implant, low projection; 210 mL). A and B, Preoperative views. C and D, Three-month postoperative views.

Fig. 6.

Patient with left breast carcinoma who underwent left nipple-sparing mastectomy and immediate reconstruction with a submuscular implant and Re-SAP flap (anatomical microtextured implant, low projection; 160 mL). A and B, Preoperative views. C and D, One-month postoperative views. E and F, Ten-month postoperative views.

Fig. 5.

Patient with left breast carcinoma who underwent left nipple-sparing mastectomy and immediate reconstruction with a submuscular implant and Re-SAP flap (anatomical microtextured implant, low projection; 140 mL). A and B, Preoperative views. C and D, One-month postoperative views.

DISCUSSION

The concept of DTI breast reconstruction was first introduced in 2006 by Salzberg.¹⁶ Since then, several studies have reported the safety of this innovative technique, and surgical strategies in DTI breast reconstruction have evolved significantly over the years, with the prepectoral approach emerging as a safe, effective method that is gaining increasing popularity.^17,18

Although the prepectoral approach offers various advantages, its feasibility mainly depends on the patient’s characteristics and comorbidities and the thickness of the mastectomy flaps.^4,5 In patients with small breasts, the mastectomy skin flaps may often be too thin to adequately accommodate a definitive breast implant. Additionally, due to the small dimensions of the chest, placing an implant completely beneath the muscle may not always be feasible. Furthermore, often the smallest expander available has a width at least 1 cm greater than the smallest anatomical implant (below 200 mL in volume—Mentor CPG Siltex). This condition often results in a mismatch with the size of the breast base, potentially leading to poorer cosmetic and reconstructive outcomes, related to lateral overexpansion, insufficient tissue coverage of the prosthesis, and an augmented risk of its superficialization out of the breast contour.

Alternative techniques, using the pectoralis major muscle and ADM for inferolateral pole coverage, have been previously described to overcome these issues and expand the indications to DTI breast reconstruction.^19–21 However, Ribuffo et al,²² recently pointed out how the action of the pectoralis major muscle on the ADM hinders integration, leading to a higher incidence of complications, including seroma formation, infections, and reconstruction failure. Numerous studies in the literature have demonstrated the advantages of using prepectoral implants with complete ADM coverage. As a result, the use of membranes, initially dedicated primarily to the inferolateral pole technique, has now become widely adopted, even in a fully prepectoral setting.²³ In this regard, Chan et al²⁴ reported on the use of the serratus anterior fascia for inferior and lateral implant support in DTI procedures following mastectomies. This method provides similar outcomes if compared with the use of ADM, but minimizes the risk of infective complications and seroma associated with the presence of a foreign material.²⁴ However, as highlighted by Saint-Cyr et al,²⁵ the thickness of the serratus fascia often correlates with the patient’s body mass index, and in very thin patients, it may not provide adequate coverage. In such cases and in selected patients with small breasts (up to 300 mL) who do not wish to increase their breast size, we propose an innovative technique that offers a viable option for an immediate ADM-free, dual-plane DTI reconstruction that combines the use of a pectoralis major flap with an Re-SAP flap. The use of submammary adipofascial flaps has been previously explored in the literature for various purposes, and several authors have presented different preparations of the inframammary adipofascial or cutaneous-subcutaneous flaps to obtain greater implant coverage after breast oncological surgery or to enhance breast contours for aesthetic purposes.^26–29 In this regard, Pelle-Ceravolo et al³⁰ described a rotated abdominal fat flap to prevent double-contour deformity following IMF-lowering breast augmentation procedures.

Ogawa et al³¹ used an inframammary adipofascial flap to enhance the contour of the lower quadrants for completely retropectoral reconstructions with tissue expanders. Both of these studies exploit the adipofascial tissue at the inframammary fold to obtain an additional component of soft tissue, to be associated with the implant and improve the contour of the lower pole. In our case, the Re-SAP flap is used not only to enhance the contours of the lower pole but, more importantly, to construct a section of the prosthetic pocket, thereby preserving additional muscular structures.

Building on these insights, we developed the Re-SAP flap to extend the indications for dual-plane DTI breast reconstruction. This approach eliminates the need for biological or synthetic slings by anchoring the flap to the inferior border of the pectoralis major muscle, so as to increase the coverage of the inferolateral pole of the breast implant and improve both the reconstructive and cosmetic outcomes. This choice is versatile when mastectomy flaps are not thick enough for a prepectoral strategy and the risk of prosthetic exposure is high. The harvesting process does not add further scarring, as it uses the same incision as the mastectomy, unlike perforator or muscle flaps such as thoracodorsal artery perforator or latissimus dorsi, where the scarring expense is certainly greater.^32,33 Furthermore, the Re-SAP flap seems to show minimal donor site morbidity. At the end of the flap harvesting at the inframammary region, a slight depression may be observed compared with the contralateral site. However, in our experience, this condition typically resolves within a few weeks. Due to the thin nature of the flap, usually measuring less than 1 cm in thickness, there is minimal alteration of the subcutaneous layers at the donor site. According to the anatomical studies, the Re-SAP flap acts as a perforator flap³⁴ by including the lateral intercostal artery perforator flap and the lateral thoracic artery perforator flap.^35–37 By using these 2 potential sources of perforators, it offers greater versatility in breast reconstructions. These anatomical and functional bases align perfectly with the current trend in autologous breast reconstruction, where harvesting flaps based on perforators ensures low donor site morbidity and high reliability, constituting the finest approach in plastic surgery.³⁸ This technique can be considered a submuscular “hybrid” DTI breast reconstruction, using both heterologous and autologous approaches, simultaneously, without adding additional scars. The creation of an autologous pocket that better fits the implant in the first instance to the small chest of the selected patients allows for the maintaining of a natural shape that respects the original breast contour. In certain heterologous reconstructive scenarios, particularly in thin patients, the well-vascularized coverage provided by the pectoralis major muscle remains necessary. This coverage helps to address common issues associated with prepectoral DTI reconstructions, including rippling, implant visibility, and the heightened risk of implant exposure and the need for surgical revision. These challenges call into question the accuracy of labeling the procedure as a single-stage procedure unless patients are carefully selected.^4,39 Despite several studies showing fewer complications and high patient satisfaction with submuscular reconstruction, it is not without drawbacks, including animation deformity and increased postoperative, sometimes chronic, pain.^40,41 Recently, De Lorenzi et al⁴² reported a series of 100 patients undergoing partially submuscular ADM-free, DTI breast reconstructions. The study showed a reduced complication rate and high patient satisfaction, highlighting the continued significance of submuscular reconstruction in contemporary practice.⁴²

In this regard, our modified DTI dual-plane technique has proven to be safe, with a low complication rate and good overall patient satisfaction (Tables 3, 4). The main limitations of this study include the small sample size and the short follow-up period, which have not yet allowed for a comprehensive evaluation of its full potential. In fact, these are preliminary results, and we expect that, with longer follow-up, scores will improve in all areas and reach valid statistical significance. Moreover, the absence of a control group represents a significant limitation, as its inclusion would provide more objective data. A larger-scale study is necessary not only to enable a more comprehensive comparison of different techniques but also to incorporate a control group, which would enhance the robustness and reliability of the findings. However, the novel technique we present provides a new foundation for assessing the ongoing relevance of submuscular reconstruction in heterologous breast reconstruction. In accurately selected patients, this approach can offer satisfactory results while reducing costs and complications.^22,43–45

The Re-SAP flap is a valuable tool for plastic surgeons in both reconstructive and nonreconstructive contexts. It can also serve as an adjunctive technique in 2-stage reconstructions and revision procedures, offering enhanced coverage of the lower poles, particularly in radiated patients or when mastectomy flaps are at risk. Additionally, it enables the creation of an internal bra, which provides better implant support and helps redefine the IMF, particularly in cases where it has been deformed by severe capsular contracture or compromised by prior mastectomy.

CONCLUSIONS

The Re-Sap flap technique represents a simple and feasible reconstructive alternative in selected cases. The data obtained from this study are promising; however, the evidence, limited to a small sample size, needs validation from a larger cohort and longer follow-up.

DISCLOSURE

In 2018, Dr. Casella appeared once as a guest speaker under an agreement with PFM Medical; since then, he has not been under contract with PFM Medical and has not provided any other services to the company. The other authors have no financial interest to declare in relation to the content of this article.

PHOTOGRAPHIC CONSENT STATEMENT

Patients provided written consent for the use of their images.