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Breast: Original Articles

Revision Breast Reconstruction with Prepectoral Pocket Conversion of Submuscular Breast Implants

Kraenzlin, Franca M.D.; Chopra, Karan M.D.; Kokosis, George M.D.; Venturi, Mark L. M.D.; Mesbahi, Ali M.D.; Nahabedian, Maurice Y. M.D.

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Plastic and Reconstructive Surgery: May 2021 - Volume 147 - Issue 5 - p 743e-748e
doi: 10.1097/PRS.0000000000007885
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Breast reconstruction with prosthetic devices remains the most common option chosen by patients following mastectomy.1 Statistics compiled by the American Society of Plastic Surgeons have demonstrated that the two-stage technique using tissue expanders followed by implants is performed in 80 percent of cases.2 For the past several decades, the most common location for device placement was the subpectoral position, with the dual-plane or partial muscle coverage modality being the most common. The benefits of the dual-plane approach were to increase soft-tissue coverage of the expander/implant, minimize the incidence of capsular contracture, and to provide a natural and tapered upper pole.3,4 The disadvantage of the dual-plane technique is that animation of the reconstructed breast associated with pectoral contraction is common and may be the cause of increased pain, muscle spasm, and displacement of the implant.5–8

Prepectoral reconstruction using prosthetic devices has demonstrated a notable increase in incidence and popularity and is now performed by the majority of reconstructive surgeons following mastectomy.9 This is based on the advancements associated with prosthetic breast reconstruction that include improved implants, autologous fat grafting, and the use of acellular dermal matrices.10 Advantages of prepectoral placement of devices include minimal animation, no pain secondary to muscle spasm, and less device displacement or malposition.11–13 As such, more women with implants in the dual-plane position are seeking a remedy for animation deformities, chronic pain caused by muscle spasm, and implant malposition.

A prepectoral conversion procedure, whereby an implant in the subpectoral position is converted to the prepectoral position, is now being performed to alleviate the animation associated with subpectoral devices. We hypothesize that conversion to the prepectoral space can be safely performed with low rates of mastectomy flap necrosis and high rates of resolution of pain and animation deformity in women who have undergone prior prosthetic breast reconstruction in the subpectoral space. The purpose of this study was to review outcomes following the conversion from subpectoral implant placement to prepectoral implant placement for the correction of animation deformity.


This was a retrospective review of patients who underwent breast implant plane conversion from subpectoral to prepectoral over a 10-year period from 2009 to 2019. Sixty-three patients were identified representing the experience of the three surgeons (M.Y.N., M.L.V., and A.M.). Twenty-two patients were not included in the analysis because of inaccessible documentation that included poor follow-up, incomplete photography, and placement of a tissue expander rather than a permanent implant at the time of conversion. One hundred percent of patients had implants placed for reconstruction after breast cancer. This study conforms to the Declaration of Helsinki ethical principles for medical research.

Patient demographics, postoperative complications, implant size and manufacturer, presenting symptoms, postoperative symptoms, and length of follow-up were obtained and patient photographs were analyzed preoperatively and postoperatively. Complications were noted for all patients and included infection that was defined as documented cellulitis, infection, or positive cultures. Seroma was defined as the accumulation of fluid demonstrated clinically or with ultrasound. Necrosis was defined as partial or full thickness and demonstrated by means of clinical examination. Data were recorded and analyzed using Microsoft Excel (Microsoft Corp., Redmond, Wash.) and Stata (StataCorp, College Station, Texas) software. In addition, t test, Fisher’s exact test, and chi-square test were used as appropriate for the data. A value of p < 0.05 was considered statistically significant. BREAST-Q data were not collected for these patients.

Patient selection criteria for conversion from the subpectoral to prepectoral space was based primarily on the presence of animation deformation with pectoralis major contraction. This was often associated with muscle spasm and pain. Consideration for this procedure also required an adequate layer (>5 mm) of subcutaneous fat within the mastectomy skin flaps. The presence of prior radiation therapy was not an absolute contraindication; however, it was important for all included patients to have good-quality skin and fat before surgery. Active tobacco use and poorly controlled diabetes mellitus were considered absolute contraindications for this procedure.

The technique of prepectoral conversion was generally similar between the three surgeons; however, there were some differences. Some surgeons would occasionally place a tissue expander at the time of conversion if the upper mastectomy skin flap appeared too thin following separation from the pectoralis major muscle. Thus, the rationale for including 41 of 63 patients was to ensure that the included patients all underwent the same exact procedure. In all included cases, the subpectoral implant was removed and replaced with a new implant. When the prior incision was through the inframammary fold, the incision was reopened and the inferior edge of the pectoralis major muscle was identified. Electrocautery was used to incise the capsule and expose the edge of the muscle. Allis clamps were used to grasp the edges of the muscle, and electrocautery was used to create the dissection plane between the muscle and the subcutaneous fat. The capsule was excised or scored and the pectoralis major muscle was repositioned onto the chest wall and the inferior edge of the muscle sutured to the chest wall. The prepectoral space was assessed visually and using sizers to assist with selecting the optimal breast implant. The perfusion of the mastectomy skin flaps was assessed clinically and sometimes with the use of fluorescent angiography. Acellular dermal matrix was used in all patients and applied using the tenting or wrap techniques. Following placement of the implant and acellular dermal matrix, a closed suction drain was positioned between the acellular dermal matrix and the mastectomy skin flap.


A total of 73 implant pocket conversions from subpectoral to prepectoral were performed on 41 women in this study. Twenty-two patients were not included in the analysis because of incomplete data that included poor follow-up and incomplete photography. Bilateral conversion was performed in 78 percent of patients. Nipple-sparing mastectomy had been performed in 51.2 percent (Table 1). Prior radiation therapy had been received by 14.6 percent of patients. No patient in this series was actively using tobacco products. A change in the volume of the implant was opted for by 58.5 percent of women as part of the conversion procedure, with an increase in volume being most common (39.0 percent). The mean time interval from the initial subpectoral operation to the prepectoral conversion was 1608.4 days, almost 4.5 years after initial implant placement.

Table 1. - Patient Characteristics
Characteristic Value (%)
No. of patients 41
Average time to implant plane change, days 1608.4
Median time to implant plane change 1418.5
Bilateral plane conversion 32 (78.0)
Nipple-sparing mastectomy 21 (51.2)
Average BMI, kg/m2 24.9
History of radiation therapy 6 (14.6)
Former or never smokers 41 (100)
Average length of follow-up, days 215.8
Increase in implant size 16 (39.0)
Decrease in implant size 8 (19.5)
BMI, body mass index.

The most common reason for prepectoral conversion was animation deformity [n = 36 (87.8 percent)] (Table 2). However, patients frequently suffered from multiple symptoms, including significant levels of pain related to the implant [n = 14 (34.1 percent)], capsular contracture [n = 11 (26.8 percent)], or asymmetries and implant displacements [n = 4 (9.8 percent)]. All prepectoral conversions were performed based on the presenting symptoms of the patients following informed consent as to the risks and benefits.

Table 2. - Indications for Plane Conversion
Indication No. (%)
Animation deformity 36 (87.8)
Pain 14 (34.1)
Capsular contracture 11 (26.8)
Asymmetry or displacement 4 (9.8)
Other* 4 (9.8)
*Included textured implant and breast cancer recurrence.

Surgical complications during the plane conversion were limited, with one patient each experiencing a hematoma, dehiscence, seroma, and infection (Table 3). Importantly, no patients experienced necrosis, either partial or full, of the mastectomy flap or nipple-areola complex as a result of the surgery. Fat grafting was performed as a subsequent procedure in eight patients (19.5 percent) for correction of upper pole contour irregularities and rippling and wrinkling. Fat grafting was not performed at the time of the prepectoral conversion but was performed as a subsequent revision at a minimum of 3 months following the conversion. The specific technique used a 10-cc syringe and a 1- to 1.2-mm cannula. Injected fat was placed within the subcutaneous layer between the skin and the acellular dermal matrix. It was not injected into the pectoralis major muscle. Injected fat volumes ranged from 15 to 40 cc per breast.

Table 3. - Surgical Complications
Complication No. (%)
Hematoma 1 (2.4)
Infection 1 (2.4)
Seroma 1 (2.4)
Dehiscence 1 (2.4)
Necrosis 0 (0.0)

Although 100 percent of individuals presented with symptoms debilitating enough to request additional surgery, only 7.8 percent of individuals continued to experience their presenting symptom after plane conversion (Table 4). Of the individuals who continued to have symptoms, one continued to experience pain and two continued to experience mild animation deformity. Eleven of 41 patients (26.0 percent) received fat grafting during their plane conversion procedure or during a subsequent procedure. Rippling and wrinkling were noted in 19.5 percent of individuals, and edge visibility was documented in 4.9 percent. No patients had capsular contracture following the conversion during the defined follow-up period ranging from 1 week to 2.9 years (mean, 7.5 months). Figures 1 and 2 illustrate two patients following conversion from subpectoral to prepectoral. Neither patient had postconversion fat grafting.

Table 4. - Outcomes
Outcome No. (%)
Persistence of presenting symptoms after plane conversion* 3 (7.3)
Implant rippling 8 (19.5)
Fat grafting after plane conversion 11 (26.9)
Edge visibility documented 2 (4.9)
*Two patients continued to experience slight animation following implant plane conversion and one continued to experience pain.

Fig. 1.
Fig. 1.:
(Above, left) Animation deformity following subpectoral prosthetic reconstruction. (Above, right) Post–prepectoral conversion frontal view. (Below, left) Post–prepectoral conversion left lateral view. (Below, right) Post–prepectoral conversion right lateral view.
Fig. 2.
Fig. 2.:
(Above, left) Animation deformity following subpectoral prosthetic reconstruction. (Above, right) Post–prepectoral conversion frontal view. (Below, left) Post–prepectoral conversion left lateral view. (Below, right) Post–prepectoral conversion right lateral view.


This study reports on a consecutive series of 41 breast reconstruction revisions where the reconstruction was converted from the subpectoral to the prepectoral space and led to complete resolution of animation deformity in 95.1 percent of patients and partial resolution in 4.6 percent of patients. It is postulated that the mild residual animation was related to adhesion between the implant and the underlying pectoralis major muscle that was denuded of its native fascia during the index mastectomy operation. Another explanation is that the sutures anchoring the pectoralis major muscle to the chest wall did not completely anchor the muscle, resulting in mild animation with contraction. The safety and efficacy of this procedure has been demonstrated based on no evidence of mastectomy skin flap compromise and a low complication profile (Figs. 1 and 2). No instances of capsular contracture were observed at the average follow-up time of 7.5 months (range, 7 days to 2.9 years).

The observed rates of low capsular contracture are reassuring and similar to a prior report by Gabriel et al. of 102 revision operations with a no incidences of grade III or IV capsular contracture following prepectoral conversion using acellular dermal matrix for animation deformity (mean follow-up. 16.7 months; range, 4 to 65.8 months).14 Moreover, Gabriel et al. reported complete resolution of animation deformity with the prepectoral approach. This is further corroborated by a smaller study by Hammond et al., which included 19 breasts (10 patients); the authors also reported complete resolution of animation in all patients (mean follow-up, 13.8 months).15 The principal difference between the two studies was that no acellular dermal matrix was used in the study by Hammond et al. Despite the complete resolution of animation, there was a 21 percent incidence of capsular contracture. Although other more recent studies have also successfully demonstrated that plane conversion is safe and efficacious in resolving animation deformity,16,17 in this study, we also demonstrate a resolution of pain secondary to plane conversion in the majority of patients experiencing those symptoms.

The introduction of acellular dermal matrices in the past decade alongside improved implant design made feasible conversion from the subpectoral to the prepectoral pocket in patients who are suffering from pain and animation deformity secondary to subpectoral breast reconstruction. This approach has been described previously with encouraging preliminary results.14,15,18 These challenges have parallels in cosmetic breast augmentation, where animation and implant malposition have been successfully managed with pocket exchange from the subpectoral plane to the prepectoral plane.19 However, there is reluctance to adopt this approach in the breast reconstruction population, given a fundamental difference—the absence of breast tissue raises concerns for vascular viability. Thin mastectomy skin flaps with a lack of soft tissue can increase the chances for complications such as malposition, rippling, visibility, and ultimately capsular contracture.

Many pearls and pitfalls for prepectoral pocket conversion in revision breast reconstruction can be guided by the parallel literature on primary implant-based prepectoral breast reconstruction. In these studies, prepectoral placement of the implant device is thought to be associated with low rates of animation deformity.10,20,21 Although the indications and contraindications for prepectoral breast reconstruction continue to evolve, the senior author (M.Y.N.) previously provided guidance regarding relative indications and contraindications to prepectoral breast reconstruction. These same principles apply to revision conversions to the prepectoral space. The ideal patient has thick, well-vascularized mastectomy skin flaps because reelevation of thin or dysvascular flaps may increase the risk of dehiscence, partial or full-thickness necrosis, or even failure of reconstruction. In addition, prior radiation therapy is a known risk factor for an increased incidence of vascular-related skin flap complications. However, of the six patients with prior radiation therapy, there were no incidences of necrosis among that cohort. Moreover, obesity did not appear to be a harbinger of complications among the three patients in this study who had a body mass index greater than or equal to 30 kg/m2.

As our experience with prepectoral conversion evolved, we noticed a modest rate of rippling implant edge visibility and some reconstructions where the overall contour could be improved. As such, 26.9 percent of our patients went on to receive fat grafting as a subsequent procedure. It is now our preference to combine pocket conversion with autologous fat transfer for improvement in contour, rippling, and implant edge visibility.

The present work is limited by the retrospective nature of its design and the lack of an acceptable control group or patient-reported outcomes. We present pain in a qualitative manner in this study, which we see as a limitation. Future use of a validated quantitative measure to assess pain would enhance study results. In addition, longer follow-up is needed to thoroughly evaluate long-term complications such as capsular contracture. Although this was not observed in any patient in this study, we are aware of this follow-up limitation but strongly believe that prepectoral conversion is safe and effective and that this operation may be a potential solution in patients complaining of animation deformity after previous subpectoral implant-based breast reconstruction. We anticipate a follow-up study to report on these patients’ long-term outcomes.


The use of prepectoral conversion for revision implant-based breast reconstruction successfully and completely resolves animation deformity in the vast majority of cases. This technique can be reliably and safely performed in a variety of patient demographics.


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