Restoring Symmetry in Challenging Revision Breast Surgery: Outcomes of Pilot Study with Poly-4-Hydroxybutyrate Implant Construct

Abstract

Background:

Revision breast reconstruction is often necessary to address complications, reduce asymmetry, or improve the aesthetic result. Our previously described use of poly-4-hydroxybutyrate (P4HB) has shown promise in primary reconstruction; limited data exist on its use in revision surgery. This study presented a single-institution case series evaluating indications and outcomes of revision breast reconstruction using a P4HB-wrapped implant.

Methods:

We retrospectively reviewed patients who underwent breast reconstruction revision with a P4HB-wrapped implant at our institution from September 2022 to May 2025. Data were collected through chart review.

Results:

Thirty-four patients (51 breasts) underwent revision surgery using a P4HB-wrapped implant. Most patients (85%) had 2-stage reconstructions. Most primary reconstructions (76%) occurred at our institution, with 96% continuity among reconstructive surgeons. Median (interquartile range) time from initial reconstruction to revision was 344 (609) days. The most common indication was radiation-associated breast asymmetry (35%). At a median (interquartile range) follow-up of 501 (410) days, 91% (31 of 34) of patients maintained stable breast symmetry. Complications occurred in 5.9% (3 of 51) of breasts: 1 implant exposure requiring explantation (1.96%) and 2 cases of persistent malposition (3.92%) despite P4HB use.

Conclusions:

The P4HB-wrapped implants achieved consistent soft-tissue support and maintained symmetry during the observed follow-up period, and for the limited number of patients studied, radiation-associated capsular contracture or shape changes were not observed during the study period. These findings support P4HB as a valuable adjunct in complex revisions, particularly in patients with prior radiation or significant asymmetry. Ongoing follow-up is needed to assess the long-term durability and aesthetic outcomes of this approach.

Takeaways

Question: What is the best way to manage patients with asymmetrical breasts after breast reconstruction?

Findings: In our retrospective cohort study of breast reconstruction patients, the poly-4-hydroxybutyrate–wrapped implant in revision breast reconstruction provided excellent symmetry restoration with a low complication rate at a mean follow-up of 16.7 months.

Meaning: Surgeons should consider this technique when facing these challenging patients, as it is effective and safe.

INTRODUCTION

Breast reconstruction following mastectomy plays an important role in restoring quality of life for patients undergoing treatment for breast cancer.^1,2 Although advances in surgical technique have significantly improved initial reconstruction outcomes, revision procedures remain common to refine the aesthetic result.^3–5 These revision breast reconstruction cases present unique challenges. Compared with primary reconstruction, patients undergoing revision often have more scar tissue, prior radiation exposure, reduced skin quality, and altered vascularity. These factors limit the reconstructive options and increase the risk of complications, underscoring the need for durable, supportive solutions tailored to the revision setting.⁶

Soft-tissue supports such as acellular dermal matrices (ADMs), meshes, and bioresorbable scaffolds have emerged as promising solutions for the setting of implant-based breast reconstruction (IBBR).^7–10 These adjuncts are particularly useful for reestablishing the inframammary fold and securing the implant position in the breast pocket. Although all products are approved for soft-tissue support by the Food and Drug Administration, none have a specific breast indication, so the use of these products is currently considered off-label.¹¹ Initially introduced in direct-to-implant (DTI) and 2-stage prepectoral breast reconstruction, our practice has evolved to use a poly-4-hydroxybutyrate (P4HB; GalaFLEX LITE; Galatea Surgical, Inc., Lexington, MA), which has proven useful in revision surgery by similarly improving implant support in difficult pockets and mitigating complications such as implant malposition.^12,13

Although prior studies have examined its use in primary reconstruction, there remains a paucity of data specifically evaluating outcomes in the setting of revision IBBR. This case series presented our single-institution experience using P4HB in revision breast reconstruction surgery and discusses clinical situations for use and their outcomes, contributing to the growing body of evidence surrounding this bioresorbable scaffold’s role in complex breast surgery.

METHODS

Study Design and Patient Selection

This study is a retrospective cohort analysis of all patients who underwent revision breast reconstruction with our P4HB-wrapped implant at NYU Langone Health between September 2022 and May 2025. Eligible patients were identified through a review of institutional medical records. Inclusion criteria included patients undergoing revision breast reconstruction surgery with a P4HB-wrapped implant by one of the senior authors of the study (N.K., M.C., O.C.). Revision breast reconstruction was defined as further surgery to address the breast implants after completion of primary reconstruction (DTI, 2-stage, or autologous). Exclusion criteria consisted of patients undergoing primary breast reconstruction, patients undergoing aesthetic breast augmentation, or patients undergoing revision breast implant surgery without a history of mastectomies. All patients undergoing revision breast reconstruction were considered for use of P4HB.

Surgical Technique

All patients previously underwent skin-sparing or nipple-sparing mastectomy and completed breast reconstruction. Revision breast reconstruction was conducted by 3 plastic surgeons using our P4HB technique, as previously published.^12,14 Briefly, 2 circular pieces of P4HB are sutured together to form a pocket that wraps the implant. Revision implant selection was based on prior implant size, patient-specific anatomical considerations, and surgeon preference, with a range of implant sizes and profiles used. P4HB size was selected based on implant size and surgeon preference. Drains were placed at the discretion of the senior surgeon and removed when output was between 20 and 30 mL for 2 consecutive days.

Data Collection and Outcome Measures

All data were manually extracted from electronic medical records by the authors. As reconstruction revision is intended to reposition the implant(s) into a favorable position, the primary outcome was restoration of symmetry and acceptable aesthetics during postoperative follow-up. Aesthetic outcomes, including symmetry, contour, and implant position, were assessed through retrospective review of standardized clinical photographs and physical examination findings documented in the electronic medical record. These evaluations were performed by the treating surgeons, and no independent or blinded third-party assessment was conducted. Additionally, formal patient-reported outcome measures (such as BREAST-Q) were not collected. The secondary outcomes included the incidence of unexpected postoperative complications (ie, hematoma, seroma, skin flap necrosis, incision dehiscence) and the incidence of known postoperative complications (rippling, capsular contracture, animation deformity). Specific case examples are addressed in the Discussion section.

Statistical Analysis

Descriptive statistics were used to summarize patient demographics and surgical characteristics. Continuous variables were reported as medians with interquartile ranges (IQRs). Categorical variables were presented as frequencies and percentages. A P value of less than 0.05 was considered statistically significant.

Ethical Considerations

This study was approved by the institutional review board at NYU Langone Health, and informed consent was waived due to the retrospective nature of the study. All patient data were de-identified and handled in compliance with Health Insurance Portability and Accountability Act regulations to ensure confidentiality.

RESULTS

Demographics

There were 34 patients with 51 reconstructed breasts requiring revision included in the study. The median (IQR) age of patients at the time of revision surgery was 48 (17.4) years. All were women. Nine (9 of 34; 27%) patients had a history of smoking, and no patients were actively smoking at the time of surgery. One (1 of 34; 2.9%) patient had diabetes mellitus. The median body mass index (BMI) of the included patients was 24 (IQR 6.9) kg/m². Two (2 of 34; 5.8%) patients had prior breast augmentations; 2 (2 of 34; 5.8%) patients had prior breast reduction surgery. Fifteen breasts (15 of 51; 29%) requiring revision had a history of radiation therapy (Table 1).

Table 1.

Summary of Demographics

	Values
Patients	34
Revised breasts	51
Median age (IQR), y	48 (17.4)
Median BMI (IQR), kg/m2	24 (6.9)
Comorbidities, n (%)
Former smoker	9 (27)
Current smoker	0 (0)
Diabetes mellitus	1 (2.9)
Prior breast surgery, n (%)
Breast augmentation	2 (5.8)
Breast reduction	2 (5.8)
Radiation therapy on revised breast, n (%)	15 (29)
Type of mastectomy (N = 34), n (%)
Skin sparing	26 (76)
Nipple sparing	8 (24)
Plane of initial reconstruction (N = 51), n (%)
Submuscular	34 (66)
Prepectoral	17 (33)

Eight (8 of 34; 24%) patients had nipple-sparing mastectomy; 26 (26 of 34; 76%) patients had skin-sparing mastectomy. Twenty-six (76%) patients had their mastectomy and primary breast reconstruction performed at our institution. For the initial reconstruction, 29 (29 of 34; 85%) patients underwent 2-stage reconstruction, 4 (4 of 34; 12%) patients underwent DTI reconstruction, and 1 (3%) patient underwent autologous reconstruction with revision surgery to insert implants for additional volume. Most initial reconstructions were performed in the submuscular plane (34 of 51; 66%); the remainder were performed in the prepectoral plane (17 of 51; 33%). Most breasts did not have soft-tissue support used during primary reconstruction (36 of 51; 71%). When soft-tissue support was used at the index operation, the most common material was AlloDerm Regenerative Tissue Matrix (AbbVie Inc, North Chicago, IL), used in 10 breasts (20%). P4HB was used in 4 breasts (4 of 51; 7.8%) during primary reconstruction.

One (1 of 26; 3.8%) patient changed reconstructive surgeons between primary reconstruction and revision reconstruction; the remainder (25 of 26; 96.2%) had the same reconstructive surgeon for primary breast reconstruction and the revision procedure. The median (IQR) time between primary breast reconstruction and revision surgery was 344 (609) days. The average time between completion of radiation and revision surgery on the radiated breast was 393 (± 211) days. The most common reason for breast reconstruction revision was radiation-related breast implant asymmetry (12 of 34; 35%) (Table 2). All patients underwent at least capsulorrhaphy during revision with 1 patient having the implant pocket changed from submuscular to prepectoral. Eleven (11 of 34; 32%) patients underwent fat grafting at the time of revision surgery.

Table 2.

Reason for Needing Breast Revision Surgery With P4HB-wrapped Implant

Reason for Needing Breast Revision	Values
Asymmetry after nonradiated implant dropped	12
Implant flipping	6
Implant lateralization	4
General asymmetry	3
Support under autologous tissue	2
Implant dropping	2
Patient weight gain	2
Implant medialization	1
Implant plane change	1
Implant deterioration	1

Outcomes

Thirty-one (31 of 34; 91%) patients had stable maintenance of breast symmetry following revision surgery during a median (IQR) follow-up period of 501 (410) days. There were 3 breasts in 3 patients with complications (3 of 51; 5.9%). One breast (1 of 51; 1.96%) had implant exposure requiring explantation, and 2 breasts (2 of 51; 3.92%) had subsequent implant malposition even after revision with P4HB-wrapped implant (Table 3). One patient had a history of smoking with a BMI greater than 30 kg/m² and underwent revision surgery with a change of the implant pocket from submuscular to prepectoral, using 565-cm³ implants and a 19-cm P4HB wrap. The other patient was healthy, with a BMI of 22 kg/m² and initially 420-cm³ implants with AlloDerm adjunct, who underwent revision surgery with implant exchange to 385-cm³ implants and a 17-cm P4HB wrap.

Table 3.

Summary of Complications

	Values, n (%)
Complications (n = 3 breasts)
Implant malposition	2 (4)
Implant extrusion	1 (2)

DISCUSSION

In this single-institution case series, we report favorable outcomes in 34 patients (51 breasts) undergoing revision breast reconstruction using the P4HB-wrapped implant. The cohort represented a diverse patient population, with the majority undergoing 2-stage reconstruction and having no soft-tissue support used during their primary reconstruction. Our findings suggest that the P4HB-wrapped implant may offer reliable support in the revision setting, with 91% of patients maintaining stable breast symmetry at an average follow-up of more than 1 year. This is particularly notable given the high proportion of patients with radiation-associated asymmetry, which has been found to substantially impact subsequent cosmetic outcomes.¹⁵

Although the use of ADM in primary breast reconstruction and revision breast augmentation is well described and not without risk, there are limited studies examining the use of ADMs or meshes in revision breast reconstruction.^16,17 The most notable is from Lentz et al,¹⁸ who reported on 31 patients (55 breasts) undergoing revision breast reconstruction with implant pocket changes for animation deformity. They found favorable results using ADM in 46 breasts, with a 9% rate of unplanned return to the operating room, a 17% rate of unplanned admission, a 17% rate of infection requiring intravenous antibiotics, and only 1 patient losing her reconstruction, resulting in an overall implant loss rate of 1.8%. Two (4.3%) patients required revision operations; however, only 7 (12.7%) of these patients had a history of breast radiation. In contrast, our overall complication rate was about 6% with an implant loss rate of 2% using the P4HB wrap in a challenging setting with many of our patients having a history of radiation. The patient who experienced implant exposure in 1 breast has not yet completed breast reconstruction, and the 2 patients with implant malposition after P4HB revision have re-revisions planned.

Although direct comparisons are limited by study design, patient heterogeneity, and limited long-term follow-up of this cohort of patients, these data suggest that P4HB may provide short-term, safe, and meaningful structural support even in compromised soft-tissue environments, with the additional long-term advantages of providing a durable scaffold for mechanical reinforcement of soft tissue even after bioresorption.^19,20 Some data have reported an increased risk of capsular contracture in DTI patients, but this is in a small cohort of patients treated with P4HB (n = 21).²¹ Additionally, unlike ADMs, which remain as permanent implants or integrate with variable resorption, P4HB is fully resorbed, typically within 12–24 months, potentially lowering the risk of chronic foreign body reaction.

In our cohort, the P4HB-wrapped implant was used across a spectrum of complex revision indications, including after radiation-related asymmetry (Fig. 1), implant malposition (Fig. 2), and after massive weight loss (Fig. 3), alongside traditional pocket control adjuncts including capsulectomy, capsulotomy, and capsulorrhaphy, as indicated. These scenarios represent some of the most technically demanding situations in IBBR, where compromised soft-tissue support, reduced skin elasticity, compromised vascularity, and distorted breast anatomy significantly increase the difficulty of achieving postoperative symmetry and aesthetic satisfaction.^22–24 Previously, these scenarios were managed with ADM. ADM has a smooth surface and frequently does not incorporate, which can allow recurrent implant malposition. Using a P4HB wrap mitigates this by effectively creating a temporary, resorbable scaffold that modulates the periprosthetic capsule environment, facilitating uniform tissue integration and reducing shear forces at the implant–soft-tissue interface during early healing. Particularly, in patients with massive weight loss, some cases of implant malposition/pseudoptosis result from excess skin elasticity and require skin excision, which may be the only correction needed to improve implant position and symmetry, without the need for adding soft-tissue support such as ADM or P4HB. The 1 area that we feel favors ADM is with fat grafting, as we observed anecdotally that the ADM creates a marginally better plane for fat grafting between the skin and implant than P4HB due to the ADM creating a more pliable and vascularized soft-tissue layer between the skin flap and implant rather than P4HB, which remains partially mobile and maintains a more organized, less compliant architecture, which may result in a thinner or less uniform plane for initial fat grafting. In the limited number of patients studied, radiation-associated capsular contracture or shape changes were not observed during the study period.

Fig. 1.

A 45-year-old patient underwent 2-stage bilateral prepectoral breast reconstruction with bilateral 450 cm³ implants and AlloDerm. A, The patient experienced post-mastectomy radiation therapy on the right side with left implant dropping. B, Revision surgery was performed in the prepectoral plane with a 415 cm³ implant wrapped with 2 pieces of 17 cm round P4HB on the left side.

Fig. 2.

A 43-year-old patient underwent 2-stage unilateral subpectoral breast reconstruction with a right breast 250 cm³ implant. A, The patient experienced right implant dropping after manual massage. B, Revision surgery was performed in the subpectoral plane with a 205 cm³ implant wrapped with 2 pieces of 15 cm round P4HB.

Fig. 3.

A 55-year-old patient underwent 2-stage bilateral subpectoral breast reconstruction with bilateral 360 cm³ implants. A, The patient experienced massive weight loss and implant dropping. B, Revision surgery was performed in the subpectoral plane with a 375 cm³ implant wrapped with 2 pieces of 15 cm round P4HB bilaterally.

The largely favorable outcomes observed in this study suggest that the P4HB-wrapped implant provides effective structural reinforcement across these diverse clinical contexts, and its ability to maintain implant position within a suboptimal pocket, while supporting soft-tissue integration, seems especially advantageous in these challenging cases. Although it is too early to report definitive long-term conclusions regarding durability, the early success across multiple revision indications underscores the versatility of P4HB in addressing a range of reconstructive challenges, which has previously been discussed by our group.²⁵

The lower complication and capsular contracture rates observed in this series compared with prior reports using P4HB mesh may reflect several contributing factors. First, patient selection likely played a role, as our cohort consisted predominantly of patients undergoing revision rather than primary reconstruction, in whom residual soft-tissue envelopes were already mature and well-vascularized. Second, all procedures were performed using a consistent operative algorithm involving capsulectomy and complete P4HB wrapping, which minimized technical variability. Third, perioperative management at our institution emphasizes rigorous control of seroma formation and antibiotic prophylaxis, which could further reduce complications. At a biological level, P4HB’s gradual resorption profile and its promotion of organized collagen deposition may attenuate the chronic inflammatory cascade associated with contracture formation. When combined with a healthy, well-vascularized soft-tissue bed, this may explain the absence of significant complications or delayed healing in our series. Nevertheless, these hypotheses should be interpreted cautiously, as inter-study variability in patient populations, surgical techniques, and follow-up durations likely contributes to the observed differences.

The favorable healing outcomes observed in radiated patients may be partially explained by the biocompatibility and gradual resorption profile of P4HB mesh, which supports tissue integration without eliciting a sustained inflammatory response. Preclinical data suggest that P4HB facilitates neovascularization and collagen remodeling, creating a more physiological capsule environment. Additionally, in our series, all reconstructions underwent at least partial capsulectomy, allowing replacement of chronically fibrotic tissue with a healthier, well-vascularized soft-tissue envelope. These technical factors may have mitigated some of the deleterious effects of prior radiation. However, given the relatively small number of radiated breasts in this cohort and the retrospective nature of our study, these results should be interpreted with caution. The absence of complications in this subset may reflect sampling bias or limited statistical power rather than a definitive protective effect.

Limitations of this study included its retrospective design, limited follow-up, and single-institution scope. Because multiple surgeons contributed to this series, variation in surgical technique, perioperative management, and experience level may have influenced outcomes. Although all procedures were performed within a single institution using a consistent reconstructive algorithm, minor technical differences among operators may have affected complication rates or aesthetic results. In addition to the inherent limitations of a single-center retrospective review, our study was also subject to potential sampling bias, as the included patients represented a subset of revision breast reconstructions managed at a tertiary referral institution with specialized expertise in complex cases. This may limit the generalizability of our findings to broader reconstructive practice settings. In our institutional experience, most patients demonstrated satisfactory aesthetic outcomes with restoration of breast symmetry as judged by clinical and photographic evaluation; however, the absence of blinded assessment and patient-reported outcomes limits the objectivity of these findings.

However, this study adds to the growing body of evidence suggesting that bioresorbable scaffolds may offer a safe and effective adjunct in breast reconstruction, including challenging revision cases. Future research should focus on large heterogeneous studies with long-term outcomes, as well as cost-benefit analyses comparing various soft tissue support options.

CONCLUSIONS

The P4HB-wrapped implants achieved consistent soft-tissue support and maintained symmetry during the observed follow-up period, and for the limited number of patients studied, radiation-associated capsular contracture or shape changes were not observed during the study period. These findings support P4HB as a potentially valuable adjunct in complex revisions, particularly in patients with prior radiation or significant asymmetry. Ongoing follow-up is needed to assess the long-term durability and aesthetic outcomes of this approach.

DISCLOSURE

The authors have no financial interest to declare in relation to the content of this article.