Comparison of Secondary Procedures and Complications Between Subpectoral and Prepectoral Direct-to-implant–based Breast Reconstruction: 5-year Retrospective Analysis

Abstract

Background:

Implant-based breast reconstruction (IBR) remains the most widely used method for breast reconstruction following mastectomy. There is significant variability in the choice between subpectoral and prepectoral approaches. This study compares the frequency of secondary procedures required to improve the aesthetic outcome between subpectoral and prepectoral IBR approaches.

Methods:

A retrospective cohort study was conducted on patients undergoing single-stage subpectoral IBR between January 2014 and June 2017 or prepectoral IBR between November 2016 and December 2019 by a single surgeon at a tertiary breast unit. The primary outcome was the number of secondary procedures performed within 5 years to improve aesthetic outcomes. Secondary outcomes included postoperative complications.

Results:

A total of 388 single-stage IBRs were analyzed (194 subpectoral and 194 prepectoral). Median age was 43.0 years in both groups, with similar body mass index (22.4 kg/m² [interquartile range 3.1] versus 22.0 kg/m² [interquartile range 3.5]; P = 0.795). The overall frequency of secondary procedures at 5 years was comparable (53.1% versus 53.6%; P = 0.650). Pocket revisions were significantly more common following subpectoral reconstruction (9.3% versus 2.6%; P = 0.005), whereas implant exchange rates were not significantly different (7.7% versus 3.1%; P = 0.216). Fat grafting rates were similar (32.5% versus 37.6%; P = 0.338). Overall complication rates did not differ significantly (20.1% versus 22.2%; P = 0.709), and implant loss was low at 5.2% in both groups.

Conclusions:

At 5-year follow-up, prepectoral and subpectoral IBR were shown to have comparable rates of secondary aesthetic procedures and postoperative complications. These findings support prepectoral IBR as a safe and effective alternative to subpectoral reconstruction.

Takeaways

Question: Does prepectoral implant-based breast reconstruction, compared with subpectoral reconstruction, result in differences in postoperative complications and the need for secondary procedures over a minimum 5-year follow-up period?

Findings: There were no differences between subpectoral and prepectoral implant–based breast reconstructions in postsurgery outcomes, including implant exchange rates, fat grafting, or overall complications.

Meaning: Long-term comparative data may help guide patient selection, inform shared decision-making, and support evidence-based counseling regarding expectations, complications, and the reconstructive journey following mastectomy.

INTRODUCTION

Breast reconstruction has evolved significantly over decades, and implant-based breast reconstruction (IBR) is still the most widely used method for reconstruction following mastectomy globally.¹ For years, the subpectoral technique, in which the pectoralis muscle provides soft tissue cover, has remained the gold standard.^2,3 More recently, and with increased use of acellular dermal matrices (ADMs), there has been a paradigm shift to the prepectoral approach, in which the implant is placed over the muscle.^4,5 The popularity of this approach lies in its potential to reduce disruption of shoulder function and postoperative pain and eliminate animation deformity, often associated with the subpectoral approach, while enabling a more natural-looking reconstruction.^6,7 It has been argued that the prepectoral approach may be associated with increased implant edge visibility and wrinkling from limited cover of the upper pole without muscle cover. Another factor in favor of prepectoral implant placement is better preservation of the vascular integrity of the nipple–areola complex, thus reducing the risk of ischemic complications.⁵ Considerable variability in patient and surgeon understanding to guide choices between subpectoral and prepectoral approaches continue.⁷

It is widely accepted that implant reconstruction is a process of care, and it is not uncommon for patients to require secondary procedures to optimize breast form and symmetry, as well as to manage postreconstruction complications and maintenance over time. These can be related to capsular contracture, seroma formation, rippling, rotation/displacement of the implant, and salvage surgery following implant loss from wound infection, ischemia, or delayed healing.⁸ The most common secondary procedures required to deal with the aesthetics of thin skin cover, implant migration, and capsular contracture are fat grafting (lipomodelling), capsulectomy or capsulotomy, implant exchange, pocket revision, and scar revision.⁹ Although recent published data and meta-analyses have compared the 2 techniques, long-term follow-up and direct comparative studies are lacking in most of the studies included in the reviews.¹⁰ This study aimed to evaluate the number of secondary procedures required to improve the overall aesthetic outcome and the postoperative complications following prepectoral and subpectoral immediate breast reconstructions after 5 years of follow-up in each group.

METHODS

This study is a retrospective cohort analysis of patients who underwent IBR either directly by or under the supervision of a single surgeon (G.G.) at a tertiary breast cancer center. This study is an extension of a previously published study by our institution with longer and equivalent 5-year follow-up data for both groups.¹¹

The study included women who received subpectoral IBR between January 2014 and June 2017 or prepectoral IBR between November 2016 and December 2019. Data were censored at 5 years in both groups, and data from the last physical clinic visit were recorded. All notes reviewed at 5 years confirmed no new clinical incidents or episodes. Patients who underwent 2-stage surgery with primary tissue expansion were excluded. Patient selection for prepectoral versus subpectoral reconstruction was primarily time-period dependent: subpectoral as the standard operation between 2014 and 2017, transitioning to prepectoral thereafter for suitable candidates. Prepectoral reconstruction transpired to be suitable for the majority of our IBR procedures.

Mastectomies were performed using hydrodissection (30-mL chirocaine with 0.5 mL of 1:1000 adrenaline in 1 L of normal saline), where 300–500 mL was infused per breast to define the mastectomy skin flap and prepectoral space. This facilitated minimal bleeding during scissor dissection. Nipple-sparing mastectomies were conducted through an inframammary crease incision, whereas skin-sparing mastectomies used a short elliptical incision to remove the nipple–areola complex.

For subpectoral implant placement, the subpectoral pocket was dissected and released from the pectoralis major muscle’s inferomedial border. In both prepectoral and subpectoral approaches, the lateral pocket was closed with absorbable sutures. Implants (Mentor, Johnson & Johnson) were handled with safety measures to minimize infection risks, including pocket lavage with sterile water and povidone–iodine and minimal handling. Biological ADMs (Surgimend, Integra Life Sciences) were prepared and rehydrated as per manufacturer instructions. One ADM per breast was used in each case. In subpectoral IBR, the ADM was positioned with absorbable sutures between the free edge and the raised inferior border of the pectoralis major muscle and the lateral breast/inframammary fold to create an inferior-lateral ADM sling. In prepectoral IBR, the ADM was secured to the muscle fascia with sutures, creating anterior ADM coverage (onlay) rather than a full circumferential wrap. All patients received intravenous antibiotic prophylaxis and a surgical drain for up to 5 days.

Patient demographics, including age, body mass index (BMI), smoking status, comorbidities, and clinical and operative details, were collected from electronic patient records. The primary outcome was the number of secondary procedures performed during follow-up. Secondary outcomes comprised comparison of the recorded complications, including seroma, infection, hematoma, skin/nipple necrosis, wound dehiscence, implant loss, and capsular contracture.

A “secondary procedure” was defined as any subsequent surgery to improve the aesthetics of the reconstructed breast, driven by patient decision in consultation with the surgical team. Procedures included fat grafting, pocket revision, implant exchange, nipple reconstruction, capsulotomy, capsulectomy, contralateral symmetrizing surgery, and revision to autologous breast reconstruction.

All procedures adhered to ethical standards, including the Declaration of Helsinki. Data collection was in accordance with the Data Protection Act (United Kingdom) and relevant guidelines. Statistical analysis used descriptive statistics, Pearson χ² tests, Fisher exact tests, and Mann-Whitney U tests. Statistical significance was set at a P value of less than 0.05.

RESULTS

A total of 388 single-stage IBRs were analyzed (subpectoral, 194 in 113 patients; prepectoral, 194 in 117 patients). Patient demographics, indications for surgery, and breast cancer characteristics of both groups are summarized in Table 1. The data were analyzed at a 5-year postreconstruction interval, and the outcomes at the 5-year time point were assessed for both cohorts. There were no patients lost to follow-up. Patient demographics, surgical indications, and breast cancer characteristics were largely comparable between the groups. The median age of patients in both groups was 43.0 years (interquartile range, 17.5; P = 0.722), and the median BMI was similar (22.4 versus 22.0 kg/m²; P = 0.795). Prior breast cancer diagnosis was more frequent in the subpectoral group (29.2% versus 15.4%; P = 0.054), and rates of local recurrence were low and comparable (4.4% versus 3.4%; P = 0.743). Bilateral risk-reducing mastectomy (RRM) was the most common indication in both groups (59.3% versus 49.6%; P = 0.146) (Table 1). The mean mastectomy weights were similar between the groups (320 g versus 380 g; P = 0.12).

Table 1.

Patient Demographics and Surgical Indications

Characteristic	Subpectoral	Prepectoral	P
No. patients	113	117
Age, y
Median	43.0	43.0	0.722
IQR	17.5	17.5
BMI, kg/m2
Median	22.4	22.0	0.795
IQR	3.1	3.5
Previous breast cancer, n (%)	33 (29.2)	18 (15.4)	0.054
Local recurrence, n (%)	5 (4.4)	4 (3.4)	0.743
Bilateral implant reconstruction, n (%)	83 (73.5)	77 (65.8)	0.254
Indication, n (%)
Bilateral RRM	67 (59.3)	58 (49.6)	0.146
Unilateral RRM	1 (0.9)	0
Bilateral cancer	0	3 (2.6)
Unilateral cancer	27 (23.9)	40 (34.2)	0.087
Unilateral cancer and contralateral RRM	16 (14.2)	16 (13.7)	1.000
Total RRM (n = 283/388), n/N (%)	151/194 (77.8)	132/194 (68.0)	0.039

IQR, interquartile range.

Potential risk factors associated with surgical complications following IBR are presented in Table 2. These were similar across both groups, as was the implant size. Nipple-sparing technique was more common in the subpectoral group (174 versus 153; P ≤ 0.05) (Table 3). Meshed ADM was used in most prepectoral IBRs, and ADM sheets were more commonly used with the subpectoral technique. The median length of stay was 2 days in the subpectoral group and 1 day in the prepectoral group (P = 0.001). There was no significant difference in reported complications between the 2 groups (20.1% versus 22.2%; P = 0.709), with a low implant loss rate of 5.2% in both cohorts (P = 1.000) (Table 4). No new incidence of primary cancer was observed in the RRM group during our follow-up period.

Table 2.

Factors Potentially Associated With Implant Complications

	Subpectoral, n (%)	Prepectoral, n (%)	P
No. patients	113	117
Smoker	8 (7.1)	4 (3.4)	0.247
Previous breast surgery	20 (17.7)	19 (16.2)	0.861
Previous radiotherapy	9 (8.0)	5 (4.3)	0.280
Neoadjuvant chemotherapy	12 (10.6)	12 (10.3)	1.000
Adjuvant radiotherapy	31 (27.4)	37 (31.6)	0.564
Adjuvant chemotherapy	12 (10.6)	12 (10.3)	1.0
Adjuvant endocrine therapy	23 (20.4)	31 (26.5)	0.2812
Implant size, cc			0.079
Median	420	420
IQR	360–460	370–475

IQR, interquartile range.

Table 3.

Operative Details and Outcomes of Subpectoral and Prepectoral IBRs

	Subpectoral, n (%)	Prepectoral, n (%)	P
No. implants	194	194
Surgery
Nipple-sparing mastectomy	174 (89.7)	153 (78.9)	0.005
Nipple-sacrificing mastectomy	20 (10.3)	41 (21.1)	0.005
ADM used
Meshed	68 (35.1)	135 (69.6)	0.387
Sheet	118 (60.8)	59 (30.4)	0.088
No ADM used	8 (4.1)	0	0.007
Outcomes
Inpatient stay, d			0.001
Median	2.0	1.0
IQR	2–3	1–4
Emergency surgery for complications	14 (7.2)	14 (11.3)	0.220
Elective secondary procedures (aesthetic)	103 (53.1)	104 (53.6)	0.650
Aesthetic surgery not required	91 (46.9)	90 (46.4)	0.950

IQR, interquartile range.

Table 4.

Surgical Outcomes Following Subpectoral and Prepectoral IBRs

	Subpectoral, n (%)	Prepectoral, n (%)	P
No. implants	194	194
Seroma	11 (5.7)	9 (4.6)	0.495
Inflamed skin	14 (7.2)	9 (4.6)	0.273
Infection	13 (6.7)	9 (4.6)	0.372
Hematoma	4 (2.1)	4 (2.1)	1.000
Skin flap necrosis	8 (4.1)	7 (3.6)	0.795
Wound dehiscence	12 (6.2)	20 (10.3)	0.196
Implant loss	10 (5.2)	10 (5.2)	1.000
Nipple necrosis	14 (7.2)	12 (6.2)	0.679
Local recurrence	5 (4.4)	4 (3.4)	0.743
Capsule Contracture	14 (7.2)	8 (4.1)	0.190

The median follow-up time in the subpectoral group was 33 months (3–60 mo) versus 20 months in the prepectoral group (3–60 mo) (P = 0.091). Overall, the frequency of secondary procedures at a 5-year follow-up interval was comparable between the 2 groups (53.1% for subpectoral versus 53.6% for prepectoral; P = 0.650). Among the most common secondary procedures, pocket revisions were more frequent in the subpectoral group (9.3% versus 2.6%; P = 0.005), whereas implant exchanges showed no significant difference (7.7% versus 3.1%; P = 0.216). The proportion of patients who received radiotherapy in both groups was low (27.4% versus 31.6%; P = 0.562), and the number of patients within this subgroup who required secondary revision was similar in both cohorts (55% versus 50%; P = 0.58).

Fat grafting was performed at similar rates between the groups (32.5% for subpectoral versus 37.6% for prepectoral; P = 0.338) and was the most common secondary procedure (Table 5). Although we do not have quantitative fat grafting volumes for all cases, in general our practice would be to inject a volume of 100–150 mL of fat into each side.

Table 5.

Secondary Procedures on Elective Operative Sessions

Characteristic	Subpectoral, n (%)	Prepectoral, n (%)	P
No. implants	194	194
No. breasts requiring aesthetic surgery overall	103 (53.1)	104 (53.6)	0.650
Fat grafting	63 (32.5)	73 (37.6)	0.338
Nipple reconstruction	9 (4.6)	7 (3.6)	0.915
Pocket revision	18 (9.3)	5 (2.6)	0.005
Implant exchange	15 (7.7)	6 (3.1)	0.216
Capsulotomy	4 (2.1)	2 (1)	0.685
Contralateral symmetrizing surgery	4 (2.1)	1 (0.5)	0.368
Other, n (%)	14 (7.2)	1 (0.5)	<0.001
Deep inferior epigastric perforator	2
Latissimus dorsi flap	1
Scar revision	2
Excision of recurrence	2
Other adjustments	7	1

DISCUSSION

Baseline Demographics and Surgical Indications

Our study provides a comprehensive review comparing complications and secondary procedures between the 2 approaches to IBR. The results are a continuum of a previously published comparison from our institution, with a larger cohort and longer follow-up, censoring data at 5 years (subpectoral group median 33 mo [3–60 mo] versus 20 mo [3–60 mo] in the prepectoral group; P = 0.091).¹¹ Baseline demographics and disease characteristics were similar between the groups. Most operations were performed within the National Health Service (NHS), where revision and symmetrizing procedures are part of standard reconstructive care. A small number of private patients were included, for whom revisions were self-paid or insurance-funded. The most common indication for reconstruction with implants in both groups was RRM (59.3% versus 49.6%; P = 0.146). Cammarata et al¹² showed that even though there is no standard technique in the field of risk-reducing surgery, IBR is the most common type of breast reconstruction. This also aligns with the national trend toward IBR in widely practiced RRMs.¹³

Risk Factors and Complications

Studies have shown that factors such as age, breast size, implant volume, smoking, and radiotherapy can significantly increase complications after IBR.^14,15 These factors were similar in both groups in our cohort. Overall complication rates between the 2 groups were statistically comparable, with no significant differences in overall complications or implant loss rates. This is in line with previously published data, including a recent systematic review by Nolan et al¹⁰ that identified a significantly lower rate of mastectomy flap necrosis after prepectoral reconstruction compared with the subpectoral approach. Ostapenko et al¹ also showed no significant difference in flap necrosis between these approaches. The hypothesis for this is improved vascularity and preservation of flaps in the absence of manipulation of musculature. Our cohort has shown a slightly higher number of patients experiencing superficial cellulitis (subpectoral, 7.2% versus prepectoral, 4.6%; P = 0.273) and skin flap necrosis (4.1% versus 3.6%, P = 0.7) in the subpectoral group, but this was not statistically significant.

The low implant loss rate in both cohorts (5.2%) supports the safety and viability of prepectoral IBR as an alternative to the traditional subpectoral approach. Although prepectoral IBR offers advantages such as reduced postoperative pain from less surgical dissection, reduced interference with shoulder function, and reduced incidence of animation deformity, concerns regarding its long-term durability have been a point of uncertainty. The findings of this study contribute to the growing body of evidence supporting the long-term safety and effectiveness of prepectoral implant placement.^9,16–20

Secondary Procedures

The frequency of secondary surgical procedures was comparable in our study during the 5-year follow-up between subpectoral and prepectoral reconstruction (subpectoral, 53.1% versus prepectoral, 53.6%; P = 0.650). There were some differences in specific types of secondary procedures observed for each approach. Notably, the requirement for pocket revision was significantly higher in the subpectoral group (9.3% versus 2.6%, P = 0.005). This may be attributed to the impact of muscle contraction on implant positioning, migration, and rotation.^21,22 In the subpectoral group, there was a trend of patients requesting to move their implant from the subpectoral plane to the prepectoral plane because of symptomatic animation deformity, muscle ache, and pain.^21,22

The implant exchange rates were not significantly different between the 2 groups (P = 0.216). This demonstrates that selection of implants, surgical technique, and patient-related factors are more influential in shaping long-term outcomes than the location of the implant pocket.²³

Rippling is an inevitable outcome if mastectomy flaps are thin, with limited subcutaneous tissue coverage over the implant. Tethering is also caused by adhesion of microtextured implants to mastectomy skin flaps to prevent rotation and by implant gel cohesive properties. Other factors that contribute to visible implant ripples include patient BMI, use of ADM, and implant cohesivity. Instinctively, palpability and visibility of the superior pole of the implant and implant wrinkles may be associated more with prepectoral rather than subpectoral implants, with muscle cover contributing to masking the underlying implant. A recent systematic analysis showed high rates of rippling in prepectoral implants compared with subpectoral implants or dual-plane reconstruction (10% versus 0.9% versus 4.8%).^6,10 In a meta-analysis by Abbate et al,²⁴ it was again noted to be the most common complication in prepectoral reconstruction. Fat grafting is a recognized method to improve implant visibility and is the most commonly used adjunct for symmetry and contour adjustment.^25,26 Our data showed similar fat grafting surgery requirements in both groups (subpectoral, 32.5% versus prepectoral, 37.6%; P = 0.338), suggesting that there is no disadvantage of prepectoral implant placement compared with subpectoral implant placement in implant visibility and tethering with appropriate patient selection and technique.

The relatively low proportion of contralateral symmetrizing procedures compared with published data likely reflects the high rate of bilateral RRMs in both cohorts, patient selection for implant reconstruction, and surgical technique to optimize the reconstruction to match the contralateral side.

Strengths and Limitations

Our study provides valuable insights into the long-term outcomes between the 2 approaches to implant placement. Its key strengths are the 5-year follow-up period and the large number of participants included in the study. Because all the procedures were performed by a single surgical firm, all surgical methods, theater procedures, and preoperative and postoperative management were minimized, contributing to consistency of the data.

An intrinsic limitation of our study is that it is retrospective, hence susceptible to selection bias and unmeasured confounding variables. A large proportion of our patients underwent bilateral RRM, which could limit generalizability to oncological cases, although in our practice, the technique and approach to mastectomy are equivalent for prophylactic and oncological cases. Although the baseline patient characteristics, treatment, and disease features were comparable, risk factors such as smoking, adjuvant therapy, and baseline tissue characteristics may have influenced the outcomes. Multivariate analysis was not performed due to the small incidence of certain outcomes.

Finally, the nonuniform follow-up duration could alter outcomes. Although censoring at 5 years was attempted to mitigate against this, long-term follow-up would strengthen our results.

Clinical Recommendations and Future Directions

The results of our study demonstrate that both prepectoral and subpectoral implant reconstructions are comparable and provide equal long-term aesthetic outcomes and complication profiles. Published data have shown that patients with prepectoral implants reported better satisfaction after 1 year of follow-up.²⁷ Further prospective studies incorporating survival analyses, quality-of-life measures, and patient-reported outcome measures can provide a more comprehensive evaluation of the impact of each technique on patient satisfaction and overall well-being.

CONCLUSIONS

In summary, this study provides robust comparative data during a 5-year follow-up period for secondary procedures between subpectoral and prepectoral IBRs, as well as complication rates. Our results demonstrate that prepectoral IBR is both safe and effective. Meticulous oncological and reconstructive surgical techniques and careful patient selection are mandatory requisites for achieving optimum outcomes following immediate breast reconstruction.

DISCLOSURES

Gerald Gui serves on the speakers bureau and is a consultant for Integra Life Science on an ad hoc basis. Dr. Tasoulis is a consultant in BMJ Best Practice and has served on the Speakers Bureau for Integra LifeScience. The other authors have no financial interest to declare in relation to the content of this article.