Keywords
breast reconstruction - prepectoral breast reconstruction - implant rippling - rippling
Introduction
Implant based breast reconstruction has become the most commonly practiced method
both in the United States and the Republic of Korea.[1]
[2] There are options that can be considered for implant-based breast reconstruction
depending on how it will be inserted. Recently, prepectoral direct-to-implant (DTI)
became a more frequently used method with advances in technology and materials, such
as intraoperative fluorescence angiography and acellular dermal matrix (ADM).[3]
[4]
[5]
[6]
Prepectoral DTI has shown its effectiveness in removing breast animation deformity,
alleviating muscle weakness, and limiting postoperative discomfort. As such, it has
become an alternative to submuscular implant placement.[7]
[8]
[9]
[10]
[11]
[12]
[13]
However, a major drawback of prepectoral implantation compared with the subpectoral
method is rippling, which indicates palpable or visible folds on the surface of the
reconstructed or augmented breast. As rippling comes with prepectoral DTI despite
advantages, patient satisfaction and aesthetic appearance cannot be free from its
effects.[14]
[15]
[16] A low body mass index (BMI), the performance of revisional surgery, the use of saline
implants, and use of textured implants are all risk factors for rippling in augmentation
mammoplasty.[17]
[18] But the study related to breast reconstruction is currently lacking.
In comparison to surgical method trend changes as aforementioned, analysis of rippling
factors from immediate prepectoral DTI reconstruction is relatively behind. The study
was aimed to understand how different demographics, oncologic treatment, and operative
techniques can affect implant rippling for immediate prepectoral DTI.
Methods
This retrospective study was approved by our facility's institutional review board
(no. 4-2022-0946). Written informed consent was obtained from all patients for preoperative
and postoperative photography. Consecutive breast cancer patients with ≥1 year of
follow-up who underwent prepectoral DTI breast reconstruction in a single center performed
by a single plastic surgeon (L. D. W.) between August 2019 and March 2021 were included
in this study. Delayed and delayed-immediate cases were excluded. Data pertaining
to patient demographics, mastectomy type, axillary lymph node dissection, oncologic
stage, implant/ADM variations, application of superior coverage technique, need for
either preoperative or postoperative adjuvant therapy, implant type, and aesthetic
outcomes were collected ([Table 1]). Procedural components were decided at the discretion of the treating physician.
The superior coverage technique has been performed in patients with prepectoral DTI
since December 2020 in our study institution.
Table 1
Patient demographics and oncologic characteristics
|
Value (%)
|
|
Number of breasts
|
186
|
|
Number of patients
|
156
|
|
Age, years
|
|
Median
|
44
|
|
IQR
|
40.0–51.0
|
|
BMI
|
|
Median
|
22.9
|
|
IQR
|
20.4–25.0
|
|
BMI ≥ 25 kg/m2
|
46 (24.7)
|
|
Diabetes mellitus
|
5 (2.7)
|
|
Active smoker
|
2 (1.1)
|
|
Prior RT
|
0
|
|
Prior CT
|
20 (10.8)
|
|
Postoperative RT
|
33 (17.7)
|
|
Postoperative CT
|
45 (24.2)
|
|
Hormone therapy
|
111 (59.7)
|
|
Cancer stage
|
|
0
|
57 (30.6)
|
|
IA/IB
|
67 (36.0)
|
|
IIA/IIB
|
58 (31.2)
|
|
IIIA/IIIB/IIIC
|
4 (2.2)
|
|
IV
|
0
|
|
Follow-up length, weeks
|
|
Median
|
64.9
|
|
IQR
|
40.0–83.1
|
Abbreviations: BMI, body mass index; CT, chemotherapy; IQR, interquartile range; RT,
radiation therapy.
Preoperative breast volume was measured using a three-dimensional scanner.[19] Follow-up assessments were performed at 1, 3, and 6 months and 1 year after the
initial operation and then annually thereafter for the duration of the study. A breast
examination was conducted at each follow-up visit to evaluate the development or progression
of rippling, implant malposition, capsular contracture, and other complications such
as infection. In this study, rippling was defined as visible implant rippling while
the patient was in a standing position, and rippling revealed during body bending
was excluded. Each postoperative physical examination was performed by a single reviewer
(L. D. W.).
Surgical Technique
Whether or not to perform prepectoral DTI was decided through an evaluation of adequate
perfusion of the mastectomy skin flaps following the completion of total mastectomy
by an oncologic surgery team. A sizer filled with silicone gel with a volume corresponding
to the approximate weight of the mastectomy specimen was inserted into the prepectoral
plane. Subsequently, indocyanine green angiography (FLUOBEAM; Fluoptics, Grenoble,
France) was performed. If sufficient vascular perfusion was maintained in the mastectomy
skin flap, then prepectoral DTI was performed. Patients were interviewed in advance,
where it was decided whether to conduct prosthesis-based breast reconstruction.
Regardless of the technique, all implants were inserted with complete implant wrapping
with ADM. All implants used in this study were either Mentor (Mentor Worldwide LLC,
Santa Barbara, CA,) or BellaGel (HansBiomed Co. Ltd., Seoul, Korea) products, which
are both smooth, round-type cohesive silicone gel-filled breast implants. In addition,
we used three types of ADMs in this study, Megaderm (L&C BIO Inc., Seongnam, Korea),
CGCryoDerm (CGBio Co., Seongnam, Korea), and DermACELL (Stryker Corp., Kalamazoo,
MI).
The superior coverage technique in the prepectoral plane was performed with patient
customization as follows. After placing the sizer over the pectoralis major muscle
and tailor-tacking the incisions, the symmetry relative to the opposite breast was
examined with the patient in a sitting position, and perfusion of the mastectomy skin
flap was rechecked to avoid disruption caused by the implant. Then, the upper round
boundary of the sizer on the pectoralis major muscle was marked, and the sizer was
removed. From approximately 1.5 cm below the marked line, an incision was made to
be long enough to cover the superior part of the implant, with partial-thickness muscle
dissection completed up to create a pectoralis slip ([Fig. 1]). In addition, incisions were created in the same direction as the muscle belly
to minimize muscle function damage. Caution should be taken when dissecting the muscle
to avoid damage to the subpectoral fat pad, which contains the thoracoacromial vascular
bundle. Also, the muscle must not be disinserted from the sternal origin. After hemostasis
was complete, antibiotic irrigation was performed, and two 15-F Blake drains were
placed on the inframammary line and the axillary line. After the implant was entirely
covered with ADM and placed in the prepectoral plane, the previously created muscle
slip was partially placed over the ADM-wrapped implant to cover the superior side.
Finally, the ADM was sutured to the inferior edge of the muscle slip with absorbable
sutures ([Fig. 2]). The suture process is performed carefully to avoid damaging the implant and includes
placing a malleable retractor through the fenestrated ADM to protect the implant from
damage.
Fig. 1 Intraoperative dissection of a pectoralis major muscle slip after the design.
Fig. 2 Intraoperative superior coverage of the ADM-wrapped implant by pectoralis muscle
slip.
The whole procedure was performed using no-touch techniques as much as possible. Prepectoral
DTI without the use of a superior coverage technique was performed in the same manner
as above except for the creation of a slip of the pectoralis major muscle. The primary
outcome was the visibility of any upper pole rippling deformity.
Statistical Analysis
Univariate logistic regression analysis was performed to calculate odds ratios (ORs)
with 95% confidence intervals (CIs) for rippling as a dependent variable. Variables
significantly associated with this outcome of interest were input into a multivariable
logistic regression model to determine independent predictors of rippling. A propensity
score was used to match the group that underwent surgery with the superior coverage
technique and the group that did not, which can be thought of as a reliable match
between experimental and control groups. A t-test (continuous variable) and chi-square test (categorical variable) were used before
matching, while a paired t-test (continuous variable) and McNemar's test (categorical variable) were used after
matching. After reliable propensity score matching, a conditional logistic regression
with rippling as a dependent variable in both groups was applied. Statistical significance
was set at p < 0.05. All statistical analyses were performed using IBM SPSS (IBM Corp., Armonk,
NY).
Results
A total of 156 eligible patients (186 breasts) was identified during the study period
([Table 1]). The average patient age was 44 years, and the average BMI was 22.9 kg/m2. Twenty patients (10.8%) had a history of neoadjuvant chemotherapy, 45 patients (24.2%)
had received adjuvant chemotherapy, and 33 patients (17.7%) had received adjuvant
radiation therapy. A total of 111 patients (59.7%) had received postoperative hormone
therapy. The average follow-up length was 64.9 weeks.
Nipple-sparing mastectomy was performed most commonly, in 158 cases (84.9%), followed
by skin-sparing mastectomy (12.4%) and total mastectomy (2.7%; [Table 2]). Five breast surgeons were involved throughout the study period without any differences
in the mastectomy technique. Patients were treated with one of two implants (Mentor,
83.3%; BellaGel, 16.7%) and one of three ADMs (Megaderm, 61.8%; CGCryoDerm, 33.9%;
and DermACELL, 4.3%). Mastectomy flap necrosis occurred in 15 cases (8.1%), infection
occurred in 4 cases (2.2%), and seroma/hematoma occurred in 6 cases (3.2%) and required
secondary operative intervention of the skin debridement/drain insertion/implant change
([Fig. 3]).
Fig. 3 A 32-year-old patient after a bilateral robot assisted nipple-sparing mastectomy
through a logitudinal midaxillary line approach for invasive ductal carcinoma (pT1pN0M0)
of the right breast and a prophylactic nipple-sparing mastectomy of the left breast
after immediate prepectoral DTI with the superior coverage technique. (above: preoperative
appearance; below: postoperative appearance at 1 year).
Table 2
Operative characteristics
|
Value (%)
|
|
Mastectomy type
|
|
Nipple-sparing mastectomy
|
158 (84.9)
|
|
Skin-sparing mastectomy
|
23 (12.4)
|
|
Total mastectomy
|
5 (2.7)
|
|
Implant type
|
|
Mentor
|
155 (83.3)
|
|
BellaGel
|
31 (16.7)
|
|
ADM type
|
|
Megaderm
|
115 (61.8)
|
|
CGCryoDerm
|
63 (33.9)
|
|
DermACELL
|
8 (4.3)
|
|
ADM thickness
|
|
1.5–2.3 mm
|
133 (71.5)
|
|
1.0–2.0 mm
|
53 (28.5)
|
|
Rippling
|
44 (23.7)
|
|
Superior coverage technique
|
51 (27.4)
|
|
Complication
|
|
Mastectomy skin flap necrosis
|
15 (8.1)
|
|
Infection
|
4 (2.2)
|
|
Implant explantation
|
2 (1.1)
|
|
Seroma/hematoma
|
6 (3.2)
|
Abbreviation: ADM, acellular dermal matrix.
The variables associated with rippling were analyzed in a univariate regression analysis
([Table 3]). A BMI (p < 0.001), postoperative chemotherapy (p = 0.027), and superior coverage technique (p = 0.004) were significantly associated with a decreased risk of rippling. Also, those
who underwent skin-sparing mastectomy (p = 0.051) showed a tendency toward less rippling compared with those who underwent
nipple-sparing mastectomy.
Table 3
Univariate logistic regression for occurrence of implant rippling
|
Variable
|
OR
|
95% CI
|
p-Value
|
|
Age
|
0.979
|
0.943–1.018
|
0.288
|
|
BMI
|
0.736
|
0.653–0.854
|
<0.001[a]
|
|
Diabetes
|
0
|
0
|
0.999
|
|
Active smoker
|
3.357
|
0.206–54.830
|
0.395
|
|
Prior RT
|
0
|
0
|
0.999
|
|
Prior CT
|
0.325
|
0.072–1.461
|
0.143
|
|
Postoperative RT
|
0.837
|
0.336–2.085
|
0.702
|
|
Postoperative CT
|
0.324
|
0.119–0.88
|
0.027[a]
|
|
Hormone therapy
|
1.587
|
0.775–3.251
|
0.207
|
|
Preoperative breast volume, cc
|
0.998
|
0.996–1.001
|
0.148
|
|
Specimen weight, g
|
0.997
|
0.995–1.000
|
0.022
|
|
Mastectomy type (NSM) (ref.)
|
|
|
|
|
SSM
|
0.132
|
0.017–1.008
|
0.051
|
|
TM
|
0.69
|
0.075–6.355
|
0.744
|
|
Implant type (BellaGel) (ref.)
|
|
|
|
|
Mentor
|
1.763
|
0.634–4.909
|
0.277
|
|
ADM (Megaderm) (ref.)
|
|
|
|
|
CGCryoDerm
|
0.478
|
0.217–1.051
|
0.066
|
|
DermACELL
|
0.355
|
0.042–2.999
|
0.342
|
|
ADM thickness (1.5–2.3 mm) (ref.)
|
|
|
|
|
ADM thickness (1.0–2.0 mm)
|
0.813
|
0.375–1.761
|
0.6
|
|
Superior coverage technique
|
0.2
|
0.068–0592
|
0.004[a]
|
|
Mastectomy skin flap necrosis
|
0.218
|
0.028–1.705
|
0.147
|
|
Infection
|
0.933
|
0.112–10.887
|
0.933
|
|
Seroma/hematoma
|
1.683
|
0.298–9.520
|
0.556
|
|
Capsular contracture
|
N/A
|
|
|
Abbreviations: ADM, acellular dermal matrix; BMI, body mass index; CI, confidence
interval; CT, chemotherapy; NSM, nipple-sparing mastectomy; OR, odds ratio; SSM, skin-sparing
mastectomy; TM, total mastectomy; RT, radiation therapy; N/A, unable to estimate due
to low frequency.
a Statistically significant.
Multivariable logistic regression analysis demonstrated that patients with BMI (OR,
0.690; 95% CI, 0.574–0.829; p < 0.001), postoperative chemotherapy (OR, 0.187; 95% CI, 0.056–0.622; p = 0.006), and superior coverage technique (OR, 0.169; 95% CI, 0.050–0.569; p = 0.004) were independently associated with decreased risk of rippling ([Table 4]). There were no significant differences in the type of mastectomy, implant, or ADM
or in ADM thickness, postoperative radiotherapy, or hormone therapy.
Table 4
Multivariate logistic regression for occurrence of implant rippling
|
Variable
|
OR
|
95% CI
|
p-Value
|
|
BMI
|
0.690
|
0.574–0.829
|
<0.001[a]
|
|
Prior CT
|
0.523
|
0.082–3.329
|
0.493
|
|
Postoperative RT
|
2.680
|
0.785–9.147
|
0.116
|
|
Postoperative CT
|
0.187
|
0.056–0.622
|
0.006[a]
|
|
Hormone therapy
|
1.519
|
0.633–3.644
|
0.349
|
|
Mastectomy type (NSM) (ref.)
|
|
SSM
|
0.156
|
0.014–1.704
|
0.128
|
|
TM
|
3.030
|
0.091–100.510
|
0.535
|
|
ADM thickness
|
0.957
|
0.372–2.462
|
0.927
|
|
Undergoing superior coverage technique
|
0.169
|
0.050–0.569
|
0.004[a]
|
Abbreviations: ADM, acellular dermal matrix; BMI, body mass index; CI, confidence
interval; CT, chemotherapy; NSM, nipple-sparing mastectomy; OR, odds ratio; SSM, skin-sparing
mastectomy; TM, total mastectomy; RT, radiation therapy.
a Statistically significant.
A total of 135 breasts (72.6%) was treated by prepectoral DTI without the superior
coverage technique (patient mean age, 45.7 ± 9.5 years), while 51 breasts (27.4%)
underwent surgery with the superior coverage technique (patient mean age, 46.6 ± 8.9
years; [Table 5]). In the groups matched by propensity score, demographics did not differ meaningfully
between treated and untreated patients (p ≥ 0.05), which suggests the existence of reliable matching between experimental and
control groups.
Table 5
Demographics before and after propensity score matching
|
Variable
|
Before matching
|
After matching
|
|
Prepectoral DTI
|
Superior coverage technique
|
p-Value
|
Prepectoral DTI
|
Superior coverage technique
|
p-Value
|
|
(n = 135)
|
(n = 51)
|
(n = 51)
|
(n = 51)
|
|
Age, years
|
45.7 ± 9.5
|
46.6 ± 8.9
|
0.540
|
47.6 ± 9.7
|
46.6 ± 8.9
|
0.792
|
|
BMI
|
|
|
0.271
|
|
|
>0.999
|
|
BMI < 25 kg/m2
|
105 (77.8%)
|
35 (68.6%)
|
|
36 (70.6%)
|
35 (68.6%)
|
|
|
BMI ≥ 25 kg/m2
|
30 (22.2%)
|
16 (31.4%)
|
|
15 (29.4%)
|
16 (31.4%)
|
|
|
Mastectomy type
|
|
|
0.013
|
|
|
0.693
|
|
NSM
|
121 (89.6%)
|
37 (72.5%)
|
|
42 (82.4%)
|
37 (72.5%)
|
|
|
SSM
|
11 (8.1%)
|
12 (23.5%)
|
|
7 (13.7%)
|
12 (23.5%)
|
|
|
TM
|
3 (2.2%)
|
2 (3.9%)
|
|
2 (3.9%)
|
2 (3.9%)
|
|
|
Cancer stage
|
|
|
0.008
|
|
|
0.859
|
|
0
|
42 (31.1%)
|
15 (29.4%)
|
|
17 (33.3%)
|
15 (29.4%)
|
|
|
IA/IB
|
56 (41.5%)
|
11 (21.6%)
|
|
12 (23.5%)
|
11 (21.6%)
|
|
|
IIA/IIB
|
36 (26.7%)
|
22 (43.1%)
|
|
21 (41.2%)
|
22 (43.1%)
|
|
|
IIIA/IIIB/IIIC
|
1 (0.7%)
|
3 (5.9%)
|
|
1 (2.0%)
|
3 (5.9%)
|
|
|
Implant type
|
|
|
<0.001
|
|
|
NA
|
|
Mentor
|
104 (77.0%)
|
51 (100.0%)
|
|
51 (100.0%)
|
51 (100.0%)
|
|
|
BellaGel
|
31 (23.0%)
|
0 (0.0%)
|
|
|
|
|
|
ADM
|
|
|
0.055
|
|
|
0.572
|
|
Megaderm
|
83 (61.5%)
|
32 (62.7%)
|
|
32 (62.7%)
|
32 (62.7%)
|
|
|
CGCryoDerm
|
49 (36.3%)
|
14 (27.5%)
|
|
16 (31.4%)
|
14 (27.5%)
|
|
|
DermACELL
|
3 (2.2%)
|
5 (9.8%)
|
|
3 (5.9%)
|
5 (9.8%)
|
|
|
ADM_thickness
|
|
|
0.474
|
|
|
>0.999
|
|
1.5–2.3 mm
|
99 (73.3%)
|
34 (66.7%)
|
|
37 (72.5%)
|
34 (66.7%)
|
|
|
1.0–2.0 mm
|
36 (26.7%)
|
17 (33.3%)
|
|
14 (27.5%)
|
17 (33.3%)
|
|
|
Prior CT
|
|
|
0.590
|
|
|
0.687
|
|
No
|
122 (90.4%)
|
44 (86.3%)
|
|
47 (92.2%)
|
44 (86.3%)
|
|
|
Yes
|
13 (9.6%)
|
7 (13.7%)
|
|
4 (7.8%)
|
7 (13.7%)
|
|
|
Postoperative CT
|
|
0.276
|
|
|
>0.999
|
|
No
|
99 (73.3%)
|
42 (82.4%)
|
|
40 (78.4%)
|
42 (82.4%)
|
|
|
Yes
|
36 (26.7%)
|
9 (17.6%)
|
|
11 (21.6%)
|
9 (17.6%)
|
|
|
Postoperative RT
|
|
0.138
|
|
|
0.727
|
|
No
|
115 (85.2%)
|
38 (74.5%)
|
|
43 (84.3%)
|
38 (74.5%)
|
|
|
Yes
|
20 (14.8%)
|
13 (25.5%)
|
|
8 (15.7%)
|
13 (25.5%)
|
|
|
Hormone therapy
|
|
|
0.517
|
|
|
0.832
|
|
No
|
52 (38.5%)
|
23 (45.1%)
|
|
25 (49.0%)
|
23 (45.1%)
|
|
|
Yes
|
83 (61.5%)
|
28 (54.9%)
|
|
26 (51.0%)
|
28 (54.9%)
|
|
Abbreviations: ADM, acellular dermal matrix; BMI, body mass index; CT, chemotherapy;
NSM, nipple-sparing mastectomy; SSM, skin-sparing mastectomy; TM, total mastectomy;
RT, radiation therapy.
As we confirmed that two groups (with or without superior coverage technique) were
matched well based on the use of the superior coverage technique ([Table 5]), we evaluated the technique's influence after matching by conducting a conditional
logistic regression with rippling as a dependent variable in both groups. After matching,
patients who underwent surgery with the superior coverage technique showed significantly
reduced rippling (OR, 0.083; 95% CI, 0.011–0.643; p < 0.017; [Table 6]).
Table 6
Rippling frequency and conditional logistic regression analysis (after propensity
score matching) for occurrence of implant rippling
|
Variable
|
Before matching
|
After matching
|
|
Prepectoral DTI (n = 135)
|
Superior coverage technique (n = 51)
|
Prepectoral DTI (n = 51)
|
Superior coverage technique (n = 51)
|
|
Rippling
|
41 (30.4%)
|
3 (6%)
|
16 (31.4%)
|
3 (6%)
|
|
Conditional logistic regression analysis (after matching)
|
OR
|
95% CI
|
p-Value
|
|
Superior coverage technique
|
0.083
|
0.011–0.643
|
0.017[a]
|
Abbreviations: CI, confidence interval; OR, odds ratio; DTI, direct-to-implant.
a Statistically significant.
Discussion
The therapeutic implications of breast reconstruction after total mastectomy due to
breast cancer have been widely demonstrated. Despite these advantages, implant rippling
is one of the most common aesthetic limitations in prepectoral DTI breast reconstruction.[20]
[21] Rippling is caused by soft tissue deficits after mastectomy and is particularly
common in the upper poles and superior implant edges.[22] Although there are some options to prevent rippling through ADM coverage, fat grafting
and other techniques are also being used.[18] Our study focuses on the factors that affect rippling in prepectoral implant breast
reconstruction and considers the effects of the recently introduced superior coverage
technique in DTI breast reconstruction.
The superior coverage technique was introduced by Pittman et al in an effort to reduce
rippling deformities after prepectoral breast reconstruction.[10] The P1 method and the superior coverage technique are similar, the difference being
that our method creates a muscle slip after complete coverage of the implant. To the
best of our knowledge, our study is the first to specifically analyze the factors
affecting rippling in all DTI patients with or without superior coverage technique
and to demonstrate a decreased risk of rippling with our superior coverage technique.
This method proceeds by covering the entire implant with ADM and then fixing it to
the already-designed pectoralis muscle slip. Superior coverage technique is different
from subpectoral breast implant insertion as it only gets a portion of pectoralis
muscle, and animation deformity that can occur from subpectoral placement was not
observed in our cases.
Among the variables presented in [Tables 1] and [2], our study included patients who only received immediate prepectoral DTI. Patients
who had already received partial mastectomy or prior radiation therapy before total
mastectomy were excluded. This enrollment scheme eliminated bias caused by radiation-induced
capsule fibrosis, poor quality of breast skin, and tissue atrophy. Nipple-sparing
mastectomy was the most common mastectomy type (84.9%), and a periareolar with lateral
extension incision approach was mainly used. This is suitable for pectoralis major
muscle access for the superior coverage technique. However, if the oncologic surgeon
prefers an inframammary fold incision when performing mastectomy, then the superior
coverage technique may be difficult to implement due to a poor visual field.
The risk of rippling is dependent on numerous extrinsic and intrinsic factors.[23] Multivariable regression analysis was performed to control multiple possible confounding
variables. According to [Tables 3] and [4], rippling was significantly less common in patients with high BMI, concurrent with
results in previous studies assessing prepectoral implant-based breast reconstruction.
This result can be attributed to the high BMI, which increases the probability of
thicker remnant subcutaneous tissue that can better cover the implant, lessening rippling.
In the same context, the greater is the subcutaneous fat preservation, the less likely
is rippling may be. Quantitative measurements of subcutaneous thickness using ultrasonic
devices and a comparison of the subcutaneous tissue preservation effect based on the
breast surgeon's preferred methods would be good focal areas of further study.
There was significantly less rippling in patients with an adjuvant chemotherapy history
among pre- and postoperative oncologic therapies in both the univariate and multivariate
analyses. Second- or third-generation taxane-based regimens (paclitaxel, docetaxel)
have been widely used as adjuvant systemic therapies in breast cancer patients.[24] Fluid retention, which includes peripheral edema and sometimes associated with weight
gain, is a side effect of docetaxel.[25]
[26]
[27]
[28] It is also known that taxane-based chemotherapy regimens can cause lymphedema.[29] Based on these studies, it may be possible to decrease the severity of rippling
by masking the edematous state of the breast upper pole skin flap. However, further
studies are needed to support this hypothesis with a better understanding of the pathophysiology
of anticancer drug side effects.
The two types of implants used in this study have different filling rates and cohesiveness.
According to previous studies,[30]
[31] the rippling rate was high in implants with low cohesivity, but this study revealed
no significant differences in rippling according to implant type.[30] Since there was no significant difference in cohesiveness between the two implants,
it is unlikely that there was a significant difference in our study. Assuming that
rippling is dependent on the thickness of the remaining breast tissue, ADMs from three
companies with two thicknesses were compared, but no significant difference was observed.
This suggests that the use of ADM may not eliminate rippling completely, as shown
in previous studies.[18]
Notably, in both the univariable and multivariable regression analyses, rippling was
significantly less common in patients who underwent breast reconstruction using the
superior coverage technique. Propensity score matching was performed by including
all variables that could affect rippling as much as possible and randomized matching
with the same number of people could be appropriate for the two experimental groups
([Table 5]). In both groups, conditional logistic regression with rippling as the dependent
variable was performed, and a significant p-value (0.017) was attained ([Table 6]). After propensity score matching, the identity document of each group was matched
to conduct conditional logistic regression by considering the matching information
between them. Through various analyses, the factors influencing rippling were analyzed,
and this may be meaningful given that it confirms the significance of the superior
coverage technique.
There are several limitations to this study given its retrospective nature, single-center
design, and limited follow-up period. Unlike previous studies assessing the superior
coverage technique, our comparison with a control group and randomizing participants
through matching increased the reliability of this study, but there may have been
bias left due to the relatively small sample size. Also, determining rippling was
a subjective criterion even though patients were evaluated by an expert. Despite these
limitations, this study can be considered meaningful given its improvements to randomize
various statistical methods and variables. A prospective and multi-institutional study
with a longer follow-up period is planned to obtain additional evidence supporting
the superior coverage technique in implant breast reconstruction procedures.
In patients undergoing prepectoral DTI breast reconstruction and implant-based breast
reconstruction, rippling continues to occur, without a clear solution. According to
our study, breast implant rippling was significantly reduced in patients with higher
BMI, postoperative chemotherapy, and superior coverage technique. We propose a modified
superior coverage technique that can significantly reduce rippling. Additional studies
are required to explore the effects of these methods in prepectoral prosthetic-based
breast reconstruction.
