INTRODUCTION
Breast augmentation with silicone implants is a common aesthetic procedure in plastic
surgery. The ideal plane to house the implants has not yet been found. Clinical inspection
and physical examination of the breasts in the preoperative period and the choice
of technique for each patient are fundamental determinants for obtaining excellent
results, excluding the concept of a universal technique for treating all types of
breasts.
Five breast implant pocket locations are used in breast augmentation: (1) Subglandular,
(2) Subfascial, (3) Retromuscular (retropectoral, total submuscular, dual plane).
Each pocket has its indication, its benefits and its complications. In an attempt
to reduce the incidence of capsular contracture, breast atrophy, seroma, implant visibility
and palpability, the pockets became deeper, the implants less palpable, and the breasts
with the most natural appearance (Chart 1).
Chart 1 - Complications and benefits related to each plane.
| Breast plane |
Complications |
Benefits |
| Subglandular |
1. Capsular contracture.
2. Rippling.
3. Short and medium-term atrophy of the mammary gland.
4. Skin distension.
5. Earlier ptosis.
6. Improved visibility and palpability of implant edges.
7. Artificial appearance.
|
Shorter surgical time. Greater control of bleeding. Greater control of the definition
of the submammary fold. Greater control of breast shape. Faster postoperative recovery.
Minimal animation with chest contraction. Periprosthetic capsule distant from the
rib cage.
|
| Subfascial |
1. Rippling and capsular contracture with an intermediate incidence in relation to
the subglandular and retromuscular planes.
|
1. Good tissue coverage of the prosthesis.
2. Periprosthetic capsule distant from the rib cage.
3. Contours in the medial quadrants with great definition.
|
| Retromuscular: (Dual Plane, retropectoral and total submuscular) |
1. Implant displacement above the second intercostal space.
2. Wide pocket.
3. Capsule adhered to the rib cage.
4. Blindspot in the second intercostal space.
5. Extreme difficulty in total capsulectomy.
6. Greater animation with muscle contraction.
|
1. Excellent implant coverage in the upper and medial quadrants.
2. Lower incidence of capsular contracture and rippling.
3. Naturalness of shape and contour.
4. Shorter surgical time.
5. Lesser glandular atrophy in the short and medium-term.
|
| Intramuscular |
1. A case of seroma caused by excess muscle debris.
2. Less muscle coverage when compared to the retromuscular plane.
3. Longer surgical time.
|
1. Periprosthetic capsule distant and free from the rib cage.
2. Intermediate coverage between the retromuscular and subfascial planes.
3. Less animation with muscle contraction (videos 1A e 1B).
4. Stability in implant positioning with less displacement.
|
Chart 1 - Complications and benefits related to each plane.
Video 1A and 1B - Patients with prostheses in the intramuscular plane, contracting the pectoralis major
muscle to show the minimum animation of the breasts.
Video 1A and 1B - Patients with prostheses in the intramuscular plane, contracting the pectoralis major
muscle to show the minimum animation of the breasts.
Contour beauty in the medial quadrants in the subfascial plane is slightly less in
the retromuscular plane. On the other hand, the richness of coverage in the retromuscular
plane reduces the incidence of rippling and presents less glandular atrophy than the
subfascial and subglandular planes1,2.
Considering the anatomical principles of irrigation and innervation of the pectoralis
major muscle (PMM), we concluded that it was feasible to use the intramuscular plane
in breast augmentation.
The intramuscular technique for gluteal implant was published by Vergara & Marcos3 in 1996; Gonzalez described the XYZ4 technique, increasing the degree of safety in performing the procedure.
This work aims to present the use of the intramuscular plane in breast augmentation
with silicone implants in thin patients who need a deep pocket.
OBJECTIVE
This work aims to present the new use of the intramuscular plane in breast augmentation
with silicone implants.
METHODS
Casuistry
This is a primary and retrospective study of 50 female patients, aged between 19 and
55 years, who underwent augmentation mammaplasty with silicone implants in the intramuscular
plane, from December 2018 to April 2020, carried out in the Camillo Plastic and Reconstructive
Surgery Clinic in the city of Toledo, PR. After explaining the risks and benefits
of the technique, the patients signed informed consent. This article was approved
by the Research Ethics Committee (Centro Universitário Assis Gurgacz - CAAE 35340220.1.0000.5219).
All patients were referred for laboratory evaluations, breast ultrasound, mammography
in specific cases and anesthetic and cardiological evaluations. We guide physical
activity for mild PMM hypertrophy in the preoperative period. The study followed the
Helsinki principles.
Surgical technique
Patients underwent intravenous anesthesia and intercostal block, antibiotic prophylaxis,
aseptic and antisepsis care, and minimal manipulation of the implants.
Through a 4.5 cm incision in the submammary crease, with the ends of the incision
equidistant from the breast midline, the adjacent topographic surface of the pectoralis
major muscle is located. In a parallel line and 2 cm medial to the lateral edge of
the pectoralis major muscle, a 4 cm incision is made in the pectoral fascia, starting
at the fifth intercostal space (Figure 1).
Figure 1 - Line 1 represents the outer edge of the pectoralis major muscle. Line 2 is parallel
and 2 cm medial to line 1, marking the position of the incision in the anterior lamina
of the deep fascia that lines the pectoralis major muscle.
Figure 1 - Line 1 represents the outer edge of the pectoralis major muscle. Line 2 is parallel
and 2 cm medial to line 1, marking the position of the incision in the anterior lamina
of the deep fascia that lines the pectoralis major muscle.
It penetrates the interior of the muscle, and the muscle fascicles are separated through
the release of the perimysium (electric scalpel in cutting function, colored tip)
throughout the area of the internal projection of the peripheral limits of the pocket
previously demarcated on the breast skin (footprint). The deeper fascicles, when separated,
are attached to the posterior layer of the deep pectoral fascia5 (Figure 2). When the separation is finished, we will have the division of the muscle in its
thickness, forming two flaps, the anterior muscle flap (roof of the pocket) and the
posterior muscle flap (floor of the pocket).
Figure 2 - Illustrative drawing of a sagittal section of the breast and chest wall. 1- Transverse
fascicles at the level of the third rib. 2- Green line: represents the division site
of the pectoralis major muscle (PMM) to form the intramuscular plane. 3- Floor of
the pocket, consisting of half the thickness of the PMM (posterior flap), posterior
layer of the deep pectoral fascia (black line exactly behind the posterior flap) and
fat pad (yellow line behind the posterior layer of the deep pectoral fascia). 4- Fascial
cleft - blue line (retromuscular plane).
Figure 2 - Illustrative drawing of a sagittal section of the breast and chest wall. 1- Transverse
fascicles at the level of the third rib. 2- Green line: represents the division site
of the pectoralis major muscle (PMM) to form the intramuscular plane. 3- Floor of
the pocket, consisting of half the thickness of the PMM (posterior flap), posterior
layer of the deep pectoral fascia (black line exactly behind the posterior flap) and
fat pad (yellow line behind the posterior layer of the deep pectoral fascia). 4- Fascial
cleft - blue line (retromuscular plane).
The mean thickness of the anterior flap on operated patients varies according to its
location and degree of muscle hypertrophy. In the lower quadrants, its smallest thickness
is found on the sixth rib (0.35 cm) and gains body, with the sum of new fascicles
that originate on the anterior surface of the sternum, approximately 0.5 cm thick
on the fifth rib, 0.75 cm over the fourth, 1.25 cm over the third, and 1.5 to 2 cm
over the second rib.
The posterior flap originates from the chondral processes of the second to seventh
ribs. Its thickness is fixed, approximately 0.3 to 0.5 cm, because the fascicles of
each chondral process are juxtaposed and do not overlap. The decision-making process
in defining the thickness of the flaps is the correct separation of the fascicles,
finding the cleavage plane between the two laminae of the PMM, which is anatomically
determined at its origins (posterior flap with fascicles originating from the chondral
processes and anterior flap with the fascicles originating on the anterior surface
of the sternum).
We ask that the patient do physical activity for 30 to 60 days, aiming to hypertrophy
the pectoralis major muscle. We did not perform the synthesis of the pectoralis major
muscle in the area of access to the intramuscular plane since the volumes placed are
modest, respect the dimensions of each thorax, and are accommodated inside the pocket
without causing bulges on the area of the muscle incision.
The upper limit of the pocket is located at the transition between the third rib and
the second intercostal space. In this location, the fascicles of the pectoralis major
muscle are in a position transverse to the thorax, with fibrous septa that adhere
to each other, which make their separation difficult, presenting themselves as a compact
and insurmountable muscle mass, which will favor the creation of a pocket with defined
limits and stable in the upper quadrants, not allowing the prosthesis to ascend (Figures 3, 4A and 4B). The pedicle of the posterior flap is the thoracoacromial artery, and the pedicle
of the anterior flap is formed by the perforating branches of the intercostal arteries6.
Figure 3 - A. Initial separation between the superficial and deep muscle fascicles of the pectoralis
major muscle (PMM) over the fifth intercostal space. B. Separation between the superficial and deep fascicles of the PMM over the fifth rib.
C. Separation between the superficial and deep fascicles of the PMM over the fourth
rib.
Figure 3 - A. Initial separation between the superficial and deep muscle fascicles of the pectoralis
major muscle (PMM) over the fifth intercostal space. B. Separation between the superficial and deep fascicles of the PMM over the fifth rib.
C. Separation between the superficial and deep fascicles of the PMM over the fourth
rib.
Figure 4 - A. Separation between the superficial and deep fascicles of the pectoralis major muscle
over the third rib, creating the intramuscular store. B. Sequence of dissection of the pocket through the groove.
Figure 4 - A. Separation between the superficial and deep fascicles of the pectoralis major muscle
over the third rib, creating the intramuscular store. B. Sequence of dissection of the pocket through the groove.
The pocket limit in the medial quadrants is 1 cm short of the conventional pre-marking
of pocket dimensions on the breast skin.
The limit of the pocket in the lateral quadrants is defined by a 2-cm-wide muscular
tape of the PMM, with its costal and abdominal origins preserved, together with part
of the fascia covering the serratus anteroinferior muscle, which will support the
prosthesis, providing support and support avoiding lateral sliding, especially in
a cylindrical chest7,8. The muscular tape is reinforced by fascicles of the posterior flap, at the level
of the union of the lateral quadrants, which are positioned on the lateral wall of
the pocket, increasing the stabilization function and decreasing the lateral displacement.
Implant stability in the pocket is inversely proportional to implant volume.
Another prevention method used to prevent displacement of the prosthesis below the
submammary fold (bottoming out) is suturing at the level of the submammary fold between
the deep layer of subcutaneous fascia (equivalent to Scarpa’s fascia in the abdomen)
with the anterior layer of fascia pectoralis deep (equivalent to the Innominate fascia
in the abdomen), eliminating the fascial cleft through which the implant slides down,
crossing the submammary fold. It is important to mention that this stabilization is
efficient only when the choice of implant base is defined, taking into account the
measurements of the hemithorax (anterior axillary line - lateral border of the sternum),
minus 2 centimeters. Therefore, we will use low-volume implants with predefined bases;
large volumes distend the entire musculature, causing implant displacement.
It is believed that the vigorous muscle contraction and muscle tone of the anterior
flap of the PMM on the implant causes a slight rise of the same (1 to 2 centimeters);
therefore, in some situations, we can use this observation in our favor, in other
situations we must avoid it. Therefore, in patients in the orthostatic position who
present a measurement of the height from the nipple to the submammary crease (measurement
made with a caliper, different from the measurement of skin extension under light
traction of the same, using a tape measure) between 5.0 and 5.5 cm we make a muscle
relaxation incision in the anterior portion of the PMM flap9, “envelope flap technique,” located at the level of the nipple projection, preventing
the implant from ascending10,11.
In patients who present a measurement of the height from the nipple to the submammary
fold equal to or above 6 centimeters, we do not make a muscle relaxation incision,
waiting for slight traction of the muscle on the prosthesis to position the prosthesis
1 cm above the submammary fold and maintain the center of the prosthesis under the
nipple-areolar complex. We will not have that long bottom pole and an empty lap. In
patients with the measurement of the height between the nipple and the submammary
crease less than or equal to 4.5 centimeters, or in constricted breasts, we perform
the muscle dieresis 1 centimeter above its costochondral origin (in these cases, the
muscle origin is high, fifth or fourth rib), in the anterior portion of the PMM flap,
and we created a neosulcus more inferiorly (Videos 1A a 1K).
Videos 2A to 2K - Temporal sequence of the intramuscular technique.
Videos 2A to 2K - Temporal sequence of the intramuscular technique.
We will have a pocket lined by muscle fascicles of the PPM on its anterior and posterior
surfaces, which is why we cannot visualize the ribs during the entire transoperative
period (Figure 5).
Figure 5 - Illustrative drawing of the prosthesis in the intramuscular plane.
Figure 5 - Illustrative drawing of the prosthesis in the intramuscular plane.
RESULTS
Round and super high-profile implants were used in 8 cases (16%), and the high-profile
was used in 42 cases (84%).
Implant volumes ranged from 250 cc to 410 cc (mean 300 cc). All surgeries were primary
augmentation. The association with other surgeries occurred in 8 cases (16%), being
5 cases of rhinoplasty (10%), 2 cases of blepharoplasty (4%), and 1 case of periareolar
skin removal for repositioning of the nipple-areolar complex (2%).
One patient had a late unilateral seroma (2%), with a slow and progressive onset,
which became clinically evident on the 90th postoperative day, and was confirmed by
breast ultrasound. The patient underwent a surgical reintervention, and we observed
the presence of muscle debris inside the pocket, probably caused by a technical error
in the separation of the fascicles. The procedure adopted was to change the implant
and clean the pocket with a 10% polyvidone-iodine degerming solution and a solution
containing antibiotics.
Another case of surgical reintervention was in a patient who presented residual ptosis
(2%) one year after augmentation mammoplasty associated with periareolar skin resection,
requiring mastopexy with a resulting inverted T scar. In cases of surgical reintervention,
we observed that the posterior flap of the PMM presented normal color and preserved
contraction function when stimulated; the distance between the posterior capsule of
the pocket and the rib cage was 6 millimeters (Video 3).
Video 3 - It was obtained from a patient initially submitted to an intramuscular technique for
breast augmentation. In the first postoperative year, she presented residual ptosis
and underwent mastopexy. Intraoperatively, we can observe the viability of the anterior
and posterior flaps.
Video 3 - It was obtained from a patient initially submitted to an intramuscular technique for
breast augmentation. In the first postoperative year, she presented residual ptosis
and underwent mastopexy. Intraoperatively, we can observe the viability of the anterior
and posterior flaps.
Aesthetically, the breasts present good contour definition in the medial quadrants.
The patients report being satisfied with the results (92%), four patients report a
small asymmetry at the height of the breasts (8%). Preoperatively, these patients’
differences in the implantation height of the breasts on the chest were identified
and noted on their consultation records, with an evident gap in the height of the
submammary folds and the height of the nipple-areolar complexes (Figures 6 to 11).
Figure 6 - Preoperative period of a 25-year-old patient; Intramuscular plane, smooth prosthesis
- 410 g.
Figure 6 - Preoperative period of a 25-year-old patient; Intramuscular plane, smooth prosthesis
- 410 g.
Figure 7 - Postoperative period of a 25-year-old patient; Intramuscular plane, smooth prosthesis
- 410 g.
Figure 7 - Postoperative period of a 25-year-old patient; Intramuscular plane, smooth prosthesis
- 410 g.
Figure 8 - Preoperative period of a 22-year-old patient; Intramuscular plane, smooth prosthesis,
300 g.
Figure 8 - Preoperative period of a 22-year-old patient; Intramuscular plane, smooth prosthesis,
300 g.
Figure 9 - Postoperative period of a 22-year-old patient; Intramuscular plane, smooth prosthesis,
300 g.
Figure 9 - Postoperative period of a 22-year-old patient; Intramuscular plane, smooth prosthesis,
300 g.
Figure 10 - Preoperative period of a 29-year-old patient; intramuscular plane, smooth prosthesis,
325 g.
Figure 10 - Preoperative period of a 29-year-old patient; intramuscular plane, smooth prosthesis,
325 g.
Figure 11 - Postoperative period of a 29-year-old patient; intramuscular plane, smooth prosthesis,
325 g.
Figure 11 - Postoperative period of a 29-year-old patient; intramuscular plane, smooth prosthesis,
325 g.
Surgical time increased by 30 minutes when compared to the retromuscular plane. We
have not yet had complications such as hematoma and capsular contracture. We need
a greater number of cases and a longer follow-up time.
DISCUSSION
The intramuscular plane is a deep plane with additional muscle coverage over the implant.
Its floor is formed by the posterior flap, with approximately 0.3 to 0.5 centimeters
in thickness of the PMM, located between the posterior capsule of the pocket and the
rib cage. This floor increases the distance and decreases the adhesion between the
posterior capsule of the pocket and the rib cage, offering safety and technical ease
in performing the posterior capsulectomy (Figure 12).
Figure 12 - Periprosthetic capsule formed on the posterior muscular flap of the intramuscular
pocket. The pinching and traction of a free capsule and away from the ribs can be
observed.
Figure 12 - Periprosthetic capsule formed on the posterior muscular flap of the intramuscular
pocket. The pinching and traction of a free capsule and away from the ribs can be
observed.
The pocket is fair in its dimensions, the transverse fascicles of the PMM at the level
of the third rib form the upper limit of the pocket, a physical barrier to the cranial
migration of the implant (Figure 13). The intramuscular technique, in relation to the thickness of the implant’s coverage,
can be compared to the hybrid technique, in which the implant is placed in a subfascial
plane and fat is grafted in specific areas of the peripheral contour of the breasts
(the anterior flap of the PMM would correspond to fat graft).
Figure 13 - Pectoralis major muscle at the height of the third rib. At this level, the muscle
is compact, and we cannot separate the fascicles (blockage to the prosthesis ascent).
Figure 13 - Pectoralis major muscle at the height of the third rib. At this level, the muscle
is compact, and we cannot separate the fascicles (blockage to the prosthesis ascent).
In the future, we will observe the degree of muscle atrophy of the flaps during reinterventions
with precise indications. So far, we know that there was no muscle atrophy in the
first postoperative year. The intramuscular technique, in relation to access to the
pocket, through the PMM, and the stabilization mechanisms used with smooth implants
(lateral tape of the PMM and fascia of the serratus anteroinferior), is very similar
to the SMS technique - Splitting Muscle Support, idealized by Khan12-14. A modification of the SMS technique was proposed by Rigo et al.15, which classifies the support of the PMM and anterior serratus fascia in SMS-1,2,3
levels, used according to the specifications of each breast. In the intramuscular
plane, the posterior flap prevents the implant from causing friction on the periosteum
and perichondrium of the ribs, so the sensory stimuli are smaller.
The fascicles with chondral origin form the floor of the pocket (posterior flap);
therefore, the barrier formed by the chondral origins of the PMM (pinnate), described
by Tebbets16, is posterior to the intramuscular plane, with greater medialization of the implant,
with the new limit medial muscle located at the ventral origin of the sternum.
In the retromuscular plane, the PMM is moved away from the ribs, which favors the
formation of a posterior capsule that is close and adhered to the rib cage, especially
at the costochondral junctions of the second to fifth ribs (Figure 14). The retromuscular plane is inside a fascial cleft, a virtual space between two
fasciae formed by loose connective tissue, which does not offer resistance to tissue
separation.
Figure 14 - Posterior capsule formed over the ribs in the retromuscular plane. The capsule cannot
be pinched or pulled, it is closely adhered to the ribs.
Figure 14 - Posterior capsule formed over the ribs in the retromuscular plane. The capsule cannot
be pinched or pulled, it is closely adhered to the ribs.
At the time of making the retromuscular pocket, the only points of resistance to dissection
coincide with the costal and sternal origins of the PMM, therefore, during the introduction
of the implant and in the first changes in the patient’s position in the immediate
postoperative period, no matter how tight the pocket has been planned, there will,
in some cases, be an enlargement of the pocket dimensions, and the superior and lateral
displacement of the implant may occur.
Thus, the subfascial plane would be our first option in patients with a pinch test
greater than or equal to 2 cm in the superomedial quadrant of the breasts, and the
intramuscular plane would be the first option in thin patients with a pinch test less
than 2 cm. In patients with extremely thin muscles, separating the flaps becomes impossible;
the retromuscular plane is better indicated in these cases.
CONCLUSION
The intramuscular technique in breast augmentation is a safe, reproducible and technically
easy procedure, with a low rate of complications.
REFERENCES
1. Tebbetts JB. Dual plane breast augmentation: optimizing implant-soft-tissue relationships
in a wide range of breast types. Plast Reconstr Surg. 2006;118(7 Suppl):81S-98S.
2. Graf RM, Bernardes A, Rippel R, Araujo LR, Damasio RC, Auersvald A. Subfascial breast
implant: a new procedure. Plast Reconstr Surg. 2003;111(2):904-8.
3. Vergara R, Marcos M. Intramuscular gluteal implants. Aesthetic Plast Surg. 1996;20(3):259-62.
4. Gonzales R. Augmentation gluteoplasty: the XYZ method. Aesthetic Plast Surg. 2004;28(6):417-25.
5. Goss CM, ed. Anatomy of the Human Body by Henry Gray. 29th ed. Philadelphia: Lea &
Ferbiger; 1997.
6. Bongiolo Junior M, Santos DN, Bittencourt RC, Pintarelli G, Joeziorowski A, Nunes
E. Uso de retalho do músculo peitoral maior para o tratamento de osteomielite de esterno.
Rev Bras Cir Plást. 2010;25(3 Suppl. 1):67.
7. Ono MT, Karner BM. Four-step Augmentation Mastopexy: Lift and Augmentation at Single
Time (LAST). Plast Reconstr Surg Glob Open. 2019;7(11):e2523.
8. Procópio LD, Silva DDP, Rosique R. Implante submuscular em duplo bolso para mastopexia
de aumento. Rev Bras Cir Plást. 2019;34(2):187-95.
9. Leão CEG. Mamoplastia de aumento: “técnica em aba de envelope”. Rev Bras Cir Plast.
2009;24(2):202-7.
10. Sper SL, Schwartz J, Dayan JH, Clemens MW. Outcome assessment of breast distortion
following submuscular breast augmentation. Aesthetic Plast Surg. 2009;33(1):44-8.
11. Pelle-Ceravolo M, Dell Vescovo A, Bertozzi E, Molinari P. A technique to decrease
breast shape deformity during Muscle contraction in submuscular augmentation mammaplasty.
Aesthetic Plast Surg. 2004;28(5):288-94.
12. Khan UD. Muscle-splitting breast augmentation: a new pocket in a different plane.
Aesthetic Plast Surg. 2007;31(5):553-8.
13. Khan UD. Multiplane technique for simultaneous submuscular breast augmentation and
internal glandulopexy using inframammary crease in selected patients with early ptosis.
Eur J Plast Surg. 2011;34(5):337-43.
14. Khan UD. Revisionary Surgery Following Primary Augmentation Mammoplasty in Muscle
Splitting Biplane Pocket: An Appraisal of 93 Revisionary Surgeries. Aesthetic Plast
Surg. 2021;45(2):462-71.
15. Rigo MH, Piccinini PS, Sartori LDP, de Carvalho LAR, Uebel CO. MS-Split Muscle Support:
A Reproducible Approach for Breast Implant Stabilization. Aesthetic Plast Surg. 2020;44(3):698-705.
DOI: 10.10071500266-019-01565-5
16. Tebbets JB. Augmentation Mammaplasty - Redefining the Patient and Surgeon Experience.
1st ed. Maryland Heights: Mosby/Elsevier; 2010.
1. Clinic of Plastic and Reconstructive Surgery Camillo, Toledo, PR, Brazil.
Corresponding author: Francisco Carlos Camillo, Rua Independência 2586, Toledo, PR, Brazil, Zip Code 85902015, E-mail: franciscocarloscamillo@gmail.com
Article received: February 26, 2021.
Article accepted: July 16, 2021.
Conflicts of interest: none.
