Tissue-Engineered Autologous Breast Regeneration with Brava®-Assisted Fat Grafting

A technique of whole and partial breast reconstruction is described based on tissue-engineering principles. Brava-assisted external tissue expansion generates an in situ biological recipient scaffold that favors the survival of large volumes of autologous fat graft required for breast reconstruction. Also presented are the results of the authors’ multicenter experience with this regenerative alternative in 488 patients over a 7-year period tracking surgical complications, patient satisfaction, efficacy, and costs.

Key points

  • For large volumes of fat graft to survive, it is necessary to prepare a well-vascularized, large-volume recipient site.

  • External tissue expansion with Brava can generate an in situ biological scaffold that will accept a large volume of fat graft required for breast reconstruction.

  • With the Brava-assisted technique, it takes an average of 2.8 grafting procedures to regenerate a nonradiated breast mound, while radiated defects require an additional 2.1 procedures to reverse the radiation damage.

  • Brava + autologous fat transfer is a minimally invasive, incisionless, safe, economic, attractive, and effective alternative method of breast reconstruction.

Introduction

Nearly 300,000 American women are diagnosed with breast cancer every year, with 118,000 opting for breast reconstruction after mastectomy. Most reconstructions are implant-based (69%), whereas the remainder are autologous flap reconstructions (31%). Over the past 7 years, the authors have offered a third alternative to more than 400 women who wished to avoid prosthetic material and invasive flap surgery.

The authors’ experience has shown that Brava-assisted external tissue expansion with subsequent autologous fat transfer (AFT) is a safe and effective minimally invasive method of regenerating a breast mound. The procedure has the added benefits of restoring a sensate breast mound with minimal morbidity and of body contour improvement through liposuction.

Brava® (Coconut Grove, FL, USA), a well-established vacuum-based external breast expander, applies a distractive mechanical force that induces the body to generate its own 3-dimensional (3D) vascularized scaffold. It not only expands the skin defect to generate the necessary skin envelope, but it also stimulates the growth of native stromal and vascular elements. Appropriate expansion creates a larger and more favorable recipient site where many more microdroplets of fat can be diffusely injected without coalescence and without significantly increasing interstitial fluid pressure ( Fig. 1 ).

Fig. 1
Tissue engineering a breast mound: 3 weeks of external Brava® expansion generates a tissue engineering scaffold with a rich capillary vascular network that can be seeded with fat microdroplets to generate a well vascularized fatty breast mound.

The authors’ published experience with Brava + AFT for primary breast augmentation and large volume fat transfer established the attractiveness, safety, and efficacy of this technique. The authors hereby review their outcomes for Brava + AFT breast reconstruction in 3 patient population subsets: delayed reconstruction, immediate reconstruction, and reconstruction of the radiated partial mastectomy defect. Each subset has unique characteristics that must be considered when undergoing Brava + AFT reconstruction.

Introduction

Nearly 300,000 American women are diagnosed with breast cancer every year, with 118,000 opting for breast reconstruction after mastectomy. Most reconstructions are implant-based (69%), whereas the remainder are autologous flap reconstructions (31%). Over the past 7 years, the authors have offered a third alternative to more than 400 women who wished to avoid prosthetic material and invasive flap surgery.

The authors’ experience has shown that Brava-assisted external tissue expansion with subsequent autologous fat transfer (AFT) is a safe and effective minimally invasive method of regenerating a breast mound. The procedure has the added benefits of restoring a sensate breast mound with minimal morbidity and of body contour improvement through liposuction.

Brava® (Coconut Grove, FL, USA), a well-established vacuum-based external breast expander, applies a distractive mechanical force that induces the body to generate its own 3-dimensional (3D) vascularized scaffold. It not only expands the skin defect to generate the necessary skin envelope, but it also stimulates the growth of native stromal and vascular elements. Appropriate expansion creates a larger and more favorable recipient site where many more microdroplets of fat can be diffusely injected without coalescence and without significantly increasing interstitial fluid pressure ( Fig. 1 ).

Fig. 1
Tissue engineering a breast mound: 3 weeks of external Brava® expansion generates a tissue engineering scaffold with a rich capillary vascular network that can be seeded with fat microdroplets to generate a well vascularized fatty breast mound.

The authors’ published experience with Brava + AFT for primary breast augmentation and large volume fat transfer established the attractiveness, safety, and efficacy of this technique. The authors hereby review their outcomes for Brava + AFT breast reconstruction in 3 patient population subsets: delayed reconstruction, immediate reconstruction, and reconstruction of the radiated partial mastectomy defect. Each subset has unique characteristics that must be considered when undergoing Brava + AFT reconstruction.

Delayed reconstruction

In the delayed reconstruction, the patient undergoes 2 to 3 weeks of Brava-mediated tissue expansion in preparation for fat transfer. Tight mastectomy defects limit the amount of fat that can be safely grafted per session, more so in noncompliant, irradiated skin. Brava helps mitigate these effects, thereby decreasing the necessary number of grafting sessions required to complete the reconstruction. Fig. 2 demonstrates a case of delayed reconstruction.

Fig. 2
Delayed breast reconstruction with Brava + AFT. A 52-year-old woman presents for reconstruction after mastectomy for right-sided breast cancer with contralateral prophylactic mastectomy ( top row ). Three sessions of Brava expansion with fat grafting were required to regenerate her breast mounds. Follow-up at 1 year after her final procedure is shown ( bottom row ).

Immediate reconstruction

Although initially lacking the benefits of expansion, immediate breast reconstruction confers 3 main advantages : (1) because the recipient muscle is exposed, fine graft ribbons can be carefully teased in between the muscle fascicles under direct vision, which is a huge advantage compared with traditional fat grafting where the surgeon cannot see graft coming out of the cannula; (2) with the investing fascia that normally restricts muscle expansion removed as part of the mastectomy, the recipient muscle can accept a large amount of graft and significantly swell without increasing its interstitial tissue pressure; and (3) closure of the wound allows the plastic surgeon to tailor the amount of residual skin deemed necessary for the optimal reconstruction. Although counterintuitive, excess skin leads to problematic folds that are difficult to subsequently release. Usually 100 to 400 mL of fat can be grafted in the submuscular and intramuscular planes and, if feasible, the base of the mastectomy flaps. With most of the grafts deposited in the upper pole, the patient wakes up with a moderate-sized medial breast mound. This “social breast” helps reduce some of the psychological trauma of the mastectomy. Four to 6 weeks after the mastectomy, once the skin flaps have healed and adhered to the grafted muscle, the patients start Brava expansion to further expand the recipient scaffold in preparation for the 1 to 6 additional grafting procedures that might be required to complete the reconstruction. If radiation was planned after mastectomy, immediate reconstruction is not offered because radiation would damage the grafted fat. Figs. 3–7 show examples of immediate reconstruction.

Fig. 3
Preoperative photos of 48-year-old woman before her planned bilateral mastectomy for right breast carcinoma and immediate breast reconstruction with fat grafting.

Fig. 4
Patient from Fig. 3 immediately after mastectomy ( left photo ) and immediately after fat grafting the exposed pectoralis muscle and mastectomy skin flaps ( second from left ). Following additional resection of her right nipple areola complex for a positive margin, Brava expansion of the mastectomy before second ( second from right ) and third ( right ) reconstructive procedures.

Fig. 5
One-year postoperative result. In addition to appearance to regenerated breast mounds, note the contour improvement of the thigh and flanks donor areas.

Fig. 6
Patient demonstrates soft breasts with light touch sensation over the nipples.

Fig. 7
After reconstruction, MRI of patient shows well-vascularized normal-appearing fat with only a solitary, subcentimeter oil cyst in left breast.

Reconstruction of lumpectomy defects

In the radiated lumpectomy, AFT immediately after completing radiation seems to have a soothing effect on the radiation-induced inflammation, and the interposed healthy grafts reduce the amount of secondary fibrosis, causing the radiated tissues to remain softer. In addition to serving as a volume filler, fat reduces fibrosis and has a regenerative effect on skin, nerves, and blood vessels. Figs. 8–10 show examples of reconstruction of lumpectomy.

Fig. 8
Preoperative ( top row ) to postoperative ( bottom row ) appearance of a 45-year-old woman with right-sided radiated lumpectomy. She required 2 Brava + AFT procedures. Note the improved and lengthened lateral mammary scar, the medialization of the nipple-areola complex, and the correction of her axillary hollow. Most striking to this patient, however, is the total resolution of her severe antecostobrachial nerve neuritis.

Fig. 9
Lateral view of the right radiated lumpectomy defect: Left, pretreatment; center, with the Brava placed horizontally to recruit more of the lateral breast; right, following 3 weeks of Brava expansion and immediately after removing the device. Brava loosened out the scar contracture, improved the contour defect, and increased the recipient size and its mechanical compliance, and the visible hyperemia reflects an overall increased vascularity of the recipient.

Fig. 10
Preoperative ( left ) and postoperative ( right ) mammogram of patient. Note correction of the axillary cleft and the improved radiolucency of breast.

Patient selection and preparation

Patients have to tolerate a 20-minute in-office test trial of Brava use, understand its use and benefits, and comply with its wear schedule. Exclusion criteria include smoking, prolonged bleeding, multiple previous liposuctions, and unrealistic expectations. Because the authors can harvest a thin layer of fat out of a large expanse, patients with low body mass index (BMI) have excellent outcome and are rarely turned down. Because prior radiation or scarring from previous failed procedures requires significantly more time and expertise, the best candidates for the beginner surgeon are unscarred, unradiated mastectomy defects in patients with moderate fat depots. Patients are required to wear Brava with 60- to 0-mm Hg cycling pressures (3 minutes on/1 minute off) for at least 10 hours a day 2 to 3 weeks before their scheduled surgery and are considered well prepared for grafting if the mastectomy defect volume immediately after Brava removal is more than or equal to 2.5 times the pre-expansion volume.

Surgical technique

The authors’ AFT technique with the Lipografter® (Lipocosm, LLC, Key Biscayne, FL, USA) has previously been described. Briefly, fat is manually liposuctioned using a 12-hole, 12-G cannula connected to the K-VAC® spring-loaded syringe, which provides a 300-mm Hg constant vacuum. Harvesting is efficient because there is no need to switch syringes; recocking the K-VAC® syringe plunger spring automatically sends the lipoaspirate to a collection bag through a 2-way atraumatic tissue valve (AT-Valve®). Once filled, the bag containing the lipoaspirate is centrifuged at 15 G for 1 to 2 minutes (or allowed to sediment at 1 G for 15 minutes). There is very little, if any, free oil with this gentle handling. After draining the infranatant fluid, the supernatant fat is concentrated in the same bag, ready for reinjection ( Fig. 11 ).

Fig. 11
The Lipografter® device allows for atraumatic harvest, preparation, and reinjection of AFT all within a closed system. ( left upper corner ) In the harvesting mode, the Lipografter consists of a 12-gauge, 12-hole harvesting cannula connected to the K-VAC® spring-loaded syringe through the AT-Valve®. The liposuctioned fat is drawn into the K-VAC® syringe as its plunger is automatically pulled up by the ribbon springs at a constant 300-mm Hg vacuum pressure. Pushing the plunger back down recocks the springs as the AT-Valve® automatically sends the lipoaspirate to the collection bag. ( right upper corner ) Once full, the collection bag is hung on an intravenous pole covered by a sterile drape with hangers made out of folded sterile endotracheal stylets. After sedimenting for about 10 minutes, the fluid is drained and the supernatant fat is concentrated in what becomes the reinjection bag. This gentle harvesting and preparation method produces little to no free oil. ( right lower corner ) In the grafting mode, the Lipografter has a gently curved 14-G, single-hole, spatulated tip grafting cannula connected to a 3-mL syringe by means of the AT-Valve® switched to the grafting mode such that AFT automatically flows from bag to syringe to patient in the direction of the arrows. ( left lower corner ) Breast reconstruction now consists of reinjecting AFT into the expanded mastectomy scaffold. Through multiple 14-G needle puncture entry sites, the authors reinject about 2 mL per 20-cm pass leaving behind 0.1 mL/cm arcuate contiguous ribbons of fat in multiple planes. Thanks to the valve, the AFT can be repeatedly aspirated from the reinjection bag into a fine syringe and automatically reinjected back through the cannula in tiny precise packages while eliminating the time wasted switching cannulas and refilling syringes.
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Nov 21, 2017 | Posted by in Dental Materials | Comments Off on Tissue-Engineered Autologous Breast Regeneration with Brava®-Assisted Fat Grafting
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