Multiple polyurethane implant punctures during fat grafting: case report and review of the literature

Background Breast augmentation with implants continues to be the most popular aesthetic surgical procedure performed worldwide. Fat grafting may improve the results of breast augmentation and breast reconstruction with implants. However, fat grafting to the breast with implants carries the risk of implant puncture. To our best knowledge this is the first case in which polyurethane implant puncture during fat grafting is described. Case presentation We report multiple bilateral implant punctures with the cannula during fat grafting in a patient who previously underwent breast reconstruction with polyurethane implants. Conclusions Implants that promote tissue ingrowth may be more prone to puncture with the cannula during fat grafting. Specific planning and surgical maneuvers decrease the risk of implant puncture. Level of evidence Level V, case report.


Background
Breast augmentation (BA) with implants continues to be the most popular aesthetic surgical procedure performed worldwide [1,2]. Fat grafting (FG) may improve the results of BA and breast reconstruction with implants by thickening and refining the skin envelope, filling residual defects (rippling, double bubble etc.), adding volume, changing the form and avoiding submuscular implant placement [3][4][5][6][7][8][9][10][11][12][13]. Simultaneous combination of BA with implants and FG is called hybrid or composite BA [6,11,12,14,15]. FG to the breast with implants inside carries the risk of the implant puncture. This is particularly possible if FG is performed as a secondary procedure without visualizing the implant pocket, when tissues are thin, fibrous and force is needed to pass the cannula. The incidence of implant puncture during fat grafting is not reported in the literature.

Case presentation
Patient B, 36 years old made an appointment at another institution complaining of multiple painful lumps in both breasts. She already had a sectoral resection of the right breast because of multiple fibroadenomas two years ago. The anamnesis was unremarkable. She was diagnosed with bilateral fibrocystic breast disease, multiple fibroadenomas of the right breast, BRCA negative. Bilateral subcutaneous mastectomy with DTI subpectoral reconstruction with polyurethane implants and periareolar mastopexy was performed. The postoperative period was unremarkable. Three months after the surgery on the follow up the patient complained of the breast asymmetry and soft tissue deformity and 4 months after primary surgery secondary periareolar mastopexy was performed. The postoperative course was uneventful. 4 months after Open Access *Correspondence: dmitry.batiukov@gmail.com 1 Medical Center "Antes Med", Kozlova Lane 25-7, 220037 Minsk, Belarus Full list of author information is available at the end of the article the second surgery the patient showed up again with the complaints on the breast asymmetry, contour deformity and skin redundancy of the lower pole (Fig. 1a, b). Secondary BA with capsulectomy, implant exchange for new polyurethane implants and circumvertical mastopexy were performed. The postoperative course was uneventful. But soft tissue deficit of the lower pole persisted (Fig. 2). One month after the last surgery FG to the breast was performed (app. 200 ml per breast). 30 days later the patient complained on the local tender nodules in breast bilaterally, redness of the skin. No hyperthermia was determined. Ultrasound revealed implants to be intact, multiple nodules of the lower and lateral quadrants containing fluid were found. Draining of several nodules was performed and antibiotic therapy started. The treatment was intermittently continued for 3 months. Then the patient made an appointment in our clinic (Fig. 3a, b). Implant rupture was suspected in MRI and implant removal with capsulectomy was done. Multiple punctures of both implants were revealed during surgery (Additional file 1, Video 1). The wounds healed primarily. The patient refused to undergo further surgeries.
FG and implant placement can be done simultaneously or in several stages. In case of simultaneous surgery, the surgeon can perform FG on the old implant or using a sizer, introducing the implant after FG or protecting the implant and visualizing its integrity before the wound closure if FG is performed after implant placement [6,35,39]. Grafting after the implant placement has the advantage of precise shaping and volume control [40,41]. It also reduces traumatization of fat and thus potentially adds to fat survival.
If FG is performed after wound closure or at the second stage, it is difficult to control the implant integrity. Recently ultrasound was proposed to intraoperatively control gluteal FG [42]. Although the authors do not have this experience, we consider it to be beneficial in compromised areas to establish proper plane of grafting.
Several measures are important to prevent implant puncture and its consequences.
Detailed informed consent in which a patient agrees to accept the risk of implant puncture, as well as the costs involved in corrective surgery should be signed [33]. Aging of the implants resulting in reduction in tensile strength, tear strength, and elongation of the shell may end with rupture or be the contributing factor of incidental implant puncture during FG [43][44][45]. Thus, MRI should be done preoperatively and the surgeon should consider feasibility of implant exchange in some cases. Optimistically MRI should be performed also postoperatively to rule out implant puncture during FG [33].
To avoid implant injury some authors do not perform FG on the implants with tight, thin breast pockets and scar tissues [33]. Not only does preinfiltration add to the vasoconstriction and anesthesia but it also expands the tissues, which facilitates FG in these problematic areas [40,41,46]. FG with the needle is also reported to be useful in scar tissue with very thin envelope over the implant [31].
However, FG to the breast is usually recommended to perform with cannulas [47]. Cannula characteristics influence the possibility of implant puncture. The greater the diameter of the cannula the less likely it may penetrate the implant, and the tip of the cannula can be controlled with more precision. Rigid bent cannulas may also prevent inadvertent implant puncture and help to stay superficially. However, big diameter of the cannula can considerably complicate its advancement in tissues and may interfere with graft survival due to substantial volumes of fat injected in the same spot. The longer the cannula itself and the longer the part of the cannula inside the body, the less the surgeon controls the position of the tip, thus increasing the possibility of inadvertent implant puncture. Obviously, blunt tipped cannulas are less capable of implant puncturing  [47]. It has also been also shown that if the holes at the tip of the cannula are positioned at the end (not on the side) significantly less force is needed to penetrate the implant [34].
Technical details of FG directly affect the possibility of implant puncture. FG should be performed subcutaneously [6]. We recommend to use multiple injection points and multiple passes not only to distribute the fat evenly but also to reach recipient areas easier which may contradict the experience of other surgeons who advise to avoid multiple passes in areas with less protection [35]. Longitudinal injection technique also may help to avoid deep injection [33]. Remaining breast implant capsule may protect the implant during FG. It also facilitates FG itself preventing fat from seeping into implant pocket. However, if capsulectomy is planned after FG extra caution is required not to leave free fat in the implant pocket.
Cannula displacement rate during FG directly correlates with the possibility of implant rupture. The more slowly the surgeon moves the cannula the more force he or she needs to rupture the implant [34]. Some authors recommend the 'sweep technique' which means that the cannula does not move freely from left to right being in subcutaneous tissues (as opposed to the implant pocket) [35]. However, if the implant is already punctured by the cannula the movements of the cannula from left to right will be also constrained. Thus, FG of the implant may occur. The other factor is that with polyurethane implants there exist no such free space at all because of tissue ingrowth. So, implant type should be known not to be mistaken.
Manipulating the tissues with nondominant hand while advancing the cannula (pinching the skin, lifting it from the implant, distracting etc.) facilitates cannula advancement in a proper direction [33].
Smooth and textured implants move freely inside the pocket. Thus, implant displacement to avoid inadvertent implant puncture is suggested [33,48]. However, with polyurethane implants this maneuver is useless and even harmful because the tissues are stuck to the implant. In the described case FG was performed one month after polyurethane implant placement when tissue ingrowth may have already become substantial [49]. This probability along with thin tissues and scaring played an important role in the implant puncture. Adherence properties of the implants were mentioned in one publication as a risk factor thus, the authors recommended an open procedure, with or without FG as a safer option [33]. However, FG seems unavoidable in many cases and scars are always the last option. Lastly, implant displacement maneuver may also lead to fat injection into implant pocket that will create another problem (fat necrosis). Thus, we consider that staying superficial with the cannula with the tip facing the skin is more reliable to avoid these two complications.
In summary, the following recommendations diminish the risk of puncture: