SurgiMend® vs. Strattice™ in Direct to Implant Breast Reconstruction- A Prospective Randomized Trial

Introduction An increasing number of Danish women undergo genetic counseling for hereditary breast cancer. If the patient´s lifetime risk is evaluated to be more than 30%, the patient may choose to undergo a risk-reducing mastectomy (prophylactic mastectomy) to reduce the risk of developing breast cancer. The mastectomy is mostly performed as a skin-sparing procedure, where only the nipple area and the breast tissue is removed leaving the skin envelope intact, in order to preserve the breast skin for an immediate breast reconstruction. In select cases the surgery may be performed as a nipple-sparing procedure. Additionally, there is an increasing group of women diagnosed with multifocal DCIS who choose risk-reducing mastectomy with an immediate reconstruction. In order for the risk-reducing mastectomy to be effective, it is of utmost importance that all the breast tissue is removed. This leaves the skin flaps covering the breast thin and vulnerable to necrosis, if not handled with utmost care. In order to spare the mastectomy skin flaps of some of the strain and pressure caused by the breast implants, acellular dermal matrixes (ADM) are increasingly used in this type of procedures. ADMs are derived from the skin of humans or animals, processed to an extent where their cellular components are completely removed, leaving only the extracellular scaffold, thus not inciting an immune response from the host. The ADM thus provides a scaffold, promoting integration of the patient's own connective tissue. In time the ADM will be repopulated and revascularized by the patient's own cells, essentially becoming an integrated part of the patients body. The ADM provides optimal definition of the breast borders, essentially allowing improved implant positioning as compared with a sub muscular coverage technique. If the circumstance of the breast reconstructions necessitates the placement of an expander implant, use of ADMs allows for a greater intraoperative expansion, and thus subsequently reduces the number of times the patients must attend the outpatient's clinic for expansion of the implant. Thus leading to a shorter time before the expander implant may be exchanged for a permanent implant. Furthermore, several studies have shown that use of ADM lowers the overall complication rate. Several types of ADM are used in a breast reconstructive setting around the world. Strattice™ is a porcine derived ADM, and has been available in Europe and Denmark since late 2008. In order to find the best available ADM for use in a immediate breast reconstructive setting, both in terms of complication rates and patient satisfaction, it is crucial that new products are continuously evaluated. SurgiMend®, another type of ADM, was recently introduced on the Danish market. SurgiMend® ADM is derived from fetal bovine dermis, and recent studies show that the use of SurgiMend® ADM is associated with a low early complication rate. Furthermore, a recent study provided evidence that ADM derived from bovine have a higher mechanical stress tolerance when compared to porcine derived ADM at equivalent thickness. Aim The aim of the present study is to evaluate two types of ADM´s in an immediate breast reconstructive setting. The data from this study will possibly help to minimize complications and increase patient satisfaction by finding the optimal ADM for immediate breast reconstructions, thereby contributing to a faster recovery for women who undergo mastectomy and immediate breast reconstruction with implant and ADM. Hypothesis SurgiMend and Strattice™ provide equal results in regards to complication rates, patient reported outcome measures and aesthetic appearance in patients undergoing immediate breast reconstruction. Methods The project is conducted as a prospective randomized trial. Patients included in the study will be randomized to receive either Strattice™ or SurgiMend® ADM. Patients are allocated in a 1:1 ratio, with 30 patients receiving Strattice™ ADM and 30 patients receiving SurgiMend® ADM. The randomization is performed using a permuted block randomization. Randomization is blinded for the patients and the outcome assessor. Regardless of which type of ADM the patient is randomized to receive, the surgical procedure will be performed in the same way. Patients included in the study will be asked to complete the BREAST-Q pre-reconstruction module before their breast reconstruction, and the BREAST-Q post-reconstruction module at 4 and 12 months after their breast reconstruction. The BREAST-Q is a patient reported outcome measure tool specifically designed and validated for use in breast reconstruction patients. The BREAST-Q modules consists of several scales, investigating the patients body image, satisfaction with breasts and satisfaction with care. The BREAST-Q modules are widely used and have been officially translated into the Danish language. Participating patients will attend the same standard post-operative controls at 4 and 12 months after their breast reconstruction as non-participating patients undergoing immediate breast reconstruction. In addition to being examined by their operating surgeon at these controls, the patients' aesthetic result will be evaluated by one of the investigators using a breast reconstruction outcome scale, previously developed at Dept. of Plastic and Reconstructive Surgery, Aarhus University Hospital, Aarhus, Denmark. The scale consists of six questions evaluating the symmetry, feel, and aesthetic appearance of the reconstructed breasts. Recruitment of participants Patients seeking an immediate breast reconstruction are routinely seen in the Dept. of Plastic and Reconstructive Surgery patient clinic by both a consultant breast surgeon and a consultant plastic surgeon at the same time. If the breast and plastic surgeon deems the patient eligible for a primary breast reconstruction and the plastic surgeon evaluates the patient to be best suited with a breast reconstruction based on an implant and ADM, the patient will be offered a consultation with the clinical investigator for the project. If the plastic surgeon believes that a patient is a better candidate for another type of breast reconstructive procedure than implant and ADM, the patient will not be offered participation. At the consultation with the investigator, or a well-instructed colleague, the patient will be given oral and written information about the research project. The patient will always be offered a period of at least 24 hours before deciding to give consent, but may also give her informed consent on site. Furthermore, the patient will be offered a second consultation, where the information about the project will be repeated and any questions regarding the research project she may have will be answered. The patient will also be encouraged to bring a family member or friend to the second meeting. The patient may at any time and without need of justification withdraw consent to participate, without affecting the present and/or future treatment of the patient. Risks, side effects and disadvantages As with all surgery, there is a risk of wound infection, blood clots and altered sensation in the operated area. This can lead to antibiotic treatment, or where appropriate, a second operation to stop bleeding or remove damaged tissue. These risks are, however, associated with the breast reconstruction itself, and not associated with participating in the current study. Both types of ADM are well described in the medical literature, and both types of ADM have achieved good results compared to not using ADM in immediate breast reconstructions. The risks for the patients choosing to participate in the project are thus solely related to the breast reconstruction itself, and not to the participation in the current study. Participating patients will have to spend approximately 10 minutes completing a questionnaire before the breast reconstruction. Additionally, the participating patients will be asked to complete another questionnaire (approximately 10 min) at 4 and 12 months after their breast reconstruction, as well as participate in an extra clinical examination at their routine follow-up examinations after 4 and 12 months. The extra examinations at the routine follow-up visits are expected to take approximately 15 min. per visit. While the questionnaire and the clinical follow-up may consume some of the patient's time, there are no risks associated with them. Ethical considerations It is expected that the number of women who choose an immediate breast reconstruction procedure will increase. Conducting studies that help bring down the complication rates for these types of surgery is of utmost importance, both for the individual patient undergoing the surgery and in a socio-economic setting.The proposed study will aid in finding the optimal method, both in terms of complication rate and patient reported outcome. All of the patients invited to participate in this study has been evaluated by experienced breast and plastic surgeons to be best suited with an immediate breast reconstruction with implant and ADM. The two types of ADMs evaluated in the study have shown good results in previous studies. As it is not expected that one of the tested ADMs is significantly better than the other, there is no predictable benefit for the individual patient in regards to participating in the study.