121 General discussion and future directions PF invasion may occur when tumors are situated within five millimeters of the PF, but is unlikely to happen with a distance of more than five millimeters.18, 19 The survey’s findings also revealed that breast surgeons’ lack of expertise with this method is an important barrier to preserve the PF, even though this seems a more logical anatomical plane, as the PF and the PM muscle should be seen as a single myofascial unit.7, 20 Therefore, in line with the development of less invasive mastectomy techniques, the next logical step would be to preserve the PF. However, current evidence is not strong enough to implement this as new golden standard technique. Despite the studies included in this thesis, not enough recent literature assessing the outcomes of PF preservation has been published. Future studies, preferably a large randomized controlled trial, reporting on all outcomes, including oncological safety, remain necessary. Meanwhile, if the PROFAS study will show favorable results of PF preservation, it could already be considered in patients undergoing prophylactic mastectomies, since this is without additional oncological risks. Implant-based reconstructions Women planned for a mastectomy should be counseled for the different options of breast reconstruction. Compared to autologous reconstruction, implantbased reconstruction (IBR) remains the most prevalent method to reconstruct the breast. Although the complication and reoperation rates are lower, the failure rate (reconstructive failure due to implant loss) for IBR is higher.21 It would be of great value if the implant loss rate could be decreased, as it leads to higher rates of re-operations and hospital costs, it might delay adjuvant therapy and leads to a significant decrease in patient satisfaction.22-26 Multiple risk factors have been described for implant loss, such as obesity, smoking, advanced age, radiotherapy, bilateral procedures, sentinel node biopsy and direct-to-implant (DTI) reconstructions.23, 27-29 All studies reported slightly different risk factors, probably due to different cohorts and different definitions of implant loss with different follow-up times. In this thesis, the risk of implant loss was investigated in three chapters. In chapter 5, six risk factors were significantly associated with implant loss; obesity, smoking, a nipple-sparing mastectomy, a DTI approach, and a lower oncological surgeon’s volume. Based on four of these risk factors, obesity, smoking, a nipple-sparing mastectomy and a DTI reconstruction, a risk-model was created. The study in chapter 6 aimed to validate this risk-model with a large database from the Dutch Breast Implant Registry (DBIR). Unfortunately this was not successful and the need for a validated risk-model remained. Consequently, in chapter 7, a successfully validated prediction-model was created with data from the DBIR, based on four risk factors; BMI, smoking, prior radiotherapy, and prepectoral placement. Risk 8
RkJQdWJsaXNoZXIy MTk4NDMw