Background: Routine application of vascularized composite allotransplantation is hampered by immunosuppression-related health comorbidities. To mitigate these, we developed an inflammation-responsive hydrogel for local immunosuppression. Here, we report on its long-term effect on graft survival, immunological, and toxicological impact. Methods: Brown Norway-to-Lewis rat hindlimb transplantations were treated either systemically with daily injections of 1 mg/kg tacrolimus (TAC) or with subcutaneous intragraft injections of hydrogel containing 7 mg TAC, every 70 days. Animals were monitored for rejection or other pathology for 280 days. Systemic and graft TAC levels, regulatory T cells, and donor cell chimerism were measured periodically. At endpoint, markers for kidney, liver, and metabolic state were compared to naive age-matched rats. Results: Both daily systemic TAC and subcutaneous intragraft TAC hydrogel at 70-day intervals were able to sustain graft survival longer than 280 days in 5 of 6 recipients. In the hydrogel group, 1 graft progressed to grade 3 rejection at postoperative day 149. In systemic TAC group, 1 animal was euthanized due to lymphoma on postoperative day 275. Hydrogel treatment provided stable graft and reduced systemic TAC levels, and a 4 times smaller total TAC dose compared with systemic immunosuppression. Hydrogel-treated animals showed preserved kidney function, absence of malignancies or opportunistic infections and increased hematopoietic chimerism compared with systemic immunosuppression. Conclusions: Our findings demonstrate that localized immunosuppression with TAC hydrogel is a long-term safe and reliable treatment. It may reduce the burden of systemic immunosuppression in vascularized composite allotransplantation, potentially boosting the clinical application of this surgical intervention.

In order to achieve a satisfactory functional and aesthetic result a thin skin flap is often required in surgical reconstruction of various body regions. Perforator flaps based on either the superficial or deep branch of the superficial circumflex iliac artery (SCIA) have been used for this purpose mainly in the Asian population. Recently the superficial plane has been established as a new way of elevating the flap. Anatomical studies and details of this new flap are lacking. Wide areas were harvested subfascially from the groin of Thiel-fixated cadavers. Both deep and superficial branches of the superficial circumflex iliac artery were carefully dissected and individually injected with μAngiofil. After CT-imaging the flaps were raised on the superficial plane, perforators were marked and the flaps subsequently rescanned. High-resolution images of regions of interest were taken using micro-CT. A total of 21 flaps were harvested and analyzed. Both the deep and superficial branch provided more than three perforators per branch, however, the deep branch based flap was significantly larger (202 vs. 112 cm2, p < 0.01) and had a longer pedicle (9.1 vs. 6.6 cm, p < 0.01). Raising the flap in the superficial plane reliably reduces bulk and increases homogeneity. The SCIP flap appears to have a reliable vascular blood supply. The SCIA and its main branches and perforators have a consistent vascular pattern. The deep branch of the SCIA has the anatomic potential to be the preferred pedicle in case larger flaps with longer pedicles are necessary.

Development and Implementation of a Web-Enabled 3D Consultation Tool for Breast Augmentation Surgery Based on 3D-Image Reconstruction of 2D Pictures

Introduction: Seroma formation is a serious postoperative complication. Since the management algorithms available in the literature are scarce, we aimed to analyze our experience with postoperative seroma in order to identify indicators for revisional surgery and propose recommendations for management. Methods: This retrospective study included all patients with postoperative seroma treated in a tertiary university hospital from 2008 to 2020. Patients’ demographics, medical history, and seroma treatment details were recorded and analyzed. Results: Overall, 156 patients were included: 41% were initially treated through needle aspiration, with 61% eventually undergoing surgical treatment for postoperative seroma. Comorbidities, such as heart failure and coronary heart disease, were significantly associated with an increased need for revisional surgery (p < 0.05). Both a duration of >40 days of repeated needle aspirations and drain re-insertions were significantly correlated with an increased risk for revisional surgery (p < 0.05). Conclusion: Patients requiring seroma aspiration should be counseled on surgical treatment sooner rather than later, as prolonged aspiration time (over 40 days) greatly increases the risk of surgical revision. Moreover, the reinsertion of a drain should only be used as a temporizing measure, at most, and patients requiring a drain to control the size of the seroma should promptly be scheduled for a surgical revision.