A novel technique for laser-assisted revascularization: an in vitro pilot study.

The common limitation of surgical revascularization procedures for severe tissue ischemia due to cardiovascular diseases is the need to interrupt blood flow during the intervention. We aim to introduce a new technique that allows a sutureless, non-occlusive revascularization. A 3-step technique was developed using rabbit's aorta to simulate a side-to-side anastomosis model. It enables the creation of a bypass circuit for revascularization. The first step was the soldering of 2 vessels in a side-to-side fashion based on the laser-assisted vascular anastomosis (LAVA) principle using a diode laser emitting irradiation at 810 nm with an albumin-based solder patch between them, followed by the creation of a channel within the patch using either a holmium-doped yttrium aluminum garnet laser (Ho:YAG) at λ = 2100 nm or a xenon-chloride excimer laser (XeCl) at λ = 308 nm. Thereby, a bypass circuit was created, thus allowing a non-ischemic revascularization. The system was deemed functional when a flow was observed across the anastomosis. The highest average tensile strength recorded after side-to-side LAVA using a diode laser power of 3.2 W for 60 s was 2278.6 ± 800 mN (n = 20). The Ho:YAG laser created the channels with less tension on the anastomosis than the excimer laser. Histological analysis showed limited thermal damage and good patch-tissue adaptation. The preliminary results of this feasibility study outline the foundations for an entirely sutureless laser-assisted revascularization procedure. The next studies will evaluate the rheological parameters across the bypass circuit to optimize the post-anastomotic flow.

Release of pig leukocytes and reduced human NK cell recruitment during ex vivo perfusion of HLA-E/human CD46 double-transgenic pig limbs with human blood.

BACKGROUND: In pig-to-human xenotransplantation, interactions between human natural killer (NK) cells and porcine endothelial cells (pEC) are characterized by recruitment and cytotoxicity. Protection from xenogeneic NK cytotoxicity can be achieved in vitro by the expression of the non-classical human leukocyte antigen-E (HLA-E) on pEC. Thus, the aim of this study was to analyze NK cell responses to vascularized xenografts using an ex vivo perfusion system of pig limbs with human blood. METHODS: Six pig forelimbs per group, respectively, stemming from either wild-type (wt) or HLA-E/hCD46 double-transgenic (tg) animals, were perfused ex vivo with heparinized human blood for 12 hours. Blood samples were collected at defined time intervals, cell numbers counted, and peripheral blood mononuclear cells analyzed for phenotype by flow cytometry. Muscle biopsies were analyzed for NK cell infiltration. In vitro NK cytotoxicity assays were performed using pEC derived from wt and tg animals as target cells. RESULTS: Ex vivo, a strong reduction in circulating human CD45 leukocytes was observed after 60 minutes of xenoperfusion in both wt and tg limb groups. NK cell numbers dropped significantly. Within the first 10 minutes, the decrease in NK cells was more significant in the wt limb perfusions as compared to tg limbs. Immunohistology of biopsies taken after 12 hours showed less NK cell tissue infiltration in the tg limbs. In vitro, NK cytotoxicity against hCD46 single tg pEC and wt pEC was similar, while lysis of double tg HLA-E/hCD46 pEC was significantly reduced. Finally, circulating cells of pig origin were observed during the ex vivo xenoperfusions. These cells expressed phenotypes mainly of monocytes, B and T lymphocytes, NK cells, as well as some activated endothelial cells. CONCLUSIONS: Ex vivo perfusion of pig forelimbs using whole human blood represents a powerful tool to study humoral and early cell-mediated rejection mechanisms of vascularized pig-to-human xenotransplantation, although there are several limitations of the model. Here, we show that (i) transgenic expression of HLA-E/hCD46 in pig limbs provides partial protection from human NK cell-mediated xeno responses and (ii) the emergence of a pig cell population during xenoperfusions with implications for the immunogenicity of xenografts.

Endoluminal laser-assisted vascular anastomosis-an in vivo study in a pig model.

Microvascular surgery is time consuming and requires high expertise. Laser-assisted vascular anastomosis (LAVA) is a promising sutureless technique that has the potential to facilitate this procedure. In this study, we evaluate the handling of our soldering material and the 1-week patency rate in a porcine model. Six pigs were subjected to LAVA. For each pig, the saphenous artery on one side was transected while the contralateral side was used as control. A porous polycaprolactone scaffold soaked in 40% (w/w) bovine serum albumin solution in combination with 0.1% (w/w) indocyanine green was wrapped at the anastomosis site and at the control site. Both sides were then soldered with a diode laser coupled into a light diffuser fiber emitting radiation with a wavelength of 808 nm and a power of 2-2.2 W. Vessels were successfully soldered with a 100% immediate patency rate. The 1-week patency rate was 83% for the anastomoses versus 67% for the control side. Vessels irradiated for 80 to 90 s tended to maintain the highest patency rate. Macroscopically, there was no difference between the two sides. The patch was easy to handle provided that the environment could be kept dry. This study shows the potential and the limitations of endoluminal LAVA as a one-step procedure without the use of stay sutures. Further studies are needed to improve the soldering material, the long-term patency rate, and standardized irradiation parameters. The long-term effects of laser soldering on the vessel wall remain to be determined.

Complement dependent early immunological responses during ex vivo xenoperfusion of hCD46/HLA-E double transgenic pig forelimbs with human blood.

BACKGROUND: Besides α1,3-galactosyltransferase gene (GGTA1) knockout, several transgene combinations to prevent pig-to-human xenograft rejection are currently being investigated. In this study, the potential of combined overexpression of human CD46 and HLA-E to prevent complement- and NK-cell-mediated xenograft rejection was tested in an ex vivo pig-to-human xenoperfusion model. METHODS: α1,3-Galactosyltransferase knockout heterozygous, hCD46/HLA-E double transgenic (transgenic) as well as wild-type pig forelimbs were ex vivo perfused with whole, heparinized human and autologous pig blood, respectively. Blood samples were analyzed for the production of porcine and/or human inflammatory cytokines as well as complement activation products. Biopsy samples were examined for deposition of human and porcine C3b/c, C4b/c, and C6 as well as CD62E (E-selectin) and CD106 (VCAM-1) expression. Apoptosis was measured in the porcine muscle tissue using TUNEL assays. Finally, the formation of thrombin-antithrombin (TAT) complexes was measured in EDTA plasma samples. RESULTS: No hyperacute rejection was seen in this model. Extremity perfusions lasted for up to 12 h without increase in vascular resistance and were terminated due to continuous small blood losses. Plasma levels of porcine cytokines IL1ß, IL-6, IL-8, IL-10, TNF-α, and MCP-1 as well as human complement activation markers C3a (P = 0.0002), C5a (P = 0.004), and soluble C5b-9 (P = 0.03) were lower in blood perfused through transgenic as compared to wild-type limbs. Human C3b/c, C4b/c, and C6 as well as CD62E and CD106 were deposited in tissue of wild-type limbs, but significantly lower levels (P < 0.0001) of C3b/c, C4b/c, and C6 deposition as well as CD62E and CD106 expression were detected in transgenic limbs perfused with human blood. Transgenic porcine tissue was protected from xenoperfusion-induced apoptosis (P < 0.0001). Finally, TAT levels were significantly lower (P < 0.0001) in transgenic limb as compared to wild-type limb xenoperfusions. CONCLUSION: Transgenic hCD46/HLA-E expression clearly reduced humoral xenoresponses since all, the terminal pathway of complement activation, endothelial cell activation, muscle cell apoptosis, inflammatory cytokine production, as well as coagulation activation, were all downregulated. Overall, this model represents a useful tool to study early immunological responses during pig-to-human vascularized xenotransplantation in the absence of hyperacute rejection.

Sonographic wrist measurements and detection of anatomical features in carpal tunnel syndrome.

INTRODUCTION: This study compares anatomical findings at wrist level in patients with known carpal tunnel syndrome (CTS) and controls by ultrasonography (US). MATERIAL AND METHODS: Wrist-US investigations of 28 consecutive patients with 38 diagnosed, idiopathic CTS were compared to 49 healthy volunteers without history of CTS. Internal wrists dimensions, the presence of flexor muscle bellies in the carpal tunnel, and cross-sectional area of the median nerve were analyzed. The findings were correlated to gender, age, and BMI. RESULTS: US demonstrated a square internal carpal tunnel configuration in CTS patients compared to controls (P < 0.001). Patients with CTS showed a trend towards the presence of flexor muscles bellies in the carpal tunnel (odds ratio 1.77, 95% CI 0.337-8.33). CTS was present in women with higher BMI (P = 0.015). CONCLUSION: US allowed detection of specific anatomical features at wrist level in CTS patients. This observation may enable--following confirmation in larger prospective studies--risk evaluation for CTS development.

[The risk-reducing mastectomy: unnecessary hysteria or life-saving prophylaxis?]. / Die prophylaktische Mastektomie: unnötige Hysterie oder nötige Vorsorge.

The prophylactic (risk-reducing) mastectomy is a world-wide recognized method for specifically treating the increased breast cancer risk in patients showing a BRCA1 and/or BRCA2 mutation as well as other patient groups at increased breast cancer risk. This option should be offered to all patients having the pertinent risk profile. Breast reconstruction is an integral part of the risk-reducing mastectomy procedure and all possible methods of breast reconstruction, especially autologous tissue reconstruction should be offered to all patients having a medical indication and desiring this surgical treatment. These patients are best managed in certified Breast Care Centres where the different medical and surgical specialists can address interdisciplinary all aspects of genetic counselling, preoperative counselling, mastectomy and reconstructive techniques as well as the necessary postoperative surveillance.

Bioglass/ceria nanoparticle hybrids for the treatment of seroma: a comparative long-term study in rats.

Background: Seroma formation is a common postoperative complication. Fibrin-based glues are typically employed in an attempt to seal the cavity. Recently, the first nanoparticle (NP)-based treatment approaches have emerged. Nanoparticle dispersions can be used as tissue glues, capitalizing on a phenomenon known as 'nanobridging'. In this process, macromolecules such as proteins physically adsorb onto the NP surface, leading to macroscopic adhesion. Although significant early seroma reduction has been shown, little is known about long-term efficacy of NPs. The aim of this study was to assess the long-term effects of NPs in reducing seroma formation, and to understand their underlying mechanism. Methods: Seroma was surgically induced bilaterally in 20 Lewis rats. On postoperative day (POD) 7, seromas were aspirated on both sides. In 10 rats, one side was treated with NPs, while the contralateral side received only NP carrier solution. In the other 10 rats, one side was treated with fibrin glue, while the other was left untreated. Seroma fluid, blood and tissue samples were obtained at defined time points. Biochemical, histopathological and immunohistochemical assessments were made. Results: NP-treated sides showed no macroscopically visible seroma formation after application on POD 7, in stark contrast to the fibrin-treated sides, where 60% of the rats had seromas on POD 14, and 50% on POD 21. At the endpoint (POD 42), sides treated with nanoparticles (NPs) exhibited significant macroscopic differences compared to other groups, including the absence of a cavity, and increased fibrous adhesions. Histologically, there were more macrophage groupings and collagen type 1 (COL1) deposits in the superficial capsule on NP-treated sides. Conclusion: NPs not only significantly reduced early manifestations of seroma and demonstrated an anti-inflammatory response, but they also led to increased adhesion formation over the long term, suggesting a decreased risk of seroma recurrence. These findings highlight both the adhesive properties of NPs and their potential for clinical therapy.

Ischemia/reperfusion injury of porcine limbs after extracorporeal perfusion.

BACKGROUND: Revascularization of amputated extremities after prolonged ischemia is complicated by reperfusion injury. We assessed ischemia/reperfusion (I/R) injury of porcine extremities after prolonged preservation using extracorporeal circulation (ECC). METHODS: Forelimbs of 32 pigs were divided into four groups based on ischemia times: group I: 6 h, group II: 12 h, group III: 0 h plus replantation, and group IV: 6 h plus replantation. Limbs were perfused with autologous blood using ECC for 12 h except group II with only 5 h perfusion. Limbs from groups III and IV were heterotopically replanted with a 7-d follow-up. Contralateral limbs served as controls in all groups. Tissue, plasma, and serum were analyzed for the extent of I/R injury. RESULTS: No significant differences in tissue wet/dry ratios were found within or between groups. This finding was confirmed by histology, except for an increased damage in group IV muscles compared with baseline (P = 0.016). Complement C3 deposition was only increased in group IV muscle (P = 0.031), group II nerves (P = 0.046), and group II vessels (P = 0.037). Group IV muscle and nerve tissues were the only ones with significant IgM antibody deposition (P = 0.031) at end of perfusion. Values were normal again after replantation. Reduced complement activity and elevated IL-6, IL-8, MCP-1, VEGF, PDGF-bb, bFGF, and complement split products were found during perfusion but were normal again after replantation. Staining for heparin sulfate proteoglycans and von Willebrand factor confirmed minimal activation of endothelial cells. CONCLUSION: The results demonstrate that prolonged limb preservation using ECC has minimal impact on I/R-induced tissue injury. Extracorporeal perfusion is a potential limb-preserving technique encouraging further studies for use in limb revascularization.

The extended diep flap: extending the possibilities for breast reconstruction with tissue from the lower abdomen.

BACKGROUND: The classical DIEP-flap is considered state-of-the-art in microsurgical autologous breast reconstruction. Some patients may require additional volume to match the contralateral breast. This quality control study prospectively evaluates the feasibility and outcome of a surgical technique, which pursues the volumetric augmentation of the DIEP-flap by harvesting of additional subscarpal fat tissue cranial to the classical flap border. PATIENTS AND METHODS: For radiologically based estimation of volumetric flap-gain potential, abdominal CT-scans of 10 Patients were randomly selected and used for computerized volumetric estimates. Surgical evaluation of the technique was prospectively performed between 09/2009 and 09/2010 in 10 patients undergoing breast reconstruction with extended DIEP-flap at two institutions. The outcome regarding size, volume, and symmetry was evaluated. RESULTS: Radiologically, the mean computed volume gain of an extended DIEP was 16.7%, when compared with the infraumbilical unilateral flap volume. Clinically, the intraoperatively measured mean volume gain was of 98.6 g (range: 75-121 g), representing 13.8% of the flap volume. All 10 flaps survived without revision surgery. In three flaps, minor fat necrosis occurred in zone III and was treated conservatively. No fat necrosis was observed in the extended flap area. CONCLUSIONS: In this first prospective series, the extended DIEP-flap proved to be feasible, reliable and safe for its use in breast reconstruction. Both radiological estimation and intraoperative measurements demonstrated a statistically significant volume gain with no complications in the extended area. The technique is of benefit in selected patients requiring additional reconstructive volume than the one achieved with the classical DIEP-flap. LEVEL OF EVIDENCE: Therapeutic Level IV.

[Surgical therapy for reconstruction of body shape and contour following massive weight reduction]. / Chirurgische massnahmen zur wiederherstellung der körperform und -konturnach massiver gewichtsreduktion.

The consequences of massive weight loss through bariatric procedures as well as diet are overall positive. However, the sequelae of massive weight loss present themselves as soft tissue redundancies in the areas of the lower abdomen, upper thigh, upper arm and breast as well as face and neck. This condition presents significant mechanical, physical and social day-to-day limitations for the quality of life of these patients. Surgical techniques are indicated for the reconstruction of the body shape and therapy of the above named problems and the coexistent psychosocial component. These surgical techniques involve dermolipectomies in different body areas and can lead to significant improvement. In view of the worldwide increase of adipositas and the increasing need for bariatric surgery, a parallel increase in demand for such reconstructive post-bariatric interventions can be foreseen. Early and precise information is crucial for the patients before engaging in weight reduction, as is the coverage of the costs of the resulting secondary reconstructive body contouring interventions by the insurance companies.

The osteocutaneous SCIP flap: A detailed description of the surgical technique and retrospective cohort study of consecutive cases in a tertiary European centre.

INTRODUCTION: In the era of increasing popularity of the superficial circumflex iliac perforator (SCIP) flap, osteocutaneous variants of the flap have been described as well. Despite their benefits such as customizability and low donor site morbidity, these flaps have not yet gained broad acceptance. By reviewing our case series, we aim to promote the safe application of this promising new tool in osteoplastic reconstructions. PATIENTS AND METHODS: We performed a single-centre, retrospective chart review of all cases in which osteocutaneous SCIP-flaps were used. We describe our surgical technique and present the surgical, functional and aesthetic outcomes of the patients in our cohort. RESULTS: Since September 2019, we have used osteocutaneous SCIP flaps in six patients, five in the extremities and one for the head and neck region. The vascularised bone segment was measured on average 4.9 cm (range 4-7 cm) x 3 cm (range 1.5-4 cm) and was combined with a skin paddle of a mean length of 14.3 cm (range 8-20 cm) and width of 6.3 cm (range 5-8 cm). One flap underwent emergency revision due to venous congestion. All flaps survived and healed uneventfully. Long-term follow-up shows adequate bony integration and stable soft tissue coverage with good functional restoration and minimal donor site morbidity. CONCLUSION: The osteocutaneous SCIP flap provides a large and thin skin island and a "moderately sized" vascularised bone segment with minimal donor site morbidity and can be successfully used in selected cases of osteoplastic reconstruction.

Topical application of 17ß-estradiol (E2) improves skin flap survival through activation of endothelial nitric oxide synthase in rats.

This study investigates the influence of 17ß-estradiol (E2) on nitric oxide (NO) production in endothelial cell cultures and the effect of topical E2 on the survival of skin flap transplants in a rat model. Human umbilical vein endothelial cells were treated with three different E2 concentrations and nitrite (NO2) concentrations, as well as endothelial nitric oxide synthase (eNOS) protein expressions were analyzed. In vivo, random-pattern skin flaps were raised in female Wistar rats 14 days following ovariectomy and treated with placebo ointment (group 1), E2 as gel (group 2), and E2 via plaster (group 3). Flap perfusion, survival, and NO2 levels were measured on postoperative day 7. In vitro, E2 treatment increased NO2 concentration in cell supernatant and eNOS expression in cell lysates (p < 0.05). In vivo, E2 treated (gel and plaster groups) demonstrated significantly increased skin flap survival compared to the placebo group (p < 0.05). E2 plaster-treated animals exhibited higher NO2 blood levels than placebo (p < 0.05) paralleling the in vitro observations. E2 increases NO production in endothelial cells via eNOS activation. Topical E2 application can significantly increase survival of ischemically challenged skin flaps in a rat model and may augment wound healing in other ischemic situations via activation of NO production.

Early versus delayed surgical treatment in open hand injuries: a paradigm revisited.

BACKGROUND: To date it remains unclear if a delayed surgical treatment of open hand injuries after more than 6 h may be detrimental to outcome. Previous investigations by McLain et al. (J Hand Surg Am 16:108-112, 1980 9), Nylen and Carlsson (Scand J Plast Reconstr Surg 14:185-189, 1991 10) could not find statistical proof of correlation between infection rate and delayed surgical treatment after open hand injuries up to 18 h. The current study was designed to investigate the outcome of early versus delayed surgical treatment after open hand injury. PATIENTS AND METHODS: A retrospective data analysis of all patients sustaining an open hand injury between January 1 and December 31 2006 was performed. Patients with incomplete data records were excluded. Patients were stratified according to time delay of surgical treatment and injury complexity. Complications, revision rate, and functional outcome were also investigated. RESULTS: Between January 1 and December 31 2006 a total of 458 patients with open hand injuries were treated at the University Hospital of Berne, Switzerland. The records were retrospectively analyzed and a subgroup of 100 patients were randomly determined for standardized follow-up evaluation. There were no significant differences regarding infection, complication, and revision rate between early (<6 h) and delayed (6-24 h) surgical treatment of open hand injuries. Independently from the time point of surgical treatment, patients with complex injuries and longer operative times had an increased infection rate (p = 0.05) and revision rate (p = 0.003). CONCLUSIONS: Delayed surgical treatment (6-24 h) of open hand injuries did not increase infection or revision rates in open non-devascularizing hand injuries.

The role of androgens on hypoxia-inducible factor (HIF)-1α-induced angiogenesis and on the survival of ischemically challenged skin flaps in a rat model.

BACKGROUND: Effects of androgens on angiogenesis are controversial. Hypoxia-inducible factor (HIF)-1α promotes expression of vascular endothelial growth factor (VEGF) that stimulates angiogenesis. PURPOSE: This study investigates whether androgens stabilize HIF-1α in endothelial cells, and androgen depletion decreases VEGF concentrations and skin flap survival. MATERIALS AND METHODS: Male human umbilical vein endothelial cells (HUVECs) were exposed to dihydrotestosterone (DHT) and HIF-1α expression was measured. In male Wistar rats, standardized proximally based random pattern dorsal skin flaps (3 × 9 cm) were raised 4 weeks after orchiectomy and sham operation, respectively (n = 10, each). Flap VEGF concentrations (immunohistochemistry), perfusion (Laser Doppler), and viability (digital planimetry) were measured. RESULTS: DHT induced HIF-1α expression in HUVECs. Androgen depletion induced decreased VEGF expression (P = 0.003), flap perfusion (P < 0.05), and survival (44.4% ± 5.2%) compared to controls (35.5% ± 4.5%; P = 0.003). CONCLUSION: In vitro, androgens may stimulate HIF-1α under normoxic conditions. In rats, androgen depletion decrease VEGF expression and flap survival.

Transcutaneous sentinel lymph node detection in cutaneous melanoma with indocyanine green and near-infrared fluorescence: A diagnostic sensitivity study.

Sentinel lymph node (SLN) biopsy with preoperative radiocolloid-based lymphoscintigraphy and blue dye injection is considered the standard procedure for staging nodal metastases in early-stage cutaneous melanoma patients with clinically uninvolved lymph nodes. While this combination renders good accuracy in SLN detection, radiation exposure and the frequent allergic reactions to the blue dye are considered drawbacks of this technique. Indocyanine green (ICG) is a water-soluble fluorescent dye that can be identified through near-infrared fluorescence imaging (NIRFI). The aim of this prospective diagnostic sensitivity study was to assess the feasibility of ICG and NIRFI to identify SLNs in melanoma transcutaneously ("before skin incision") and to analyze the various factors influencing detection rate, in comparison to lymphoscintigraphy. This study included 93 patients undergoing SLN biopsy for cutaneous melanoma. The region and the number of the SLNs identified with lymphoscintigraphy and with ICG were recorded. Patients' characteristics, as well as tumor details were also recorded preoperatively. One hundred and ninety-four SLNs were identified through lymphoscintigraphy. The sensitivity of ICG for transcutaneous identification of the location of the SLNs was 96.1% overall, while the sensitivity rate for the number of SLNs was 79.4%. Gender and age did not seem to influence detection rate, but a body mass index >30 kg/m2 was associated with a lower identification rate of the number of SLNs (P = .045). Transcutaneous identification of SLNs through ICG and NIRFI technology is a feasible technique that could potentially replace in selected patients the standard SLN detection methodology in cutaneous melanoma.

Preservation of amputated extremities by extracorporeal blood perfusion; a feasibility study in a porcine model.

BACKGROUND: Successful extremity transplantations and replantations have to be performed within 6 h of amputation to avoid irreversible tissue loss. This study investigates ex vivo the technical feasibility and the limb preservation potential of extracorporeal whole blood perfusion in a porcine model. METHODS: Forelimbs of eight large white pigs were divided into paired groups: I perfusion group, II contralateral cold ischemia controls. In group I axillary arteries and veins were cannulated and perfusion with anticoagulated autologous blood was performed for 12 h; O(2), CO(2), Hb, lactate, potassium, pH, and muscle contractility were monitored. Tissue biopsies were examined by histology and immunofluorescence. Group II was stored at 4°C. RESULTS: Continuous limb perfusion could be performed in all extremities of group I for 12 h. pH was maintained normal and potassium controlled with insulin and glucose. Lactate levels increased initially during perfusion due to the lack of a metabolizing liver. Muscle stimulation was possible throughout the entire perfusion, whereas a complete loss of response was noted in cold ischemia controls. Minor tissue damage was observed histologically and by immunofluorescence in group I, whereas the samples of group II were apparently preserved with the exception of a loss of endothelial heparan sulfate. CONCLUSIONS: The tissue preserving potential and the feasibility of extremity perfusion using common extracorporeal blood circulation techniques was demonstrated in this ex vivo study. The results encourage further investigations in prolonged perfusion followed by limb replantation. This approach harbors promising clinical potential for extremity preservation in extremity transplantation and replantation.

The anatomical reliability of the superficial circumflex iliac artery perforator (SCIP) flap.

INTRODUCTION: 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. MATERIAL AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Prepectoral versus subpectoral implant-based breast reconstruction after skin-sparing mastectomy or nipple-sparing mastectomy (OPBC-02/ PREPEC): a pragmatic, multicentre, randomised, superiority trial.

INTRODUCTION: The emphasis on aesthetic outcomes and quality of life (QoL) has motivated surgeons to develop skin-sparing or nipple-sparing mastectomy (SSM/ NSM) for breast cancer treatment or prevention. During the same operation, a so-called immediate breast reconstruction is performed. The breast can be reconstructed by positioning of a breast implant above (prepectoral) or below (subpectoral) the pectoralis major muscle or by using the patients' own tissue (autologous reconstruction). The optimal positioning of the implant prepectoral or subpectoral is currently not clear. Subpectoral implant-based breast reconstruction (IBBR) is still standard care in many countries, but prepectoral IBBR is increasingly performed. This heterogeneity in breast reconstruction practice is calling for randomised clinical trials (RCTs) to guide treatment decisions. METHODS AND ANALYSIS: International, pragmatic, multicentre, randomised, superiority trial. The primary objective of this trial is to test whether prepectoral IBBR provides better QoL with respect to long-term (24 months) physical well-being (chest) compared with subpectoral IBBR for patients undergoing SSM or NSM for prevention or treatment of breast cancer. Secondary objectives will compare prepectoral versus subpectoral IBBR in terms of safety, QoL and patient satisfaction, aesthetic outcomes and burden on patients. Total number of patients to be included: 372 (186 per arm). ETHICS AND DISSEMINATION: This study will be conducted in compliance with the Declaration of Helsinki. Ethical approval has been obtained for the lead investigator's site by the Ethics Committee 'Ethikkommission Nordwest- und Zentralschweiz' (2020-00256, 26 March 2020). The results of this study will be published in a peer-reviewed medical journal, independent of the results, following the Consolidated Standards of Reporting Trials standards for RCTs and good publication practice. Metadata describing the type, size and content of the datasets will be shared along with the study protocol and case report forms on public repositories adhering to the FAIR (Findability, Accessibility, Interoperability, and Reuse) principles. TRIAL REGISTRATION NUMBER: NCT04293146.

Regional Lymphatic Inclusion in Orthotopic Hindlimb Transplantation: Establishment and Assessment of Feasibility in a Rodent Model.

BACKGROUND: The lymphatic system may play an important role in local immunomodulation in vascularized composite allotransplantation (VCA). Currently, there is no standardized VCA model that includes the regional draining lymphatic tissue. The aim of this study was to develop a rapid and efficient orthotopic hindlimb transplantation model in rats that included the draining lymphatic basin to permit further evaluation of the lymphatic system's role in VCA. METHODS: Thirty transplantations from Brown Norway rats to Lewis rats were performed. To include the regional lymphatic tissue, the superficial epigastric vessels were preserved to allow retrieval of the corresponding inguinal lymph nodes, including the inguinal fat pad, with the hindlimb. A cuff technique was used for the vein, whereas the conventional microsurgical technique was used for the arterial anastomosis. Vascular patency was confirmed through laser Doppler analysis at postoperative day 1 and histological analysis after euthanasia. RESULTS: The presence and vascularization of the inguinal lymph nodes were verified with indocyanine green lymphoscintigraphy at the time of transplantation. Mean total ischemia time was 69 ± 24 minutes, and mean recipient operation time was 80 ± 19 minutes. Overall transplant survival rate was 93.3%. Laser Doppler analysis showed vascular (technical) success, indocyanine green lymphoscintigraphy confirmed the presence of lymph nodes and the histological analysis revealed patent anastomoses. CONCLUSIONS: We successfully developed an experimental orthotopic hindlimb transplantation model in rats that includes the draining inguinal lymphatic basin, which is an important asset in further research on lymphatic tissue and its role in VCA.

The Propeller Flap for Traumatic Distal Lower-Limb Reconstruction: Risk Factors, Pitfalls, and Recommendations.

BACKGROUND: Defects in the distal third of the leg are difficult to cover and often require free tissue transfer, even for defects of limited sizes. Propeller flaps have been designed specifically as an alternative to free tissue transfer but at times have been associated with unacceptably high complication rates. We therefore aimed to prospectively assess our own institutional experience with this technique and to define its role in lower-limb reconstruction. METHODS: All patients who had been managed with reconstruction of the distal part of the leg with a propeller flap between 2014 and 2017 were included in the study. Demographic, clinical, and follow-up data on the patients and surgical procedures were recorded with special focus on the complication profile. RESULTS: Twenty-six patients underwent propeller flap reconstruction of the distal part of the leg: 12 flaps were based on the posterior tibial artery, and 14 were based on the peroneal artery. Postoperative complications developed in association with 1 of the 12 flaps based on the posterior tibial artery, compared with 8 of the 14 flaps based on the peroneal artery (p = 0.015). Moreover, the presence of a higher Charlson comorbidity index (≥2) was strongly associated with the development of postoperative complications (p < 0.001). CONCLUSIONS: Propeller flaps are a reliable option for traumatic reconstruction in carefully selected patients with lower-limb defects. In our experience, the rate of complications was higher for propeller flaps based on the peroneal artery and for patients with a Charlson comorbidity index of ≥2, whereas posterior tibial artery-based propeller flap reconstruction was a reliable surgical option for patients with a small defect in the distal third of the lower limb. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.