The versatility of the islanded posterior arm flap for regional reconstruction around the axilla.

INTRODUCTION: Defects in the region of the axilla pose a difficult reconstructive problem. Various methods for restoration have been described. We present our experience with the islanded posterior arm flap for regional reconstruction around the axilla. PATIENTS AND METHODS: Between 2008 and 2013, all patients receiving a posterior arm flap for regional reconstruction around the axilla were entered in a prospectively maintained database. Patient data, surgical details, complications and the need for revisional procedures were recorded. RESULTS: In the study period, 35 posterior arm flaps were used in 24 patients (f:m = 11:13; mean age at surgery: 41,3 ± 18,5 years; 11 bilateral procedures) with defects predominately due to hidradenitis suppurativa (n = 31). The remaining indications included tumor resection (n = 2), burn contracture release or thoracic surgery (n = 1 each). The majority of defects were located at the axilla, but also in the proximal upper arm or the adjacent thoracic wall. Major wound complications such as total or partial flap necrosis were not encountered in our series. Minor complications included partial superficial wound dehiscence (n = 4) and superficial wound infection (n = 1), all of which were managed conservatively. In 4 patients a secondary flap trimming procedure was required. CONCLUSION: In our hands, the posterior arm flap is an excellent choice for axillary reconstruction due to its constant anatomy, robust vascularity, unrivaled freedom of flap insetting, excellent recipient site matching and favorable donor site morbidity. Besides axillary defects, the posterior arm flap may additionally be employed for defects of the adjacent thoracic wall or the proximal two thirds of the upper arm.

Optical magnification should be mandatory for microsurgery: scientific basis and clinical data contributing to quality assurance.

BACKGROUND: Microsurgical techniques are considered standard procedures in reconstructive surgery. Although microsurgery by itself is defined as surgery aided by optical magnification, there are no guidelines for determining in which clinical situations a microscope or loupe should be used. Therefore, we conducted standardized experiments to objectively assess the impact of optical magnification in microsurgery. METHODS: Sixteen participants of microsurgical training courses had to complete 2 sets of experiments. Each set had to be performed with an unaided eye, surgical loupes, and a regular operating microscope. The first set of experiments included coaptation of a chicken femoral nerve, and the second set consisted of anastomosing porcine coronary arteries. Evaluation of the sutured nerves and vessels were performed by 2 experienced microsurgeons using an operating microscope. RESULTS: The 16 participants of the study completed all of the experiments. The nerve coaptation and vascular anastomoses exercises showed a direct relationship of error frequency and lower optical magnification, meaning that the highest number of microsurgical errors occurred with the unaided eye. For nerve coaptation, there was a strong relationship (P<0.05) between the number of mistakes and magnification, and this relationship was very strong (P<0.01) for vascular anastomoses. CONCLUSIONS: We were able to prove that microsurgical success is directly related to optical magnification. The human eye's ability to discriminate potentially important anatomical structures is limited, which might be detrimental for clinical results. Although not legally mandatory, surgeries such as reparative surgery after hand trauma should be conducted with magnifying devices for achieving optimal patient outcomes.

Negative regulation of RPE cell attachment by carbohydrate-dependent cell surface binding of galectin-3 and inhibition of the ERK-MAPK pathway.

Adhesion and spreading of retinal pigment epithelial (RPE) cells on fibronectin-rich extracellular matrices is a crucial event in the pathogenesis of proliferative vitreoretinopathy (PVR). In the present study we explored the capacity of galectin-3, a ß-galactoside-binding endogenous lectin, to inhibit early PVR-associated cellular events from a therapeutic perspective. We assessed the relative expression levels of galectin-3 in native RPE and dedifferentiated, cultured RPE. Galectin-3 was constitutively expressed under in vivo and in vitro conditions and was abundant in cultured cells. Treatment of human RPE cells with soluble galectin-3 disclosed no toxicity within control limits up to 250 µg/ml. When added to the medium, galectin-3 dose-dependently inhibited attachment and spreading of the cells on fibronectin by more than 75%. When coated on the plastic surface, galectin-3 alone impaired attachment and spreading of RPE cells, and reduced attachment but not spreading on fibronectin. Galectin-3 bound to the cell surface, and, as determined by the use of the competing sugar ß-lactose, galectin-3-mediated effects were dependent on carbohydrate binding. To ascertain the role of the ability of galectin-3 to form pentamers, we proteolytically removed the N-terminal, cross-linking section. The remaining C-terminal carbohydrate-binding domain alone failed to bind to cells and was functionally inactive. These results emphasize the relevance of both properties, i.e., glycan-binding and cross-linking of glycan moieties, for the inhibitory activity of galectin-3. Incubation of mobilized RPE cells with galectin-3 significantly disturbed microfilament assembly and, in correlation with decreased attachment, inhibited ERK phosphorylation. Therefore, galectin-3, acting as a cross-linking lectin on the cell surface, negatively regulates attachment and spreading of RPE cells in vitro. This effect, at least in part, is attributed to an inhibition of the ERK-MAPK pathway, which prevents cytoskeletal rearrangements needed for RPE cell attachment and spreading. Further investigation at this pathway may disclose a promising nouveau perspective for treatment and prophylaxis of early PVR.

Introducing the concept of the 3Rs into tissue engineering research.

Tissue engineering, defined as using a combination of cultured cells and biodegradable scaffolds to repair tissue damaged by injury or disease, represents a booming sector of biomedical research. Animal experimentation is routinely performed prior to clinical trials. The presented study tries to translate the aspect of the 3Rs to tissue engineering research: Cell culture protocols were adapted to antibiotic free and serum free conditions. Biomaterials (Bio-Gide and a collagen sponge prototype) were pre-tested using the HET-CAM assay. CAM-testing suggested a protocol change for application of the Bio-Gide scaffold and demonstrated unsuitable material properties of the collagen sponge. Application of 3R compliant protocols for tissue engineering research led to increased cell proliferation, higher synthesis of extracellular matrix molecules, reduced dedifferentiation and more information about the biomaterials at an early experimental stage. Tissue engineering research can therefore profit from the increased efforts to validate in vitro alternatives and supplements to animal testing.