In a recently described model for tissue engineering, an arteriovenous loop comprising the femoral artery and vein with interposed vein graft is fabricated in the groin of an adult male rat, placed inside a polycarbonate chamber, and incubated subcutaneously. New vascularized granulation tissue will generate on this loop for up to 12 weeks. In the study described in this paper three different extracellular matrices were investigated for their ability to accelerate the amount of tissue generated compared with a no‐matrix control. Poly‐d,l‐lactic‐co‐glycolic acid (PLGA) produced the maximal weight of new tissue and vascularization and this peaked at two weeks, but regressed by four weeks. Matrigel was next best. It peaked at four weeks but by eight weeks it also had regressed. Fibrin (20 and 80 mg/ml), by contrast, did not integrate with the generating vascularized tissue and produced less weight and volume of tissue than controls without matrix. The limiting factors to growth appear to be the chamber size and the capacity of the neotissue to integrate with the matrix. Once the sides of the chamber are reached or tissue fails to integrate, encapsulation and regression follow. The intrinsic position of the blood supply within the neotissue has many advantages for tissue and organ engineering, such as ability to seed the construct with stem cells and microsurgically transfer new tissue to another site within the individual. In conclusion, this study has found that PLGA and Matrigel are the best matrices for the rapid growth of new vascularized tissue suitable for replantation or transplantation.

The technology required for creating an in vivo microenvironment and a neovasculature that can grow with and service new tissue is lacking, precluding the possibility of engineering complex three-dimensional organs. We have shown that when an arterio-venous (AV) loop is constructed in vivo in the rat groin, and placed inside a semisealed chamber, an extensive functional vasculature is generated. To test whether this unusually angiogenic environment supports the survival and growth of implanted tissue or cells, we inserted various preparations of rat and human skeletal muscle. We show that after 6 weeks incubation of muscle tissue, the chamber filled with predominantly well-vascularized recipient-derived adipose tissue, but some new donor-derived skeletal muscle and connective tissue were also evident. When primary cultured myoblasts were inserted into the chamber with the AV loop, they converted to mature striated muscle fibers. Furthermore, we identify novel adipogenesis-inducing properties of skeletal muscle. This represents the first report of a specific three-dimensional tissue grown on its own vascular supply.

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We recommend this technique of primary closure of the RFFF donor site: it is well tolerated by the patient, with good cosmesis and is associated with no discernable functional morbidity.

This study was conducted to evaluate quality of life in a cohort of patients with squamous cell carcinoma of the tongue base, treated with primary surgery, reconstruction and postoperative radiotherapy. Twelve patients were assessed in a cross-sectional study using the University of Washington Quality of Life Instrument (UW-QOL). All patients underwent external beam irradiation following primary resection of their tumour and reconstruction. Patients on average reported their overall and health related QOL to be good. Functionally they had good pain control, speech intelligibility, activity and recreational levels. There were some limitations in chewing, swallowing and taste. The results suggest that surgical resection can offer good functional and overall QOL results for advanced tumours when combined with reconstruction. The morbidity associated with postoperative radiotherapy includes reduced swallowing, taste, saliva production and difficulty chewing.

BackgroundThere is a lack of consensus regarding optimal surgical excision margins for primary cutaneous melanoma > 1 mm in Breslow thickness (BT). A narrower surgical margin is expected to be associated with lower morbidity, improved quality of life (QoL), and reduced cost. We report the results of a pilot international study (MelMarT) comparing a 1 versus 2-cm surgical margin for patients with primary melanoma > 1 mm in BT.MethodsThis phase III, multicentre trial [NCT02385214] administered by the Australia & New Zealand Medical Trials Group (ANZMTG 03.12) randomised patients with a primary cutaneous melanoma > 1 mm in BT to a 1 versus 2-cm wide excision margin to be performed with sentinel lymph node biopsy. Surgical closure technique was at the discretion of the treating surgeon. Patients’ QoL was measured (FACT-M questionnaire) at baseline, 3, 6, and 12 months after randomisation.ResultsBetween January 2015 and June 2016, 400 patients were randomised from 17 centres in 5 countries. A total of 377 patients were available for analysis. Primary melanomas were located on the trunk (56.9%), extremities (35.6%), and head and neck (7.4%). More patients in the 2-cm margin group required reconstruction (34.9 vs. 13.6%; p < 0.0001). There was an increased wound necrosis rate in the 2-cm arm (0.5 vs. 3.6%; p = 0.036). After 12 months’ follow-up, no differences were noted in QoL between groups.DiscussionThis pilot study demonstrates the feasibility of a large international RCT to provide a definitive answer to the optimal excision margin for patients with intermediate- to high-risk primary cutaneous melanoma.