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Watford, United Kingdom

Chadha P.,SHO | Hachach-Haram N.,The Royal Free Hospital | Shurey S.,NPIMR | Mohanna P.-N.,SHO
Journal of Reconstructive Microsurgery | Year: 2016

Background Many factors are known to influence the performance of surgeons within the operating theater, including tiredness, previous experience, and stress levels. The effects of mental rehearsal and cognitive visualization on microsurgical skills have not been assessed. Methods Thirty-six subjects recruited from the Northwick Park Microsurgery Skills Course were randomized into three groups; (1) a control group (C) with no mental rehearsal script, (2) a visual anastomosis group (VA), with a detailed rat anastomosis script, and (3) a visual relaxation (VR) group with a relaxation script, unrelated to the anastomosis. Participants ran through relevant scripts from day 2 to 5 and were assessed through recorded arterial rat anastomosis, scored using the structured assessment of microsurgery skills. Results Results were analyzed by double-blinded assessors. No statistical significance was found on Monday and Tuesday (first day post intervention), p = 0.326 (VA vs. C) and p = 0.283 (VR vs. C). A statistically significant difference was noted at the end of day 4; p < 0.001 (VA vs. VR) and p = 0.001 (VA vs. C). Further analysis demonstrated that domains within the global rating scoring system showed statistical significance for (1) dexterity: VA versus VR, p = 0.001, (2) visuospatial skills: VA versus VR, p = 0.001, and VA versus C, p = 0.002, and (3) operative flow: VA versus VR, p = 0.044, and VA versus C, p = 0.026. Conclusion The benefits of cognitive visualization and mental rehearsal in microsurgery may result in fewer complications from errors and thus lead to enhanced patient safety and better operative outcomes. Copyright © 2016, Thieme Medical Publishers. All rights reserved.

Nowocin A.K.,NPIMR | Southgate A.,NPIMR | Shurey S.,NPIMR | Sibbons P.,NPIMR | And 3 more authors.
Journal of Tissue Engineering and Regenerative Medicine | Year: 2016

Biologically derived scaffolds are becoming viable treatment options for tissue/organ repair and regeneration. A continuing hurdle is the need for a functional blood supply to and from the implanted scaffold. We have addressed this problem by constructing an acellular ileal scaffold with an attached vascular network suitable for implantation and immediate reperfusion with the host's blood. Using a vascular perfusion approach, a segment of porcine ileum up to 30cm long, together with its attached vasculature, was decellularized as a single entity. The quality of the decellularized scaffold was assessed histologically and using molecular tools. To establish vascular perfusion potentials of the scaffold, a right-sided nephrectomy and end-to-end anastomosis of the decellularized scaffold's vasculature to a renal artery and vein were performed in a pig of similar size to the donor animal. Lengths of ileal scaffold, together with its attached vasculature, were successfully decellularized, with no evidence of intact cells/nuclear material or collagen degradation. The scaffold's decellularized vascular network demonstrated optimum perfusion at 1, 2 and 24h post-implantation and the mesenteric arcade remained patent throughout the assessment. The 1, 2 and 24h explanted scaffolds demonstrated signs of cellular attachment, with cells positive for CD68 and CD133 on the vascular luminal aspect. It is possible to decellularize clinically relevant lengths of small intestine, together with the associated vasculature, as a single segment. The functional vascular network may represent a route for recellularization for future regeneration of bowel tissue for patients with short bowel syndrome. © 2016 John Wiley & Sons, Ltd.

Gerhardt L.-C.,Imperial College London | Widdows K.L.,NPIMR | Erol M.M.,Technical University of Istanbul | Nandakumar A.,Xeltis B.V. | And 4 more authors.
Journal of Biomedical Materials Research - Part A | Year: 2013

In this study, the in vivo recellularization and neovascularization of nanosized bioactive glass (n-BG)-coated decellu-larized trabecular bone scaffolds were studied in a rat model and quantified using stereological analyses. Based on the highest amount of vascular endothelial growth factor (VEGF) secreted by human fibroblasts grown on n-BG coatings (0-1.245 mg/cm 2), decellularized trabecular bone samples (porosity: 43-81%) were coated with n-BG particles. Grown on n-BG particles at a coating density of 0.263 mg/cm2, human fibroblasts produced 4.3 times more VEGF than on uncoated controls. After 8 weeks of implantation in Sprague-Dawley rats, both uncoated and n-BG-coated samples were well infiltrated with newly formed tissue (47-48%) and blood vessels (3-4%). No significant differences were found in cellularization and vascularization between uncoated bone scaffolds and n-BG-coated scaffolds. This finding indicates that the decellularized bone itself may exhibit growth-promoting properties induced by the highly interconnected pore microarchitecture and/or proteins left behind on decellularized scaffolds. Even if we did not find proangiogenic effects in n-BG-coated bone scaffolds, a bioactive coating is considered to be beneficial to impart osteoinductive and osteoconductive properties to decellularized bone. n-BG-coated bone grafts have thus high clinical potential for the regeneration of complex tissue defects given their ability for recellularization and neovascularization. © 2012 Wiley Periodicals, Inc.

Nowocin A.K.,NPIMR | Southgate A.,NPIMR | Gabe S.M.,St. Marks Hospital | Ansari T.,NPIMR
Journal of Tissue Engineering and Regenerative Medicine | Year: 2016

The aim of this study was to decellularize a 30cm long segment of porcine small intestine, determine its in vivo behaviour and assess the type of immunological reaction it induces in a quantitative manner. A segment of porcine ileum up to 30cm long, together with its attached vasculature, was decellularized via its mesenteric arcade as a single entity. The quality of the acellular scaffold was assessed histologically and using molecular tools. The host response to the scaffold was evaluated in a rodent model. Stereological techniques were incorporated into quantitative analysis of the phenotype of the macrophages infiltrating the scaffold in vivo. Lengths of ileal scaffold, together with its attached vasculature, were successfully decellularized, with no evidence of intact cells and DNA or collagen and GAGs overdegradation. Analysis of explants harvested over 2months postimplantation revealed full-thickness recellularization and no signs of foreign body or immune reactions. Macrophage profiling proved that between weeks 4 and 8 in vivo there was a switch from an M1 (pro-inflammatory) to an M2 (pro-remodelling) type of response. We show here that the decellularization process results in a biocompatible and non-toxic matrix that upon implantation triggers cellular infiltration and angiogenesis, primarily characterized by a pro-remodelling type of mononuclear response, without inducing foreign body reaction or fibrosis. © 2016 John Wiley & Sons, Ltd.

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