Microsurgery
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We investigated the feasibility in rats of enhancing skin-flap prefabrication with subdermal injections of adenovirus-encoding vascular endothelial growth factor (Ad-VEGF). The left saphenous vascular pedicle was used as a source for vascular induction. A peninsular abdominal flap (8 x 8 cm) was elevated as distally based, keeping the epigastric vessels intact on both sides. ⋯ Microangiographic studies showed increased vascularity around the implanted pedicle, which was similar in all groups. However, vascularization was distributed in a larger area in the prefabricated flaps treated with Ad-VEGF. In this study, the authors demonstrated that adenovirus-mediated VEGF gene therapy increased the survival of prefabricated flaps, suggesting that it may allow prefabrication of larger flaps and have the potential to reduce the time required for flap maturation.
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Mechanical couplers are successfully used for microvascular venous anastomoses. The advantages include a simple and fast technique and a high patency rate. Couplers offer a secluded coaptation site, and might also be of use in peripheral nerve repair. ⋯ However, this did not impair axonal regeneration. Importantly, axonal outgrowth from the repair site to the surrounding tissue was not observed after coupler coaptation, but it was observed after suture repair. These results suggest that couplers may be of value for repair of nerves in adjacency to avoid axonal crisscrossing between nerves during regeneration.
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Comparative Study
Longitudinal intrafascicular electrodes in collection and analysis of sensory signals of the peripheral nerve in a feline model.
The purpose of this study was to evaluate the value of utilizing longitudinal intrafascicular electrodes (LIFEs) in collecting and analyzing sensory signals from the peripheral nerve. The longitudinal intrafascicular electrodes were made of 25-microm Teflon-insulated Pt/Ir wire and implanted into the fascicle of the superficial peroneal nerves in a feline model. The sensory signals at rest status and induced with various stimulations were recorded. ⋯ The functional spectrum analysis showed that the frequency of action potential increased when the stress stimulation was applied. In conclusion, LIFEs can sensitively collect sensory signals and provide a good interface to analyze sensory information from peripheral fasciculi. These data provide useful information for further study of control of electronic prostheses.
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Comparative Study
Modified distally based sural neuro-veno-fasciocutaneous flap: anatomical study and clinical applications.
The distally based sural neuro-veno-fasciocutaneous flap has been used widely for reconstruction of foot and ankle soft-tissue defects. The distal pivot point of the flap is designed at the lowest septocutaneous perforator from the peroneal artery of the posterolateral septum, which is, on average, 5 cm (4-7 cm) above the lateral malleolus. A longer neuro-veno-adipofascial pedicle would be needed to reversely reach the distal foot defect when the flap is dissected based on this perforating branch, which may result in more trauma in flap elevation and morbidity of the donor site. ⋯ Neither arterial ischemia nor venous congestion was noted. In conclusion, the vascular pivot point of a distally based sural flap can be safely designed at 1.5 cm proximal to the tip of the lateral malleolus. This modified flap provides a valuable tool for repair of foot and ankle soft-tissue defects.
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As microsurgery advances, microsurgical free-tissue transfers have become the reconstructive method of choice over staged or primary amputation, and enabling independent ambulation in difficult lower-extremity wounds. In this report, we present our experiences with free-tissue transfer for the reconstruction of soft-tissue defects in 13 diabetic foot ulcers. Following radical debridement, soft-tissue reconstruction was achieved in the following ways: anterolateral thigh fasciocutaneous flap in 5 patients, radial forearm fasciocutaneous flap in 3 patients, lateral arm fasciocutaneous flap in 1 patient, gracilis musculocutaneous flap in 1 patient, tensor fascia latae flap in 1 patient, deep inferior epigastric perforator flap in 1 patient, and a parascapular flap in the remaining patient. ⋯ During the follow-up period of 8 months to 2 years, no ulcer recurrence was noted, and no revascularization or vascular bypass surgery was needed before or after the free-tissue transfers. The authors conclude that free-tissue transfer for diabetic foot ulcers is a reliable procedure, despite pessimistic opinions regarding the flap survival and low limb salvage rates. It should be considered a useful reconstructive option for serious defects in well-selected cases.