• Archives of Reconstructive Microsurgery
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• v.11 no.2
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• pp.125-134
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• 2002

This study was designed to investigate the process of re- or neo-vascularization in the prefabricated cutaneous flap using a skeletonized arteriovenous pedicle implantation. Fourty-eight flaps were divided into six groups of eight flaps, including control group of the conventional epigastric flap. In experimental groups, skin flap was fabricated by subcutaneous implantation of a distally ligated saphenous arteriovenous pedicle in left abdomen. At 2, 4, 6, 8, and 10 weeks after, prefabricated flap was elevated as an island flap based on implanted pedicle and sutured back in place. Three days after flap repositioning, the area of flap viability was quantified, the pattern of flap vascularization was evaluated with microangiography, and the quantification of vessels was assessed histologically. There were statistically significant differences in flap viability between group 2, 3, 4, and the control (p<0.05), with increased survival area in order. But Group 5 and 6 showed higher flap viability as much as the control did. In the microangiographis study, numerous small meander vessels were newly developed in the vicinity of the implanted pedicle just only 2 weeks after pedicle implantation, but neovascularization around the tip of implanted pedicle, and its anastomosis with native vasculatures was more important for overall flap survival, which was usually developed at least 4 weeks after pedicle implantation. Histologically, vessels are evenly spread over all layers of the flap at 6 weeks after pedicle implantation. The quantification of vessels was correlated well with the improvement of flap viability (p<0.05). In conclusion, neo- and re-vascularization around the tip of implanted pedicle was an important factor for overall survival of the prefabricated flap. Therefore, skeletonized pure vascular pedicle transfer, even though it used alone without surrounding was sufficient to get higher flap viability. The optimal duration of pedicle implantation was8 weeks to obtain maximal survival.

• Archives of Plastic Surgery
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• v.32 no.3
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• pp.319-326
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• 2005

This study was designed to investigate the optimal period of pedicles implantation in the prefabricated periosteofascial flap using a vascular tissue transfer. Flap prefabrication was prepared with a transposition of the central pedicles of right auricle on the calvarium of the New Zealand white rabbit. Thirty flaps were divided into five groups of six flaps, including control group (group I) of the conventional periosteofascial flap based on the right lateral border of parietal bone. The prefabricated flap was elevated as a $2{\times}2cm$ sized island flap and reposed in place in 1, 2, 3, and 4 weeks after the pedicles transfer in groups II, III, IV, and V, respectively. Five days after flap repositioning, the flap viability and vascularity were evaluated with microangiography and histological study quantitatively. The flap survival was increased in accordance with the implanted period of the pedicle. New vessels developed around the implanted pedicle in the 2nd week, and overall vascularization of the flap was accomplished in the 3rd week. The flap with 4 weeks of implantation period, however, showed the same survival rate as the control group. In conclusion, prefabricated periosteo- fascial flap can be created with a vascular tissue transfer, and the optimal duration of the pedicle implantation is more than 4 weeks to obtain adequate flap survival.

• Archives of Plastic Surgery
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• v.32 no.3
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• pp.327-334
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• 2005

This study was designed to investigate the effect of the surgical delay in the prefabricated cutaneous flap. Abdominal skin flaps (n=40), $4.5{\times}6.0cm$ in size, were created by the subcutaneous implantation of a saphenous vascular tissue in the male Sprague-Dawley rats. In the groups 1 and 2, the pedicle was skeletonized. In the groups 3 and 4, perivascular muscle cuff or gracilis fascia was retained, respectively. Six weeks later, each flap was elevated as an island flap and reposed in place. All flaps of the group 2 had a 72-hours of delay period. Five days after the flap repositioning, estimation of flap viability, microangiographies, and histological evaluation of vessel development were performed. The groups 2 and 3 showed higher viability in flap survival. The dilated choke vessels and fully developed vascular network were observed in the flap of the group 2, but not typically seen in the other groups. New vessels around the implanted pedicle were more developed in the group 2. Amount of the vessels in the mid-portion of the flap was significantly increased in the groups 2 and 4. In conclusion, the delay procedure enhanced the viability, and its effect was dependent on the new vessel formation around the implanted pedicle.

• Journal of Biomedical Engineering Research
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• v.36 no.6
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• pp.276-282
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• 2015

Recently, during the multi-level fusion with pedicle screws, interspinous spacer are sometimes substituted for the most superior level of the fusion in an attempt to reduce the number of fusion level and likelihood of degeneration process at the adjacent level. In this study, a finite element (FE) study was performed to assess biomechanical efficacies of the interspinous spacer combined with posterior lumbar fusion with a previously-validated 3-dimensional FE model of the intact lumbar spine (L1-S1). The post-operative models were made by modifying the intact model to simulate the implantation of interspinous spacer and pedicle screws at the L3-4 and L4-5. Four different configurations of the post-op model were considered: (1) a normal spinal model; (2) Type 1, one-level fusion using posterior pedicle screws at the L4-5; (3) Type 2, two-level (L3-5) fusion; (4) Type 3, Type 1 plus Coflex$^{TM}$ at the L3-4. hybrid protocol (intact: 10 Nm) with a compressive follower load of 400N were used to flex, extend, axially rotate and laterally bend the FE model. As compared to the intact model, Type 2 showed the greatest increase in Range of motion (ROM) at the adjacent level (L2-3), followed Type 3, and Type 1 depending on the loading type. At L3-4, ROM of Type 2 was reduced by 34~56% regardless of loading mode, as compared to decrease of 55% in Type 3 only in extension. In case of normal bone strength model (Type 3_Normal), PVMS at the process and the pedicle remained less than 20% of their yield strengths regardless of loading, except in extension (about 35%). However, for the osteoporotic model (Type 3_Osteoporotic), it reached up to 56% in extension indicating increased susceptibility to fracture. This study suggested that substitution of the superior level fusion with the interspinous spacer in multi-level fusion may be able to offer similar biomechanical outcome and stability while reducing likelihood of adjacent level degeneration.

• Archives of Reconstructive Microsurgery
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• v.13 no.2
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• pp.93-100
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• 2004

This study was designed to investigate the optimal period of pedicles implantation in the prefabricated periosteofascial flap with a vascular tissue transfer. The flap prefabrication was prepared with a transposition of left occipital pedicles on the calvarial fascia of male Sprague-Dawley rats. Thirty flaps were divided into five groups of six flaps, including control group (group I) of the conventional periosteofascial flap based on the lateral border of the rat calvarium. The prefabricated flap was elevated as an $1{\times}1cm$ sized island flap based on the implanted pedicle at 1, 2, 3, and 4 weeks after the pedicles transfer in groups II, III, IV, and V, respectively. After the completion of creating a critical-sized calvarial defect and implanting with hydroxyapatite granules, the flap was sutured back for covering the defect and kept isolated from surrounding tissues. Six weeks after flap repositioning, the osseous changes of the defect were examined with simple radiographic findings, radiodensitometric analysis, and histological studies. By simple radiographic findings, specimens of the control, groups IV and V showed homogeneous radioopacity within the defect. But in groups II and III, focal radiolucency was observed in the defect. In the radiodensitometric analysis, the control group and the group V showed significant increased radiodensites statistically. Histologically, the implanted hydroxyapatite was absorbed partly in the defect in groups II, III, and IV. In the defects of the control group and the group V, the implanted hydroxyapatite was kept in its volume and the deposition of the bone cells was observed sparsely. In conclusion, the prefabricated periosteofascial flap can be created with a vascular tissue transfer and the pedicles should be implanted at least for 4 weeks to bring out positive osseous changes in the calvarial defect.

• Journal of Veterinary Clinics
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• v.32 no.1
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• pp.108-111
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• 2015

A 7-month-old intact male Maltese dog was presented with a 1.5-month history of glaucoma in the right eye (OD). Ophthalmic examinations revealed a corneal perforation with iris entrapment, corneal edema and neovascularization, and buphthalmos OD. Intraocular pressures were 33 mmHg OD and 19 mmHg in left eye (OS). The right eye was diagnosed with chronic glaucoma and corneal perforation with iris entrapment. Now that the eye was blind, implantation of intraocular silicone prosthesis (ISP) and conjunctival flap were elected to salvage the globe. The corneal perforation healed with the conjunctival pedicle flap and the cornea accommodated the ISP properly. A satisfactory cosmetic result was achieved without complications in the 15 months following the procedure. Therefore, this case report indicates the combined an ISP and a conjunctival flap would be an alternative for the treatment of glaucoma associated with corneal perforation in dogs.

• Archives of Reconstructive Microsurgery
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• v.9 no.2
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• pp.139-146
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• 2000

The aim of this study was to assess whether the functional regeneration of a lyophilized autografted cartilage could be improved by implanting a vascularized muscle flap into the medullary canal of autografted proximal humerus. A hemijoint reconstruction using a lyophilized osteochondral autograft in proximal humerus was done in 4 rabbits for control, and combined with an vascularized intramedullary muscle flap in another 4 rabbits for the experimental group. Graft healing and the repair process of osteochondral graft were followed by serial radiographs and histologic changes for 9 weeks after experiments. Each two rabbits in control and in experimental group on 5th and 9th week after implantation of hemijoint were sacrified. The results were as follows: 1. All of control and experimental froups on 5th week united solidly on osteotomized site radiologically, but their articular cartilages were destroyed more seriously in the control than that in experimental group with muscle flap on 5th and 9th week after experiment... 2. Histochemically, the cartilage surface are completely destroyed and revealed with severe osteoarthritic changes on all cartilage layers in control, but cartilaginous erosions are mild to moderate and their arthritic changes are also mild with somewhat regeneration of chondrocytes on deep layers more prominetly on 9th week of the experimental group. 3. The amount of collagen and protenized matrix which was determined by Masson-Trichrome stain was markedly decreased that means the weakness of bony strength and low osteogenic potential in lyophilized cartilage. These results suggest that an intramedullary vascularized muscle flap can improve the functional results of lyophilized osteochondral autograft by providing both increased vascularity and populations of mesenchymal cells to initiate new bone formation on osteotomized site as well as the regeneration of deep layers in articular cartilage. In clinical relevances, this lyophilized hemijoint autograft combined with an intramedullary vascularized muscle pedicle graft might be used very effectively for the treatment of malignant long bone tumors to preserve the joint functions, all or partly, and so to replace it with the artificial joint after tumor excision and hemijoint autograft.