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Biomedical subjects

M O Yenidunya

Publications and source records attributed to M O Yenidunya.

14 recordsLinked to original sources
PubMed1999

Experimental vascular graft using small-caliber fascia-wrapped fibrocollagenous tube: short-term evaluation.

This study was undertaken to evaluate the application of autogenous fascia as a framework for a fibrocollagen tube for small-caliber vascular prostheses in Japanese white rabbits (n = 15). The fascia, measuring 10 x 40 mm, was harvested from the dorsal fascia and was carefully wrapped around a silicone rod of 1.5 mm in diameter. Then, the fascia-wrapped silicone rod was implanted into a subcutaneous pocket on the medial thigh. Four weeks later, the fascia-wrapped silicone rod was removed from the subcutaneous pocket. The rod was removed from the material, and the fascia-wrapped fibrocollagen tube was treated to make it antithrombogenic. Subsequently, the 1.5 x 10-mm fascia-wrapped tube was prepared as an arterial conduit. Using microvascular techniques, the tube was interposed into the divided femoral artery. Eleven of 15 grafts maintained patency over the follow-up period and no aneurysmal formation was found at any graft site. Microscopically, there was an ingrowth of endothelium with fibroblast proliferation from each end of the recipient vessel at 2 weeks after interposition; however, no neointima was found to line the center of the conduit. At 5 weeks after interposition, the neointimal growth rate was 70 percent. There was an ingrowth of endothelium with fibroblast proliferation from each end onto the entire internal surface of the conduit at 8 weeks after interposition. Further study is required before any long-term conclusions can be drawn.

Animals↗
PubMed1999

Arteriovenous fistula and skin flaps.

An experimental study was done in a rat groin flap model to assess the possible effects of arteriovenous fistulas (AVF) on the viability of skin flaps. The animals were randomly divided into three groups. In Group 1, an island flap, and in Groups 2 and 3, peninsular flaps, including the superficial epigastric artery and vein, were elevated. In Group 2, the base of the peninsula was on the rectus side of the flap; in Group 3, the base of the peninsula was located on the lower extremity side. After elevation of the flap and following arteriovenotomy, an A-V fistula was produced by side-to-side anastomosis proximal to the pedicle at the level of the common femoral vessels. Then the flaps were sutured back into their beds. All the island groin flaps with the AVF failed to survive. In Group 3, there was a severe reduction of blood flow in the flap and no flaps survived; however, all the flaps in Group 2 survived totally with no problem. It was concluded that island skin flap circulation is negatively affected by an AVF proximal to the flap pedicle. If the flap and AVF are treated as in Group 2, then flap necrosis caused by reduced blood flow can be overcome in this model.

Anastomosis, Surgical↗
PubMed1998

Microsurgical training with beads.

To assist beginners in the microsurgical practices of handling instruments and tying knots before using an animal model, the authors suggest the use of colored beads. These beads will diminish eyestrain and secondary fatigue. Also, working with colored beads might be a little more amusing and enjoyable for beginners in learning microsurgical techniques during preliminary studies to achieve the necessary orientation for working under the operating microscope.

Microsurgery↗
PubMed1998

An axial-pattern skin flap in the rat.

An axial-pattern rat skin flap based on the caudal femoral artery is described with orthotopic and heterotopic island flap transfers. Free-tissue transfers could also be carried out based on the common femoral artery. Since the pedicle is very small, instead of selective dye injection, a nonselective dye injection was utilized, elevating a very large island skin flap based on the caudal femoral artery. This flap model can provide an alternative opportunity to study the physiology of skin flaps and for training in the basic principles of plastic surgery, including microsurgical practice, with a more challenging model.

Anastomosis, Surgical↗
PubMed1998

Prefabricated osteomusculocutaneous flaps using calvarial bone: experimental study.

Prefabricated osteomusculocutaneous flaps using free calvarial bone were examined and evaluated in a rat model. The animals were divided into two groups according to prefabrication time: 14 days in Group 1 (n = 10) and 28 days in Group 2 (n = 10). Nine of 10 preparations demonstrated neovascularization in Group 1, and all flaps showed neovascularization in Group 2. One flap was lost in Group 1 as a result of infection. Each group was evaluated histopathologically before the second stage of the experiment. Muscles without atrophy and osteocytes were noted in Group 1; however, Group 2 animals had both muscle atrophy and nonviable bone. The prefabricated osteomusculocutaneous flaps were then transferred as both island and free flaps. Flap viability was assessed on postoperative day 7 by macroscopic observation. Although all flaps survived in the island-flap group, two flaps failed to survive due to technical error in the free-flap group. Neovascularization was clearly evident by 2 weeks in the osteomusculocutaneous flaps; after 4 weeks, complete atrophy of the muscle meant that the flaps could no longer be characterized as osteomusculocutaneous. Clinically, it might be possible to use the outer table alone, in which case both thin skin and bone would be desirable. This study may provide a model for this approach.

Animals↗