The definiton of lateral thoracic artery perforator island flap in rat

In reconstructive surgery, flaps which are focus of attention because of their complex structure and an option of complicated wound treatment frequently are performed. The vascular supply to the integument is crucial to the survival of surgical skin flaps. The areas perfused by blood vessels to the skin are termed angiosomes which is defined by Taylor et al and then perforator flap became popular. Arteriolar connections, in the form of choke vessels, exist between angiosomes. Choke vessels normally experience little blood flow, due to the opposing pressures from adjacent vascular networks and the point of equilibrium lying in the choke vessels. When blood flow to a region of skin is disrupted, however, an adjacent cutaneous perfusion territory can expand via choke vessels to compensate for the decreased blood flow. The angiosome concept and choke vessels are used by surgeons in planning flaps. Perforator flaps have been used for last decade so that experimental study of perforator flap are still actual. However, experimental perforator flaps model are limited. In this study, we aimed to describe the experimental extended lateral thoracic artery perforator flap and standardized size of flap, in addition to show different angiosome area and choke vessel zone in lateral thoracic artery perforator flap by angiography and immunohistochemical analysis. The rats were randomly assigned to one of three groups according to the flap design (n=30). Group 1: vertical lateral thoracic artery perforator flap Group 2: horizontal lateral thoracic artery perforator flap Group 3: extended lateral thoracic artery perforator flap. Group 3 is designed according to result of group 1 and group 2. Flap was raised on cranial perforator from dorsal branch of lateral thoracic artery by following criteria of group. In 7. day of postoperative period surface area of flaps were measured and 3 section within 1 cm were taken from flap for histopathological and immunohistochemical analysis. Relationship of flap viability and vascularization area were revealed by angiography. Ratio of flap viability is determined average 95.8% (4.8), flap necrosis is determined average 4.2% (4.8) in group 1; Ratio of flap viability is determined average 89.1% (7.8), flap necrosis is determined average 11.3% (8.0) in group 2; Ratio of flap viability is determined average 92.3% (5.0), flap necrosis is determined average 7.7% (5.0) in group 3. Histopathologic results were obtained in accordance with angiographic finding and topographical analysis. CD 11b, ICAM-1 and VEGFR-2 parameters has been detected that they increased in greater rate in the area which is called 'choke zone'. The subsequent increases are respectively in the form of perforator area and contralateral area in group 1. However, In group 2, the highest increase is observed in 'choke zone', vertical sections and also in perforator region is seen to be increased more than the contralateral region. This result indicates the area which increases necrosis rate in group 2 and 3 in harmony with angiography and the topographic investigations that we use for flap viability assessment. The increase in the 'choke zone' has statistically been shown to be meaningful. The changes in choke vessel which are known to be quite important for flap viability is observed less condense in angiosome area of the opposite back- half compared to the other areas. Of this finding, we believe that there is a reason for over rate of our necrosis. Experimental lateral thoracic artery perforator flap have several major advantages that are quickly and easily dissection of flap, harvesting from dorsal skin of which protection and care are comfortable, a consistent percentage of necrosis, ability to plan in large size. We believe that our new flap model will be helpful and safe for the experimental study of perforator flap and research of microsurgery