Effects of insulin-dependent diabetes mellitus on perforator-based flaps in streptozotocin diabetic rats

The purpose of this study was to investigate the effects of insulin-dependent diabetes mellitus (IDDM) on the viability of perforator-based flaps (pbf) in diabetic rats. Random-pattern flaps were also used as a control flap group. Wistar Albino rats, female, n = 60, were used. The study was done with four groups: Group 1 (diabetic rats, pbf), Group 2 (non-diabetic rats, pbf), Group 3 (diabetic rats, McFarlane flap), and Group 4 (non-diabetic rats, McFarlane flap). Streptozocin (STZ, 55 mg/kg) in a vehicle (sodium citrate, pH 4.5) was injected into the rats intraperitonally to create an IDDM model in the diabetic groups. Only the vehicle without STZ was injected into the rats intraperitonally in the non-diabetic groups. All flaps were elevated 10 weeks after injections. Measurements of the surviving areas of the flaps, and microangiographic and histopathologic studies were done 7 days after flap elevation. Blood glucose levels of the diabetic rats were significantly higher than those of the non-diabetic groups ( p < 0.001). The surviving flap areas were 41 +/- 21 percent in Group 1, 65 +/- 25 percent in Group 2, 49 +/- 10 percent in Group 3, and 66 +/- 10 percent in Group 4. The surviving flap areas of the diabetic groups were significantly less than those of the non-diabetic groups ( p < 0.001). Specific histopathologic changes of IDDM were seen only in the diabetic groups. Microangiographies in the diabetic and non-diabetic groups were very similar. The surviving flap areas of the perforator-based and random-pattern skin flaps in the diabetic rats were decreased by IDDM. If a flap is planned for diabetic wounds, it should be kept in mind that the area of flap necrosis may be larger than those of non-diabetics.