Gelatin sheet incorporating basic fibroblast growth factor enhances healing of devascularized sternum in diabetic rats

Background-Poor healing of the sternum often limits the use of bilateral in ternal thoracic arteries (BITAs) after coronary bypass surgery in diabetic patients. We have reported that a gelatin sheet that incorporates basic fib roblast growth factor (bFGF) accelerates sternal healing after BITA removal in normal rats. This study evaluated the effects of the above method for s ternal healing in diabetic animals. Methods and Results-Diabetic Wistar rats with blood glucose levels > 400 mg /dL and body-weight loss > 20 g were established by a single intravenous in jection of streptozotocin (55 mg/kg). After median sternotomy and BITA remo val, 16 diabetic rats received either a gelatin sheet that incorporated bFG F (100 mug/sheet) on the posterior table of the sternum (FGF group. n=9) or no gelatin sheet (control, n=7). Peristernal blood flow, as measured by a noncontact laser Doppler 4 weeks after surgery in the FGF group, recovered to the preoperative level (106 +/- 10% versus 82 +/-9%, P <0.01), and marke d angiogenesis was also observed around the sternum in the FGF group (30.5 +/-3.2 versus 15.8 +/-2.7 vessels/unit area, P <0.01). Deep sternal wound c omplications developed in 5 control rats but only in I rat in the FGF group (P <0.05). In the FGF group, histological examination showed improved ster nal healing (excellent in 6 rats and slow/poor healing in 3). Bone mineral content as assessed by dual-energy x-ray absorptometry was greater in the F GF group (75.9 +/- 18.1 versus 48.9 +/- 10.7 mg, P <0.05). Bone mineral den sity of the sternum was similar between the 2 groups. Conclusions-A gelatin sheet that incorporates bFGF may offset sternal ische mia and accelerate sternal bone regeneration and healing, even in diabetic patients.