[The effect of basic fibroblast growth factor (bFGF) on early bronchial revascularization].

We examined local effects of basic fibroblast growth factor (bFGF) on early bronchial revascularization following bronchial anastomosis. The left main bronchi of mongrel dogs (8-15 kg) were cut and sutured following peripheral radical hilar stripping. The anastomotic sites were wrapped with a pericardial fat tissue pedicle, including branches of the internal thoracic artery and vein (8 dogs group A). One ml of bFGF (Biomedical Tecnologies Inc.) dissolved in 1 ml of fibrin glue (final concentration of 20 ng/ml for a total dose of 100 ng, pH 7.15-7.5) was applied to the anastomotic sites in order to deliver the bFGF gradually and selectively (12 dogs group B). At various timepoints, changes in bronchial mucosal blood flow were measured using a laser Doppler flowmeter and left internal thoracic artery (LITA) blood flow, using an implanted electromagnetic flowmeter. On the 7th postoperative day, silicone rubber was injected into the left subclavian artery, and the revascularization pattern from branches of the LITA to the bronchus was examined histologically. Specimens were labeled as (-) when the neogenic vessels were only observed outside the bronchial wall, (1+) when observed inside the bronchial wall but not in the mucosa, and (2+) when clearly observed in the mucosa. Blood flow in the bronchial mucosa was measured as the left/right ratio. For group A, the averages immediately after operation, and on the 3rd and on the 7th postoperative days, were 0.35 +/- 0.10, 0.46 +/- 0.04, and 0.70 +/- 0.14 respectively; while, for group B, they were 0.27 +/- 0.09, 0.78 +/- 0.15, and 0.90 +/- 0.15, respectively (p < 0.01). Our results show that blood flow in the LITA increased more in group B than in group A (average 2.7 +/- 1.8 ml/min in group A, vs. 4.7 +/- 2.9 ml/min in group B). Furthermore, the pathologic findings of neovascularization were (-) in 3 cases and (1+) in 2 cases in group A, while group B showed (1+) neovascularization in 1 case and (2+) in 4 cases. These results clearly demonstrate increased revascularization in the bFGF treatment group B. We conclude that local application of bFGF is effective in stimulating early bronchial revascularization.