Inhibition of Myointimal Proliferation by Octreotide in Canine Vein Interposition Grafts

Purpose: The aim of this study was to evaluate the efficacy of octreotide in modulating the progression of intimal hyperplasia in autogenous vein bypass grafts in a canine model. The effect of the drug on the progression of intimal hyperplasia was measured with the Gilman parameter, a measure used extensively as a wound-healing descriptor. Methods: 12 mongrel dogs were randomly and equally divided into two groups. The first group (octreotide group) was administered octreotide 20 µg/kg/day. The control group (group II) received saline solution by subcutaneous injection. Each dog had 8- to 10-cm segments of autogenous jugular vein bypassed to the femoral arteries. Quantitative data on luminel narrowing over time from intimal hyperplasia were compared from calculated Gilman parameters after image analysis of retrieved, histologically processed graft sections. Each vein graft was analyzed by computerized morphometric analysis. Results: The mean Gilman parameter for distal graft segments was 0.47 ± 0.17 mm in the control group and 0.25 ± 0.07 mm in the octreotide group 6 weeks after operation (p < 0.05). Distal graft segments between the control and octreotide groups were statistically significant. In proximal, medial and distal graft segments, the mean Gilman parameters were 0.51 ± 0.16 mm in the control group and 0.37 ± 0.18 mm in the octreotide group, the difference being statistically significant (p < 0.01). Conclusion: Octreotide significantly inhibits myointimal thickening, and these data support the efficacy of octreotide in reducing intimal hyperplasia in arterialized vein grafts during the short postoperative period. Further investigations are required to as certain whether this beneficial effect of octretide persists in the long term.