Abstract

Background: The purpose of this study was to investigate the efficacy of cilostazol for prevention of thrombosis in microsurgical anastomosis. We used not only a patency test, but also ultrasonography to evaluate the blood flow volume more accurately and objectivity. In addition, we evaluated the accuracy and sensitivity of the patency test.

Materials and Methods: Thrombogenic anastomoses were performed on rat external iliac arteries. Forty-six rats were randomly allocated into the following 5 experimental groups: negative control, without any surgery and medication; control, received distilled water orally; group A, received aspirin orally; group B, received cilostazol orally; and group C, received aspirin and cilostazol orally 3 hours before a thrombogenic artery anastomosis. The artery was evaluated by flow volume using ultrasonography and a patency test 10, 30, and 120 minutes after clamp removal.

Results: The flow volume in group C was significantly larger than the control group 30 minutes after clamp removal. The flow volumes in groups A, B, and C were significantly larger than the control group 120 minutes after clamp removal. The flow volume decreased in all groups with time. The patency rate between the control group and group C 120 minutes after clamp removal was significantly different. There were eight false negatives in a total of 114 patency tests. The total accuracy and sensitivity of the patency test were 93.0 and 92.7%, respectively.

Conclusions: Cilostazol plus aspirin therapy is recommended for reducing thrombosis and increasing flow volume without increasing the risk of bleeding during microsurgery. The patency test cannot evaluate the state of the anastomotic vessels accurately and objectively.

Figure 1. (Above, left) Ultrasonographic view of a thrombotic anastomosis model. The arrow indicates an intraluminally inverted portion of the arterial wall. (Above, right) Measurement of the arterial diameter on a magnified B-mode image. (Below, left) A color Doppler image confirms the arterial flow. (Below, right) Automatic measurement of the time-averaged mean velocity (TAMV). The value of TAMV is 12.2 cm/s.

Figure 2. Flow volumes assessed for each group 10, 30, and 120 minutes after clamp removal. The statistical significance of the flow volumes among groups was evaluated by one-way ANOVA, followed by the Duncan test. *, The flow volumes were significantly different with groups; A<B<C, results of the Duncan test; NC, negative control group; Control, control group.