Superficial blood flow, blood volume, and blood velocity in colorectal tubular adenomas and adenocarcinomas.

To clarify differences in the vasculature of benign and malignant colorectal tumors, we compared blood flow (which has been examined in previous studies) as well as blood volume and blood velocity in two types of human colorectal tumors. We measured blood flow and blood volume with an endoscopic laser-Doppler flowmeter in the lesions and the normal mucosa near the lesions of 79 tubular adenomas with mild dysplasia and 38 adenocarcinomas. Blood velocity was defined as blood flow per blood volume. The ratio of each value in the lesions to that in the neighboring normal mucosa was defined as the relative value, and the mean relative values in the two groups were compared. The relative blood flow was 1.89 +/- 0.64 in the tubular adenomas and 1.49 +/- 0.66 in the adenocarcinomas (P < 0.005), and the relative blood volume was 1.10 +/- 0.14 and 0.90 +/- 0.13, respectively (P < 0.001). The relative blood velocity was approximately 1.7 in both groups (NS). This study demonstrated that the superficial blood flow in adenocarcinomas is increased due to increased blood velocity, despite blood volume being decreased.