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

To clarify differences in the vasculature of benign and malignant colorecta l tumors, we compared blood flow (which has been examined in previous studi es) as well as blood volume and blood velocity in two types of human colore ctal tumors. We measured blood flow and blood volume with an endoscopic las er-Doppler flowmeter in the lesions and the normal mucosa near the lesions of 79 tubular adenomas with mild dysplasia and 38 adenocarcinomas. Blood ve locity 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 compare d. 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 volu me was 1.10 +/- 0.14 and 0.90 +/-: 0.13, respectively (P < 0.001). The rela tive blood velocity was approximately 1.7 in both groups (NS). This study d emonstrated that the superficial blood flow in adenocarcinomas is increased due to increased blood velocity, despite blood volume being decreased.