INFLUENCE OF DEARTERIALIZATION ON DISTRIBUTION OF ABSOLUTE TUMOR BLOOD-FLOW BETWEEN HEPATIC-ARTERY AND PORTAL-VEIN

Background. Conflicting results have been obtained regarding blood dow distribution to liver tumors. The emphasis on portal vein perfusion h as had a great impact on the design of treatment protocols. Methods. D ouble microsphere technique with reference organ sampling was used for the measurement of hepatic artery and portal vein blood flow of an im planted liver tumor in 42 rats after permanent dearterialization and r epeated dearterialization (2 hours/day) compared with untreated sham-o perated controls. Results. Portal veinous blood flow constituted 16% o f total tumor blood flow and slightly increased after permanent and re peat dearterializations, though the elevation was not statistically si gnificant as compared with sham-treatment (P > 0.05). In another 3 gro ups, the treatment was extended to 10 days, and tumor blood flow was m easured in central and peripheral parts separately. Arterial blood flo w further decreased in tumor periphery and was still lower in the tumo r center (P < 0.01 versus tumor periphery), and portal blood flow decl ined concomitantly to 4% of total tumor blood perfusion. However, no d ifference in portal blood flow between the tumor center and periphery could be demonstrated (P > 0.05). Furthermore, portal supply increased neither in tumor periphery nor in tumor center after both permanent a nd repeated dearterialization (P > 0.05). Conclusion. The authors' res ults showed that portal blood flow did contribute to tumor circulation , but made up only 16% of blood flow when tumors were small and declin ed to 4% of entire tumor blood supply when tumors became large. Portal perfusion also declined as tumors grew larger and did not compensate for the withdrawal of tumor arterial blood supply after dearterializat ion.