REARTERIALIZATION OF LIVER-TUMORS AFTER VARIOUS DEARTERIALIZATION PROCEDURES

Repeat dearterializations seem to be a means to prevent collateral for mation, which is partly responsible for the failure of hepatic artery ligation (HAL) or permanent dearterialization when used to treat liver tumors. In this study restoration of tumor blood flow was evaluated a fter various procedures: HAL (n = 12), permanent dearterialization (n = 18), repeated dearterializations for 2 hr/day (n = 12), and sham dea rterialization (n = 12). Tumor blood flow was measured 10 days after s ham dearterialization, permanent dearterialization, and repeated deart erializations for 2 hr in order to further illustrate the effect of pr olonged dearterialization on tumor rearterialization. Hepatic and tumo r arterial blood flow was measured using the reference organ method (N EN, Ce-141 microspheres with diameter 15 mu m). Our results showed tha t during a transient dearterialization blood flow decreased to 1% (0.0 1 +/- 0.01 ml/min/g) of the flow in the controls (0.82 +/- 0.10 ml/min /g) (P < 0.01). After HAL tumor blood flow recovered to initial levels after 48 hr (0.73 +/- 0.17 ml/min/g. Even in rats subjected to a perm anent dearterialization blood flow was reestablished at Day 6 (0.59 +/ - 0.21 ml/min/g). In contrast, after repeat daily 2-hr dearterializati ons blood flow remained significantly very low during the 6th transien t dearterialization (0.11 +/- 0.03 ml/min/g) compared with both sham-o peration and HAL as well as permanent dearterialization (P < 0.01). Du ring the 10th daily dearterialization tumor blood flow was still signi ficantly low compared with both controls (P < 0.001) and permanent dea rterialization (P < 0.05). Our results indicate that both HAL and perm anent dearterialization are inefficient to prevent rearterialization o f tumor, although permanent dearterialization may keep blood flow redu ced for a few days. However, repeat dearterializations significantly d elay tumor growth and prevent tumor rearterialization for a prolonged period. (C) 1994 Academic Press, Inc.