HEPATIC ARTERIAL HEMODYNAMICS CHANGES FOLLOWING INTRAARTERIAL ANGIOTENSIN-II INFUSION - DUPLEX COLOR DOPPLER SONOGRAPHY

Previous studies have shown that the delivery of cytotoxic microsphere s to liver tumours may be improved by manipulating the tumour to norma l liver blood flow ratio using angiotensin II (AT-II). The optimizatio n of this targeting requires the assessment of the temporal blood flow changes induced by agents such as AT-II. Duplex/colour Doppler sonogr aphy (DCDS) was evaluated as a means of studying the effects of AT-II infusion on hepatic arterial blood flow (HABF) and arterial resistance in patients with colorectal liver metastases. HABF was measured conti nuously in six patients with colorectal liver metastases using DCDS be fore, during and after an infusion of AT-II (15 mug in 3 ml of saline over 90 s) via a hepatic artery catheter. The baseline level of HABF w as 320 +/- 87 ml/min (mean +/- S.D.), and this was reduced by 70-76% w ithin 30 s of the start of AT-11 infusion. HABF recovered rapidly from the end of the infusion, and increased by up to 20% above the baselin e for approximately 2 min. Arterial resistance showed reciprocal chang es in all cases. These changes were both quantitatively and qualitativ ely similar to intra-operative measurements previously performed in th e same patients using a standard intra-operative flowmeter. The degree of concordance obtained from the intra- and post-operative measuremen ts confirms the effectiveness of DCDS in assessing the temporal change s in hepatic arterial blood flow caused by AT-II. Prior to the start o f therapy, the evaluation of vasoconstrictor agents should be carried out in individual patients to predict response, in order to establish the optimal phase for the injection of cytotoxic microspheres.