title: Increasing hepatic arterial flow to hypovascular hepatic tumours using degradable starch microspheres.
abstract: The effect of degradable starch microspheres (DSM) on the intrahepatic distribution of a low molecular weight marker, 99Tcm-labelled methylene diphosphonate (MDP), was studied in rats with hypovascular HSN liver tumours. MDP was injected regionally, via the hepatic artery, alone or co-administered with DSM, with or without subsequent occlusion of either the hepatic artery or the portal vein. Tumour vascularity was measured with 57Co-labelled microspheres. Co-injection with DSM immediately significantly increased hepatic retention of marker in both tumour (T) (median 22.40 (range 16.82-39.58)% injected dose) and normal liver (N) (9.08 (4.85-12.59) %ID) the greater effect seen in T (P < 0.01). After DSM degradation, very little MDP remained in N (0.61 (0.28-1.40) %ID) but there was significant retention in T (10.01 (6.73-20.28) %ID, P < 0.01). Clamping the hepatic artery had minimal effect on the retention of MDP when administered alone. Regional injection of 16.5 microM 57Co microspheres resulted in a N:T ratio of 2.25:1. Concomitant injection of the 40 microM DSM was 57Co microspheres reversed this ratio to 1:2. The results indicate that DSM selectively enhances the retention of MDP to a hypovascular hepatic tumour, not by causing intra-tumour stasis, but by directing a greater arterial flow to hypovascular areas in the liver.
authors.affiliation: University Departments of Surgery, Royal Liverpool Hospital, UK.
authors.forename: D
authors.initials: D
authors.lastname: Chang
authors.forename: S A
authors.initials: SA
authors.lastname: Jenkins
authors.forename: S J
authors.initials: SJ
authors.lastname: Grime
authors.forename: D M
authors.initials: DM
authors.lastname: Nott
authors.forename: T
authors.initials: T
authors.lastname: Cooke
mesh_terms: D000818:Animals; D006499:Hepatic Artery / Q000503:physiopathology*; D008102:Liver Circulation / Q000187:drug effects*; D008114:Liver Neoplasms, Experimental / Q000098:blood supply*; D008863:Microspheres; D051381:Rats; D013213:Starch / Q000494:pharmacology*; D013669:Technetium Tc 99m Medronate
chemical_list: D013213:Starch; D013669:Technetium Tc 99m Medronate