Changes in pelvic and systemic platinum concentrations during negative-balance isolated pelvic perfusion: Correlation between platinum concentration and method of administration in a pig model

Purpose: To assess the effect of altering the method of administration during negative-balance isolated pelvic perfusion (NIPP) on the platinum concentration in the pelvic or systemic circulation. Methods: Twenty female pigs were used in this study. The abdominal aorta and the infra-renal vena cava were occluded with two balloon catheters and blood in the extracorporeal circuit was circulated with twin rotary pumps. NIPP was then performed with cisplatin (5 mg/kg) in 15 pigs. Three types of NIPP administration method (group A: 1 bolus, B: 2 same doses boluses, C: 3 same doses boluses) were used, five pigs being subjected to each treatment. The remaining five pigs were administered cisplatin systemically as a control study (group D). The platinum concentrations in the pelvic and systemic circulation were measured and compared. Results: (1) Pelvic circulation: There was a tendency for the platinum concentration to increase as the bolus time decreased. The platinum concentration in groups A and B was significantly (P < 0.05) higher than that in group C. Significant differences (P < 0.05) between groups A and B until 10 min after the start of NIPP. (2) Systemic circulation: Significant differences (P < 0.05) were observed between NIPP groups and D during NIPP. The platinum concentration in group D was five times higher than that in group C. (3) Plasma pelvic to systemic exposure ratio: there were no significant differences among the three NIPP groups. Conclusions: The platinum concentrations in the pelvic and systemic circulation increased as the bolus time decreased. The plasma pelvic to systemic exposure ratio was not influenced by bolus time.