True versus mild hyperthermia during isolated hepatic perfusion: effects on melphalan pharmacokinetics and liver function

Retrograde-outflow percutaneous isolated hepatic perfusion using cisplatin: A pilot study on pharmacokinetics and feasibility

OBJECTIVES

This study aimed to evaluate the feasibility and underlying pharmacokinetics of the retrograde-outflow technique for percutaneous isolated hepatic perfusion (PIHP).

METHODS

Retrograde-outflow PIHP was performed in 12 male pigs (weight, 37-44 kg) by redirecting hepatic outflow through the portal vein. Blood with cisplatin (2.5 mg/kg) in an extracorporeal circuit was circulated through the liver under isolation using rotary pumps with balloon catheters. Hepatic angiographic examinations were conducted during perfusion, and histopathological examinations of the organs were conducted after perfusion. The maximum platinum concentration (C max), area under the concentration-time curve (AUC), and chronologic laboratory data were measured.

RESULTS

Retrograde-outflow isolated hepatic angiography confirmed that contrast media flowed into the portal veins in all 12 pigs. The hepatic veins and inferior vena cava were not opacified. Hepatic C max (86.3 mg/l) was 39-fold greater than systemic C max (2.2 mg/l), and hepatic AUC (1330.8 min · mg/l) was 30-fold greater than systemic AUC (44.6 min · mg/l). Histopathological examinations revealed no ischaemic changes or other abnormalities in the liver, duodenum, small intestine, or colon. Within 1 week of the procedure, chronologic laboratory data (n = 3) normalized or returned to pre-therapy levels.

CONCLUSIONS

The retrograde-outflow technique appears to enable safe and feasible PIHP therapy.

KEY POINTS

• The portal vein acted as an outflow tract under retrograde-outflow PIHP. • Plasma hepatic-to-systemic exposure ratio was 39.2 for the maximum platinum concentration. • Plasma hepatic-to-systemic exposure ratio was 29.8 for the AUC. • The retrograde-outflow technique appears to enable safe and feasible PIHP.

Drug selection in isolated hepatic perfusion for nonresectable liver tumors: recent trends and perspectives

Isolated hepatic perfusion (IHP) involves a method of complete vascular isolation of the liver to take the advantage of directed intensive chemotherapy that has minimal systemic toxicity. Recent clinical studies mainly employed melphalan with or without tumor necrosis factor alpha (TNF-α), or with hyperthermia in IHP. The results of these studies showed that higher response rates and survival rates could be achieved by IHP than by traditional therapeutics for non-resectable liver tumors. In this article, we discussed the current status, recent developments and future perspectives of drug selection in IHP.

Correlation between melphalan pharmacokinetics and hepatic toxicity following hyperthermic isolated liver perfusion for unresectable metastatic disease

BACKGROUND

In the present work, we report on the results of our pilot study of hyperthermic isolated hepatic perfusion (IHP) with melphalan alone for patients with unresectable metastatic liver tumors refractory to conventional treatments, with particular regard to the correlation between pharmacokinetic findings and hepatic toxicity.

PATIENTS AND METHODS

Inclusion criteria were unresectable liver metastases, hepatic parenchyma replacement <or=50%, normal liver function, and previous failure of at least one conventional treatment. IHP was performed under hyperthermic conditions with melphalan (1.5 mg/kg body weight). Completeness of vascular isolation of the liver and drug distribution volumes of the perfusion circuit were assessed by a radiolabeled albumin-based method. Drug concentrations in perfusate and plasma were measured by means of high-performance liquid chromatography (HPLC).

RESULTS

Twenty patients with unresectable liver metastases underwent IHP. No intraoperative mortality occurred. Treatment-related systemic toxicity was minimal and reversible. Three patients (15%) experienced grade 4 hepatic toxicity and died due to liver failure and subsequent multiorgan failure. Other six patients had significant (grade 3-4) but transitory hepatic toxicity. Complete and partial responses were observed in three and nine out of 17 evaluable patients, respectively (overall response rate = 70%). The pharmacokinetics study showed a 3% mean perfusate-to-plasma drug leakage (range 1-6%). Logistic regression analysis showed that drug concentration in the perfusate circuit, but not preoperative tests, significantly and independently correlated with hepatic toxicity (P = 0.028).

CONCLUSIONS

Following melphalan-based IHP, objective tumor regression could be observed in a remarkable percentage of patients refractory to standard treatments. However, hepatic toxicity and related mortality were significant. Our findings suggest that drug dosage personalization based on the measurement of drug distribution volumes might minimize hepatic toxicity.