Continuous leakage measurement during hyperthermic isolated limb perfusion

Background: Continuous measurement of perfusate leakage into the systemic c irculation is of the utmost importance and can be performed with the help o f radioactive tracers. The purpose of this study was to assess changes in t he perfusion leakage rate between two periods: 1977-1990 and 1991-2000, and to determine the factors responsible for these changes. Methods: During the 1991-2000 period. 119 patients underwent HILP mainly fo r locally recurrent melanoma or Locally advanced soft tissue sarcoma. HILP was performed with melphalan (33%) or in combination with TNF alpha (65%). There were 67 iliacal, 12 femoral, 25 popliteal, and 15 axillary perfusions performed. Leakage into the systemic circulation was monitored continuousl y with the help of I-131-albumin and a stationary scintillation detector pl aced above the heart. Results: The median maximum leakage was 2.7% {range 0%-21%) which is signif icantly less than the previous period (1977-1990) where leakage of 8% (rang e 0%-30%) was reposed (P <.05). A statistical difference in leakage was det ected among perfusion locations where the iliac and femoral vessels showed more leakage than the axillary and popliteal vessels (P <.05). Furthermore, there appeared to be significantly less leakage when TNF alpha was used th an when melphalan was the sole drug (P <.05). Conclusions: Nowadays leakage from isolated perfusions into the systemic ci rculation is further minimized compared with the days when me1phalos was th e sole drug used. Increased awareness about TNF<alpha> leakage, continuous external monitoring with I-131-albumin as the main isotope, flow rate regul ation in the perfusion circuit, and regulation of the patient's systemic bl ood pressure have all been major contributors to this improvement.