NIV Congres

Introduction Reduction of metabolic rate is the key factor in organ preservation. Systemic flush-out with ice-cold preservation solutions is considered to be the start of Cold Ischemia Time. Cooling to 0-4°C is however likely first reached when organs are packed and stored on ice. 

Methods In this study liver and kidney temperature during flush-out and retrieval until removal were measured during MOD procedures by the Leiden team. Both Brain-Dead (n=8) and Non-Heart-Beating (n=5) donors were studied. Standard retrieval procedures including crushed ice and topical cooling were followed.

Results For BD-donors significantly less preservation solution (UW: 6.9±0.35 liters) was used compared to NHB-donors (HTK: 12.6±1.2 liters). Total flush time for BD and NHB donors tended to be different (BD:17.8±3.1 minutes; NHB: 25.8±4.5 minutes). Flow rate was not significantly different between donor types (BD: 454±66 ml/min; NHB: 580±138 ml/min).  In BD-donors, liver temperature decreased rapidly to 11.3±0.7°C after 15min but increased again to 17.5±0.5°C after 60min. For NHB-donors no temperature dip was observed (17.9±2.6°C at 15min vs 16.4±2.3°C at 60min). Renal temperatures dropped to 11.2°C (n=1) after 15min in the BD-group and in he NHB-group mean temperature was 15±2.6°C.  After 60 minutes, in the BD-donors 18.7±1.9°C was measured and 17.6±1.0°C in the NHB donors.

Discussion The incomplete cooling during flush-out as well as the warm-up before organ removal observed in this study may lead to ischemic damage and may therefore explain the inferior outcome of deceased donors compared to living donors. The use of more fluid in the NHB-donors did not lead to lower temperatures questioning the assumption that HTK is preferable in NHB donation. Distribution of the preservation solution to organs may be more relevant illustrated by the lower liver temperature in the UW flushed HB-donors although other donor factors can not be ruled out.