There were several presentations at the recent World Transplant Congress in San Francisco that discussed the latest developments in hypothermic organ preservation techniques. Using the Scientific Registry of Transplant Recipients, Gill et al of the Vancouver group examined the impact of Hypothermic Machine Perfusion (HMP) on the risk of DGF depending on the Kidney Donor Profile Index (KDPI). When corrected for confounders, HMP was associated with approximately 20-30% reduction in odds of DGF in all but the lowest KDPI decile; If KDPI was less than 0.3 and CIT less than 12 hours, there was no reduction in DGF.
A paired DCD kidney study from Guangzhou, China (Yuan et al) compared HMP with static cold storage (40 donors). Unfortunately the study was small and 16 kidneys were discarded before transplantation, resulting in overall low rates of DGF, but no discernible difference between the two arms of the study. In another paired DCD kidney study, Zhong et al of the Hunan group, China, presented reduced rates of DGF with HMP. In a parallel laboratory study they showed reduced vasospasm and oedema of sertoli cells/renal tubular epithelial cells as a potential mechanism of action.
Considerable experience with HMP for liver preservation was presented by James Guarrera and the Columbia University group. The so-called “orphan” extended criteria donor livers used had been turned down by all other centres in the UNOS region. The livers were perfused with vasosol for 3-7 hours and transplanted into recipients with MELD scores less than 35. These cases were matched to historical controls preserved by static cold storage. Biliary complications were significantly lower in the HMP group, as was post-operative stay. Patient survival and early allograft dysfunction were not significantly affected however. Sanna op den Dries and a collaboration between Groningen and Harvard Universities have added to our understanding of non-anastomotic biliary strictures by demonstrating that injury to peri-biliary glands and vascular plexus before liver transplantation was predictive of later stricture formation.