Microcirculatory disturbance is an obstacle to liver transplantation from agonal NHBD

Donation after cardio-circulatory death liver transplantation

The renewed interest in donation after cardio-circulatory death (DCD) started in the 1990s following the limited success of the transplant community to expand the donation after brain-death (DBD) organ supply and following the request of potential DCD families. Since then, DCD organ procurement and transplantation activities have rapidly expanded, particularly for non-vital organs, like kidneys. In liver transplantation (LT), DCD donors are a valuable organ source that helps to decrease the mortality rate on the waiting lists and to increase the availability of organs for transplantation despite a higher risk of early graft dysfunction, more frequent vascular and ischemia-type biliary lesions, higher rates of re-listing and re-transplantation and lower graft survival, which are obviously due to the inevitable warm ischemia occurring during the declaration of death and organ retrieval process. Experimental strategies intervening in both donors and recipients at different phases of the transplantation process have focused on the attenuation of ischemia-reperfusion injury and already gained encouraging results, and some of them have found their way from pre-clinical success into clinical reality. The future of DCD-LT is promising. Concerted efforts should concentrate on the identification of suitable donors (probably Maastricht category III DCD donors), better donor and recipient matching (high risk donors to low risk recipients), use of advanced organ preservation techniques (oxygenated hypothermic machine perfusion, normothermic machine perfusion, venous systemic oxygen persufflation), and pharmacological modulation (probably a multi-factorial biologic modulation strategy) so that DCD liver allografts could be safely utilized and attain equivalent results as DBD-LT.

Detrimental effect of sinusoidal overperfusion after liver resection and partial liver transplantation

Liver resection exposes the remaining sinusoids to an over-proportional blood flow. This mechanism may aggravate ischaemia/reperfusion damage and rejection in partial liver transplants. We studied the potential relevance of this mechanism for the pathogenesis of partial liver transplant dysfunction. Eighty-four isogeneic Lewis rats were divided into four groups: (I) sham operation; (II) partial liver resection (30% residual liver volume); (III) orthotopic transplantation of a full-size liver; (IV) transplantation of a reduced-size liver (30% transplant volume). Microcirculation was determined by intravital microscopy 90 min after surgery. Survival rates, liver function and morphology were monitored over a period of 14 days. Lowest survival rates and impaired liver function were observed after partial liver transplantation (group IV). These transplants displayed the lowest perfusion rate and an increased rate of leukocyte-endothelium interactions in the presence of a significantly increased sinusoidal blood flow velocity compared with those in groups I and III. Sinusoidal overperfusion in groups II and IV resulted in widespread endothelium lesions. Sinusoidal overperfusion seems to be a significant factor impairing liver function after liver resection. In addition to other adverse factors, such as ischaemia/reperfusion injury, it can contribute to the pathogenesis of postoperative dysfunction of partial liver transplants.

Detrimental effect of sinusoidal overperfusion after liver resection and partial liver transplantation

Liver resection exposes the remaining sinusoids to an over-proportional blood flow. This mechanism may aggravate ischaemia/reperfusion damage and rejection in partial liver transplants. We studied the potential relevance of this mechanism for the pathogenesis of partial liver transplant dysfunction. Eighty-four isogeneic Lewis rats were divided into four groups: (I) sham operation; (II) partial liver resection (30% residual liver volume); (III) orthotopic transplantation of a full-size liver; (IV) transplantation of a reduced-size liver (30% transplant volume). Microcirculation was determined by intravital microscopy 90 min after surgery. Survival rates, liver function and morphology were monitored over a period of 14 days. Lowest survival rates and impaired liver function were observed after partial liver transplantation (group IV). These transplants displayed the lowest perfusion rate and an increased rate of leukocyte-endothelium interactions in the presence of a significantly increased sinusoidal blood flow velocity compared with those in groups I and III. Sinusoidal overperfusion in groups II and IV resulted in widespread endothelium lesions. Sinusoidal overperfusion seems to be a significant factor impairing liver function after liver resection. In addition to other adverse factors, such as ischaemia/reperfusion injury, it can contribute to the pathogenesis of postoperative dysfunction of partial liver transplants.