Keon Hee Ryu

The effects of magnesium pretreatment on reperfusion injury during living donor liver transplantation

Background Ischemia reperfusion (IR) injury is a complex phenomenon that leads to organ dysfunction and causes primary liver failure following liver transplantation. We investigated whether an intravenous administration of magnesium before reperfusion can prevent or reduce IR injury. Methods Fifty-nine living donor liver transplant recipients were randomly assigned to an MG group (n = 31) or an NS group (n = 28). Each group was also divided in two groups based on the preoperative magnesium levels (normal: ≥ 0.70 mmol/L, low: < 0.70 mmol/L). The MG groups received 25 mg/kg of MgSO4 mixed in 100 ml normal saline intravenously before reperfusion and the NS groups received an equal volume of normal saline. The levels of lactate, pH, arterial oxygen tension, and base excess were measured to assess reperfusion injury at five specific times, which were 10 min after the beginning of anhepatic phase, and 10, 30, 60 and 120 min after reperfusion. To evaluate postoperative organ function, the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin and creatinine levels were measured at preoperative day 1, postoperative day 1 and 5. Results The blood lactate levels were significantly lower at 10, 30, 60 and 120 min after reperfusion in the MG groups compared to the NS groups. In addition, significantly higher blood lactate levels were observed in the NS group with preoperative hypomagnesemia than in MG groups. Conclusions Magnesium administration before reperfusion of liver transplantation significantly reduces blood lactate levels. These findings suggest that magnesium treatment may have protective effects on IR injury during living donor liver transplantation.

Factors Influencing the Concentration of Cytokines During Liver Transplantation

Not only does the underlying disease that requires surgery constitute a significant stress to the human body, but also the surgery itself serves as a stressor. Cytokine secretion is activated in response to the surgical stress during liver transplantation. We examined 44 patients to compare cytokine levels, according to the underlying diseases causing liver failure (viral hepatitis vs alcoholic hepatitis), examining whether the values differed according to the model for end-stage liver disease (MELD) score [high (≥20) vs low (<20)]. Pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)1β, and IL-6 and anti-inflammatory cytokines IL-4 and IL-10 were quantified using sandwich enzyme- linked immunoassays at three times: (1) after inducing anesthesia, (2) 60 minutes after the start of the anhepatic period, and (3) 60 minutes after reperfusion. No difference in the level of any cytokine measured in our study was detected at any time point between the viral and the alcoholic hepatitis groups. Among the high MELD group, IL-1β and IL-4 contents were higher than in the low MELD group at all time points (P < .05). IL-10 concentrations at time 1 and TNF-α at time 2 were higher among the high MELD group (P < .05). In conclusion, the severity of the inflammatory and stress reactions expressed as cytokine concentrations did not differ according to the underlying liver disease, but did associate with the MELD score.