The Effects of the Anhepatic Phase Extended by Temporary Portocaval Shunt on Anesthetic Sensitivity and Cognitive Function
Condition: Liver Cirrhoses
MeSH terms: Liver Cirrhosis
Study type: Interventional

Summary: 
      This study aims to investigate the effects of the anhepatic phase extended by temporary
      portocaval shunt on the sensitivity to desflurane administered at 0.6 age-adjusted minimum
      alveolar concentration and its associative postoperative cognitive function.
    

Detailed description: 
      The primary end point of this study is the mini-mental state examination in the Korean
      version of the consortium to establish a registry for Alzheimer's disease assessment packet
      (MMSE-KC) score obtained 7 days after living donor liver transplantation (LDLT). A sample
      size of 78 patients was calculated to detect a difference of 2.5 in the MMSE-KC score 7 days
      after LDLT between the temporary portocaval shunt (TPCS) and non-TPCS groups, achieving a
      statistical power of 80% at a two-tailed alpha error of 5% under a standard deviation of 3,
      an unequal allocation ratio between the groups (non-TPCS:TPCS = 83:33), which is the ratio of
      both types of surgery performed between May 2011 and October 2013 in our institution, and a
      drop-out rate of 20%, on the assumption that the Mann-Whitney U test would be performed due
      to the non-normal distribution of MMSE-KC scores in the TPCS group. A small number of
      patients was expected to be assigned to the TPCS group based on the number of previous cases
      in our institution and the stringent exclusion criteria.

      The data are presented as the means ± standard deviations for normally distributed data,
      medians (1st quartile - 3rd quartile) for non-normally distributed data, and numbers of
      patients (percentage) for qualitative data. The assumption of normality is tested using the
      Kolmogorov-Smirnov and Shapiro-Wilk tests. If at least one null hypothesis of the two tests
      is not rejected, the data are determined to be normally distributed. Univariate comparisons
      between the two groups are performed using independent samples Student's t-test for normally
      distributed variables, the Mann-Whitney U test for non-normally distributed variables, and
      Fisher's exact test for categorical variables. If Student's t-test is used, the 95%
      confidence interval of the mean difference and the corresponding P-value is presented.
      Repeated measures analysis of variance with post hoc paired Student's t-test using Bonferroni
      correction is performed for normally distributed variables to determine the significance of
      between- and within-groups effects and interaction between the variables (group versus
      phase). To determine the significant interval change in non-normally distributed variables
      during surgery, Friedman's test with post hoc Wilcoxon signed-rank test under Bonferroni
      correction is used. For the comparison of within-group changes in the total sum scores and
      subscores of the MMSE-KC, Wilcoxon signed rank test is used. Rank analysis of covariance is
      used to compare the MMSE-KC score obtained 7 days after surgery between the groups by
      controlling for the covariates that are found to correlate with the score based on
      nonparametric Spearman's correlation analysis. The statistical analysis is performed using
      IBM SPSS Statistics software, version 19.0.0 (IBM Corp., Armonk, NY, United States). A
      two-tailed P < 0.05 is considered statistically significant.
    

Intervention name(s): Temporary portocaval shunt
Intervention type(s): Procedure
Intervention description(s): The hepatic artery, bile duct, and portal vein are dissected and clamped. The retrohepatic vena cava is preserved with selective clamping of the hepatic veins during total hepatectomy. Then, temporary portocaval shunt is constructed by end-to-end anastomosis of the portal vein stump to the middle and left hepatic vein trunk or by end-to-side anastomosis of the stump to the infrahepatic vena cava depending on the remaining length of the vessels.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Diagnostic