Impact of alcohol & smoking on the surgical management of gastrointestinal patients

Different ethanol exposure durations affect cytochrome P450 2E1-mediated sevoflurane metabolism in rat liver

BACKGROUND

Chronic alcohol users often exhibit an increased minimum alveolar concentration (MAC) of sevoflurane, yet the specific mechanism remains unclear. It has been reported that ethanol exposure can upregulate the protein expression and enzyme activity of cytochrome P450 2E1 (CYP2E1). CYP2E1 is a key enzyme that converts 2-5% of sevoflurane into equimolar amounts of hexafluoroisopropanol (HFIP) and F-. This study aims to explore whether ethanol exposure could alter sevoflurane metabolism through CYP2E1 modulation, potentially explaining the increased MAC observed in alcohol users.

METHODS

Eighty adult male Sprague-Dawley (SD) rats were randomly divided into two groups and received either 50% ethanol (dose: 3 g/kg) or 0.9% saline twice daily by gavage. After 1, 2, 3, and 4 weeks of gavage, ten rats were randomly selected from each group to undergo 1-hour anesthesia with 2.3% sevoflurane. Blood samples were collected after anesthesia to measure the concentration of free HFIP using gas chromatography. Additionally, the left lobe tissue of the liver was collected for the analysis of CYP2E1 protein expression by Western blot and CYP2E1 enzyme activity by colorimetric assay. Correlations between these parameters were analyzed using Pearson's correlation.

RESULTS

In the ethanol group, CYP2E1 expression, activity, and the concentration of free HFIP were significantly higher at all time points compared to the control group (P < 0.05), except for protein expression in the first week (P > 0.05). Within-group comparisons indicated no significant changes in any of the parameters for the control group (P > 0.05). In the ethanol group, there was no difference in free HFIP concentration between the first and second weeks (P > 0.05), but a significant increase was observed in the third and fourth weeks (P < 0.01); protein expression and enzyme activity significantly varied over time, especially showing a notable increase from the first to the third and fourth weeks (P < 0.05). Correlation analysis revealed strong positive correlations between free HFIP concentration and CYP2E1 activity (r = 0.7898), free HFIP concentration and CYP2E1 expression (r = 0.8418), and CYP2E1 activity and expression (r = 0.8740), all with P < 0.001.

CONCLUSIONS

Ethanol exposure increased both the expression and enzymatic activity of CYP2E1, consequently enhancing the metabolism of sevoflurane.

Risk factors for esophagojejunal anastomotic leakage after curative total gastrectomy combined with D2 lymph node dissection for gastric cancer

OBJECTIVE

To explore the risk factors associated with esophagojejunal anastomotic leakage (EJAL) after curative total gastrectomy combined with D2 lymph node dissection for gastric cancer.

METHODS

We reviewed the data for 390 consecutive patients undergoing Roux-en-Y esophagojejunostomy reconstruction after total gastrectomy. Multivariate analysis was performed using a logistic regression model to identify the independent risk factors for EJAL.

RESULTS

Of the 390 patients enrolled in this study, EJAL occurred in 10 patients (2.6%), and one patient (1/10) with EJAL died. Univariate analysis identified age, alcohol consumption, pulmonary insufficiency, and intraoperative blood loss as risk factors for EJAL. Of these four risk factors, age and alcohol consumption were retained as independent risk factors by multivariate analysis.

CONCLUSION

Surgeons should be very careful regarding anastomotic leakage after esophagojejunal anastomosis, perioperatively, especially in patients with advanced age and a history of alcohol consumption. Pulmonary insufficiency and intraoperative blood loss, although not identified as independent risk factors, should also be considered.