Hepatic Histopathology of Patients with Morbid Obesity Submitted to Gastric Bypass

Background: The authors analyze and describe the hepatic histopathology of patients with morbid obesity submitted to gastric bypass. Methods: A liver biopsy was performed in 112 patients at the beginning of gastric bypass, and clinical data (gender, age, BMI and associated diseases) were obtained from the patient records. Results: Among the patients, 74.1% (n=83) were females and 25.9% (n=29) were males, age 39.59±10.12 years, with BMI 48.79±7.54. Regarding the diseases associated with morbid obesity, arterial hypertension was observed in 67.9% (n=76) of the patients, joint diseases in 55.4% (n=62), dyslipidemia in 40.2% (n=45), and diabetes type 2 in 27.7% (n=31). 111 patients (99.1%) showed different types of non-alcoholic fatty liver disease (NAFLD) (types 1, 2, 3 and 4), with types 3 and 4 accounting for 57.7% (n=64). A significant association was observed between NAFLD type 4 and diabetes type 2 ( P =0.018). The presence of glycogen nuclei was significantly correlated with steatosis ( P =0.000), lobular inflammation ( P =0.019) and perisinusoidal fibrosis ( P =0.000). Conclusion: 1) Liver biopsy taken at gastric bypass reveals different types of NAFLD; 2) Diabetes type 2 is associated with NAFLD type 4; 3) Glycogen nuclei are correlated with steatosis, lobular inflammation and perisinusoidal fibrosis; 4) Steatosis represents the basic injury in NAFLD and is associated with hepato-cellular ballooning. 5) In view of the frequency of hepatic alterations, a biopsy should be part of the surgical protocol of morbid obesity, this method being the only one able to determine the presence of lesions and to stage fibrosis.