Histological findings in the liver before and after gastric bypass

Background: Bariatric surgery results in massive loss of excess weight, changes in co-morbidities and improvement in quality of life. In these patients, liver histology taken before or during surgery reveals several histological abnormalities. In a prospective study of patients previously submitted to gastric bypass, we determined the changes in liver histology late after the surgery. Methods: In 16 out of a total of 557 patients who were submitted to open gastric bypass, a second liver biopsy was taken during the repair of an incisional hernia, performed at a mean of 17 months after the gastric bypass. Results: All patients had lost weight, now having a mean BMI of 28.6 kg/m(2) (which had been 44.3 kg/m(2) before gastric bypass). One patient with normal preoperative liver histology remained normal at the second study. 11 out of 15 who had had liver abnormalities returned to a normal condition or had only minimal change (73.3%). 2 patients (13.3%) showed improvement, while 1 patient presented a slight worsening of liver condition. One patient who had had liver cirrhosis showed no change. Conclusion: Gastric bypass for morbid obesity is followed by a dramatic improvement or normalization of liver histological abnormalities in the great majority of the patients. Liver cirrhosis in the one patient remained unchanged.