Rhabdomyolysis (RML) indicates a skeletal muscle necrosis which results in an emission of intracellular contents from myocytes into the circulatory system. It has been recognized to be a complication of bariatric surgery. A high BMI and a prolonged operative time are the main risk factors associated to the development of RML. The aim of this study is to define the incidence and the main features of RML in a cohort of obese patients undergoing bariatric surgery.

a retrospective observational analysis was carried out on 100 patients undergone bariatric surgery. The bariatric operations were open or laparoscopic Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (SG); they were performed at the university hospital Nuovo S. Chiara in 2011.

6 of 100 patients enrolled developed RML. Three of these also showed acute kidney injury due to RML (50%). A significant correlation between post-operative increased creatine phosphokinase (CPK) levels and BMI was found (r=0.369; r2=0,137; p=0.005) as well as a significant correlation between the increased levels of creatine phosphokinase, myoglobin and operative time (increased operative time - highest CPK: r=0.550; r2=0.302; p<0.0001; increased operative time - highest myoglobin: r=0.553; r²=0.305; p<0.0001). Moreover, hypertension and prolonged operative time were found to be variables associated with RML in bivariate analysis.

The incidence of RML following bariatric surgery was 6%. Since rhabdomyolysis is the most important complication of bariatric surgery, appropriate precautions should be taken during surgery. Post-operative monitoring of CPK and myoglobin levels is essential for an early diagnosis of RML.