Abstract
The incidence of internal hernias is rare (0.2-0.9%). The prevalence of intestinal obstruction for an internal hernia is low (0.5-5%), however if strangulation is present the overall mortality is higher than 50%. There are multiple places where an internal hernia may be localized, with transmesenteric: transmesocolic (8%) and transomental (1-4%) as the rarest. We report a series of two cases (men with 40 years-old and women with 92 years old) of volvulus of colon sigmoid in a strangulated transverse and descendent transmesocolic hernia, with one case associated also to a transomental hernia. Both patients were submitted to a Hartmann procedure and on follow-up remained free of complains. In conclusion, transmesenteric internal hernia should be included as diagnosis hypothesis for intestinal occlusion and if the diagnosis is made, the patient should be submitted to emergency surgery due to high rates of complications, high morbidity and mortality.