Case ReportIncarcerated incisional hernia of the sigmoid colon after appendectomy: A case report

•Incisional hernia after appendectomy is rare because the incision is small.•Small bowel and omentum are commonly herniated through the weak abdominal wall.•Incisional hernia of the colon after appendectomy is extremely rare.•Computed tomography is a useful diagnostic tool for differentiating unusual abdominal wall mass.

IntroductionIncisional hernia after appendectomy is rare, affecting 0.4% to 0.9% of cases. The small bowel and omentum are commonly herniated through the abdominal wall defect, but incisional hernia of the sigmoid colon is extremely rare.Case presentationA 78-year-old man presented with a right lower quadrant abdominal wall mass on the previous McBurney incision site. He had a history of appendectomy for appendicitis 40 years ago. Computed tomography (CT) showed the sigmoid colon herniated thorough the abdominal wall defect. During the operation, a feces-impacted sigmoid colon was found protruding through the defect of the abdominal wall. Reduction of the sigmoid colon into the peritoneal cavity and herniorrhaphy with primary repair were performed.DiscussionThe ascending and descending colon are fixed into the retroperitoneum, whereas the transverse and sigmoid colon are not, which can allow these bowel segments to herniate through a weak abdominal wall just as small bowel loops do. However, incisional hernia of the colon is extremely rare. The diagnosis of incisional hernia can be easily made because a reducible abdominal wall mass can be detected by physical examination. In cases with rare type of hernia, CT can identify unusual types of abdominal hernias and differentiate hernias from neoplasms, inflammatory disease, and hematoma.ConclusionAlthough incisional hernia of the colon after appendectomy is extremely rare and preoperative diagnosis by physical examination is difficult, CT is a useful method to make the correct diagnosis, avoiding unnecessary invasive intervention, particularly in patients with an unusual abdominal wall mass.