Ischemic colitis is ischemia of the intestinal mucosa despite the absence of occlusion of the main arteries. This condition often occurs in elderly individuals [3, 4]. The causes of ischemic colitis can be classified as occlusive and non-occlusive [5]. Occlusive factors include atherosclerosis, thromboembolization, venous occlusion, and mechanical bowel obstruction. Non-occlusive cecal necrosis reportedly occurs in association with open-heart surgery, chronic heart disease, certain drugs, and hemodialysis [6,7,8,9].
The rectal sigmoid junction and splenic flexure are common sites of ischemic colitis. These sites are frequently associated with “watershed” areas of blood flow. The rectal sigmoid colon forms the boundary between the blood flow from the inferior mesenteric artery and internal iliac artery. Similarly, the splenic flexure constitutes part of the boundary of the superior and inferior mesenteric arteries. Therefore, these areas are anatomically vulnerable to blood supply instability compared to other parts of the colon. In addition to these two areas, the cecum is anatomically prone to ischemia, although this is not well known [10].
The cecum receives blood flow from the cecal arteries, which often branch from the arcade of the colonic and ileal branches of the ileocolic artery [11]. The diameter of the cecum is large; therefore, the lateral wall is at risk for ischemia owing to the long distance from the origin of the cecal artery [12]. Additionally, in some cases, the origin of the cecal artery is more proximal, thus making the cecal wall more prone to ischemia [13].
CT may reveal thickening of the cecal wall, intramural bleeding, focal or diffused increase in the intestinal diameter, mesenteric arterial thrombus, intestinal pneumatosis, portal or mesenteric venous gas, pneumoperitoneum, and intra-abdominal free fluid in patients with cecal necrosis [14, 15]. In our patient, abdominal CT showed thickening of the cecal wall with poor enhancement, cecal dilation, and intrahepatic portal emphysema. Guitart et al. reported that the combination of cecal wall thickening and edematous characteristics accompanied by the lack of changes in the appendix, ileum, and colon is suggestive of a diagnosis of cecal ischemia [16].
In clinical practice, the symptoms and the course of treatment of ischemic colitis vary according to the site of occurrence. In ischemic colitis of the left colon, constipation often triggers ischemia, resulting in bloody diarrhea. Ischemic colitis in the right colon rarely presents with bloody diarrhea; however, vomiting, diarrhea, and right abdominal pain are typical manifestations. Conservative treatment is usually effective for left-sided ischemic colitis. However, surgical treatment is often required for right-sided ischemic colitis because it is more likely to be accompanied by gangrene. The duration of hospitalization was longer (median length of stay, 10 days vs 6 days), and the frequency of surgery (44.3% vs 11.5%) and mortality rate were higher in patients with right-sided colonic involvement compared to those with left-sided colonic involvement [1]. Montoro et al. also reported that mortality and/or the need for surgery were higher for isolated right-sided ischemic colitis compared to ischemic colitis occurring at other sites (40.9% vs 10.3%) [2]. Therefore, right-sided ischemic colitis requires more careful treatment, including surgical intervention.
Our patient had a history of hemodialysis. Studies have reported a relationship between chronic renal failure or hemodialysis and ischemic colitis [3, 14, 17, 18]. Lawrence et al. evaluated 313 cases of ischemic colitis and reported that the frequency of comorbidities, such as coronary artery disease and end-stage renal failure requiring hemodialysis, was higher in right-sided involvement than in left-side involvement [1]. Flobert et al. reported that chronic renal failure, hemodialysis, and right-sided colon involvement are associated with the severity of ischemic colitis [14] and that hemodialysis patients tend to develop ischemic colitis on the right side. Therefore, it is worth noting that hemodialysis patients could develop right-side ischemic colitis and may be prone to serious disease.
Nielsen et al. reported the usefulness of an initial laparoscopic approach in the event of abdominal emergency [19]. In our case, we chose open surgery at the outset, since the patient was undergoing dialysis, and there was a risk of hemodynamic failure due to the long operative duration. However, depending on the patient and circumstances, the laparoscopic approach may be selected initially.
This patient had multiple arteriosclerosis comorbidities, such as hypertension, dyslipidemia, and diabetic nephropathy. We postulated that the hemodynamic changes attributable to hemodialysis were responsible for gangrenous ischemic colitis of the cecum, which is anatomically prone to ischemia.
