Ileo-ileal fistula with severe malnutrition caused by strangulated ileus surgery while preserving ischemic ileum: A case report

INTRODUCTION: Entero-enteric fistulas are rare complications that occur in patients with inflammatory bowel disease and other intestinal diseases. In this report, we present an ileo-ileal fistula accompanied by severe malnutrition caused by strangulated ileus surgery while preserving the ischemic ileum in a very elderly patient. CASE PRESENTATION: A 90-year-old woman underwent emergency surgery without bowel resection for strangulated ileus in another hospital. Minor abdominal pain and slight fever persisted after surgery. She lost weight, losing approximately 10 kg within half a year. She gradually became difficult to move due to dyspnea upon exertion and generalized edema and visited at our hospital. Pleural effusions, ascites and severe malnutrition were observed. An elastic hard mass with mild tenderness was palpated in her abdomen. Computed tomography showed a loop-like ileum and ileo-ileal fistula with adjacent fat stranding. We performed a partial small bowel resection. The resected specimen demonstrated an ileo-ileal fistula and circumferential ulceration in the loop-like adhesion. After the operation, the nutrition status was resolved immediately without any medications. DISCUSSION: In cases of strangulated ileus, there are no deterministic criteria for evaluating intestinal blood flow. This is the first report of ileo-ileal fistula onset after surgery for strangulated ileus without intestinal resection. Furthermore, this fistula caused severe malnutrition duo to chronic inflammation, ulcer formation, and the blind-loop syndrome. CONCLUSIONS: When preserving the intestinal tract in the operation of strangulated ileus, the occurrence of entero-enteric fistulas should be considered. Since malnutrition in the elderly is a serious problem, it should be treated promptly.