ダブルバルーン内視鏡を用いた小腸腫瘍性疾患の診断と治療

Diagnostic and Therapeutic Impact of Double-balloon Endoscopy for Patients with Small Bowel Tumors

要旨　小腸腫瘍はまれではあるが，腸重積，イレウス，出血の原因となりうるため臨床上重要である．小腸悪性腫瘍では小腸癌と悪性リンパ腫が多く，癌は上部空腸またはBauhin弁近傍の回腸に好発し，悪性リンパ腫は回腸に多い．一方，良性腫瘍ではGIST，脂肪腫，血管腫の順で頻度が高いが，GISTは空腸に多く脂肪腫と血管腫は回腸に多い．いずれも特異的な臨床症状はなく腹部超音波検査，小腸透視検査，CT検査などのスクリーニング検査での検出率は50％前後であるため，疑った場合には小腸内視鏡検査の適応となる．また，小腸腫瘍性疾患に対する内視鏡治療には，出血例に対する止血術と，病変の摘除術が挙げられる．

　Unlike the colon and rectum, the small intestine is associated with a very low rate of tumor occurrence. Symptoms encountered in this rare tumor are ones such as abdominal pain, nausea and vomiting, which are usually due to obstruction and gastrointestinal bleeding. Those symptoms may have a serious clinical course sometimes. From this standpoint, it is important to understand small bowel tumors. In malignant tumors of the small bowel, adenocarcinoma and malignant lymphoma are most prevalent. It is believed that adencarcinoma are usually located either in the upper part of the jejunum or the ileum near the Bauhin valve, and malignant lymphoma are usually located in the ileum. On the other hand in benign tumors of the small bowel, gastrointestinal stromal tumor, lipoma and hemangioma are seen more frequently, and gastrointestinal stromal tumors are usually located in the jejunum, and lipoma and hemangioma are usually located in the ileum. Symptoms related to small bowel tumors are nonspecific. Screening tests such as transabdominal ultrasound, enterography or computed tomography were able to detect only half of these tumors. If patients are suspected because of their clinical condition to have small bowel tumor small bowel endoscopy can be applied for them. Double-balloon endoscopy has the capability of enabling scrutiny and endoscopic therapy of these small bowel tumors. Endoscopic therapy using double-balloon endoscopy includes hemostasis and polypectomy.