腸間膜静脈硬化症の臨床像

Clinical Pictures of Mesenteric Phlebosclerosis

要旨●腸間膜静脈硬化症は右側結腸を中心に慢性虚血性変化を来すまれな疾患である．内視鏡検査では特徴的な粘膜色調（青銅色〜暗紫色）や腸管伸展不良がみられ，潰瘍を伴うことも多い．生検では粘膜固有層の膠原線維沈着や静脈壁肥厚がみられる．CTでは腸管壁内外の静脈の石灰化と腸管壁肥厚が特徴的である．山梔子を含む漢方薬の長期服用が病因として知られている．症状は腹痛，下痢が多いが無症状例も少なくない．病変が進行すると手術が必要になる場合があり，約20%の症例で手術が施行されている．山梔子を含む漢方薬の中止で病状が改善することが多い．全国調査の成績を中心に本症の臨床像について解説した．

　MP（mesenteric phlebosclerosis）is a rare disease that causes chronic bowel ischemia mainly in the right side of the colon. Endoscopic findings indicate mucosal discoloration（bronze to deep purple）and poor luminal distensibility, frequently accompanied by ulcerations. Histologically, collagen deposition in the lamina propria and thickening of the venous wall are found in the biopsy samples. Computed tomography frequently delineates venous calcifications in and around the colonic wall and colonic wall thickening. Etiologically, long-term use of herbal medicine, including sanshishi, has been associated with MP development. Major symptoms of MP include abdominal pain and diarrhea ; however, one-fourth of cases are asymptomatic. Surgery may be required for advanced disease, and, so far, approximately 20% of the cases have undergone surgery. Herbal medicine withdrawal, including sanshishi, frequently ameliorates the disease. Clinical pictures of MP are described mainly based on the nation-wide survey.