図３〜図５で膵尾部周辺に脂肪組織の濃度上昇を認め（△），急性膵炎（慢性膵炎の急性増悪）である．図６の1〜図４の3は脾静脈であるが開存している．

下段の2日後のCTで，図７〜図９で膵尾部周囲に相当量の液貯留を認め（▲）急性膵炎であり，尾部の壊死を伴う（白矢印）．図１６で脾静脈が造影効果を失っており（↑），血栓で閉塞している．図１５で門脈へ，図１７でSMVへ波及し始めている（↑）ので早期に発見し早期に抗凝固剤治療をスタートしないとさらに上下へ進展し腸管壊死を起こす可能性さえあるので，脾静脈血栓症は膵炎の合併症として認識しておくべきである．正確に診断されヘパリン投与が開始され，以後は順調に経過し2週間で退院した．

下段の11日目のCTで，脾静脈は閉塞のままで静脈径は縮小しつつある．門脈内に少量の血栓を残す（↑）がSMVは開存したままである．尾部の壊死（白矢印）がさらに明白になった．

参考症例（膵尾部壊死を伴う急性膵炎・脾静脈血栓症）：29歳男性，アルコール性膵炎で入院し3日目のCT．白矢印は尾部の壊死を示し，↑は門脈に伸展する脾静脈の血栓．脾静脈は一部造影されており部分的な血栓症である．

文献考察１）：膵炎による脾静脈血栓症．胃静脈瘤は77％に発生するが，吐血は5%に，吐血のため手術を必要としたのは4％だけであった．従来言われたほど吐血の頻度は高くなく予防的脾摘は不要である．
Ann Surg. 2004 Jun;239(6):876-80; discussion 880-2.
The natural history of pancreatitis-induced splenic vein thrombosis.
Heider TR, Azeem S, Galanko JA, Behrns KE.

OBJECTIVE: To determine the natural history of pancreatitis-induced splenic vein thrombosis with particular attention to the risk of gastric variceal hemorrhage. SUMMARY BACKGROUND DATA: Previous studies have suggested that splenic vein thrombosis results in a high likelihood of gastric variceal bleeding and that splenectomy should be performed to prevent hemorrhage. Recent improvements in cross-sectional imaging have led to the identification of splenic vein thrombosis in patients with minimal symptoms. Our clinical experience suggested that gastric variceal bleeding in these patients was uncommon. METHODS: A computerized index search from 1993 to 2002 for the medical records of patients with a diagnosis of pancreatitis was performed. Fifty-three patients with a diagnosis of pancreatitis and splenic vein thrombosis were identified. The medical records of these patients were reviewed, and follow-up was completed, including the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC-QLQ). RESULTS: Gastrosplenic varices were identified in 41 patients (77%) with varices evident on computed tomography (CT) in 40 of 53 patients, on esophagogastroduodenoscopy (EGD) in 11 of 36 patients, and on both CT and EGD in 10 of 36 patients. This risk of variceal bleeding was 5% for patients with CT-identified varices and 18% for EGD-identified varices. Overall, only 2 patients (4%) had gastric variceal bleeding and required splenectomy. Functional quality of life was better than historical controls surgically treated for chronic pancreatitis. CONCLUSION: Gastric variceal bleeding from pancreatitis-induced splenic vein thrombosis occurs in only 4% of patients; therefore, routine splenectomy is not recommended.PMID: 15166967

文献考察２）：慢性膵炎例で（脾静脈血栓による）左側門脈圧亢進症は7％に合併し，食道または胃静脈瘤はその35％に，hypersplenismは25％に見られた．
Am J Surg. 2000 Feb;179(2):129-33.
The significance of sinistral portal hypertension complicating chronic pancreatitis.
Sakorafas GH, Sarr MG, Farley DR, Farnell MB.

BACKGROUND: Sinistral portal hypertension, a localized (left-sided) form of portal hypertension may complicate chronic pancreatitis as a result of splenic vein thrombosis/obstruction. AIM:To determine appropriate surgical strategy for patients with splenic vein thrombosis/obstruction secondary to chronic pancreatitis. METHODS: We reviewed our experience with operative management of 484 consecutive patients with histologically documented chronic pancreatitis treated between 1976 and 1997. The diagnosis of sinistral portal hypertension was based on clinical presentation, preoperative endoscopic and radiographic imaging, and operative findings. "Symptomatic," herein defined, denotes those patients with sinistral hypertension and either gastrointestinal bleeding or hypersplenism. "Asymptomatic" patients were those with sinistral hypertension alone. RESULTS: Sinistral portal hypertension was present in 34 of the 484 patients (7%). Gastric or gastroesophageal varices were confirmed in 12 patients (35%), of whom 6 had variceal bleeding and 4 had hypersplenism (25%). All symptomatic patients were treated by splenectomy alone or in conjunction with distal pancreatectomy. Splenectomy at the time of pancreatectomy for primary pancreatic symptoms was also performed in 15 patients with (asymptomatic) sinistral portal hypertension. None of the 23 patients who had splenectomy rebled in mean follow-up of 4.8 years. In contrast, 1 of the 11 patients with asymptomatic sinistral portal hypertension who underwent pancreatic surgery without splenectomy died of later variceal bleeding 3 years after lateral pancreatojejunostomy. CONCLUSIONS: Symptomatic sinistral portal hypertension is best treated by splenectomy. Concomitant splenectomy should be strongly considered in patients undergoing operative treatment of symptomatic chronic pancreatitis if sinistral portal hypertension and gastroesophageal varices are also present.PMID: 10773149