24.消化管憩室性疾患

Diverticular Diseases of the Alimentary Tract and their Hemorrhage

要旨　食道憩室に由来する消化管出血は，極めてまれで，食道壁内偽憩室症，Zenker憩室（咽頭食道憩室）など数例が報告されているに過ぎない．十二指腸憩室は，大腸憩室に次いで多いが出血はまれで，以前は外科的治療や動脈塞栓術が選択されることが多かったが，1990年以降内視鏡的治療での止血例が多くなっている．小腸憩室は，Meckel憩室以外は後天性の仮性憩室で，その約80％は空腸，約15％が回腸，5％が空腸・回腸に発生する．外科治療を要する小腸憩室の頻度は，炎症：3.5％，閉塞：2.8％，出血：2.1％である．大腸憩室は，仮性憩室であり，その頻度は年齢とともに上がり，局在については，以前から欧米では遠位側に多く，アジア地域では近位側に多いと報告されている．当科での集計では，8,014例の大腸内視鏡症例で，21％に憩室を認め，そのうち56％は右側に，26％はS状結腸に，18％は両方に存在していた．大腸憩室出血では，一般に先端キャップを装着して，適時吸引を加えて憩室内腔を観察して出血部位を確認して，クリップを用いた憩室口閉鎖術が行われている．

　Bleeding due to esophageal diverticula is very rare. A case of esophageal intramural pseudodiverticulosis with bleeding was reported. Zenker's diverticulum is also an unusual site for gastrointestinal hemorrhage, and only a few cases have been reported. Duodenal diverticula are usually asymptomatic but may induce hemorrhage on rare occasions. Diverticula of the small intestine are rare clinical entities, and they are acquired lesions which are considered to be false diverticula. 80 ％ of them are located in the jejunum and their rate of bleeding is estimated at 4～5 ％. The colon is the most vulnerable site of diverticula and prevalence increases with age. In Western societies, diverticula occur mainly in the distal colon, which is in contrast to Asian countries in which proximal involvement seems more prevalent. Severe hemorrhage has been reported to occur in 3 to 5 ％ of patients. As for endoscopic therapy for diverticular hemorrhage, hemostasis is usually carried out using a hemoclip with a hood device.