右下腹部痛(Right Lower Quadrant Pain)シリーズ19 EXPERT COURSE 解答 【症例 RE 92】

回腸壊死.necrosis of ileum






回腸末端は図1の1から始まり,数字順に尾側へ下行し,図12の12でUターンする.図8〜図11の回腸末端の↑は壁内気腫であり,周囲小腸と比較して壁の造影効果も減弱しており,回腸の壊死または高度虚血状態と診断する.部位は盲腸から15cm程度の回腸末端である.翌日,腹膜刺激症状を呈したので手術となった.盲腸から15cmの部位で,約20cm長の回腸(腸間膜対側)に壊死を認め切除した.病理:possible ischemic necrosis of ileum.原因不明の回腸壊死であった.







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文献考察:腸管嚢腫様気腫症pneumatosis intestinalis壁内気腫intramural gas
Radiology. 1998 Apr;207(1):13-9.
Pneumatosis intestinalis: a review.
Pear BL.

This review illustrates the changing paradigms in the understanding of the pathogenesis of pneumatosis intestinalis. Although many theories have been evoked, pragmatically there appear to be four major clinical and diagnostic imaging considerations. The most common and most emergent life-threatening cause of intramural bowel gas is the result of bowel necrosis due to bowel ischemia, infarction, necrotizing enterocolitis, neutropenic colitis, volvulus, and sepsis. In the stomach, intramural gas can be caused by emphysematous gastritis or ingestion of caustic agents. These situations represent surgical emergencies. Pneumatosis is found secondary to mucosal disruption presumably due to over-distention from peptic ulcer, pyloric stenosis, annular pancreas, and even to more distal obstruction. Disruption can also be caused by ulceration, erosions, or trauma, including the trauma of child abuse. Disruption can also be iatrogenic from intracatheter jejunal feeding tubes, stent perforation, sclerotherapy, or surgical or endoscopic trauma. In these cases, the gas may be focal or linear. Treatment depends on the extent of the disruption and the underlying cause. A more subtle form of mucosal disruption may occur due to mucosal erosions and also to defects in intestinal crypts secondary to acute and subclinical enteritides that allow intraluminal bacterial gas under pressure to percolate into the bowel wall layers, particularly the submucosa (29). Pneumatosis, often linear or cystic in appearance, is seen with increased frequency in patients who are immunocompromised because of steroids, chemotherapy, radiation therapy, or AIDS. In these cases, the pneumatosis may result from intraluminal bacterial gas entering the bowel wall due to increased mucosal permeability caused by defects in bowel wall lymphoid tissue. Clinical and imaging findings are important in the differentiation of this transient pneumatosis from fulminant life-threatening causes in this subset of patients. A pulmonary cause must still be considered in cases of chronic obstructive pulmonary disease, asthma, and cystic fibrosis. It can occur with barotrauma and after chest tube placement. It may relate to increased intrathoracic pressure associated with retching and vomiting. The possibility remains that occasionally the origin of pneumatosis intestinalis will remain cryptogenic--caused but unexplained.PMID: 9530294
  【参照症例】   1. 下腹部痛シリーズ 3 【症例 LE 15】
2. 腹部全体痛シリーズ10 【症例 GE 48】

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