下段の図９〜図１２で下行結腸を36〜33（実は横行結腸）と判断すると閉塞部位の診断は困難となる．上行結腸（A）は拡張し，下行結腸（D）は虚脱しているので図８の1から肛門側へ追跡することが閉塞部位に至る正しい追跡法である．図４の41で閉塞し，図１〜図３の腫瘤（▲）と，図４と図５の壁肥厚（↑）が閉塞の原因病変で，不整に良好に造影されるので横行結腸脾弯曲部癌による結腸閉塞と診断する．△は壁内気腫である．緊急手術にて同所見が確認されHartmann手術が施行された．

参考症例（横行結腸癌）：79歳男性．便秘のため下剤を服用したら差し込むような上腹部痛が出現し来院． 図８で上行結腸（A）が拡張し，下行結腸（D）は固形便を含み正常な所見である．上行結腸を肛門側へ追跡すると図６の11で閉塞するが，病変は図３から始まる壁肥厚（↑）と図３〜図７の腫瘤（▲）であり，横行結腸癌の可能性が極めて高い． T：横行結腸．図Aが注腸造影で，辺縁不整な陰影欠損（白矢印）と高度の狭窄（apple core：△）を認めた．手術および病理所見：進行性横行結腸癌．　

文献考察：閉塞（45例），穿孔（13例）または大量出血（1例）のため緊急手術を要した大腸癌は全大腸癌の22.2％．68.6％に根治手術が行われ，根治手術例の生存率は待機手術例の生存率に近い．
Am J Surg. 2005 Apr;189(4):377-83.
A prospective study of outcomes of emergency and elective surgeries for complicated colonic cancer.
Biondo S, Marti-Rague J, Kreisler E, Pares D, Martin A, Navarro M, Pareja L, Jaurrieta E.

BACKGROUND: Although a significantly decreased long-term survival has been observed in patients undergoing surgery for complicated colorectal tumors compared with uncomplicated ones, the role of radical oncologic surgery on emergency colonic cancer is not defined clearly. The aim of this study was to analyze the efficacy of a curative emergency surgery in terms of tumor recurrence and cancer-related survival compared with elective colonic surgery. METHODS: Between January 1996 and December 1998, all patients with colonic cancer deemed to have undergone a curative resection were considered for inclusion in this prospective study. Patients were classified into 2 groups: group 1, after emergency surgery for complicated colonic cancer, and group 2, patients undergoing elective surgery. The main end points were cancer-related survival and the probability of being free from recurrence at 3 years. RESULTS: Of the 266 patients included in the study, 59 patients (22.2%) were in group 1 and 207 patients (77.8%) were in group 2. Postoperative mortality was higher in group 1 (P=.0004). After patients were stratified by the tumor node metastasis system, differences between the groups with respect to overall survival of stage II tumors (P=.0728), the probability of being free from recurrence (P=.0827), and cancer-related survival (P=.1071) of stage III cancers did not reach statistical significance. Differences were observed for the overall survival in stage III tumors (P=.0007), and for the probability of being free from recurrence (P=.0011) and cancer-related survival (P=.0029) in stage II cancers. When patients with elective stage II tumors presenting 1 or more negative prognostic factor were compared with emergency patients affected by a stage II colonic cancer, no differences were observed. CONCLUSION: Curative surgeries for complicated colonic cancer are acceptable in emergency conditions. Cancer-related survival and recurrence in patients with complicated colonic cancers may approach that of elective surgery if a surgical treatment with radical oncologic criteria is performed.PMID: 15820446