Objective: Total mesorectal excision (TME) is the gold standard for surgical treatment of mid-low rectal cancer, but the postoperative incidence of urination and sexual dysfunction is relatively high. Preserving the Denonvilliers fascia (DF) during TME can reduce the postoperative incidence of urination and sexual dysfunction. In this study, high resolution magnetic resonance imaging (MRI) was used to observe the imaging performance and display of DF, so as to determine the value of this technique in preoperative evaluation of the preservation of DF. Methods: A descriptive cohort study was carried out. Clinical data of patients with rectal cancer who underwent TME and received preoperative high-resolution MRI at department of Gastrointestinal Surgery, the Third Affiliated Hospital of Sun Yat-sen University from August 2015 to June 2017 were retrospectively analyzed. The characteristics of DF were examined, and the shortest distance (d) between the anterior edge of tumor and DF was measured on high-resolution MRI. The distance d was compared between patients with stage T1-T2 and those with stage T3. Receiver operating characteristic (ROC) analysis was used to determine the predictive value of d for stage T1-T2 disease. Results: Thirty-two patients were enrolled in the study, including 27 males and 5 females with mean age of (62.9±8.9) years. DF was visualized in 96.9% (31/32) of cases on the T2WI sequence. The mean distance d in patients with stage T1-T2 disease (n=23) was (6.73±2.65) mm, and in those with stage T3 disease (n=9) was (1.30±1.15) mm (t=5.893, P<0.001). A cutoff of d >3 mm yielded specificity and positive predictive value for diagnosing stage T1-T2 disease of both 100%, sensitivity of 95.7% and negative predictive value of 90%. The optimum threshold of d was >3.05 mm, and Youden index was 0.957. Conclusions: High-resolution MRI can show the DF and accurately evaluate the relationship of DF with tumor in rectal cancer patients. Analysis on d value can provide an objective basis for the safe preservation of DF.
目的： 全直肠系膜切除术（TME）是中低位直肠癌手术治疗的金标准，但术后排尿和性功能障碍的发生率较高。TME术中保留Denonvilliers筋膜可降低直肠癌术后排尿及性功能障碍的发生率。本研究通过高分辨率磁共振成像（MRI）观察Denonvilliers筋膜成像表现及显示情况，确定这一技术对术前评估保留Denonvilliers筋膜的应用价值。 方法： 采用描述性病例系列研究的方法。回顾分析中山大学附属第三医院胃肠外科2015年8月至2017年6月期间，行手术治疗的直肠癌病例资料，选取术前接受高分辨率MRI检查的患者资料，观察高分辨率MRI中的Denonvilliers筋膜特征，测量肿瘤前缘与Denonvilliers筋膜的最短距离（以d表示）。比较T(1~2)期和T(3)期患者的d，并使用受试者工作特征（ROC）曲线分析确定d对T(1~2)期疾病的预测值。 结果： 纳入32例患者，男27例，女5例；年龄（62.9±8.9）岁。在MRI非抑脂T2WI序列下，Denonvilliers筋膜在96.9%（31/32）的病例中清晰可见。23例T(1~2)期患者肿瘤前缘与Denonvilliers筋膜的d值为（6.73±2.65）mm，另9例T(3)期患者则为（1.30±1.15）mm（t=5.893，P<0.001）。以d>3 mm为临界值时，诊断T(1~2)期患者的特异度和阳性预测值均为100%，灵敏度为95.7%，阴性预测值为90%。d的最准确阈值>3.05 mm；Youden指数=0.957。 结论： 高分辨率MRI可以显示Denonvilliers筋膜结构，并准确评估直肠癌患者的Denonvilliers筋膜与肿瘤间的关系，分析d值可以为直肠癌手术安全保留Denonvilliers筋膜提供客观依据。.
Keywords: Denonvilliers fascia; High-resolution magentic resonance imaging; Preoperative evaluation; Rectal neoplasms; T stage.