探讨经瘘管超声造影在复杂性肛瘘术前诊断中的应用价值。

选取24例经手术证实的复杂性肛瘘患者，术前经体表常规超声检查，并采用血池造影剂行瘘管超声造影，观察瘘管的内、外口，主管及支管的走行、数量，是否存在脓腔。以手术结果为"金标准"，采用χ²检验或Fisher精确检验进行统计学分析，比较常规经体表超声检查及常规超声联合瘘管超声造影2种方法的诊断准确率。

常规经体表超声联合经瘘管超声造影对内口、支管的诊断准确率分别为83.3%，86.7%，均显著高于常规超声（分别为33.3%、40.0%），差异均有统计学意义（χ²=12.343、7.033，P均<0.01），对主管、脓腔的诊断准确率分别为100.0%、100.0%，均高于常规超声（分别为87.5%、62.5%），差异均无统计学意义（P均>0.05）。

经瘘管超声造影为复杂性肛瘘提供丰富的诊断依据，提高术前诊断准确率，有助于手术方案的制定；其最大优势在于显著提高对复杂性肛瘘内口及支管的诊断能力，对提高主管及脓腔的显示率也有一定作用。

To explore the value of trans-fistula contrast-enhanced ultrasound (CEUS) using blood pool contrast agent in the preoperative diagnosis of complex fistula-in-ano.

Twenty-four cases of complex fistula-in-ano confirmed by surgery were retrospectively analyzed. Conventional ultrasonography and trans-fistula CEUS were both applied before operation. The internal and external opening of fistula were observed, and the number and tract of primary fistula and secondary fistula were detected. The existence of abscess was also observed. Statistical analysis was performed to compare the diagnostic efficacy between these two methods.

The diagnostic accuracy of internal opening and secondary fistula using conventional ultrasonography combined with CEUS were 83.3%, 86.7%, respectively. They were significantly higher than those of conventional ultrasound (33.3%, 40%, respectively; χ²=12.343, 7.033, all P>0.01). Although the diagnostic accuracy of primary fistula and abscess using conventional ultrasonography combined with CEUS were higher than those of conventional ultrasound (100% vs 87.5%, 100% vs 62.5%, respectively), no significant difference was found (all P>0.05).

Trans-fistula CEUS provides abundant diagnostic information for complex fistula-in-ano, improves the accuracy of preoperative diagnosis, and is beneficial to surgical procedures. The greatest advantage of CEUS is the indication of the internal opening and secondary fistula of complex fistula-in-ano.