克罗恩病外科并发症的影像学特征

Imaging features of surgical complications of Crohn＇s disease

目的探讨克罗恩病外科并发症的影像学特征。方法采用回顾性横断面研究方法。收集2014年1月至2015年12月中山大学附属第六医院收治的128例合并外科并发症的克罗恩病患者的临床资料。患者行CT小肠造影（CTE）、MR小肠造影（MRE）、肛管MRI及X线检查，完善检查后行手术治疗。观察指标：（1）克罗恩病术前并发症临床特点：克罗恩病术前并发症发生情况，术前并发症与克罗恩病蒙特利尔分型的相关性。（2）CTE、MRE以及肛管MRI检查诊断克罗恩病术前并发症及克罗恩病肛周病变的准确性。（3）克罗恩病术前并发症的影像学表现。（4）治疗及随访情况。采用电话或门诊方式进行随访，随访内容为患者术后恢复情况及二次手术情况。随访时间截至2016年3月。计数资料以频数或百分比表示。术前并发症与克罗恩病蒙特利尔分型的相关性采用比值比（OR）及95％可信区间（95％CI）表示。诊断指标特征以敏感度及特异度表示。结果（1）克罗恩病术前并发症临床特点：128例克罗恩病患者均合并术前并发症，包括肛瘘或肛瘘合并肛周脓肿71例，肠瘘26例，肠梗阻24例，腹腔脓肿23例，消化道穿孔3例，肾结石1例，肾积水1例；其中12例患者为肠瘘合并腹腔脓肿，1例肠瘘合并肠梗阻，3例肠瘘合并腹腔脓肿及肠梗阻，1例肠瘘合并消化道穿孔，1例肠瘘合并肾积水。克罗恩病病变位置与并发症类别有一定相关性，51例回肠型克罗恩病患者中35例发生狭窄或穿透型病变，狭窄或穿透型病变与回肠型克罗恩病相关（OR=6．23，95％CI：2．86～13．61，P〈0．05）；77例结肠型及回结肠型克罗恩病患者中56例发生肛瘘，提示并发肛瘘与克罗恩病出现结肠病变相关（OR=6．40，95％CI：2．92～14．01，P〈0．05）。（2）CTE或MRE及肛管MRI检查诊断的准确性：以患者术中探查结果为标准，CTE或MRE检查诊断克罗恩病外科并发症的敏感度及特异度为84％和95％。肛管MRI检查诊断克罗恩病肛瘘的敏感度及特异度为100％和100％。（3）克罗恩病术前并发症的影像学表现：①71例肛瘘患者中，65例表现为2个以上内口或瘘管的复杂性肛瘘。内口为瘘管发出的起始点，肛管MRI增强检查示肛管黏膜下-括约肌间的点状、细条状或小圆形异常强化灶。瘘管表现为水平或垂直走行的管状、索条状结构，肛管MRI检查他加权成像示瘘管呈稍高-高信号，增强检查示瘘管呈明显较均匀强化或管壁强化、管腔无强化。38例合并肛周脓肿患者肛管MRI检查他加权成像示脓肿呈明显高信号，增强呈环形强化，内部无强化。②26例肠瘘患者中，17例出现肠间瘘。CTE增强检查示多段肠壁增厚，较正常肠管强化明显，肠管互相纠集、粘连，呈网状连接，形似花瓣样改变。14例患者出现肠-皮肤瘘（其中6例合并肠间瘘，1例合并肠间瘘及肠-膀胱瘘），4例出现肠-膀胱瘘（其中2例合并肠间瘘、1例合并肠间瘘及肠-皮肤瘘），1例出现肠-阴道瘘，CTE或MRE检查示病变肠管肠壁增厚，显示管道影与腹壁、膀胱、阴道的直接相通，管状影呓加权图像呈高信号，增强呈管壁强化；部分肠管与脏器空间位置近，无管道直接沟通，仅显示邻近器官的异常强化或局部积气。③肠梗阻CTE检查示增厚的肠壁管腔变窄，合并近端肠管扩张。增厚肠壁强化方式不一。24例肠梗阻患者呈3种不同的强化方式：12例表现为肠壁黏膜层强化，黏膜下层及肌层无强化；4例表现为肠壁黏膜层及肌层强化，黏膜下层无强化；8例表现为肠壁全层均匀或不均匀强化。④23例患者并发腹腔脓肿，其中15例同时合并肠瘘。CTE或MRE检查示腹部类圆形或椭圆形的包块，T2加权成像呈高信号，周围系膜出现炎性渗出，内部为液性成分，增强见边缘环壁强化，内部脓液无强化。⑤3例患者合并消化道穿孔，其中1例同时合并肠瘘。CTE和X线片检查示肠旁系膜或腹腔膈下出现游离气体影。⑥2例患者分别合并肾结石和肾积水。肾结石X线检查示肾盏内多发边缘锐利的致密影沉积，肾积水CTE检查示输尿管壁炎性增厚并近端管腔扩张。（4）治疗及随访情况：128例患者均成功行手术治疗及获得随访，随访时间为4—27个月。10例患者因术后并发症再次手术，7例肛瘘复发肛管MRI检查示既往病变部位的瘘管或脓肿愈合不全或进展，病灶形态及位置与术前大致相仿。2例吻合口狭窄CTE检查示肠壁增厚，吻合口近端梗阻扩张。1例吻合口瘘CTE增强检查示金属吻合环旁不规则腔样灶，病灶内部积液，可见边缘强化。其余118例患者术后恢复良好，CTE或MRE检查未见肠瘘、肠梗阻并发症。结论克罗恩病外科并发症以肛瘘最多见，肠瘘、肠梗阻及腹腔脓肿相对多见。术后早期并发症以肛瘘复发多见。克罗恩病病变部位与并发症类别相关。CTE、MRE及肛管MRI检查对克罗恩病合并的不同并发症表现为不同的影像学特点，其在评估克罗恩病腹腔及肛周并发症上具有重要价值。

Objective To investigate the imaging features of surgical complications of Crohn＇s disease （CD）. Methods The retrospective cross-sectional study was conducted. The clinical data of 128 CD patients with surgical complications who were admitted to the Sixth Affiliated Hospital of Sun Yat-sen Univemity from January 2014 to December 2015 were collected. All the patients underwent computed tomography enterography （CTE）, magnetic resonance enterography （MRE）, magnetic resonance imaging （MRI） of anal tube and X-ray examination. The patients underwent surgical therapies after examinations. Observation indicators： （1） clinical characteristics of surgical complications of CD ： occurrence of surgical complications of CD, correlation between preoperative complications and Montreal types of CD, （2） diagnostic accuracy of surgical complications and pcrianal lesions through CTE, MRE and MRI of anal tube, （3） imaging findings of preoperative complications of CD, （4） treatment and follow-up situations. Follow-up using telephone interview and outpatient examination was performed to detect the postoperative recovery and reoperations of patients up to March 2016. Count data were represented as frequency or percentage. The correlation between preoperative complications and Montreal types of CD was represented as the odds ratio （OR） and 95% confidence interval （CI）. The features of diagnostic indexes were described as the sensitivity and specificity. Results （1） Clinical characteristics of preoperative complications of CD： all the 128 patients had preoperative complications, including 71 with anal fistula or anal fistula combined with perianal abscess, 26 with intestinal fistula, 24 with intestinal obstruction, 23 with abdominal abscess, 3 with digestive tract perforation, 1 with kidney stone and 1 with hydronephrosis. Of 128 patients, 12 had intestinal fistula combined with abdominal abscess, 1 had intestinal fistula combined with intestinal obstruction, 3 had intestinal fistula combined with abdominal abscess and intestinal obstruction, 1 had intestinal fistula combined with digestive tract perforation and 1 had intestinal fistula combined with hydronephrosis. There was a correlation between lesion location of CD and type of complications. Thirty-five of 51 patients had strictures or penetrationtype lesions, with a correlation between strictures or penetration-type lesions and ileal CD [ OR = 6.23, 95% confidence interval （95% CI） ： 2. 86-13.61, P 〈 0.05 ]. Fifty-six of 77 patients had anal fistula, showing a correlation between combined anal fistula and colonic lesions of CD （ OR = 6. 40, 95% CI： 2.92-14. 01, P 〈 0.05 ）. （2） Diagnostic accuracy of CTE, MRE and MRI of anal tube ： with intraoperative exploration findings as the standard, the sensitivity and specificity of surgical complications of CD were 84% and 95% through CTE or MRE, and the sensitivity and specificity of anal fistula were 100% and 100% through MRI of anal tube. （3） Imaging findings of surgical complications of CD. ① Of 71 patients with anal fistula, 65 had 2 or more internal openings or fistula tract of complex anal fistula. The internal opening was a starting point of the fistula tract, and enhanced scans of MRI displayed punctate, shredded or small round abnormal strengthening signals between under mucous membrane of the anal canal and sphincter. The tubular and striped fistula tract was horizontal or vertical distribution, with a lightly high-high signal on T2 weighted-images （WI）. The results of enhanced scans of MRI showed that there was an obvious homogeneous enhancement in the fistula tract or enhancement in the fistula tract wall, and no enhancement in the cavity of fistula tract. MRI findings in 38 patients combined with perianal abscess included a obvious high-signal on T2WI, and enhanced scans of MRI showed circular enhancement and no internal enhancement. ② Of 26 patients with intestinal fistula, 17 had intestinal fistula, imaging findings included multiple thickened intestinal walls and more obvious enhancement compared with normal intestinal canal. There was gathering and adhesions among intestinal canals, showing mash connections and petal-like changes. Fourteen patients had enterocutaneous fistula （6 combined with intestinal fistula and 1 patient combined with intestinal fistula and intestine-bladder fistula）. Four patients had intestine-bladder fistula （2 combined with intestinal fistula and 1 combined with intestinal fistula and enterocutaneous fistula）. One patient had intestine-vagina fistula. The results of CTE and MRE examinations showed that thickened intestinal canals and intestinal walls in the lesions, and shadows of intestinal canals communicated with the abdominal, bladder wall and vagina, with a high signal on T2WI and enhancement of intestinal wall by enhanced scan. The partial intestinal canals were physically close to other organs, without a connection between them, and anomalous enhancement or local pneumatosis among the adjacent organs were detected. ③ CTE findings of intestinal obstruction included constriction of intestinal canal combined with dilatation of proximal intestinal canal. There were 3 enhancement methods of thickened intestinal wall in 24 patients with intestine obstruction. Imaging findings of 12 patients included enhancement in the intestinal mucosa and no enhancement in the submucosa and muscularis mucosa. Imaging findings of 4 patients included enhancement of intestinal mucosa and muscularis mucosa and no enhancement in the submucosa. Imaging findings of 8 patients included homogenous and heterogeneous enhancements in the intestinal walls. ④ Twenty- three patients were complicated with abdominal abscess, including 15 combined with intestine fistula. The scans of CTE showed that there was a round-like or oval mass in the abdomen, with a high signal on T2WI, fluid-dominated inflammatory exudation around the mesentery, the enhancement of annular wall of mesentery and no enhancement of pus within the mesentery. ⑤Three patients were combined with digestive tract perforation, including 1 combined with intestine fistula. CTE and X-ray detections showed there was a shadow of free gas in the intestinal mesentery and under abdominal diaphragm. ⑥ Two patients were combined with kidney stone and hydronephrosis. X-ray findings of kidney stone included the deposition of multiple and sharp-edged dense shadows within the renal calices. CTE findings of hydronephrosis included inflammatory thickening of ureteric wall with proximal ureter dilatation. （4） Treatment and follow-up situations： 128 patients underwent successful operation and were followed up for 4-27 months. Of 10 patients undergoing reoperations due to postoperative complications, MRI detection of 7 patients with recurrence of anal fistula showed fistula tract or abscess located at the previous loci was incompletely healed or progressed, morphous and location of lesions were roughly the same as the preoperative situations. The scans of CTE in 2 patients with anastomotic stricture showed that there were the thickening of intestinal wall and obstruction and dilatation at the proximal anastomotic-site. The enhanced scan of CTE in 1 patient with anastomofic fistula showed that there were irregularly cavity-like lesion beside the metal anastomotic ring, and effusion was seen within the lesions, with an edge enhancement. The other 118 patients recovered well without intestinal fistula or intestinal obstruction on CTE or MRE examination. Conclusions Anal fistula is the most common surgical complication of CD, and intestinal fistula, intestinal obstruction and abdominal abscess are also relatively common. The early postoperative complications consist of the recurrence of anal fistula. Location of lesions in CD is associated with the type of complications. CTE or MRE and anal MRI findings have different imaging characteristics for CD combined with different complications, with a certain value in the assessment of abdominal and perianal complications.