Objective: To evaluate the long-term effects of anal fistula plug treatment on postoperative anal function in patients with trans-sphincteric perianal fistula, and identify risk factors associated with anal function. Methods: A case-control study was conducted. Clinical and follow-up data of 123 patients with trans-sphincteric perianal fistula receiving anal fistula plug treatment in Beijing Chaoyang Hospital from August 2008 to September 2012 were retrospectively analyzed. The follow-up deadline was April 30, 2020. The Wexner score for incontinence was used to evaluate pre-and postoperative anal function (range from 0 to 20, with higher score representing worse function). The potential risk factors affecting postoperative anal function, including gender, age, fasting blood glucose, diabetes, smoking, alcoholism, location of external opening of anal fistula, surgeon expertise and operation time, were statistically analyzed. Results: Among the 123 patients, 114 were male and 9 were female, the median age was 39 (15-69) years, body mass index (BMI) was (26.2±3.9) kg/m(2), and the median distance between the external opening of anal fistula and the anal verge was 2.6 (1.0-5.0) cm. The median operation time was 30.4 (15.0-60.0) minutes. The median follow-up time was 120 (93-141) months. Sixty-nine patients (56.5%) were healed. The assessment of anal function by Wexner incontinence score showed that 33 (26.8%) patients had anal functional decline after surgery, and the postoperative median Wexner score was 1.34 (0-8), which was significantly higher than preoperative score of 0.17 (0-4) (Z=-5.057, P<0.001). Compared with preoperative levers, postoperative subscores of flatus incontinence, liquid incontinence, solid incontinence and alteration in lifestyle were increased significantly (all P<0.05). Subgroup analysis showed that both in the healed and unhealed groups, the postoperative Wexner scores were higher than those before surgery [healed group: 1.22 (0-8) vs. 0.17 (0-1), Z=-3.796, P<0.001; unhealed group: 1.5 (0-8) vs.0.17 (0-3), Z=-3.422, P=0.001]. Univariate analysis revealed that 33 patients with postoperative anal functional decline had higher BMI, higher fasting blood glucose, higher proportion of alcoholism, longer distance between external opening of anal fistula and the anal verge, and longer operation time (all P<0.05). Multivariate logistic regression analysis testified that higher BMI (OR=1.485, 95% CI: 1.220-1.807, P<0.001) and longer distance between external opening and anal verge (OR=2.207, 95% CI: 1.276-3.220, P=0.003) were independent risk factors for postoperative anal functional decline. Conclusions: The treatment for trans-sphincteric anal fistula with anal fistula plug leads to long-term postoperative anal function decline. For patients with obesity and longer distance between external opening of anal fistula and the anal verge, this procedure should be performed with particular caution, and the anal sphincter should be preserved as much as possible during the operation.
目的： 肛瘘栓填塞治疗具有手术创伤小、治疗费用低、对肛门括约肌损伤较小等优势，但其对患者肛门功能的长期影响目前尚存在争议。本研究评估肛瘘栓填塞治疗对经括约肌型肛瘘患者术后肛门功能的长期影响，并分析影响术后肛门功能的相关因素。 方法： 本研究采用病例对照研究方法。分析2008年8月至2012年9月期间，首都医科大学附属北京朝阳医院普通外科接受肛瘘栓填塞治疗的123例经括约肌型肛瘘患者资料。采用Wexner失禁评分评估手术前后肛门功能（0~20分，分值越高，功能越差），分析影响术后肛门功能的相关因素（包括性别、年龄、空腹血糖、糖尿病史、吸烟史、酗酒史、肛瘘外口位置、术者职称、手术时间等）。 结果： 123例接受肛瘘栓填塞治疗的经括约肌型肛瘘患者，男性114例，女性9例，中位年龄39（15~69）岁，体质指数（26.2±3.9）kg/m(2)，肛瘘外口至肛缘距离的中位数为2.6（1.0~5.0）cm。全组中位手术时间为30.4（15.0~60.0）min，术后中位随访10年（93~141个月），69例（56.5%）愈合。肛门功能评分显示，33例（26.8%）患者术后肛门功能下降；全组患者术后Wexner失禁评分中位数为1.34（0~8.00）分，高于术前评分0.17（0~4.00）分，差异有统计学意义（Z=-5.057，P<0.001）；术后的肛门控气、控液体粪便、控固体粪便、生活方式评分均较术前增加（均P<0.05）。亚组分析显示，肛瘘愈合患者和肛瘘未愈合患者的术后Wexner失禁评分均较术前上升[肛瘘愈合者：0.17（0~1.00）分升至1.22（0~8.00）分，Z=-3.796，P<0.001；肛瘘未愈合者：0.17（0~3.00）分升至1.5（0~8.00）分，Z=-3.422，P=0.001]。单因素分析显示，33例术后肛门功能下降的患者体质指数更高，术前空腹血糖更高，酗酒史人数比例更高，肛瘘外口至肛缘距离更远，手术时间更长（均P<0.05）；多因素Logistic回归分析显示，体质指数升高（OR=1.485，95% CI：1.220~1.807，P<0.001）和肛瘘外口至肛缘距离增加（OR=2.207，95% CI：1.276~3.220，P=0.003），是影响肛瘘栓填塞术后肛门功能下降的独立危险因素。 结论： 肛瘘栓填塞治疗会导致术后肛门长期功能降低；针对肥胖和肛瘘外口至肛缘距离较远的患者，进行肛瘘栓填塞治疗时需尤为谨慎，术中应尽可能保护肛门括约肌。.
Keywords: Anal fistula; Anal fistula plug; Anal function; Transsphincteric.