摘要目的:探讨直肠癌保肛术后存活5年以上患者的低位前切除综合征（LARS）发生情况，并分析其与术后恢复时间的关系。方法:本研究采用单中心回顾性横断面研究方法。病例纳入标准：（1）接受直肠癌保肛根治手术；（2）病理确诊腺癌；（3）肿瘤下缘距肛缘15 cm以内；（4）术后存活且随访至少满5年（60个月）。排除标准：（1）局部切除；（2）永久性造口；（3）反复肠道感染；（4）局部复发；（5）既往直肠肛门手术史；（6）术前长期排粪障碍。北京大学人民医院胃肠外科2005年1月至2016年5月期间收治的160例患者入组。采用电话访谈的方式进行LARS评分问卷调查，测试症状包括排气失禁（0~7分）、稀粪失禁（0~3分）、排粪频率（0~5分）、排粪聚集（0~11分）和排粪急迫（0~16分）；各项分值相加从好到差依次分为3类：无LARS（0~20分）、轻度LARS（21~29分）和重度LARS（30~42分）。分析术后存活5年以上患者的LARS和重度LARS的患病率、术后时间与LARS评分的相关性、以及术后时间是否是重度LARS和各种LARS症状的相关危险因素。结果:160例受访者完成电话访谈，中位随访时间为97（60~193）个月。有81例（50.6%）患者存在LARS，其中34例（21.3%）为轻度LARS，47例（29.4%）为重度LARS。Spearman相关性分析未发现LARS总分与术后时间存在相关性（相关系数α=-0.016， P=0.832）。多因素分析结果显示，吻合口高度（RR=0.850， P=0.022）和放疗（RR=5.760， P<0.001）是重度LARS的独立危险因素；而术后时间在本研究术后重度LARS发生风险的多因素分析模型中未显示出统计学意义（RR=1.003， P=0.598）。术后时间与LARS分级与排粪次数、排粪聚集和排粪急迫症状严重程度均无关（均 P>0.05），但术后存活10年以上的患者发生排气失禁（3/31， P=0.003）和稀便失禁（8/31， P=0.005）的比例较低。 结论:直肠癌保肛术后存活5年以上患者群体仍有较高的LARS患病率。远期重度LARS症状并未显示随时间进一步延长而缓解的迹象。

abstractsObjective:In this study, we aimed to investigate the prevalence of low anterior resection syndrome (LARS) in patients who had survived for more than 5 years after sphincter-preserving surgery for rectal cancer and to analyze its relationship with postoperative time.Methods:This was a single-center, retrospective, cross-sectional study. The study cohort comprised patients who had survived for at least 5 years (60 months) after undergoing sphincter- preserving radical resection of pathologically diagnosed rectal adenocarcinoma within 15 cm of the anal verge in the Department of Gastrointestinal Surgery, Peking University People's Hospital from January 2005 to May 2016. Patients who had undergone local resection, had permanent stomas, recurrent intestinal infection, local recurrence, history of previous anorectal surgery, or long- term preoperative defecation disorders were excluded. A LARS questionnaire was administered by telephone interview, points being allocated for incontinence for flatus (0-7 points), incontinence for liquid stools (0-3 points), frequency of bowel movements (0-5 points), clustering of stools (0–11 points), and urgency (0-16 points). The patients were allocated to three groups based on these scores: no LARS (0-20 points), minor LARS (21-29 points), and major LARS (30-42 points). The prevalence of LARS and major LARS in patients who had survived more than 5 years after surgery, correlation between postoperative time and LARS score, and whether postoperative time was a risk factor for major LARS and LARS symptoms were analyzed.Results:The median follow-up time of the 160 patients who completed the telephone interview was 97 (60–193) months; 81 (50.6%) of them had LARS, comprising 34 (21.3%) with minor LARS and 47 (29.4%) with major LARS. Spearman correlation analysis showed no significant correlation between LARS score and postoperative time (correlation coefficient α=-0.016, P=0.832). Multivariate analysis identified anastomotic height (RR=0.850, P=0.022) and radiotherapy (RR=5.760, P<0.001) as independent risk factors for major LARS; whereas the postoperative time was not a significant risk factor (RR=1.003, P=0.598). The postoperative time was also not associated with LARS score rank and frequency of bowel movements, clustering, or urgency ( P>0.05). However, the rates of incontinence for flatus (3/31, P=0.003) and incontinence for liquid stools (8/31, P=0.005) were lower in patients who had survived more than 10 years after surgery. Conclusions:Patients with rectal cancer who have survived more than 5 years after sphincter-preserving surgery still have a high prevalence of LARS. We found no evidence of major LARS symptoms resolving over time.