[Analysis on prognosis and influencing factors of postoperative low anterior resection syndrome for rectal cancer patients undergoing laparoscopic anus-preserving radical resection].

Objective: To investigate the prognosis and influencing factors of postoperative low anterior resection syndrome (LARS) for rectal cancer patients undergoing laparoscopic sphincter-preserving radical resection. Methods: A retrospective case-control study was used in this study. Clinical data of 268 rectal cancer patients undergoing laparoscopic sphincter-preserving radical resection at Department of Gastrointestinal Surgery of The First Affiliated Hospital of Bengbu Medical College from January 2016 to January 2018 were retrospectively collected. Inclusion criteria: (1) operation procedure was total mesorectal excision (TME) and sphincter-preserving radical resection; (2) rectal cancer was confirmed by postoperative pathology; (3) age of patient was ≥ 18 years old. Exclusion criteria: (1) patient who had history of pelvic surgery and pelvic fractures, which would affect the anorectal function; (2) patient who had history of preoperative chronic constipation and irritable bowel syndrome, which would affect defecation; (3) patient who developed postoperative complications, such as anastomotic leakage, which would affect defecation function; (4) patient who received long-term use of drugs, which would affect the function of gastrointestinal tract or anus; (5) patient suffered from mental illness, who was unable to communicate properly; (6) patient who was lack of clinical data or had incomplete clinical data. Patients were followed up at 3, 6 and 12 months postoperatively, and LARS was diagnosed and graded according to the LARS score scale. The LARS score ranged from 0 to 42 points, and 0 to 20 was difined as no LARS, 21 to 29 was mild LARS, and 30 to 42 was severe LARS. LARS score >20 points at any time point was defined as postoperative LARS. Severe LARS transferring into mild LARS and mild LARS transferring into no LARS was defined as symptom improvement. Incidence and outcomes of LARS were evaluated. The factors associated with LARS outcomes were analyzed using χ(2) test and logistic regression model. Results: A total of 268 patients were enrolled. The incidence of LARS was 42.9% (115/268), 32.5% (87/268) and 20.1% (54/268) at 3, 6, and 12 months postoperatively respectively, and no new case of LARS was found after 3 months postoperatively. The incidence of mild LARS was 25.7% (69/268), 17.2% (46/268) and 8.6% (23/268) at 3, 6, and 12 months postoperatively respectively, and mild LARS incidence at 6 months was significantly lower than that at 3 months (χ(2)=5.857, P=0.016), and was significantly higher than that at 12 months (χ(2)=8.799, P=0.003). The incidence of severe LARS was 17.2% (46/268), 15.3% (41/268) and 11.6% (31/268) at 3, 6, and 12 months postoperatively respectively, without significant difference among 3 time points (all P>0.05). The improvement rate within one year after surgery in patients with mild LARS diagnosed at 3 months was significantly higher than that in patients with severe LARS (88.4% vs. 32.6%, χ(2)=38.340, P<0.001). Univariate analysis showed that female, distance from anastomosis to anal verge < 5 cm and tumor diameter ≥ 5 cm were associated with unsatisfied LARS outcomes (all P<0.05). Logistic regression analysis showed that distance from anastomosis to anal verge <5 cm was an independent risk factor for LARS outcome (OR=3.589, 95% CI: 1.163 to 2.198, P<0.001). Conclusions: The incidence of LARS after laparoscopic sphincter-preserving radical resection decreases with time. The improvement rate within postoperative 1-year of severe LARS is lower than that of mild LARS. Low anastomotic position may lead to impaired improvement of LARS.目的： 探讨腹腔镜直肠癌保肛根治术后低位前切除综合征（LARS）的病情转归及其影响因素。 方法： 采用回顾性病例对照研究方法。收集2016年1月至2018年1月期间在蚌埠医学院第一附属医院胃肠外科接受手术治疗的直肠癌患者资料。病例纳入标准：（1）患者接受的手术方式为腹腔镜全直肠系膜切除术（TME）直肠癌保肛根治术；（2）术后病理证实为直肠癌；（3）患者年龄≥18岁。排除标准：（1）术前有盆腔手术史、骨盆骨折等可能影响直肠肛门功能的病史；（2）术前合并慢性便秘、肠易激综合征等影响排粪的病史；（3）术后并发吻合口漏，影响术后排粪功能；（4）术后长期服用影响胃肠道或肛门功能的药物；（5）患有精神疾病，无法正常交流沟通；（6）临床资料缺失。分别于术后3、6及12个月对患者进行随访，并依据LARS评分量表对LARS进行诊断及分级。LARS评分范围为0~42分，0~20分为无LARS，21~29分为轻度LARS，30~42分为重度LARS；任意时间点LARS评分>20分则为术后并发LARS；症状好转定义为重度转轻度及轻度转为无LARS。计算LARS的发生率及转归情况，采用χ(2)检验及logistic回归模型分析影响LARS转归的因素。 结果： 共纳入268例患者。术后3个月LARS的发生率为42.9%（115/268），术后6个及12个月分别为32.5%（87/268）和20.1%（54/268），术后3个月后无新发LARS病例。轻度LARS发生率在术后3、6及12个月分别为25.7%（69/268）、17.2%（46/268）和8.6%（23/268），术后6个月发生率明显低于术后3个月（χ(2)=5.857，P=0.016），明显高于术后12个月（χ(2)=8.799，P=0.003），差异均具有统计学意义（均P<0.05）；重度LARS发生率在术后3、6及12个月分别为17.2%（46/268）、15.3%（41/268）和11.6%（31/268），两两比较，差异均无统计学意义（均P>0.05）。术后3个月评定为轻度LARS的患者术后1年内好转率显著高于重度LARS患者[88.4%（61/69）比32.6%（15/46），χ(2)=38.340，P<0.001]。单因素分析结果显示，性别、吻合口距肛缘距离及肿瘤直径与术后LARS转归有关（均P<0.05）。logistic回归模型分析结果显示，吻合口距离肛缘<5 cm是影响直肠癌术后LARS转归的独立危险因素（OR=3.589，95%CI：1.163~2.198，P<0.001）。 结论： 腹腔镜直肠癌保肛根治术后LARS的发生率随时间延长而逐渐降低；重度LARS术后1年的好转率低于轻度LARS患者；吻合口位置低，会影响LARS好转。.