Anal Function And Risk Factors For Fecal Incontinence After Laparoscopic Intersphincteric Resection For Low Rectal Cancer

ObjectiveThe purpose of this prospective study was to assess anal function and risk factors for fecal Incontinence after laparoscopic intersphincteric resection(Lap-ISR)for the treatment of low rectal cancer.MethodsFrom June 2011 to August 2017,108 patients underwent Lap-ISR at the Department of Colorectal Surgery in our hospital.In line with the inclusion and exclusion criteria of the current study,a total of 68 patients were included for analysis at the end of follow-up(December 31,2017).Incontinence after surgery was assessed by Wexner incontinence score(WIS)and Kirwan’s classification,anal function was evaluated by the standardized gastrointestinal questionnaire,and patients’satisfaction was appraised by visual analogue scale(VAS).The patients were divided into two groups,including the good anal function(WIS≤10)and the poor anal function(WIS>10).The baseline characteristics,clinicopathological results,perioperative morbidities,physiology parameters and anal function were compared between the two groups.Univariate and multivariate analyses were adopted to assess the risk factors for fecal Incontinence after surgery.ResultsIn the current series,54.4%(37/68)were men,the median age was 61years(range,25-79 years).The body mass index(BMI)was 26.03±3.01kg/m~2.There were 29(42.6%)and 13(19.2%)patients who underwent partial and total intersphincteric resection respectively.The median operating time was 187 min(range,120~345 min),median intraoperative blood loss was 50 ml(range,20~300 ml),median distal resection margin was 1.5 cm(range,0.8-3.0 cm),median number of harvested lymph nodes was 14(1~31).The overall R0resection rate was 100%.No hospital mortality or conversion was presented in this study.A total of 19 morbidity episodes were noted in 15(22.1%)patiens during the perioperative period,but only 15.8%(3/19)complication was gradeⅢ-Ⅳaccording to the Dindo system.In addition,6(8.8%)individuals accepted long-course neoadjuvant chemoradiotherapy(CRT)and 24(35.3%)cases adopted radiotherapy.Our data indicated that the WIS was 9.56±5.86 in this series,58.8%(40/68)patients was classified as good function(WIS≤10)and 41.2%(28/68)as poor function(WIS>10).The median Kirwan’s classification was 3(range,1-5),and there was 49(72.1%)patients with Kirwan’s grade≤3.The VAS score was 5.5±1.76,and the rate of patients’satisfaction with anal functional(VAS>5 points)was 69.1%(47/68).Moreover,the standardized gastrointestinal questionnaire results suggested that 14(20.5%)patients had 1 to 3 defecations per day,21(30.9%)had 4 to 5 defecations per day,18(26.5%)had 6 to 8defecations per day,15(22.1%)had more than 9 times defecations per day;54.4%(37/68)had urgency,17.6%(12/68)required antidiarrheal medications,57.4%(39/68)had soiling during the daytime,50%(34/68)suffered from soiling during the nighttime,82.4%(56/68)had faces/flatus discrimination,21(30.9%)need restricted diet.In addition to therapy(25%vs 50%,P=0.03),there were no significant differences in the baseline characteristics,clinicopathological results and surgical morbidities between the good anal function(WIS score≤10)and poor anal function(WIS score>10)groups.Multivariate analysis confirmed that adjuvant radiotherapy(OR,4.19.59,95%CI,1.32-13.32,P=0.015)and anastomotic leakage(OR,10.67;95%CI,1.08-105.28;P=0.043)were independent risk factors for poor anal function after Lap-ISR.Compared with the good anal function group,the frequency of poor anal function with defecations more than 9 times per day,solid or liquid incontinence,daytime or nighttime soiling,faces/flatus discrimination,pad wearing,lifestyle alteration was more significantly higher in the control group(P<0.01).Furthermore,the rate of decrease in resting or squeeze pressure and the frequency of abnormal rectoanal inhibitory reflex(RAIR)after surgery were obviously higher in the poor anal function group than that in the good anal function group.ConclusionsPatients with low rectal cancer may acquire satisfactory anal function after Lap-ISR.Radiotherapy and anastomotic leakage are independent risk factors for poor function.Additionally,the decrease in resting or squeeze pressure and the abnormal RAIR may be associated with incontinence after surgery.