Comparison Of Clinical Efficacy Of Different Approaches For Laparoscopic Sphincterectomy (ISR) In The Treatment Of Low Rectal Cancer

Objective:Comparison of radical curative effect、short-term efficacy、postoperative anal function、long-term prognosis of low rectal cancer by laparoscopic intersphincter(ISR)resection with different approaches.Methods:We retrospectively collected clinical data of 235 patients undergoing laparoscopic assisted ISR surgery for low rectal cancer from October 2010 to September 2016,including 142 cases of pelvic approach ISR(hereinafter referred to as pelvic group),57 cases of perineal approach ISR(hereinafter referred to as perineal group),36 cases of trans-anal pull-through group ISR(hereinafter referred to as pull-through group).All operations followed the principle of total mesorectal excision.Using SPSS20.0 statistical software,measurement data was represented by?x±s and chi-square test or Fisher’s exact probability method was used for count data.Comparing the three groups of patients preoperative clinical basic data,intraoperative conditions,postoperative pathological data,postoperative complications,anal function and long-term prognosis.The Kaplan-Meier method was used to plot the survival curve and calculate the survival rate.Log rank test was used to compare the survival rate.The Cox model was used to analyze the prognosis of the patients.Results:(1)Comparison of preoperative basic clinical features:gender、age、AS A rating、abdominal surgery history、tumor size、tumor marker levels(CEA,C A199),neoadjuvant chemoradiation and preoperative clinical staging differences i n the three groups of patients no statistically significant(P>0.05).The BMI inde x of patients in the pull-through group was smaller than that of the perineum g roup(21.8±2.3 kg/m~2 vs 23.2±2.7 kg/m~2,P=0.020).The distance from the anal margin of the lower edge of the pull-through and perineum group tumors(3.8±0.5cm、3.9±0.6cm)were significantly lower than the pelvic group(4.7±0.5cm)(b oth P<0.001).The proportion of tumors occupying more than 1/2 of the intestin e in the pull-through group(27.8%)was significantly less than the perineum gr oup(63.2%)(P=0.001).(2)Comparison of intraoperative conditions:(1)Surgical ti me:The pull-through group(214±40min)and the pelvic group(212±51min)wer e shorter than the perineal group(263±68min)(P<0.001);(2)The intraoperative bl ood loss was less in the pull-through group(62.8±33.5ml)and in the pelvic gro up(62.6±56.7ml)than in the perineum group(86.9±65.3ml)(P=0.045,and P=0.006);(3)Anastomotic distance from the anus marginal distance:the pull-through g roup(1.8±0.5cm)was comparable to the perineum group(1.7±0.5cm)(P=0.360)but lower than the pelvic group(2.6±0.5cm)(P<0.001);(4)Distal margin length:There were no significant differences between the perineal、pelvic and pull-thro ugh groups(1.8±0.5cm,1.8±0.8cm,and1.7±0.5cm,P>0.05).(3)Postoperative recovery:There was no significant difference in postoperative venting time between the t hree groups(P>0.05).Although the mean length of hospital stay in the pull-thro ugh group(8.5±2.9d)and pelvic group(8.0±5.0d)was shorter than that in the perineal group(9.3±2.7d),there was no significant difference in hospitalization d ays after operation in the three groups(P>0.05).(4)Surgical safety:The incidenc e of total complications in the perineal、pelvic and pull-through groups was 29.8%,26.8%,and 11.4%,respectively,and there was no statistically significant di fference between the three groups(P>0.05).There was no significant difference in the incidence of major complications such as anastomotic leakage、intestinal obstruction、pelvic infection、anastomotic stenosis、and urinary retention among the three groups(P>0.05).There was no significant difference in the incidence of surgical relative complications such as pulmonary infection、deep vein thromb osis、urinary tract infection(P>0.05).(5)Postoperative pathology:The positive ra te of distal margin,positive rate of CRM、total number of lymph nodes、numb er of positive lymph nodes、pT stage、pN stage and pTNM stage between the t hree groups were not statistically significant(P>0.05).(6)Anal function:At 3 m onths after ostomy closure,the pelvic group’s function score(14.5±5.6)was sig nificantly lower than the perineum group(16.7±3.9)(P=0.008),but there was n o significant difference between the pelvic group and the pull-through group(16.2±1.1)(P>0.05).At 6 months after ostomy closure,the anal function score(10.4±4.7)in the pelvic group was still significantly lower than the perineal group(12.2±3.9)(P=0.013),and was still not significantly different from the pull-throu gh group(10.7±1.2)(P>0.05).However,at the 12 months after stoma closure,t he three groups of Wexner scores were 8.0±4.0、7.0±4.1 and 7.2±0.9,respectivel y.There was no significant difference in the anal function between the three gr oups(P>0.05).(7)Long-term prognosis:1.3-year DFS in the perineal、pelvic an d pull-through groups(79%vs 83.4%vs.81.8%)、LRFS(93.7%vs 9 7.7%vs90.0%)、DMFS(84.3%vs 86.6%vs 90.9%)and overall survival(97.1%vs 89.4%vs 100%)were no significant difference(P>0.05);2.COX univariate analysi s suggested that CEA>5ng/mL(HR:2.239,95%CI:1.099-4.564,P=0.026),postope rative pN stage(N1)(HR:3.211,95%CI:1.587-6.500,P=0.001)were long-term prognosis risk factors for patients with low rectal cancer,and multivariate anal ysis of COX risk regression model Lymph node metastasis(N1)(HR:2.818,95%CI:1.349-5.885,P=0.06)was an independent risk factor for long-term prognosis in patients with low rectal cancer.3.Surgical approach was not a risk factor for long-term prognosis of patients with low rectal cancer(P>0.05).Inconclusion:1.Three groups of different approaches of laparoscopic ISR(pelvic,transperineal,pull-through)were safe and feasible surgical methods.2.Based on accurate preoperative staging of low rectal cancer,according to the patient’s sex、body mass index、tumor size、anal distance and lymph node metastasis,appropriate ISR surgical approach should be choosen.3.Compared with pelvic ISR and perineal ISR,pull-through ISR had the advantages of shorter operation time、less bleeding and can achieve a lower anastomosis based on a safe distal margin,and was more suitable for lower BMI、the tumor occupies with less than 1/2 in the intestine、lower location and no lymph node metastasis.4.Surgical approach was not an influential factor for the long-term prognosis of low rectal cancer.Lymph node metastasis was an independent risk factor for the long-term prognosis of low rectal cancer.