Machine learning model for prediction of low anterior resection syndrome following laparoscopic anterior resection of rectal cancer:A multicenter study

BACKGROUND Low anterior resection syndrome(LARS)severely impairs patient postoperative quality of life,especially major LARS.However,there are few tools that can accurately predict major LARS in clinical practice.AIM To develop a machine learning model using preoperative and intraoperative factors for predicting major LARS following laparoscopic surgery of rectal cancer in Chinese populations.METHODS Clinical data and follow-up information of patients who received laparoscopic anterior resection for rectal cancer from two medical centers(one discovery cohort and one external validation cohort)were included in this retrospective study.For the discovery cohort,the machine learning prediction algorithms were developed and internally validated.In the external validation cohort,we evaluated the trained model using various performance metrics.Further,the clinical utility of the model was tested by decision curve analysis.RESULTS Overall,1651 patients were included in the present study.Anastomotic height,neoadjuvant therapy,diverting stoma,body mass index,clinical stage,specimen length,tumor size,and age were the risk factors associated with major LARS.They were used to construct the machine learning model to predict major LARS.The trained random forest(RF)model performed with an area under the curve of 0.852 and a sensitivity of 0.795(95%CI:0.681-0.877),a specificity of 0.758(95%CI:0.671-0.828),and Brier score of 0.166 in the external validation set.Compared to the previous preoperative LARS score model,the current model exhibited superior predictive performance in predicting major LARS in our cohort(accuracy of 0.772 for the RF model vs 0.355 for the preoperative LARS score model).CONCLUSION We developed and validated a robust tool for predicting major LARS.This model could potentially be used in the clinic to identify patients with a high risk of developing major LARS and then improve the quality of life.

Effect of low anterior resection syndrome on quality of life in colorectal cancer patients:A retrospective observational study

BACKGROUND Low anterior resection syndrome(LARS)is a common complication of anuspreserving surgery in patients with colorectal cancer,which significantly affects patients'quality of life.AIM To determine the relationship between the incidence of LARS and patient quality of life after colorectal cancer surgery and to establish a LARS prediction model to allow perioperative precision nursing.METHODS We reviewed the data from patients who underwent elective radical resection for colorectal cancer at our institution from April 2013 to June 2020 and completed the LARS score questionnaire and the European Organization for Research and Treatment of Cancer Core Quality of Life and Colorectal Cancer Module questionnaires.According to the LARS score results,the patients were divided into no LARS,mild LARS,and severe LARS groups.The incidence of LARS and the effects of this condition on patient quality of life were determined.Univariate and multivariate analyses were performed to identify independent risk factors for the occurrence of LARS.Based on these factors,we established a risk prediction model for LARS and evaluated its performance.RESULTS Among the 223 patients included,51 did not develop LARS and 171 had mild or severe LARS.The following quality of life indicators showed significant differences between patients without LARS and those with mild or severe LARS:Physical,role,emotional,and cognitive function,total health status,fatigue,pain,shortness of breath,insomnia,constipation,and diarrhea.Tumor size,partial/total mesorectal excision,colostomy,preoperative radiotherapy,and neoadjuvant chemotherapy were identified to be independent risk factors for LARS.A LARS prediction model was successfully established,which demonstrated an accuracy of 0.808 for predicting the occurrence of LARS.CONCLUSION The quality of life of patients with LARS after colorectal cancer surgery is significantly reduced.

Application of electroacupuncture in the prevention of low anterior resection syndrome after rectal cancer surgery

BACKGROUND Low anterior resection syndrome(LARS)is one of the common postoperative complications in patients with rectal cancer,which seriously affects their postoperative recovery and quality of life(QoL).Electroacupuncture therapy is one of the characteristic therapies of traditional Chinese medicine.There are few reports on the prevention and treatment of LARS by electroacupuncture therapy.AIM To explore the clinical effectiveness of electroacupuncture in managing rectal cancer patients with postoperative LARS.METHODS A total of 50 patients with LARS after rectal cancer surgery were retrospectively selected as the research subjects.According to the treatment methods,they were divided into an observation group(n=25)and a control group(n=25).During the four-week treatment period,the control group received standard defecation function training,while the observation group received electroacupuncture care and traditional defecation function training.The anal pressure index(which includes anal resting pressure,anal systolic pressure,and maximum tolerable volume),European Organization of Research and Treatment of Cancer(EORTC)QoL C30(QLQ-C30)score,LARS Scale(LARSS)score,Wexner anal incontinence scale score,Xu Zhongfa five-item 10-point scale score,and the occurrence of adverse reactions were compared between the two groups before and after treatment.RESULTS The experimental group showed considerably enhanced LARSS scores compared to those in the control group after four weeks of treatment.In the first week,second week,and fourth week,the LARSS score and Wexner anal incontinence scale score decreased,and the Xu Zhong method five-item 10-point scale score increased,with significant differences(P<0.05).The experimental group showed substantial improvements in anal resting pressure,anal systolic pressure,and maximum tolerance volume after undergoing 4 wk of therapy in the untreated group(P<0.05).The experimental group's QLQ-C30 score on the EORTC QoL questionnaire was higher than that of the control group during the 1st,2nd,and 4th wk(P<0.05).No significant variation between the groups in the frequency of adverse reactions(P>0.05)was observed.CONCLUSION Electroacupuncture positively impacted LARS following rectal cancer surgery,effectively improving clinical symptoms and anal pressure indicators and patients’standard of life.

Assessment and management of low anterior resection syndrome after sphincter preserving surgery for rectal cancer

Many patients develop a variety of bowel dysfunction after sphincter preserving surgeries(SPS)for rectal cancer.The bowel dysfunction usually manifests in the form of low anterior resection syndrome(LARS),which has a negative impact on the patients'quality of life.This study reviewed the LARS after SPS,its mechanism,risk factors,diagnosis,prevention,and treatment based on previously published studies.Adequate history taking,physical examination of the patients,using validated questionnaires and other diagnostic tools are important for assessment of LARS severity.Treatment of LARS should be tailored to each patient.Multimodal therapy is usually needed for patients with major LARS with acceptable results.The treatment includes conservative management in the form of medical,pelvic floor rehabilitation and transanal irrigation and invasive procedures including neuromodulation.If this treatment failed,fecal diversion may be needed.In conclusion,Initial meticulous dissection with preservation of nerves and creation of a neorectal reservoir during anastomosis and proper Kegel exercise of the anal sphincter can minimize the occurrence of LARS.Pre-treatment counseling is an essential step for patients who have risk factors for developing LARS.

Anorectal dysfunction in patients with mid-low rectal cancer after surgery: A pilot study with three-dimensional high-resolution manometry

BACKGROUND The quality of life in patients who develop low anterior resection syndrome(LARS)after surgery for mid-low rectal cancer is seriously impaired.The underlying pathophysiological mechanism of LARS has not been fully investigated.AIM To assess anorectal function of mid-low rectal cancer patients developing LARS perioperatively.METHODS Patients diagnosed with mid-low rectal cancer were included.The LARS score was used to evaluate defecation symptoms 3 and 6 mo after anterior resection or a stoma reversal procedure.Anorectal functions were assessed by threedimensional high resolution anorectal manometry preoperatively and 3-6 mo after surgery.RESULTS The study population consisted of 24 patients.The total LARS score was decreased at 6 mo compared with 3 mo after surgery(P<0.05),but 58.3%(14/24)lasted as major LARS at 6 mo after surgery.The length of the high-pressure zone of the anal sphincter was significantly shorter,the mean resting pressure and maximal squeeze pressure of the anus were significantly lower than those before surgery in allpatients (P < 0.05), especially in the neoadjuvant therapy group after surgery (n = 18). The focalpressure defects of the anal canal were detected in 70.8% of patients, and those patients had higherLARS scores at 3 mo postoperatively than those without focal pressure defects (P < 0.05). Spasticperistaltic contractions from the new rectum to anus were detected in 45.8% of patients, whichwere associated with a higher LARS score at 3 mo postoperatively (P < 0.05).CONCLUSIONThe LARS score decreases over time after surgery in the majority of patients with mid-low rectalcancer. Anorectal dysfunctions, especially focal pressure defects of the anal canal and spasticperistaltic contractions from the new rectum to anus postoperatively, might be the majorpathophysiological mechanisms of LARS.