Predictive factors of low anterior resection syndrome following anterior resection of the rectum

Low Anterior Resection Syndrome in Total Mesorectal Excision: Risk Factors and Its Relationship with Quality of Life

Background: Low anterior resection syndrome (LARS) is a bowel dysfunction following sphincter-sparing proctectomy. The occurrence of LARS may affect a patient's overall quality of life (QoL) after surgery. Current research was aimed to investigate related factors of LARS and major LARS in total mesorectal excision (TME) and its relationship with QoL. Methods: This study included patients who underwent TME at authors' institutes. LARS was evaluated with an LARS score. QoL was identified using the European Organization for Research and Treatment of Cancer QLQ-C30 questionnaire, version 3.0. Appropriate statistical methods were used to ascertain risk factors for LARS and major LARS and to analyze the relationships between QoL and LARS. The primary objective was to identify related factors of LARS and major LARS. The secondary objective was to examine the relationships between QoL and LARS. Results: Multivariable analysis identified neoadjuvant chemoradiotherapy (odds ratio [OR] 4.923, 95% confidence interval [CI] 2.335-10.379, P < .001), local anal distance from the lower edge of the tumor (OR 6.199, 95% CI 2.701-14.266, P < .001), and anastomotic leakage (OR 5.624, 95% CI 1.463-21.614, P = .012) as independent predictors for development of LARS. Meanwhile, neoadjuvant chemoradiotherapy (OR 4.693, 95% CI 1.368-16.107, P = .014) and local anal distance from the lower edge of the tumor (OR 4.935, 95% CI 1.332-18.285, P = .017) were dramatically correlated with development of major LARS in a multivariable analysis. In the major LARS group, statistically significant differences (P < .05) were ascertained, include physical functioning, role functioning, emotional functioning, social functioning, and global health. In addition, pain and diarrhea were evidently higher. Conclusions: Neoadjuvant chemoradiotherapy, local anal distance from the lower edge of the tumor, and anastomotic leakage correlated strongly with development of LARS, and neoadjuvant chemoradiotherapy and local anal distance from the lower edge of the tumor correlated strongly with development of major LARS. Meanwhile, the QoL of patients with major LARS was lower than that of patients with no/minor LARS.

Segmental Rectum Resection for Deep Endometriosis and Excision Similarly Improve Sexual Function and Pain

Segmental rectum resections for indications other than endometriosis were reported to result in up to 40% sexual dysfunctions. We, therefore, evaluated sexual function after low bowel resection (n = 33) for deep endometriosis in comparison with conservative excision (n = 23). Sexual function was evaluated with the FSFI-19 (Female Sexuality Functioning Index) and EHP 30 (Endometriosis Health Profile). The pain was evaluated with visual analogue scales. Linear excision and bowel resections improved FSFI, EHP 30, and postoperative pain comparably. By univariate analysis, a decreased sexual function was strongly associated with pain both before (p < 0.0001) and after surgery (p = 0.0012), age (p = 0.05), and duration of surgery (p = 0.023). By multivariate analysis (proc logistic), the FSFI after surgery was predicted only by FSFI before or EHP after surgery. No differences were found between low bowel segmental resection and a more conservative excision. In conclusion, improving pain after surgery can explain the improvement in sexual function. A deleterious effect of a bowel resection on sexual function was not observed for endometriosis. Sexual function in women with endometriosis can be evaluated using a simplified questionnaire such as FSFI-6.

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.

The risk factors of low anterior resection syndrome after colorectal cancer surgery: A retrospective study of 566 patients in a single institution in China

PURPOSE

This study aims to identify the independent risk factors in the low anterior resection syndrome (LARS) after surgery for colorectal cancer (CRC).

METHOD

This was a retrospective, single-institution study in the Second Affiliation Hospital of Dalian Medical University, China. Patients underwent sphincter-preserving low anterior resection with total or partial mesorectal resection (with or without protective ileostomy) and completed a self-filled questionnaire over the phone to assess postoperative bowel dysfunction from January 2017 to December 2019. The predictors of LAR were evaluated using univariate and multivariate analyses.

RESULT

The study population was 566 patients, 264 (46.64%), 224 (39.58%), and 78 (13.78%) patients with no, minor, and major LARS, respectively. In the univariate analysis, independent factors such as tumor location and size, anastomotic height, protective ileostomy, post-operation chemoradiotherapy, tumor T stage, lymphatic nodal metastasis classification, surgery duration, and time interval for closure of stoma were significantly associated with LARS points while we found the tumor T stage and lymphatic nodal metastasis classification as the new independent risk factors compared with the last decade studies. In the multivariate analysis, factors such as low and middle tumor location and protective ileostomy, and post operation treatment, nodal metastasis classification were the independent risk factors for major LARS.

CONCLUSION

The new independence risk factors were tumor T stage and lymphatic nodal metastasis status in univariate analysis in our study, with anastomotic height, low and middle tumor location, protective ileostomy, post-operation chemoradiotherapy, nodal metastasis status increasing LARS point in multivariate analysis after surgery for CRC.

Factors influencing anterior/low anterior resection syndrome after rectal or sigmoid resections

Background/aim

Sphincter-preserving surgery is one of the main goals in the treatment of rectal cancer because it improves the quality of life (QoL). However, some patients may experience disrupted symptoms called anterior or low anterior resection syndrome (LARS). This study was designed to evaluate the frequency and influencing factors of LARS in patients who underwent sigmoid or rectal resection.

Materials and methods

In this retrospective, clinical study, patients who underwent rectal or sigmoid resection and anastomosis due to any benign and malignant reasons were evaluated in terms of LARS between January 2010 and November 2019 at Medical Faculty Hospital of Mersin University. The frequency and severity of LARS were determined by using a standard scale. Furthermore, influencing factors including lesion localization, operation, the proximity of anastomosis to the anal verge, creation of stoma, chemotherapy, and radiotherapy application were investigated.

Results

Out of a total of 550 patients, 276 were included in this study. The major LARS incidence was found as 27.2%. Very low anterior resection (VLAR) (OR = 42.40 (95% CI [11.14–161.36], P < 0.0001), protective ileostomy (OR = 12.83 (95% CI [6.58–25.0], P < 0.0001), end colostomy (OR = 8.55 (95% CI [1.36–53.61], P = 0.022), receiving chemotherapy (OR = 3.08 (95% CI [1.71–5.53], P < 0.0001), and radiotherapy (OR = 2.51 (95% CI [1.38–4.57], P = 0.003) and the ROC analysis showed that creating an anastomosis placed at most 8.5 cm from the anal verge was found to be a major influencing factor on LARS (P < 0.05).

Conclusions

LARS may frequently occur in patients who have undergone rectal resection. In this study, the most important factors influencing LARS were found to be the proximity of anastomosis to the anal canal and creating a protective stoma. Receiving chemoradiotherapy also plays an important role in LARS.