Nomogram for benign anastomotic stricture after surgery for rectal cancer

Analysis of treatment methods and relapse factors of postoperative anastomotic stenosis in colorectal cancer

BACKGROUND

Anastomotic stenosis following surgical intervention for colorectal cancer is a frequently encountered complication. Nevertheless, the optimal approach to effectively manage anastomotic stenosis at varying distances from the anal margin remains uncertain. The primary objective of this research endeavor was to explore the risk factors associated with recurrent anastomotic stenosis subsequent to colorectal cancer surgery, as well as to evaluate potential strategies for its management.

METHODS

The present study retrospectively analyzed the clinical data and treatment outcomes of 244 patients who underwent colorectal surgery and were subsequently diagnosed with anastomotic stenosis. The patients were categorized into two groups based on the location of anastomotic stenosis relative to the anal verge: the low anastomotic stenosis group (n = 107) and the high anastomotic stenosis group (n = 137).

RESULTS

The severity of anastomotic stenosis was found to be significantly higher in the low anastomotic stenosis group compared to the high anastomotic stenosis group (71.0% vs 57.7%, P = 0.031). Furthermore, the high anastomotic stenosis group exhibited a greater inclination toward opting for endoscopic treatment when it came to the choice of treatment for anastomotic stenosis (62.8% vs 27.1%, P < 0.001). In addition, logistic regression analysis showed that stenosis length ≥ 0.8 cm (odds ratio = 0.481; 95% CI = 0.248-0.936; P = 0.031) and lymph node metastasis (OR = 0.559, 95%CI = 0.313-0.998, P = 0.049) were independent risk factor for recurrence of anastomotic stenosis. Finally further build colorectal surgery of tumor recurrent anastomotic stenosis nomogram prediction model, using the internal validation and calculation model of the receiver-operating characteristic curve (ROC) area under curve (AUC) to evaluate the reliability and accuracy of the model.

CONCLUSION

There exist variations in the severity of anastomotic stenosis, the extent of stenosis, and the selection of treatment modalities across different anatomic locations. Regarding the choice of anastomotic treatment, patients with elevated anastomotic stenosis exhibited a preference for endoscopic intervention. Furthermore, a multivariate analysis showed that stenosis length equal to or greater than 0.8 cm and lymph node metastasis were autonomous risk factors for recurrence of benign stenosis after colorectal cancer surgery.

Comparison of short-term surgical outcomes between high and low tie ligation of the inferior mesenteric artery in robotic rectal cancer surgery: a propensity score matching analysis

Robotic surgery is extensively used for rectal cancer treatment. Nonetheless, studies on whether to preserve the left colonic artery (LCA) during robotic rectal cancer surgery to reduce complications remain scarce and controversial. This study compared short-term outcomes of high tie (HT) and low tie (LT) ligation of the inferior mesenteric artery in 455 patients undergoing robotic rectal cancer surgery between May 2018 and July 2022. Propensity score matching (PSM) minimized selection bias, resulting in 124 patients in each group. The LT group had a longer operative time (P < 0.001), but there were no significant differences in estimated blood loss, lymph node harvest, lymph node positivity, AJCC stage, hospital stay, or costs. Postoperative complications, 30-day mortality, and reoperations were also comparable. Univariate analysis identified hypoalbuminaemia, low tumor location, ASA scores III, and neoadjuvant chemoradiotherapy as risk factors for postoperative complications. Multivariate analysis confirmed low serum albumin and low tumor location as significant factors. Importantly, HT did not increase the risk of complications in either analysis. These findings indicate that high ligation does not adversely affect short-term outcomes and highlight the need for further research to refine surgical strategies.

A nomogram of anastomotic stricture after rectal cancer: a retrospective cohort analysis

BACKGROUND

Anastomotic stricture significantly impacts patients' quality of life and long-term prognosis. However, current clinical practice lacks accurate tools for predicting anastomotic stricture. This study aimed to develop a nomogram to predict anastomotic stricture in patients with rectal cancer who have undergone anterior resection.

METHODS

A total of 1542 eligible patients were recruited for the study. Least absolute shrinkage selection operator (Lasso) analysis was used to preliminarily select predictors. A prediction model was constructed using multivariate logistic regression and presented as a nomogram. The performance of the nomogram was evaluated using receiver operating characteristic (ROC) curves, calibration diagrams, and decision curve analysis (DCA). Internal validation was conducted by assessing the model's performance on a validation cohort.

RESULTS

72 (4.7%) patients were diagnosed with anastomotic stricture. Participants were randomly divided into training (n = 1079) and validation (n = 463) sets. Predictors included in this nomogram were radiotherapy, diverting stoma, anastomotic leakage, and anastomotic distance. The area under the ROC curve (AUC) for the training set was 0.889 [95% confidence interval (CI) 0.840-0.937] and for the validation set, it was 0.930 (95%CI 0.879-0.981). The calibration curve demonstrated a strong correlation between predicted and observed outcomes. DCA results showed that the nomogram had clinical value in predicting anastomotic stricture in patients after anterior resection of rectal cancer.

CONCLUSION

We developed a predictive model for anastomotic stricture following anterior resection of rectal cancer. This nomogram could assist clinicians in predicting the risk of anastomotic stricture, thus improving patients' quality of life and long-term prognosis.

Treatment of rectal anastomotic atresia with transurethral prostate resection instrumentation: A report of three cases

Dixon surgery for rectal cancer can lead to severe intestinal narrowing and blockage that is difficult to treat with open surgery or colonoscopy. The aim of the present study was to develop a minimally invasive approach for treating rectal anastomotic atresia based on three cases that were managed with transurethral prostate resection instrumentation. Preoperative imaging determined the distance from the anastomotic closure to the anal margin, the length of the anastomotic closure and the degree of proximal intestinal dilation for all cases. During the procedure, the anastomotic site was visualized, and a circular electrode was used to excavate and open the blockage. Membrane-like closures were directly incised to achieve satisfactory results, with an anastomotic diameter >20 mm. Those cases with tubular atresia required an initial incision using the prostate resectoscope to relieve the obstruction, followed by radial incisions until achieving an anastomotic diameter >20 mm. At 3-6 months post-dilation, two of the patients with anastomotic atresia >20 mm had satisfactory bowel movements, whereas the remaining patient experienced tumor recurrence at the anastomotic site and discontinued treatment. This case series demonstrates the potential of transurethral prostate resection instrumentation as a safe and effective minimally invasive approach for rectal anastomotic atresia. Given that prostate resection instrumentation is readily available in hospitals in China, this approach is widely accessible to most patients. Furthermore, the technique leverages existing surgical technology and practices, requiring only a shift in the surgical site.

Risk factors for anastomotic stenosis after radical resection of rectal cancer: A systematic review and meta-analysis

Radical resection of rectal cancer is a safe and effective treatment, but there remain several complications related to anastomosis. We aimed to assess the risk factors and incidence of rectal anastomotic stenosis (AS) after rectal cancer resection. We conducted a systematic review and meta-analysis after searching PubMed, Embase, Web of Science, and Medline databases from inception until May 2023. Data are reported as the combined odds ratio (OR) for categorical variables and the weighted mean difference (WMD) for continuous variables. Six hundred and fifty-nine studies were retrieved, nine (3031 patients) of which were included in the meta-analysis. Young age (WMD = -3.09, P = 0.0002), male sex (OR = 1.53, P = 0.0002), smoking (OR = 1.54, P = 0.009), radiotherapy (OR = 2.34, P = 0.0002), protective stoma (OR = 2.88, P = 0.007), intersphincteric resection surgery (OR = 6.28, P = 0.05), anastomotic fistula (OR = 3.72, P = 0.003), and anastomotic distance (WMD = -3.11, P = 0.0006) were identified as factors that increased the risk of AS, while staple (OR = 0.39, P < 0.001) was a protective factor. The incidence of AS after rectal cancer resection was approximately 17% (95% CI: 13%-21%). We identified eight risk factors and one protective factor associated with AS after rectal cancer resection. These factors may be combined in future studies to develop a more comprehensive and accurate prediction model related to AS after rectal cancer resection.

Automated machine learning-based model for predicting benign anastomotic strictures in patients with rectal cancer who have received anterior resection

BACKGROUND

Benign anastomotic strictures (BAS) significantly impact patients' quality of life and long-term prognosis. However, the current clinical practice lacks accurate tools for predicting BAS. This study aimed to develop a machine-learning model to predict BAS in patients with rectal cancer who have undergone anterior resection.

METHODS

Data from 1973 patients who underwent anterior resection for rectal cancer were collected. Multiple machine learning classification models were integrated to analyze the data and identify the optimal model. Model performance was evaluated using receiver operator characteristic (ROC) curves, decision curve analysis (DCA), and calibration curves. The Shapley Additive exPlanation (SHAP) algorithm was utilized to assess the impact of various clinical characteristics on the optimal model to enhance the interpretability of the model results.

RESULTS

A total of 10 clinical features were considered in constructing the machine learning model. The model evaluation results indicated that the random forest (RF)model was optimal, with the area under the test set curve (AUC: 0.888, 95% CI: 0.810-0.965), accuracy: 0.792, sensitivity: 0.846, specificity: 0.791. The SHAP algorithm analysis identified prophylactic ileostomy, operative time, and anastomotic leakage as significant contributing factors influencing the predictions of the RF model.

CONCLUSION

We developed a robust machine-learning model and user-friendly online prediction tool for predicting BAS following anterior resection of rectal cancer. This tool offers a potential foundation for BAS prevention and aids clinical practice by enabling more efficient disease management and precise medical interventions.

The impact of circular stapler size on the risk of anastomotic stricture following total mesorectal excision in rectal cancer patients: A retrospective cross-sectional study

Introduction

Colorectal cancer (CRC) surgery complications are a major issue affecting morbidity and mortality rates. Anastomotic stricture, which occurs in almost 30% of patients after surgery for rectal cancer, is one of the most serious but underreported side effects. In this study, we tried to assess the effect of stapler size on anastomotic stricture rate.

Materials and Methods

At our facility, all patients underwent low anterior resections (LAR) performed using an open laparotomy technique. A contour-curved stapler and an end-to-end anastomosis (EEA) circular stapler were used in the double stapling technique (DST). All patients also underwent a protective loop ileostomy. Patients who developed stricture following leakage were excluded.

Results

This study comprised a total of 173 rectal cancer patients. A 29-mm circle stapler was used to anastomose 77 patients (44.5%), while a 31-mm circular stapler was used to anastomose 96 patients (55.5%). Six individuals experienced strictures; two had a 29 mm stamper and four (4.4%) had a 31 mm one. There was no significant difference between the two groups (p:0.575). On aggregate, 8 patients experienced leakage; 3 (3.8%) of these patients received treatment with a 29 mm stapler, whereas 5 (5.2%) received treatment with a 31 mm stapler.

Conclusion

this study found no statistically significant difference in the stricture rates and stapler size. The findings of this study provide credibility to the notion that in rectal cancer patients having LAR, strictures can be safely avoided by performing the anastomoses with both staplers.

Defunctioning stoma and anastomotic stricture in rectal cancer surgery: a propensity score matching study

BACKGROUND

In cases of rectal cancer surgery, patients at high risk of anastomotic leakage often receive a defunctioning stoma (DS). However, its role in postoperative anastomotic strictures (AS) remains unclear. This study aimed to investigate the correlation between DS and AS and outcomes of transanal endoscopic microsurgery (TEM) in treating rectal AS.

METHODS

This retrospective study was conducted from January 2019 to September 2021 and included patients who underwent rectal cancer surgery. A 1:1 ratio was used for propensity score matching (PSM). Univariate analyses were performed to identify statistically significant variables, and multivariate analyses were conducted to determine the factors affecting AS.

RESULTS

This study included 383 patients. The results of the univariate analysis suggested that surgery time (HR 4.597, 95% CI 1.563-13.525, P=0.006), postoperative anastomotic leakage (HR 11.830, 95% CI 3.773-37.094, P<0.001), and DS (HR 15.475, 95% CI 6.042-39.641, P<0.001) were significantly associated with AS. In the multivariate analysis, postoperative anastomotic leakage (HR 7.596, 95% CI 1.987-29.044, P= 0.003) and DS (HR 11.252, 95% CI 4.113-30.779, P<0.001) were identified as significant risk factors for AS. After matching, the univariate analysis revealed that postoperative anastomotic leakage (HR 8.333, 95% CI 1.541-45.052, P= 0.014) and DS (HR 9.965, 95% CI 2.200-45.142, P= 0.003) were associated with AS. The multivariate analysis indicated that postoperative anastomotic leakage (HR 14.549, 95% CI 1.765-119.913, P= 0.013) and DS (HR 12.450, 95% CI 2.418-64.108, P= 0.003) were significant risk factors for AS.

CONCLUSIONS

This study provides evidence that DS is independently associated with AS, and postoperative anastomotic leakage increases the risk of AS. Furthermore, this study suggests that TEM could be a valuable treatment option for AS.