The Role of Indocyanine Green in Laparoscopic Low Anterior Resections for Rectal Cancer Previously Treated With Chemo-radiotherapy: A Single-center Retrospective Analysis

LoG-staging: a rectal cancer staging method with LoG operator based on maximization of mutual information

Deep learning methods have been migrated to rectal cancer staging as a classification process based on magnetic resonance images (MRIs). Typical approaches suffer from the imperceptible variation of images from different stage. The data augmentation also introduces scale invariance and rotation consistency problems after converting MRIs to 2D visible images. Moreover, the correctly labeled images are inadequate since T-staging requires pathological examination for confirmation. It is difficult for classification model to characterize the distinguishable features with limited labeled data. In this article, Laplace of Gaussian (LoG) filter is used to enhance the texture details of converted MRIs and we propose a new method named LoG-staging to predict the T stages of rectal cancer patients. We first use the LoG operator to clarify the fuzzy boundaries of rectal cancer cell proliferation. Then, we propose a new feature clustering method by leveraging the maximization of mutual information (MMI) mechanism which jointly learns the parameters of a neural network and the cluster assignments of features. The assignments are used as labels for the next round of training, which compensate the inadequacy of labeled training data. Finally, we experimentally verify that the LoG-staging is more accurate than the nonlinear dimensionality reduction in predicting the T stages of rectal cancer. We innovatively implement information bottleneck (IB) method in T-staging of rectal cancer based on image classification and impressive results are obtained.

Surgical effect and gastrointestinal functional recovery of laparoscopic-guided total mesorectal excision in patients with rectal cancer

INTRODUCTION

To explore the surgical effect and gastrointestinal functional recovery of laparoscopic-guided total mesorectal excision (LGTME) in patients with rectal cancer.

PATIENTS AND METHODS

A total of 150 rectal cancer patients who underwent surgical treatment in our hospital from July 2022 to July 2023 were selected and randomly divided into two groups using a random number table. There were 75 cases in the control group (CG) who underwent traditional open rectal total mesorectal excision surgery and 75 cases in the experimental group (EG) who underwent LGTME. The surgical effects of the two groups were compared, and the gastrointestinal and anal functional recovery of the two groups were compared before and after treatment.

RESULTS

Intraoperative bleeding, incision length, time to initial feeding and time to anal exhaust in the EG were significantly lower than those in the CG ( P < 0.05). Before treatment, there was no significant difference in gastrointestinal function and anal function between the two groups ( P > 0.05). After treatment, the levels of motilin, gastrin, neuropeptide Y and basic fibroblast growth factor in the EG were significantly higher than those in the CG, with statistical significance ( P < 0.05); the maximum anal systolic pressure and resting anal sphincter pressure in the EG were significantly lower than those in the CG ( P < 0.05); the rectal sensitivity threshold volume (RSTV) and rectal maximum volume threshold in the EG were significantly higher than those in the CG ( P < 0.05). There was no significant difference in most postoperative complications between the two groups ( P > 0.05).

CONCLUSION

LGTME improves the surgical effects of rectal cancer patients, promotes the recovery of gastrointestinal function and has a small effect on anal function indicators, thereby reducing hospital stay.

Low Anterior Resection Syndrome (LARS) after Surgery for Rectal Cancer: An Inevitable Price to Pay for Survival, or a Preventable Complication?

BACKGROUND

Rectal cancer is frequent and often treated with sphincter-saving procedures that may cause LARS, a syndrome characterized by symptoms of bowel disfunction that may severely affect quality of life. LARS is common, but its pathogenesis is mostly unknown. The aim of this study is to assess the incidence of LARS and to identify potential risk factors.

METHODS

We performed an observational retrospective single center analysis. The following data were collected and analyzed for each patient: demographics, tumor-related data, and intra- and peri-operative data. Statistical analysis was conducted, including descriptive statistics and multivariate logistic regression to identify independent risk factors.

RESULTS

Total LARS incidence was 31%. Statistically significant differences were found in tumor distance from anal verge, tumor extension (pT and diameter) and tumor grading (G). Multivariate analysis identified tumor distance from anal verge and tumor extension as an independent predictive factor for both major and total LARS. Adjuvant therapy, although not significant at univariate analysis, was identified as an independent predictive factor. Time to stoma closure within 10 weeks seems to reduce incidence of major LARS.

CONCLUSIONS

bold LARS affects a considerable portion of patients. This study identified potential predictive factors that could be useful to identify high risk patients for LARS.

Indocyanine Green (ICG) and Colorectal Surgery: A Literature Review on Qualitative and Quantitative Methods of Usage

Background: Due to its many benefits, indocyanine green (ICG) has gained progressive popularity in operating rooms (ORs) globally. This literature review examines its qualitative and quantitative usage in surgical treatment. Method: Relevant terms were searched in five international databases (1. Pubmed, 2. Sciencedirect, 3. Scopus, 4. Oxfordjournals, 5. Reaxys) for a comprehensive literature review. The main benefits of using ICG in colorectal surgery are: intraoperative fluorescence angiography; fluorescence-guided lymph node involvement detection and the sentinel technique; the fluorescent emphasis of a minute liver tumour, counting just 200 tumour cells; facilitation of fistula diagnosis; and tumour tattooing. This methodology can also be used with quantitative characteristics such as maximum intensity, relative maximum intensity, and in-flow parameters such as time-to-peak, slope, and t1/2max. This article concludes that fluorescence surgery with ICG and near-infrared (NIR) light is a relatively new technology that improves anatomical and functional information, allowing more comprehensive and safer tumour removal and the preservation of important structures.

Short-term outcomes of near-infrared imaging using indocyanine green in laparoscopic lateral pelvic lymph node dissection for middle-lower rectal cancer: A propensity score-matched cohort analysis

Laparoscopic lateral pelvic lymph node dissection (LPND) is limited by complex neurovascular bundles in the narrow pelvic sidewall and various post-operative complications. Indocyanine green (ICG) has been applied to increase the number of harvested lymph nodes and reduce the injury of irrelevant vessels in patients with rectal cancer. However, few studies on the recurrence rate of ICG fluorescence imaging-guided laparoscopic LPND were reported. This retrospective study enrolled 50 middle- low rectal cancer patients who were treated by LPND. After propensity score matching, 20 patients were matched in each of the indocyanine green (ICG) guided imaging group (ICG group) and non-ICG guided imaging group (non-ICG group). The average follow-up time was 13.5 months (12-15 months). Our results showed that the total number of harvested lymph nodes in the ICG group was significantly higher than that in the non-ICG group (P < 0.05), and intraoperative blood loss and post-operative hospital stay times in the ICG group were less than those in the non-ICG group (P < 0.05). After 12 months of follow-up, no residual lymph node and local tumor recurrence were found for patients in the ICG group. Four patients in the non-ICG group detected residual lymph nodes at the 3-month visit. Our findings highlighted the importance of ICG fluorescence-guided imaging in LPND because it has unique advantages in improving the number of lymph node dissections, surgical accuracy, and decreasing the residual lymph nodes and local tumor recurrence. In addition, ICG fluorescence guidance technology can effectively shorten the operation time, and it is simple to operate, which is worth popularizing.

Anastomotic occlusion after laparoscopic low anterior rectal resection: a rare case study and literature review

Background

With the development of laparoscopic techniques and the broad clinical application of various anastomotic types, anal-preserving low anterior rectal resection and ultra-low anterior rectal resection have been popularized. Some patients with rectal cancer have retained their anus and improved their quality of life. Nevertheless, the incidence of postoperative anastomotic stenosis remains high, and anastomotic occlusion is even rarer.

Case presentation

We report a case of anastomotic occlusion in a patient with rectal cancer, which occurred after undergoing laparoscopic low anterior rectal resection + prophylactic terminal ileal fistulation at our department. Under endoscopy, we used a small guidewire to break through the occluded anastomosis, thereby finding the lacuna. After endoscopic balloon dilation, digital anal dilatation, and continuous dilator-assisted dilation, the desired efficacy was achieved, ultimately recovering ileal stoma. Postoperative follow-up condition was generally acceptable, without symptoms like abdominal pain, bloating, or difficulty in defecation.

Conclusion

Numerous factors cause postoperative anastomotic stenosis in patients with rectal cancer. Complete occlusion of anastomosis occurs relatively rare in clinical practice, and is challenging to treat. This case was our first attempt to remove the anastomotic occlusion successfully, which avoided re-operation or pain from the permanent fistula.

Indocyanine Green Near-Infrared Fluoroangiography Is a Useful Tool in Reducing the Risk of Anastomotic Leakage Following Left Colectomy

Purpose

To evaluate whether visualization of the colon perfusion with indocyanine green near-infrared fluoroangiography (ICG-NIFA) reduces the rate of anastomotic leakage (AL) after colorectal anastomosis.

Methods

Patients who underwent elective left colectomy, including all procedures involving the sigmoid colon and the rectum with a colorectal or coloanal anastomosis, were retrospectively analyzed for their demographics, operative details, and the rate of AL. Univariate and multivariate analyses were used to compare patients with and without ICG-NIFA-based evaluation.

Results

Overall, our study included 132 colorectal resections [70 sigmoid resections and 62 total mesorectal excisions (TMEs)], of which 70 (53%) were performed with and 62 (47%) without ICG-NIFA. Patients' characteristics were similar between both the groups. The majority of the procedures [91 (69%)] were performed by certified colorectal surgeons, while 41 (31%) operations were supervised teaching procedures. In the ICG-NIFA group, bowel perfusion could be visualized by fluorescence (dye) in all 70 cases, and no adverse effects related to the fluorescent dye were observed. Following ICG-NIFA, the transection line was changed in 9 (12.9%) cases. Overall, 10 (7.6%) patients developed AL, 1 (1.4%) in the ICG-NIFA group and 9 (14.5%) in the no-ICG-NIFA group (p = 0.006). The multivariate analysis revealed ICG-NIFA as an independent factor to reduce AL.

Conclusion

These results suggest that ICG-NIFA might be a valuable tool to reduce the rate of AL in sigmoid and rectal resections in an educational setting.