Introduction

Although sigmoid volvulus is potentially life-threatening condition in elderly patients, prognostic factors for sigmoid volvulus are not well known.

Aims & Methods

The aim of this study is to evaluate clinical outcomes and investigate prognostic factors for patients with sigmoid volvulus. We retrospectively reviewed 85 patients who were treated with sigmoid volvulus from January 2005 to January 2023 at a single tertiary referral center. After exclusion of patients who received emergency bowel resection surgery or improved by conversative treatment alone, a total of 59 patients were included. Patient and abdominal computed tomography (CT)-related factors potentially associated with clinical outcomes were analyzed by logistic and Cox regression analyses.

Results

The mean age of the patients was 72.4 years, and 74.3% were male. 49 patients (83.1%) were improved on initial endoscopic decompression therapy. Regarding factors related with failure of initial endoscopic decompression therapy, suspected bowel ischemia on initial CT (odds ratio 8.847, 95% CI 0.666–117.462), age<65 (odds ratio 5.138, 95% CI 0.574–46.025), larger (>85 mm) cross-sectional diameter of distended colon (odds ratio 25.400, 95% CI 1.015–635.804) were related with endoscopic treatment failure. On the other hand, of the 35 patients without previous volvulus episode who improved after initial endoscopic decompression therapy, 14 patients (40.0%) had recurrence of sigmoid volvulus during a mean follow-up of 411 days. Patients showing larger cross-sectional diameter of distended colon (>85mm, hazard ratio 9.925, 95% CI 1.618–60.863), larger maximal long (>230mm, hazard ratio 4.456, 95% CI 0.931–21.327) and short (>150mm, hazard ratio 2.828, 95% CI 0.639–12.505) axis length of overall twisted sigmoid colon were related with volvulus recurrence.

Conclusion

Prognostic factors unravelled in our study may be useful in management of patients with sigmoid volvulus. Early surgical backup consultation may be needed in patients having factors related with failure of endoscopic decompression therapy. Meanwhile, elective surgical treatment after improvement on initial endoscopic therapy may be considered in patients showing high risk features for recurrence on CT scan.

References

1. R. Kusunoki et al, Initial Computed Tomography Findings of Long and Distended Colon Are Risk Factors for the Recurrence of Sigmoid Volvulus, Digestive Diseases and Sciences (2021) 66:1162–1167
2. C. Humbert et al, Stratification of sigmoid volvulus early recurrence risk using a combination of CT features, Diagnostic and Interventional Imaging 103 (2022) 79-85
3. Z. Slack et al, Prognostic factors in the decision-making process for sigmoid volvulus: results of a single-centre retrospective cohort study, BMC Surgery (2022) 22:95
4. EM Kim et al, Clinical outcomes of sigmoid volvulus and risk factors for its recurrence: a multicenter study in Korea, International Journal of Colorectal Disease (2020) 35:1841–1847
5. A Abdelrahim et al, Dilemma of sigmoid volvulus management, Ann R Coll Surg Engl 2021; 104: 95–99

Introduction

There are insufficient data to guide clinical decision-making regarding the implementation of additional surgery following endoscopic therapy in patients with deep submucosal invasive colorectal cancer (T1b CRC) and no additional risk factors for lymph node metastasis (LNM). This investigation sought to identify factors associated with LNM in cases of T1b CRC without other risk factors.

Aims & Methods

Consecutive cases with pathologically proven T1b CRC were retrospectively collected from 2014 to 2023 at a single tertiary hospital in Korea. These patients received either surgical or endoscopic treatment. In patients who received endoscopic treatment alone, no LNM was deemed to exist if there was no recurrence after at least 3 years of follow-up. Excluded were cases with other risk factors, including poor differentiation, lymphovascular invasion, perineural invasion. The cases were compared based on the presence of LNM.

Results

A total of 305 cases were enrolled and LNM was observed in 28 cases (9.18%). In univariate analysis, differentiation, sm3 invasion, tumor growth pattern, and peri-tumoral white spots were related with LNM. Multivariate analysis identified presence of non-polypoid growth parts (odd ratio [OR] 6.39; 95% CI 2.76-14.79), and peri-tumoral white spots (OR 2.85; 95% CI 1.22-6.64) as significant predictive factors for LNM.

Table. Multivariate analysis

Conclusion

Endoscopic findings including presence of non-polypoid growth and peri-tumoral white spots were related with increased risk of LNM in T1b CRC in the absence of other pathologic risk factors. These findings may be useful in determining further treatment strategy for patients with Tb1 CRC received endoscopic resection.

References

Liselotte W. Zwager,1,2,3 Barbara A. J. Bastiaansen, et al.
Deep Submucosal Invasion Is Not an Independent Risk
Factor for Lymph Node Metastasis in T1 Colorectal Cancer:
A Meta-Analysis. Gut 2022;163:174-189

Chihiro Yasue, Akiko Chino, et al.
Pathological risk factors and predictive endoscopic factors
for lymph node metastasis of T1 colorectal cancer: a single-center
study of 846 lesions. J Gastroenterol(2019) 54: 708-717

Introduction

Colorectal polyposis, characterized by more than 10 adenomas, indicates a higher risk of malignancy and necessitates more frequent screening and genetic assessment. However, there are still a large number of polyposis patients with negative genetic test results. This study aimed to explore the risk genetic variants associated with non-hereditary colorectal polyposis through a genome-wide association study (GWAS).

Aims & Methods

Among patients who underwent colonoscopy at a single referral university hospital from January 2012 to September 2021, a total of 638 patients with 10 or more biopsy-proven cumulative polyps on colonoscopies and without genetic mutations or family history related to colorectal polyposis were included in this study. For the control group, a total of 7087 people who underwent colonoscopy for the purpose of health check-up at the Korea Medical Institute and were normal at least twice in a row were included. To find susceptible loci to non-hereditary colorectal polyposis, GWAS was performed and a genome-wide p-value threshold of 5 × 10^-7 was set to assess statistical significance.
We compared the genetic differences between two groups of patients with non-hereditary colorectal polyposis: those with 10 or more polyp recurrences observed during follow-up colonoscopies and those without such recurrences. We utilized SNPs that were identified as risk variants for non-hereditary colorectal polyposis in this GWAS. For each SNP, we defined the risk allele as the allele associated with increased risk of non-hereditary colorectal polyposis as identified in this GWAS. Genotypes were coded as 0, 1, or 2 based on the number of risk alleles identified at each SNP. We used a polytomous logistic regression model to identify SNPs that significantly increased the risk of polyp recurrence compared to the group without recurrence. Results of all regression analyses were adjusted for age, sex, BMI, smoking history, alcohol consumption history, family history of cancer, history of cancer other than colorectal cancer, comorbidities, and history of medication use.

Results

A total of 71 risk variants were discovered, which were new single-nucleotide polymorphisms (SNPs) not found in previous GWAS associated with colorectal cancer and polyp (Figure 1). 5 genes (UPF3A, BICRA, CBWD6, PDE4DIP, ABCC4) nearest or overlapped with 7 SNPs (rs566295755, rs2770288, rs1012003, rs201270202, rs71264659, rs1699813, rs149368557) previously reported directly or indirectly related to the development of colorectal cancer were proven to be risk variants significantly associated with non-hereditary colorectal polyposis. In addition, two new genes (CNTN4, CNTNAP3B) that have not previously been reported to be associated with colorectal cancer or polyp were newly identified.
The SNP rs149368557 was identified as being significantly associated with an increased risk of polyp recurrence in non-polyposis hereditary colorectal cancer (p-value: 0.049, odds ratio: 2.991, 95% confidence interval: 1.006–8.899).

Conclusion

In this study, we found 71 novel risk variants associated with non-hereditary colorectal polyposis. The SNP rs149368557 was identified as being significantly associated with an increased risk of polyp recurrence in non-hereditary colorectal polyposis. The risk variants and genes discovered in this study might be utilized as novel targets to prevent colorectal cancer in the future.

Introduction

Considering the impaired platelet function in uremic patients, the risk of post-polypectomy bleeding may increase in patients with end-stage renal disease undergoing colonoscopic polypectomy. Nevertheless, little is known about the risk factors of bleeding after colonoscopic polypectomy in these patients. This study investigated the incidence and risk factors of post-polypectomy bleeding, including immediate and delayed bleeding, in patients with end-stage renal disease (ESRD).

Aims & Methods

Ninety-two patients with ESRD who underwent colonoscopic polypectomy between September 2005 and June 2020 at a single tertiary referral center were included. The patients’ medical records were retrospectively reviewed. Patient- and polyp-related factors associated with immediate PPB (IPPB) were analyzed using logistic regression analysis. Additionally, the optimal cutoff polyp size related to a significant increase in the risk of IPPB was determined by performing receiver operating characteristic (ROC) analysis and calculating the area under the ROC curve (AUC).

Results

In total, 286 polyps were removed. IPPB occurred in 24 (26.1%) patients and 46 (16.1%) polyps, and delayed post-polypectomy bleeding occurred in 2 (2.2%) patients. Regarding the hemostasis method for IPPB, clipping was used in 31 (67.4%) cases and a combined method with clipping and coagulation was used in 15 (32.6%) cases. According to multivariate analysis, the polyp size (> 7 mm) (odds ratio=5.259, 95% confidence interval [CI]: 2.367–11.684), old age (>70) (odds ratio=4.186, 95% CI: 2.012–8.708), and endoscopic mucosal resection (EMR) as the polypectomy method (EMR versus non-EMR: odds ratio=3.339, 95% CI: 1.440–7.743) were found to be independent risk factors for IPPB. According to the Youden index method, the optimal cutoff polyp size to identify high-risk polyps for IPPB was 7 mm (AUC=0.755; sensitivity, 76.1%; specificity, 69.6%).

Conclusion

Colonoscopic polypectomy should be performed with caution in patients with ESRD, especially in those with the following risk factors: advanced age (>70 years), polyp size >7 mm, and EMR as the polypectomy method.

Introduction

To improve the effectiveness of screening colonoscopies, it is important to maintain a high level of colonoscopy quality. We aimed to develop an artificial intelligence (AI) system to monitor key quality indicators for colonoscopy.

Aims & Methods

We implemented and tested the YOLOv8 model in various configurations (ranging from nano to extra-large) across multiple datasets, including five public datasets: Kavasir-SEG, which consists of 5597 polyp images, and the Severance Hospital colonoscopy database, which comprises 6316 images including polyps, the ileocecal valve, appendix orifice, and fecal materials. The model focused on detecting polyps and key anatomical landmarks such as the ileocecal valve and appendix orifice. Performance was evaluated based on the accuracy of detecting these features. Additionally, we investigated a novel path prediction method using a calibration plate and stereo matching.

Results

The integration of the YOLOv8 model into colonoscopy procedures has significantly improved the detection capabilities for colonic polyps, essential anatomical landmarks, and fecal materials indicative of bowel preparation quality. The precision and mAP50 for each metric were as follows: 0.90 and 0.85 for Polyp Detection, 0.99 and 0.94 for the Appendix Orifice, 0.90 and 0.82 for the Ileocecal Valve, 0.61 and 0.58 for Fecal Material, and 0.75 and 0.77 for Four-Class Detection, as detailed in Table 1. Additionally, a novel path prediction method has demonstrated potential for accurately measuring the colon path in short-term frames.

Table 1. Results of AI system for major quality indicators detection.

Conclusion

We developed a colonoscopy quality indicator monitoring system utilizing the YOLOv8 model. Further research is required to refine and validate the model's performance.

Introduction

The incidence of rectal neuroendocrine neoplasms (R-NENs) has been increasing annually. While most R-NENs are solitary, multiple lesions are relatively rare. Previous studies have suggested that patients with ≥8 lesions are more likely to exhibit lymphatic invasion and metastasis, indicating higher risk. However, the clinical and pathological features, prognosis, and endoscopic treatment outcomes of multiple R-NENs remain poorly understood. This study aimed to clarify the clinical characteristics and endoscopic treatment efficacy of multiple R-NENs through a retrospective analysis of cases from our hospital, providing evidence for clinical management.

Aims & Methods

This retrospective study included 28 patients with multiple R-NENs treated endoscopically at the Cancer Hospital of the Chinese Academy of Medical Sciences between January 2010 and January 2024. Patients were divided into two groups based on lesion count: the "several group" (n < 8) and the "numerous group" (n ≥ 8). All patients underwent preoperative imaging to exclude lymph node metastasis and distant metastases. Data on demographics, lesion characteristics, endoscopic procedures, pathological findings, and follow-up outcomes were collected and analyzed.

Results

We compared endoscopic treatment outcomes between patients with several (＜8, n=24) and numerous (≥8, n=4) rectal neuroendocrine tumors. The numerous group had a larger median maximum diameter (9.50 mm vs. 6.00 mm, p=0.337) and included one G2 case (25.0%) versus none in the several group, though differences were not significant. Notably, endoscopic complete resection was achieved in 100% of patients in both groups. All other parameters, including margin positivity, vascular invasion, neural invasion, and R0 resection rate, showed no significant differences. However, the numerous group had a significantly higher recurrence rate (75.0% vs. 0%, p=0.001). These findings highlight lesion count as a critical prognostic indicator for recurrence after endoscopic treatment.

Conclusion

Patients with ≥8 rectal neuroendocrine tumors exhibited more aggressive disease behavior, characterized by higher recurrence rates. These findings underscore the importance of lesion count as a prognostic indicator and suggest that patients with ≥8 lesions may require more intensive follow-up and management. For patients with <8 lesions, endoscopic treatment is effective when lymph node and distant metastases are excluded preoperatively. Future studies with larger datasets are needed to validate these findings and explore optimized treatment strategies.

Disclosure

The authors declare no conflicts of interest in relation to this study.