Introduction

Fusobacterium nucleatum (Fn) and other species typical of the oral cavity are implicated in colorectal oncogenesis. The pathogenesis of serrated polyposis syndrome (SPS), the most common polyposis syndrome, remains unknown, and to date, the oral and gut microbiota of these patients has not been characterized.

Aims & Methods

The primary objective of this study was to describe and compare the composition of the oral and gut microbiota in individuals with SPS versus individuals without polyps, with sporadic serrated polyps, and with adenomas.
A prospective, observational, and bicentric study was conducted. Clinical and endoscopic data were collected, along with information obtained from a questionnaire on diet and dental health. Additionally, saliva and stool samples were obtained from 126 individuals divided into four groups: SPS (n=32), serrated (n=30), adenoma (n=32), and control (n=32). The microbiota was analyzed using 16S rRNA amplicon sequencing, and qPCR was performed for the detection of Fn.

Results

The main clinical, dietary, and dental health characteristics of the groups are presented in Table 1. Regarding the oral microbiota, no differences were observed in alpha diversity (species variety) among the groups. However, the composition of the oral microbiota in the SPS group showed significant differences compared to the other groups, as evidenced by a greater unweighted UniFrac distance (differences in bacterial taxonomy) (p<0.001). In the gut microbiota, the adenoma group exhibited lower species richness than the control group, according to the Chao1 index (p=0.03), while no differences were found in the other groups. Statistically significant differences in beta diversity, measured using unweighted UniFrac distance, were observed between the SPS group and the adenoma and control groups (p<0.001).
Regarding taxonomy, Porphyromonas gingivalis, an oral bacterium associated with colorectal cancer (CRC) development and progression, showed higher oral abundance in the SPS group compared to the control and adenoma groups (p<0.05; FDR p=0.104). Treponema denticola and Prevotella intermedia, two oral bacteria related to CRC, were more abundant in the SPS group than in the control group (p<0.05; FDR p=0.09). Additionally, Peptoanaerobacter stomatis, an oral bacterium linked to CRC via the serrated pathway, was more prevalent in the SPS group compared to the serrated and adenoma groups (p<0.05; FDR p=0.26).
No differences in the abundance of Fn were found among the groups, either in saliva or stool samples.

Conclusion

The oral and gut microbiota of individuals with SPS exhibit a distinct bacterial composition compared to individuals without polyps and those with adenomas. Furthermore, certain oral bacteria associated with colorectal carcinogenesis are increased in SPS patients.

Disclosure

There are no conflicts of interest to declare.

Introduction

Acute appendicitis is a widely encountered emergency across the globe, showcasing the resilience of modern medicine, as it is traditionally addressed through the transformative procedure of appendectomy. Endoscopic Retrograde Appendicitis Therapy (ERAT) has emerged as a minimally invasive alternative; however recurrence is a worry.

Aims & Methods

This multi-center retrospective study aimed to evaluate the long-term safety, efficacy, and recurrence-related risk factors of ERAT to guide clinical decision-making. A total of 435 patients who underwent ERAT for acute appendicitis between October 2017 and October 2024 at three Chinese medical centers were included. Appendicitis recurrence was defined as imaging-confirmed symptoms returning within one-month post-ERAT. Univariate and multivariate regression analysis identified independent recurrence risk variables.

Results

All ERAT procedures were technically successful and achieved a clinical success rate of 92.4%. Over a median follow-up period of 37 months, the overall recurrence rate was 16.1%, with the majority of recurrences (13%) observed within the first year. Independent risk factors for recurrence included recurrent appendicitis (HR=1.916), appendiceal lumen distortion (HR=7.996), absence of stent placement (HR=0.375, protective), and operator inexperience (HR=2.318). Stent implantation effectively minimizes recurrence risk, especially in complicated incidents. ERAT facilitated overseeing appendicolith elimination, which assisted in occurring appendicolith-associated appendicitis.

Conclusion

ERAT is deemed safe and effective for acute appendicitis, with the highest recurrence risk occurring within the first year. Effective stent placement and skilled operators are crucial for reducing recurrence in complex cases. The aforementioned findings put forward significant insights for enhancing ERAT and advancing therapeutic outcomes.

Clinical Case Summary

Introduction: Intra-abdominal sepsis from colonic perforation is a surgical emergency with high mortality. While diverticulitis is a common cause in older adults, its presence in young, healthy individuals suggests additional etiologies. Parasitic infestations such as Ascaris lumbricoides, though rare in developed regions, can complicate outcomes.
Case presentation: A 35-year-old previously healthy male presented with 3 days of severe abdominal pain and vomiting. CT scan revealed pneumoperitoneum. Emergency laparotomy showed perforated sigmoid diverticulitis with fecal peritonitis. A Hartmann’s procedure was performed with an open abdomen due to gross contamination. Despite surgery, the patient developed persistent sepsis, requiring seven relook laparotomies. During the fourth, live Ascaris worms were seen emerging from the bowel during ileostomy creation, prompting Albendazole treatment. Histopathology confirmed diverticulitis with perforation. Recovery was complicated by multidrug-resistant infections, anemia, malnutrition, and thrombotic events, prolonging ICU stay.
Discussion: This case highlights how unrecognized parasitic infestation can worsen intra-abdominal sepsis. Ascaris may contribute to mucosal damage, obstruction, and inflammation, exacerbating outcomes. Early hypoalbuminemia might have reflected chronic enteric loss or parasite burden.
Conclusion: In endemic areas, chronic helminthic infections should be considered in young patients with unusual presentations or poor postoperative progress. Timely recognition may impact treatment and recovery.

References

Figure 1: CT Abdomen with Contrast showing Moderate Pneumoperitoneum
Figure 2: Worm coming out of iliostomy
Figure 3: acsaris
Figure 4 : CT Chest showing bilateral moderate pleural effusion more on the right side with underlying lung consolidation collapse.
Figure 5 : US Neck showing Left internal jugular vein central line with echogenic thrombus not completely occluding the lumen.

Introduction

Prophylactic clip closure is known to avoid delayed adverse events post colorectal endoscopic submucosal dissection (ESD).¹ It may also improve reduce the duration of hospitalization.² However, endoscopic clips have limitation of defect size that can be completely closed due to their limited opening width. Other studies have suggested methods to completely close a mucosal defect using special devices^{3, 4} which have limitations of availability, learning curve, scope removal and reinsertion, and negotiation in narrow spaces. An ideal closure technique has been described as a technique which is technically easy, requiring no special accessories or endoscopes, managed through accessory channel without endoscope removal, possible in narrow space, creating no dead space, and being economical.⁵ We recently developed a Clip with Line Pulley Securing (CLiPS) technique to completely close large mucosal defect which fulfils the criteria for an ideal closure technique.⁶

Aims & Methods

The aim of this study was to report the feasibility and efficacy of CLiPS technique for closure of large mucosal defects following colorectal ESD. This study retrospectively evaluated 53 consecutive patients who underwent closure using CLiPS technique post colorectal ESD. CLiPS technique involves deployment of a clip with nylon line on the edges of the ulcer which are approximated using external counter traction. An endoloop is deployed to fix the line. The principle is supporting the clip line with an endoloop and creating a pulley system by giving external countertraction to the line, to facilitate a strong, stable approximation of edges, thereby making the defect more linear. The line is cut and final closure is completed with conventional clips. The primary outcomes were complete closure rate and adverse events. The secondary outcomes were closure time and defect size.

Results

The lesion characteristics are given in the 'table'. Complete closure was achieved in 94.3%(50/53) of cases. The mean defect size was 48.2­+18.8 mm and median closure time was 14(5-58) minutes. There was one case each of delayed bleeding and perforation which were managed by endoscopic clipping.

Conclusion

CLiPS technique has reasonable outcomes and can be considered to be a safe and effective closure method for large post ESD colorectal defects. Further prospective study may be undertaken to establish wider acceptability of this method.

References

1. Liu M, Zhang Y, Wang Y, et al. Effect of prophylactic closure on adverse events after colorectal endoscopic submucosal dissection: A meta‐analysis. Journal of Gastroenterology and Hepatology. 2020 Nov;35(11):1869-77.
2. Abe S, Saito Y, Tanaka Y, et al. A novel endoscopic hand-suturing technique for defect closure after colorectal endoscopic submucosal dissection: a pilot study. Endoscopy. 2020 Sep;52(09):780-5.
3. Farha J, Ramberan H, Aihara H, et al. A novel through-the-scope helix tack-and-suture device for mucosal defect closure following colorectal endoscopic submucosal dissection: a multicenter study. Endoscopy. 2023 Jun;55(06):571-7.
4. Keihanian T, Zabad N, Khalaf M, et al. Safety and efficacy of a novel suturing device for closure of large defects after endoscopic submucosal dissection (with video). Gastrointestinal Endoscopy. 2023 Sep 1;98(3):381-91.
5. Nomura T, Sugimoto S, Temma T, et al. Suturing techniques with endoscopic clips and special devices after endoscopic resection. Digestive Endoscopy. 2023 Mar;35(3):287-301.
6. Minato Y, Ohata K, Kimoto Y, et al. A modified approach for closing endoscopic submucosal dissection defects using clip with line pulley securing technique and endoloop. VideoGIE. 2024 Mar 27.
   

Introduction

Colon cancer is one of the most common malignant tumors in humans, with colon adenocarcinoma (COAD) being the predominant type. It typically arises from the transformation of colon adenomas. However, the cellular and molecular mechanisms driving the progression from adenoma to adenocarcinoma remain incompletely understood. Investigating this transformation process is crucial for the early intervention and treatment of colon cancer.

Aims & Methods

To elucidate the mechanisms driving the adenoma-carcinoma transition in COAD, we conducted single-cell sequencing on samples from adjacent normal tissue, adenomatous tissue, and colon adenocarcinoma tissue. We also integrated single-cell datasets from two GEO databases. Through cell communication analysis, differential gene expression analysis, and pseudotime analysis, we explored the role of the CD8⁺ Tex subset in the adenoma-carcinoma transition. Utilizing GEO transcriptome datasets, we constructed a disease risk prediction model based on nine genes (CEBPB, LEF1, ANXA2, SERPINE2, RUNX2, MLLT6, MAT2A, STAT1, NOTCH1). This model was validated using the TCGA transcriptome dataset and the IMvigor210 immunotherapy cohort. Combining the risk coefficients of the nine genes with survival analysis results, we identified RUNX2 as a potentially significant risk factor. The function of key molecules was further validated using an in vivo AOM/DSS colon cancer model and the HCT116 colon cancer cell line in vitro. Additionally, the interaction between CD8⁺ Tex cells and tumor cells was confirmed through multiplex immunofluorescence.

Results

The study found that the proportion of CD8⁺ Tex cells significantly increased in colon adenoma and carcinoma samples compared to adjacent normal tissue. These cells may promote the transition from adenoma to COAD through multiple mechanisms. Pseudotime analysis indicated that CD8⁺ Tex cells in COAD might differentiate from those in adenomas, and highly malignant COAD epithelial cells may originate from highly malignant adenoma cells. The risk score model based on nine genes identified RUNX2 as a potentially significant risk factor. Both in vivo and in vitro experiments confirmed that RUNX2 promotes the proliferation, invasion, and migration of the HCT116 colon cancer cell line, while the RUNX2 inhibitor CADD522 can suppress the adenoma-to-carcinoma transition. Additionally, TNF-α was found to enhance RUNX2 mRNA and protein expression, thereby promoting the malignant behavior of HCT116 cells and the expression of genes related to the adenoma-to-carcinoma transition.

Conclusion

This study identifies that CD8+ Tex cells may activate the transcription factor RUNX2 in colon cancer cells by binding the ligand TNF-α to the TNFR1 receptor on the membrane of malignant epithelial cells. This activation promotes the transition of malignant epithelial cells in colon adenomas to malignant cancer cells, leading to poor prognosis in COAD. This finding not only elucidates the key cellular and molecular mechanisms of the adenoma-to-carcinoma transition but also provides new potential targets for early intervention and treatment of colon cancer.

Clinical Case Summary

A 19-year-old man with a long-standing history of recurrent abdominal pain and a recent episode of melena of unknown origin. He presented to the emergency department (ED) with hematochezia and asthenia, with a drop in hemoglobin to 8.9 g/dL. Upper and lower endoscopy were inconclusive. Capsule enteroscopy revealed a double-lumen sign and mildly erythematous mucosa, raising suspicion of Meckel’s diverticulum. A technetium-99m pertechnetate (Tc-99m) scan confirmed the presence of ectopic gastric mucosa. The patient subsequently underwent enterectomy, and histological analysis confirmed gastric mucosal heterotopia.
A 13-year-old man with a history of iron-deficiency anaemia requiring transfusion at 7 years old, and previous episodes of abdominal pain due to ileo-ileal intussusception. He had
undergone an inconclusive exploratory laparoscopy. He was admitted to the ED with melena and hypogastric pain. Blood tests revealed hemoglobin of 12.9 g/dL. Abdominal ultrasound showed thickening of the distal ileum over 11 cm, without signs of intussusception. Capsule enteroscopy revealed a segment of circumferential edema and erythema in the ileum, with absence of a clear villous pattern and an appearance suggestive of gastric mucosa. A Tc-99m scan confirmed the presence of ectopic gastric mucosa. Exploratory laparoscopy identified a 10–15 cm segment with gastric fold-like appearance within otherwise normal small intestinal mucosa, in the absence of a diverticulum. Histological analysis confirmed gastric mucosal heterotopia.
Gastric heterotopia is an important differential diagnosis in patients with gastrointestinal bleeding and can occur independently of the presence of Meckel’s diverticulum. The authors highlight the role of capsule enteroscopy in the diagnostic algorithm.