Endoscopic Management of Complex Colorectal Polyps: Current Insights and Future Trends

A staged approach to resecting a large rectal polyp using endoscopic mucosal resection and trans-anal endoscopic microsurgery: a case report

Large rectal adenomatous polyps are not uncommon. Proctectomy sparing interventions are favored when feasible. We present a case of a 62-year-old woman, who presented with diarrhea for several years. Colonoscopy revealed a very large 60 mm rectal polyp, biopsied as tubulovillous adenoma. This was successfully resected using a staged approach with endoscopic mucosal resection and trans-anal endoscopic microsurgery. Endoscopic mucosal resection removed 70% of the lesion with central scarred not amenable to resection but amenable to transanal excision. Pathology demonstrated tubulovillous adenoma with negative margins. Flexible sigmoidoscopy at 6-month follow-up revealed well healed scar without recurrence or residual disease. This demonstrates a staged resection for a large rectal polyp which is minimally invasive and organ preserving.

Meta-Analysis of Endoscopic Full-Thickness Resection Versus Endoscopic Submucosal Dissection for Complex Colorectal Lesions

BACKGROUND

Studies evaluating endoscopic full-thickness resection (EFTR) and endoscopic submucosal dissection (ESD) for complex colorectal lesions have shown variable results. We conducted a meta-analysis of the available data.

METHODS

Online databases were searched for studies comparing EFTR versus ESD for complex colorectal lesions. The outcomes of interest were resection rates, procedure time (min), and complications. Pooled odds ratios (OR) and standardized mean difference (SMD) along with 95% CI were calculated.

RESULTS

A total of 4 studies with 530 patients (n=215 EFTR, n=315 ESD) were included. The mean follow-up duration was 5 months. The mean age of the patients was 68 years and 64% were men. The EFTR and ESD groups had similar rates of en bloc resection (OR: 1.73, 95% CI: 0.60-4.97, P =0.31) and R0 resection (OR: 1.52, 95% CI: 0.55-4.14, P =0.42). The EFTR group had significantly reduced procedure time (SMD -1.87, 95% CI: -3.13 to -0.61, P =0.004), total complications (OR: 0.24, 95% CI: 0.13-0.44, P <0.00001), perforation (OR: 0.12, 95% CI: 0.03-0.39, P =0.0005) and postresection electrocoagulation syndrome (OR: 0.06, 95% CI: 0.01-0.48, P =0.008). Delayed bleeding was similar in the 2 groups (OR: 0.80, 95% CI: 0.30-2.12, P =0.66). Residual/recurrent lesions were significantly higher in the EFTR group (OR: 4.67, 95% CI: 1.39-15.66, P =0.01).

DISCUSSION

This meta-analysis of small studies with high heterogeneity showed that EFTR and ESD have comparable resection rates for complex colorectal lesions. EFTR is faster and has fewer complications, but it increases residual or recurrent lesions.

In vivo evaluation of complex polyps with endoscopic optical coherence tomography and deep learning during routine colonoscopy: a feasibility study

Standard-of-care (SoC) imaging for assessing colorectal polyps during colonoscopy, based on white-light colonoscopy (WLC) and narrow-band imaging (NBI), does not have sufficient accuracy to assess the invasion depth of complex polyps non-invasively during colonoscopy. We aimed to evaluate the feasibility of a custom endoscopic optical coherence tomography (OCT) probe for assessing colorectal polyps during routine colonoscopy. Patients referred for endoscopic treatment of large colorectal polyps were enrolled in this pilot clinical study, which used a side-viewing OCT catheter developed for use with an adult colonoscope. OCT images of polyps were captured during colonoscopy immediately before SoC treatment. A deep learning model was trained to differentiate benign from deeply invasive lesions for real-time diagnosis. 35 polyps from 32 patients were included. OCT imaging added on average 3:40 min (range 1:54-8:20) to the total procedure time. No complications due to OCT were observed. OCT revealed distinct subsurface tissue structures that correlated with histological findings, including tubular adenoma (n = 20), tubulovillous adenoma (n = 10), sessile serrated polyps (n = 3), and invasive cancer (n = 2). The deep learning model achieved an area under the receiver operating characteristic curve (AUROC) of 0.984 (95%CI 0.972-0.996) and Cohen's kappa of 0.845 (95%CI 0.774-0.915) when compared to gold standard histopathology. OCT is feasible and safe for polyp assessment during routine colonoscopy. When combined with deep learning, OCT offers clinicians increase confidence in identifying deeply invasive cancers, potentially improving clinical decision-making. Compared to previous studies, ours offers a nuanced comparison between not just benign and malignant lesions, but across multiple histological subtypes of polyps.

Assessment and Techniques for Endoscopic Closure

Endoscopic closure is an essential technique to perform safe advanced endoscopy. Without appropriate closure of a defect, patients can experience spillage of fecal contents into the peritoneal cavity resulting in abdominal sepsis. The essential components to performing endoscopic closure are assessing the defect appropriately and choosing the correct closure technique. Assessing the defect involves five separate elements: timing, size, depth, shape, blood flow, and location in the colon or rectum. Understanding how each of these elements contributes toward a successful closure allows an endoscopist to choose the proper technique for closure. There have been many types of closure techniques described in the literature but the most common are through the scope clips, over the scope clips, and endoscopic suturing. There are advantages and disadvantages of each of these closure techniques. In this manuscript, we will discuss these common techniques as well as some additional techniques and the situations where they can be employed.

Best practices in wound care for gastrointestinal stoma and colorectal cancer patients from a nursing perspective: A meta-analysis

Colorectal cancer, a type of colon or bowel cancer, poses a major challenge in the treatment of colorectal lesions. Colorectal endoscopic mucosal resection (EMR) is a minimally invasive technique, but the risk of wound infections remains a significant concern. These infections can impede the healing process, affecting daily activities and patient satisfaction. To mitigate the risk of wound infections, various prophylactic measures have been explored, including medication, vaccines, lifestyle adjustments and hygiene practices. This study aims to investigate the prevention of wound infections through prophylactic measures in colorectal EMR. A comprehensive literature review was conducted to identify prophylactic measures that can prevent wound infections. A systematic literature search was conducted using both free words and search terms. The data extraction was performed after a comprehensive literature screening. The meta-analysis was performed using the metabin function of the meta library in R to evaluate the infection incidences in intervention and control groups. A total of 599 infection incidences were considered, with 267 in intervention and 332 in the control group. The results of meta analysis demonstrated significant reduction of wound incidences following the prophylactic measures (risk ratio [RR] = 0.77, 95% confidence interval [CI]: 0.6747; 0.9016, I2 = 78.5%, p < 0.01). The wound infection ratio analysis also exhibited an approximate 6.6% less infection rate in the intervention group, demonstrating significantly less wound infection following the implementation of prophylactic measures. This study highlights the crucial significance of prevention of wound infections by prophylactic measures in colorectal EMR.

A balance of clinical assessment and use of diagnostic imaging: A CT colonography comparative case report

Computer tomography colonography (CTC) is a non-invasive procedure which has replaced barium enema. CTC uses helical images of a cleansed and gas-distended colon for the diagnosis and treatment of colonic neoplasms. This case study compares 2 patients: one with positive pathology (patient A) and another as comparator (patient B) with a similar pathology to discuss and debate possible treatment pathways. Patient (A) CTC showed 2 polyps: 6 mm and 10 mm, which the colorectal surgeons thought only needed follow-up. Our comparator (patient B) displayed a similar pathology which measured 9 mm. In this case (patient B), there was mutual agreement with the surgeons for polypectomy but without haematology involvement which was atypical of the usual pathway. The surgeons did not see the 9 mm polyp at polypectomy which could be due to observer error or radiology reporter error. Given that conventional colonoscopy is more sensitive in detecting polyps; a repeat of both tests could confirm the presence of polyp, however, the surgeons gave patient (B) a virtual appointment and requested a repeat CTC in 12 months. In colorectal medicine there can be variations in the treatment of patients with polyps. While a repeat of both tests could confirm the presence of polyp in patient (B), the surgeons' decisions regarding the patient's treatment reflected a balance of confidence in clinical assessment and use of diagnostic imaging which can reduce unnecessary requests and use of diagnostic tests.

Colonoscopic-assisted laparoscopic wedge resection for colonic neoplasms: a systematic review

OBJECTIVES

The current literature describes a variety of techniques detailed under the name of combined endoscopic-laparoscopic surgery (CELS) procedures. This systematic review of literature assessed the outcomes of colonoscopic-assisted laparoscopic-wedge resection (CAL-WR) in particular to evaluate its feasibility to remove colonic lesions that do not qualify for endoscopic resection.

MATERIALS AND METHODS

Electronic databases (PubMed, Embase, and Cochrane) were searched for studies evaluating CAL-WR for the treatment of colonic lesions. Studies with missing full text, language other than English, systematic reviews, and studies with fewer than ten patients were excluded. The quality of the studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

Out of 68 results, duplicate studies (n = 27) as well as studies that did not meet the inclusion criteria (n = 32) were removed. Nine studies were included, encompassing 326 patients who underwent a CAL-WR of the colon. The technical success rate varied from 93 to 100%, with an R0 resection rate of 91-100%. Morbidity ranged from 6% to 20%. The quality of the included studies was rated as low to moderate and contained heterogeneous terminology, methodology, and outcome measures.

CONCLUSIONS

There is insufficient high-quality data and substantial variation in outcome measures to draw firm conclusions regarding the value of CAL-WR. Although CAL-WR is a promising local resection technique for endoscopically unremovable neoplasms of the colon, further investigation of this technique in well-designed prospective, multicenter studies with predefined outcome measures is required.Trial registration: A protocol for this systematic review was registered in PROSPERO with the number CRD42023407966.

Colorectal cancer: a comprehensive review of carcinogenesis, diagnosis, and novel strategies for classified treatments

Colorectal cancer is the third most common and the second deadliest cancer worldwide. To date, colorectal cancer becomes one of the most important challenges of the health system in many countries. Since the clinical symptoms of this cancer appear in the final stages of the disease and there is a significant golden time between the formation of polyps and the onset of cancer, early diagnosis can play a significant role in reducing mortality. Today, in addition to colonoscopy, minimally invasive methods such as liquid biopsy have received much attention. The treatment of this complex disease has been mostly based on traditional treatments including surgery, radiotherapy, and chemotherapy; the high mortality rate indicates a lack of success for current treatment methods. Moreover, disease recurrence is another problem of traditional treatments. Recently, new approaches such as targeted therapy, immunotherapy, and nanomedicine have opened new doors for cancer treatment, some of which have already entered the market, and many methods have shown promising results in clinical trials. The success of immunotherapy in the treatment of refractory disease, the introduction of these methods into neoadjuvant therapy, and the successful results in tumor shrinkage without surgery have made immunotherapy a tough competitor for conventional treatments. It seems that the combination of those methods with such targeted therapies will go through promising changes in the future of colorectal cancer treatment.

Causal association between telomere length and colorectal polyps: A bidirectional two-sample Mendelian randomization study

We performed a bidirectional 2-sample Mendelian randomization (MR) design to explore the causal relation between telomere length (TL) and colorectal polyps. Genome-wide association study summary data of TL and colorectal polyps were extracted from the IEU open genome-wide association study database. Single nucleotide polymorphisms were served as instrumental variables at the significance threshold of P < 5 × 10-8. The inverse variance weighted method, MR-Egger method, and weight median method were performed for causal estimation in MR. Cochran Q test, MR-Egger intercept test, and leave-one-out analyses were performed to evaluate the pleiotropy of the MR results. One hundred and twenty-four single nucleotide polymorphisms were selected as instrumental variables. We found significant casual association between TL and colorectal polyps. Long TL increased the risk of colorectal polyps using the inverse variance weighted method [ukb-a-521: odds ratio (OR): 1.004, 95% confidence interval (CI): 1.001-1.007, P = .004; ukb-d-D12: OR: 1.008, CI: 1.004-1.012, P < .001; finn-b-CD2_BENIGN_COLORECANI_EXALLC2: OR: 1.170, CI: 1.027-1.332, P = .018]. Sensitivity analyses validated that the causality between TL and colorectal polyps was robust. The study provided a causal association between TL and colorectal polyps which indicated that TL might be served as a potential biomarker of colorectal polyps for screening and prevention. Nonetheless, the conclusions need further validation.

Safety and efficacy of underwater versus conventional endoscopic mucosal resection for colorectal polyps: Systematic review and meta-analysis of RCTs

Background and study aims Conventional endoscopic mucosal resection (C-EMR) is limited by low en-bloc resection rates, especially for large (> 20 mm) lesions. Underwater EMR (U-EMR) has emerged as an alternative for colorectal polyps and is being shown to improve en-bloc resection rates. We conducted a systematic review and meta-analysis comparing the two techniques. Methods Multiple databases were searched through November 2022 for randomized controlled trials (RCTs) comparing outcomes of U-EMR and C-EMR for colorectal polyps. Meta-analysis was performed to determine pooled proportions and relative risks (RRs) of R0 and en-bloc resection, polyp recurrence, resection time, and adverse events. Results Seven RCTs with 1458 patients (U-EMR: 739, C-EMR: 719) were included. The pooled rate of en-bloc resection was significantly higher with U-EMR vs C-EMR, 70.17% (confidence interval [CI] 46.68-86.34) vs 58.14% (CI 31.59-80.68), respectively, RR 1.21 (CI 1.01-1.44). R0 resection rates were higher with U-EMR vs C-EMR, 58.1% (CI 29.75-81.9) vs 44.6% (CI 17.4-75.4), RR 1.25 (CI 0.99-1.6). For large polyps (> 20 mm), en-bloc resection rates were comparable between the two techniques, RR 1.24 (CI 0.83-1.84). Resection times were comparable between U-EMR and C-EMR, standardized mean difference -1.21 min (CI -2.57 to -0.16). Overall pooled rates of perforation, and immediate and delayed bleeding were comparable between U-EMR and C-EMR. Pooled rate of polyp recurrence at surveillance colonoscopy was significantly lower with U-EMR than with C-EMR, RR 0.62 (CI 0.41-0.94). Conclusions Colorectal U-EMR results in higher en-bloc resection and lower recurrence rates when compared to C-EMR. Both techniques have comparable resection times and safety profiles.

Difficult colorectal polypectomy: Technical tips and recent advances

Colonoscopy has been shown to be an effective modality to prevent colorectal cancer (CRC) development. CRC reduction is achieved by detecting and removing adenomas, which are precursors of CRC. Most colorectal polyps are small and do not pose a significant challenge for trained and skilled endoscopists. However, up to 15% of polyps are considered “difficult”, potentially causing life-threatening complications. A difficult polyp is defined as any polyp that is challenging for the endoscopist to remove owing to its size, shape, or location. Advanced polypectomy techniques and skills are required to resect difficult colorectal polyps. There were various polypectomy techniques for difficult polyps such as endoscopic mucosal resection (EMR), underwater EMR, Tip-in EMR, endoscopic submucosal dissection (ESD), or endoscopic full-thickness resection. The selection of the appropriate modality depends on the morphology and endoscopic diagnosis. Several technologies have been developed to aid endoscopists in performing safe and effective polypectomies, especially complex procedures such as ESD. These advances include video endoscopy system, equipment assisting in advanced polypectomy, and closure devices/techniques for complication management. Endoscopists should know how to use these devices and their availability in practice to enhance polypectomy performance. This review describes several useful strategies and tips for managing difficult colorectal polyps. We also propose the stepwise approach for difficult colorectal polyps.

Endoscopic submucosal dissection for colorectal polyps: outcome determining factors

BACKGROUND

Endoscopic submucosal dissection (ESD) has gained increasing popularity in the management of complicated colorectal polyps. However, clinical outcomes for ESD have remained highly inconsistent worldwide. This study investigated and analysed factors that significantly affect ESD outcomes.

METHODS

We conducted a single-centred retrospective study on 220 colorectal polyps removed by ESD from 1st January 2016 to 31st December 2020. Data were collected and retrieved from clinical records. Variables studied included patient demographics, ESD technicalities and polyp characteristics. The primary outcome was completeness of resection based on en bloc and R0 resection rates. The secondary outcomes were recurrence, complications and hospital stay. Further analysis was performed for significant outcome determining factors.

RESULTS

The en bloc resection and R0 resection rates were 97.3% and 65% respectively. Intraprocedural and delayed perforation rates were 3.2% and 0.5% respectively. Intraprocedural and delayed bleeding rates were both 1.8%. Post-polypectomy syndrome rate was 2.7%. The median hospital stay was 4 days. Submucosal fibrosis was a significant determining factor for lower en bloc resection (p = 0.004), lower R0 resection (p = 0.002), intraprocedural perforation (p = 0.001), intraprocedural bleeding (p = 0.025) and post-polypectomy syndrome (p = 0.039). Hybrid snaring was associated with lower en bloc resection (p < 0.001), while longer ESD time was associated with lower R0 resection (p = 0.003) and post-polypectomy syndrome (p = 0.025). Other significant factors for post-polypectomy syndrome included young age (p = 0.021) and large polyp size (p = 0.018). Secondary analysis showed that submucosal fibrosis was significantly associated with non-granular lesions (p < 0.001) and prior biopsy (p = 0.003).

CONCLUSION

Submucosal fibrosis, hybrid snaring, ESD time, age and polyp size were significant outcome determining factors for ESD. By identifying these factors, strategies may be formulated to improve ESD outcomes.

Clinical presentation, management, screening and surveillance for colorectal cancer during the COVID-19 pandemic

Management of colorectal cancer (CRC) was severely affected by the changes implemented during the pandemic, and this resulted in delayed elective presentation, increased emergency presentation, reduced screening and delayed definitive therapy. This review was conducted to analyze the impact of the coronavirus disease 2019 (COVID-19) pandemic on management of CRC and to identify the changes made in order to adapt to the pandemic. We performed a literature search in PubMed, Medline, Index Medicus, EMBASE, SCOPUS, Reference Citation Analysis (https://www.referencecitationanalysis.com/) and Google Scholar using the following keywords in various combinations: Colorectal cancer, elective surgery, emergency surgery, stage upgrading, screening, surveillance and the COVID-19 pandemic. Only studies published in English were included. To curtail the spread of COVID-19 infection, there were modifications made in the management of CRC. Screening was limited to high risk individuals, and the screening tests of choice during the pandemic were fecal occult blood test, fecal immunochemical test and stool DNA testing. The use of capsule colonoscopy and open access colonoscopy was also encouraged. Blood-based tests like serum methylated septin 9 were also encouraged for screening of CRC during the pandemic. The presentation of CRC was also affected by the pandemic with more patients presenting with emergencies like obstruction and perforation. Stage migration was also observed during the pandemic with more patients presenting with more advanced tumors. The operative therapy of CRC was altered by the pandemic as more emergencies surgeries were done, which may require exteriorization by stoma. This was to reduce the morbidity associated with anastomosis and encourage early discharge from the hospital. There was also an initial reduction in laparoscopic surgical procedures due to the fear of aerosols and COVID-19 infection. As we gradually come out of the pandemic, we should remember the lessons learned and continue to apply them even after the pandemic passes.

Rapid Polyp Classification in Colonoscopy Using Textural and Convolutional Features

Colorectal cancer is the leading cause of cancer-associated morbidity and mortality worldwide. One of the causes of developing colorectal cancer is untreated colon adenomatous polyps. Clinically, polyps are detected in colonoscopy and the malignancies are determined according to the biopsy. To provide a quick and objective assessment to gastroenterologists, this study proposed a quantitative polyp classification via various image features in colonoscopy. The collected image database was composed of 1991 images including 1053 hyperplastic polyps and 938 adenomatous polyps and adenocarcinomas. From each image, textural features were extracted and combined in machine learning classifiers and machine-generated features were automatically selected in deep convolutional neural networks (DCNN). The DCNNs included AlexNet, Inception-V3, ResNet-101, and DenseNet-201. AlexNet trained from scratch achieved the best performance of 96.4% accuracy which is better than transfer learning and textural features. Using the prediction models, the malignancy level of polyps can be evaluated during a colonoscopy to provide a rapid treatment plan.