Endoscopic management of difficult laterally spreading tumors in colorectum

Endoscopic mucosal resection with an over-the-scope clip for colorectal tumors (with video)

Background

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection may result in complications or may be unsuitable for tumors that are difficult to treat endoscopically. We investigated the usefulness of a newly developed endoscopic resection technique-EMR with an over-the-scope clip (EMR-O)-for difficult-to-treat lesions.

Method

We retrospectively examined patients who underwent EMR-O for colorectal tumors between September 2017 and January 2024. Patient and lesion characteristics, technical success rates, en bloc resection rates, R0 resection rates, procedure time, histopathology, and the clinical course were evaluated.

Results

EMR-O was performed for 18 patients. Indications for EMR-O included residual or recurrent lesions (seven patients; 38.9%), diverticulum lesions (five patients; 27.8%), appendiceal orifice lesions (three patients; 16.7%), T1 cancers (two patients; 11.1%), and subepithelial tumors (one patient; 5.5%). The median lesion size was 11 mm. The rates of technical success, en bloc resection, and R0 resection were 100%, 86.7%, and 86.7%. The median procedure time was 10 min. The only adverse event was diverticulitis (one patient; 5.5%). Intraoperative and delayed perforation and bleeding were not observed. The pathological resection depths were full-thickness for three patients (16.7%), muscularis resection for four patients (22.2%), and deep submucosal resection for 11 patients (61.1%).

Conclusion

Although EMR-O is limited by the target lesion size, it shortens the procedure time, prevents perforation, and avoids the need for surgery. EMR-O may be a minimally invasive treatment option for small lesions that are difficult to treat endoscopically.

A deep neural network improves endoscopic detection of laterally spreading tumors

BACKGROUND

Colorectal cancer (CRC) is the malignant tumor of the digestive system with the highest incidence and mortality rate worldwide. Laterally spreading tumors (LSTs) of the large intestine have unique morphological characteristics, special growth patterns and higher malignant potential. Therefore, LSTs are a precancerous lesion of CRC that could be easily missed.

OBJECTIVE

The purpose of this study was to establish an LSTs lesion detection algorithm based on the YOLOv7 model and to evaluate the detection performance of the algorithm on LSTs.

METHOD

A total of 7985 LSTs images and 93,197 non-LSTs images were included in this study, and the training set, validation set, and 80% of the data in the dataset is used for training, 10% for validation, and 10% for testing. In detail, a total of 6261 LSTs images and 74,798 non-LSTs images were used as the training set to train the LSTs lesion detection algorithm to identify LSTs. A total of 743 LSTs images and 9486 non-LSTs images were used as validation set to evaluate the learning ability of the LSTs lesion detection algorithm. A total of 981 LSTs images and 8913 non-LSTs images were used as test set to evaluate the generalization ability of the LSTs lesion detection algorithm. To evaluate the diagnostic ability of the LSTs lesion detection algorithm for LSTs, we selected 3636 images (562 LSTs, 3074 non-LSTs) images from the test set as the subtest set. Finally, we compared the performance of the AI algorithm with endoscopist in the diagnosis of LSTs.

RESULT

The accuracy of LSTs lesion detection algorithm in identifying LSTs is 99.34%, sensitivity is 96.88%, specificity is 99.8%, positive predictive value is 98.94%, and negative predictive value is 99.41%.

CONCLUSION

Our model based on the YOLOv7 achieved high diagnostic accuracy in LSTs lesion, significantly better than that of novice and senior doctors, and reaching the same level as expert endoscopists.

Clinical audit of endoscopic sub-mucosal dissection performed for complex lateral spreading colorectal tumors from a region non-endemic for colorectal cancer

BACKGROUND

Endoscopic resection is currently the treatment of choice for laterally spreading tumors (LSTs). Endoscopic sub-mucosal dissection (ESD) can achieve higher enbloc resection and R0 resection, albeit at a slightly higher risk of complications. Given scarce data on ESD from India, we performed a retrospective analysis of our experience with colorectal ESD (CR-ESD) to know its clinical efficacy and complications as well as to assess the learning curve of CR-ESD in non-endemic-areas.

METHODS

Retrospective analysis of prospectively maintained datasheet performed. All patients with large (>2cm), complex or recurrent colorectal LST who underwent ESD at our center between 2012 and 2021 were included in the study. Various baseline lesion-related parameters, procedure-related parameters, enbloc resection (ER) rates, R0 margins and adverse event rates were retrieved. CUSUM analysis was performed to calculate the minimum required procedures to achieve competency in CR-ESD.

RESULTS

Total 149 patients were included in the study; mean patient age was 61.36±18.21 years. Most patients had lesions in rectum (n=102; 68.5%) followed by sigmoid colon (n=25; 16.8%). The mean lesion size was 46.62 ± 25.46 mm and the mean procedure duration for ESD was 219.30 ± 150.05 min. ER was achieved in 94.6% of lesions. R0 resection was achieved in 132 patients (88.6%). Overall, six (4%) adverse events were noted, of which one required surgical intervention. As many as 105 patients (70.5%) had adenomatous lesions on histology. Seventy-four patients underwent follow-up colonoscopy, of which three had a recurrence of adenomatous lesions and five had post-resection stricture requiring endoscopic dilation. CUSUM curve analysis calculated the learning curve for ESD was 47 resections for ER and 55 for the occurrence of AEs, with a composite CUSUM at 47 procedures.

CONCLUSION

CR-ESD even in non-endemic area is associated with high en bloc resection rates, R0 resection rates and acceptable complication profile. Approximately 50 cases of CR-ESD are required to achieve competency.

Laparoscopic resection of a descending colon tumor with right-sided fixation of the sigmoid colon: a case report

BACKGROUND

Intestinal malrotation is a condition in which the process of counterclockwise rotation and fixation to the peritoneum and retroperitoneum during fetal life is incomplete. In adults, it is generally asymptomatic and is often discovered incidentally. We report a case of laparoscopic partial resection of the descending colon for a tumor of the descending colon with a rare form of intestinal malrotation in which the inferior mesenteric artery ran symmetrically and the sigmoid colon was fixed to the dorsal cecum and right-sided retroperitoneum.

CASE PRESENTATION

A 75-year-old man was referred to our department of internal medicine due to a positive fecal occult blood test. Lower endoscopy revealed a laterally spreading tumor in the descending colon, and endoscopic submucosal dissection was attempted; however, this procedure was difficult, and the patient was referred to our department for surgical treatment. Contrast-enhanced computed tomography revealed that the endoscopic clip was located in the descending colon on the right side, the inferior mesenteric artery was symmetrical, and the sigmoid colon was located on both the right and dorsal sides of the cecum. Laparoscopic ileocecum and sigmoid colon mobilization was performed from the left side of the patient. After the completion of sigmoid colon mobilization, which returned the sigmoid colon and descending colon to anatomical normalcy, laparoscopic partial resection of the descending colon was performed. Based on the results of a histopathological examination, a granular type of laterally spreading tumor was diagnosed. The patient was discharged uneventfully on postoperative day 8.

CONCLUSIONS

Detailed preoperative imaging and surgical simulation are necessary for abdominal surgery involving intestinal malrotation.

Cap-assisted endoscopic mucosal resection as a salvage technique for challenging colorectal laterally spreading tumors

BACKGROUND

Cap-assisted endoscopic mucosal resection (EMR-c) has emerged as a potential alternative to standard piecemeal wide-field EMR (WF-EMR) for the resection of laterally spreading tumors (LSTs). However, clear indications for this technique are still lacking. Our objective was to investigate the performance of salvage EMR-c after WF-EMR failure in the resection of large colorectal LSTs.

METHODS

The data of consecutive patients undergoing WF-EMR for large colorectal LSTs (2015-2021) were analyzed in this single-center, retrospective, observational study. In the event of a WF-EMR failure, the procedure was switched to EMR-c in the same session. The efficacy of the two techniques was evaluated in terms of complete endoscopic resection, R0 resection, and recurrence rate. Safety was also assessed.

RESULTS

Overall, the data from 81 WF-EMRs were collected. Eighteen cases of WF-EMR failure were switched to EMR-c in the same session and complete endoscopic resection was achieved in 17/18 patients (94.4%). No statistically significant difference was observed between WF-EMR and salvage EMR-c in terms of macroscopic radicality (P = 0.40) and R0 resection (P = 0.12). However, recurrence was more common with EMR-c (44.4% vs. 23.5%; P = 0.05), as were adverse events, particularly intraprocedural bleeding (27.8% vs. 7.9%; P = 0.04).

CONCLUSION

EMR-c is an effective salvage technique for challenging colorectal LSTs following WF-EMR failure. Due to the elevated risk of adverse events associated with this procedure, careful patient selection, endoscopic expertise, and close follow-up are strongly recommended.