Introduction

Bevacizumab is an anti-angiogenic monoclonal antibody targeting vascular endothelial growth factor used to treat advanced colorectal cancer (CRC). Self-expandable metal stents (SEMS) are employed in cases of advanced obstructive CRC but are linked to adverse events like bleeding, stent migration, and bowel perforation. To date, it is unclear whether bevacizumab-based chemotherapy increases the risk of perforation in patients with SEMS. Therefore, we conducted a systematic review and meta-analysis to evaluate the risk of bevacizumab-related perforation in these patients.

Aims & Methods

We conducted a comprehensive literature search from major databases until December 2023. We identified all potential studies that evaluated the risk of colonic perforation in patients with bevacizumab-based chemotherapy after SEMS insertion. We compared the risk of colonic perforation in patients who received bevacizumab-based chemotherapy with patients who received chemotherapy without bevacizumab or best supportive care. We calculated the odds ratio (OR) and 95% confidence interval (CI) using a M-H random-effects model and I-square method.

Results

Twelve studies, including 1,599 patients, met our inclusion criteria and were included in the meta-analysis. Of 1,559 SEMS patients, 320 received bevacizumab-based chemotherapy, and 1,274 received chemotherapy without bevacizumab or best supportive care. A total of 106 perforations have been reported. The risk ratio for colonic perforation in bevacizumab-based chemotherapy was 2.78 (95% CI: 1.21-6.38, p=0.02; I2=57%) when compared to non-bevacizumab-based therapy. In sub-group analysis, bevacizumab-based chemotherapy showed an increased risk of perforation when compared with chemotherapy without bevacizumab (OR, 3.71; 95% CI: 1.43-93.5; p=0.007; I2=0), but no statistically significant difference when compared with SEMS alone (OR, 3.75; 95% CI: 0.64-22.08; p=0.14; I2=62%).

Conclusion

Bevacizumab-based chemotherapy appears to increase the risk of perforation in advanced CRC patients after SEMS compared with non-bevacizumab-based therapy. These results were especially pronounced in chemotherapy without bevacizumab than in SEMS alone.

References

1. van Hooft JE, Veld JV, Arnold D, et al. Self-expandable metal stents for obstructing colonic and extracolonic cancer: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2020. Endoscopy 2020;52:389-407.
2. van Halsema EE, van Hooft JE, Small AJ, et al. Perforation in colorectal stenting: a meta-analysis and a search for risk factors. Gastrointest Endosc 2014;79:970-82.
3. Lee JH, Emelogu IE, Kukreja K, et al. Safety and efficacy of metal stents for malignant colonic obstruction in patients treated with bevacizumab. Gastrointest Endosc 2019;90:116-124.

Introduction

Computer-Aided Diagnosis (CADx) allows for real-time characterisation of polyps. In a small number of studies to date, CADx accuracy in polyp characterisation has been similar to expert endoscopists and better than novel endoscopists. CADx may allow for a resect and discard strategy with sub-centimetre polyps which would have significant economic impacts on our health service. CADx may also be a useful tool in improving the accuracy and efficiency of polyp diagnosis and management in a training setting.

Aims & Methods

To compare the performance of expert endoscopists, trainee endoscopists and CADx in characterising colonic polyps.

In this multi-centre prospective comparison study, two endoscopists performed high-definition colonoscopies with GI Genius (Medtronic, Dublin, Ireland) between August and November 2022. All detected polyps were photo-documented (white light imaging, narrow band imaging and near focus), resected and retrieved. CADx diagnosis was recorded (adenoma/non-adenoma/no prediction). Histologic diagnosis was recorded. Blinded to both CADx and histologic diagnosis, expert and trainee endoscopists independently predicted polyp type based on photo documentation. Comparison of diagnosis was made between experts, trainees & CADx and compared against final histologic diagnosis. Sensitivity and specificity was calculated for each group using histologic diagnosis as gold standard.

Results

139 polyps across two centres were photo-documented during the study timeframe. Expert endoscopists (Sensitivity 91.67% [95% CI 77.53-98.25%]) were better at polyp characterisation than both CADx (Sensitivity 84.31% [95% CI 71.41-92.98%]) and trainee endoscopists (Sensitivity 87.23% [95% CI 74.26-95.17%]). Expert endoscopists (Sensitivity 77.27% [95% CI 54.63-92.18%] and trainee endoscopists (Sensitivity 63.16% [95% CI 38.36-83.71%]) performed better than CADx (Sensitivity 42.11% [95% CI 20.25-66.50%]) in the characterisation of non-adenomatous polyps.

Conclusion

Our data corresponds with previously published studies. Interestingly, trainee characterisation was similar to CADx predictions in our study. Both trainee endoscopists are experienced endoscopists nearing the end of their respective training schemes. CADx polyp characterisation may be useful in an earlier training phase but further studies are necessary. A resect and discard strategy utilising CADx does not at present appear feasible.

References

1. Hassan C, Wallace MB, Sharma P, et al. New artificial intelligence system: first validation study versus experienced endoscopists for colorectal polyp detection. Gut. 2020; 69:799-800.

2. Li, MD., Huang, ZR., Shan, QY. et al. Performance and comparison of artificial intelligence and human experts in the detection and classification of colonic polyps. BMC Gastroenterol 22, 517 (2022). https://doi.org/10.1186/s12876-022-02605-2

Introduction

In Crohn’s disease (CD) a symptomatic luminal stricture occurs in up to 20% of patients at the diagnosis and in more than 50% during lifetime (1,2). Endoscopic balloon dilatation (EBD) or surgical procedures are the currently available treatments (3,4). However, a considerable percentage of patients often require further surgery for post-operative CD recurrence (5). A consequent increased burden of short bowel syndrome is warranted. The combination of biological therapy with EBD could potentially reduce this risk.

Aims & Methods

The aim of our study was to evaluate the efficacy of EBD combined with biologic therapy in symptomatic gastrointestinal strictures in CD’s patients. We conducted a retrospective study including consecutive CD patients who underwent EBD for low bowel strictures from December 2015 until November 2022 at our tertiary IBD Center. Clinical strictures recurrence, needs for steroids and for surgery due to CD stenosis relapse were the primary outcomes evaluated during a follow-up period of six and twelve months. Chi-square and univariate statistical analyses were used when appropriate.

Results

A total of 52 patients treated with EBD with an overall number of 55 strictures were included. In the study population, 14 patients (27%) were smoker, the mean age was of 46,8 (18-77) years; the median of disease duration was 9 (0-42) years. Thirty-nine patients (75%) were in active treatment with biologic therapy at the moment of EBD. Twenty-three patients (44%) underwent EBD for anastomotic stricture, 8 (15%) for ileal stricture, 11 (21%) for ileocecal valve stricture, 5 (6%) for anal stricture and 4 (8%) for colic stricture. Three patients (6%) underwent EBD for multifocal bowel stenosis. Twenty-two (42%) patients had increased CRP value, 40 patients (77%) had evidence of moderate or severe endoscopic disease activity and 42 (81%) patients showed ulcerative lesions at stricture site. EBD was performed by 8-10, 12-15 or 15-18 mm dilation balloon. Technical success was reported in 60% of procedures and no adverse events were registered.
After 6 months from EBD, at univariate analysis, active smoke resulted a risk factor for clinical stricture recurrence (OR 10,25; IC 1,350 to 135,4; p value = 0,022) and for subsequent surgery (OR 10,25; IC 1,350 to 135,4; p value = 0,022). Moreover, increased CRP at the time of dilatation resulted a risk factor for need of steroids (OR 14,63; IC 2,69 to 71,50; p value = 0,0006). Concomitant biologic therapy and presence of ulcerative lesions did not show significative correlation with considered outcomes.
After 12 months from EBD, concomitant biologic therapy resulted a protective factor for prevention of surgery (OR 0,061; IC 0,005 to 0,502; p value = 0,0047), while anastomotic strictures were associated with a lower risk of sub-occlusion events than ileal stenosis (OR 0,07; IC 0,005 to 0,651; p value = 0,015). Increased CRP at the time of EBD, ulcerative lesions at the stricture site and active smoke were not significantly correlated with the considered outcome.

Conclusion

Our results suggest that in patients with CD undergoing EBD for bowel CD stricture, concomitant biological therapy reduces the risk of surgery for CD stenosis recurrence. Further prospective and controlled studies are underway to confirm these observations.

References

1. Rieder F Managing Intestinal Fibrosis in Patients With Inflammatory Bowel Disease. Gastroenterology & hepatology. 2018. February; 14(2):120–122
2. Yoo JH, Holubar S, Rieder F. Fibrostenotic strictures in Crohn’s disease. Intest Res. 2020;0.
3. Paine E, Shen B. Endoscopic therapy in inflammatory bowel diseases (with videos). Gastrointest Endosc 2013;78:819–35.
4. Hassan C, Zullo A, De Francesco V, Ierardi E, Giustini M, Pitidis A, Taggi F, Winn S, Morini S. Systematic review:
Endoscopic dilatation in Crohn's disease. Aliment Pharmacol Ther. 2007 Dec;26(11-12):1457-64
5. Olaison G, Smedh K, Sjödahl R. Natural course of Crohn’s disease after ileocolic resection: endoscopically visualised ileal ulcers preceding symptoms. Gut 1992;33:331–5.

Introduction

Emergency surgery (ES) is associated with higher morbidity and mortality for acute left colonic malignant obstruction. Since the first application of self-expandable metallic stent (SEMS), the technique has been popularly applied as “bridge to surgery (BTS)”. The short-term clinical outcomes and long-term oncologic prognosis remain controversial.

Aims & Methods

This retrospective study aimed to compare the performance for managing acute left colonic malignant obstruction by ES or BTS. The medical records were collected from May 2015 to December 2019 in two tertiary hospitals in Eastern China. Patients were followed up after surgery every 6 months for 3 years and once a year afterwards. Clinical success was defined as resumption of intestinal function for 30 days without morbidity or mortality after surgical procedure. All demographics, intervention procedures and follow-up were analyzed for short-term and long-term outcomes. Risk factors for long-term survival were discussed as well.

Results

A total of 136 patients were eligible for the study, 67 in BTS group and 69 in ES group. No significant differences concerning demographics were found, including age, sex, body-mass index (BMI), symptoms, coexisting disorders, laboratory tests, preoperative radiotherapy or chemotherapy, previous history of abdominal surgery, cancer location, obstructive degree and TNM stage. Technical success of SEMS insertion was achieved in 64 patients (95.5%). The interval from SEMS placement to elective surgery was 16 days. Minor perforation was detected on 4 patients during the elective surgery, while no symptomatic complaint was recorded.
BTS group showed better short-term performance, including less intraoperative decompressive intervention (85.1% vs. 69.6%, p=0.045), more complete decompression (64.2% vs. 27.5%, p＜0.001), more primary anastomosis (65.7% vs. 17.4%, p＜0.001), less temporary and permanent stoma (34.3% vs. 82.6%, 13.4% vs. 58.7%, both p＜0.001), less intensive care unit requirement (10.4% vs. 27.5%, p=0.011), less intraoperative complications (3.0% vs. 13.0%, p=0.031) and reduced 30-day mortality (0 vs. 8.7%, p=0.028). Longer hospitalization was observed in the BTS group (21.7±13.3 days vs. 14.9±7.6 days, p＜0.001). Postoperative hospitalization and total cost were comparable between the two groups. No significant difference was observed about clinical success (73.1% vs. 63.8%, p=0.240), overall mortality (53.7% vs. 64.4%, p=0.247) or long-term survival (52.0 months vs. 35.0 months, p=0.121). TNM stage Ⅳ, permanent stoma and postoperative complication were the independent risk factors for long-term survival.

Table.1 Operation related characteristics

Conclusion

SEMS served as a safe and effective bridge to elective surgery for acute left colonic malignant obstruction, without adverse effect on long-term survival. It significantly improved short-term outcomes by reducing perioperative complication, 30-day mortality and stoma. More prospective studies are necessary for further evaluating the clinical values of SEMS, and weighing its benefits against potential complications.

References

1. Manfredi S, Sabbagh C, Vanbiervliet G, et al. Place of colorectal stents in therapeutic management of malignant large bowel obstructions. Endoscopy. 2014;46:546-552.
2. Frago R, Ramirez E, Millan M, et al. Current management of acute malignant large bowel obstruction: a systematic review. Am J Surg. 2014;207:127-138.
3. Arezzo A, Passera R, Lo Secco G, et al. Stent as bridge to surgery for left-sided malignant colonic obstruction reduces adverse events and stoma rate compared with emergency surgery: results of a systematic review and meta-analysis of randomized controlled trials. Gastrointest Endosc. 2017;86:416-426.
4. van Hooft JE, van Halsema EE, Vanbiervliet G, et al. Self-expandable metal stents for obstructing colonic and extracolonic cancer: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline. Gastrointest Endosc. 2014;80:747-761 e741-775.
5. Pisano MA-O, Zorcolo L, Merli C, et al. 2017 WSES guidelines on colon and rectal cancer emergencies: obstruction and perforation. 2017.
6. Kawachi J, Kashiwagi H, Shimoyama R, et al. Comparison of efficacies of the self-expandable metallic stent versus transanal drainage tube and emergency surgery for malignant left-sided colon obstruction. Asian J Surg. 2018;41:498-505.