COPENHAGEN — Cold snare endoscopic mucosal resection (CS-EMR) is safer than hot snare (HS)-EMR for resection of large non-pedunculated colorectal polyps, but after cold snare The general recurrence rate is higher, initial data from one research institution reveals. A prospective, multicenter, randomized controlled trial (RCT) shows.
“The safety of cold snare EMR is superior to hot snare EMR, and serious complications are almost completely eliminated,” says the gastroenterologist at Evangelis Diaconie Krankenhaus Freiburg in Germany. said Ingo Steinbrück, MD, an internist who presented the study results at the European Society of Gastroenterology. (U.E.G. ) week 2023.
“However, the general recurrence rate is [residual neoplasia] “After a cold snare, it is higher, so you need to carefully select the target lesion,” he said. Based on the study results, they said, “Cold snare EMR should be considered the new standard of care in cases of suspected sessile serrated adenoma, a tumor with lateral spread.” [LSTs] Select homogeneous granular lateral spreading tumors of 20 mm or larger with no macroscopic signs of malignancy. ”
Another summary of the same session was presented by Oscar Nogales, MD.
According to data from gastroenterologists at the Gregorio Maranhão General Hospital in Spain, the recurrence rate of large non-pedunculated colonic lesions after CS-EMR is significantly lower compared to the standard technique (conventional EMR). However, it was also shown that there was a tendency for recurrence. There will be fewer negative effects.
First RCT of Cold EMR and Hot Snare EMR
According to the guidelines, polyps smaller than 10 mm should be removed with a cold snare technique, while polyps larger than 10 mm should undergo hot snare EMR, Steinbrück said. “but, recent data Cold snares were found to have no significant adverse events and similar adenoma survival rates, suggesting that large polyps larger than 20 mm may also be beneficial with cold snares. [to hot snare EMR]” he explained.
To investigate this further, he and his colleagues set out to conduct a randomized controlled trial known as CHRONICLE (Cold vs. Hot Snare Excision of Nonpedunculated Polyps 2 cm or Larger in the Colorectum). “We hypothesized that a cold snare would be superior to a hot snare for resection of nonpedunculated colorectal polyps larger than 20 mm,” he said.
A total of 399 participants from 19 gastroenterology centers in Germany were randomly assigned to either the cold snare group (192 with therapeutic intent) or the hot snare group (202 with therapeutic intent). All had nonpedunculated polyps in the colorectum larger than 20 mm. Patients were followed up by telephone approximately 4 weeks after surgery to check for any complications, followed by a first endoscopy approximately 4 months later and a second follow-up examination approximately 12 months later. was held.
Major adverse events, including perforation and/or clinically significant post-endoscopic bleeding, constituted the primary endpoint. Secondary endpoints were intraoperative bleeding, post-polypectomy syndrome, technical success, resection speed, and recurrence rate at 4 months.
Reduced adverse events and increased residual tumor
“The lesions were mainly located in the right colon, were mostly LST, granular and homogeneous, and were suspected of being mostly solid serrated lesions.The average diameter was 3-8 cm, and most had mild abnormalities. It was an adenoma with formation and solid serrated lesions,” Steinbrück said.
The incidence of major adverse events was significantly lower in the cold snare group compared to the hot snare group, 1% vs. 8%, respectively (P = .001), perforations 0% vs. 4% (P = .007), delayed bleeding 1% vs. 4.5% (P = .03), respectively, he reported. “This is a clear advantage [for CS-EMR]. ”
Intraoperative bleeding rate was also significantly lower in cold snare patients compared with hot snare patients (14% vs. 29.9%, respectively). P = .02), but post-polypectomy syndrome was comparable between groups, he added.
But the other part of the story is efficacy, Steinbrück continued. “Look, the picture is different.”
Of the 283 patients included in this analysis, 24.8% in the cold snare group and 15% in the hot snare group had residual tumor at the first endoscopic follow-up.P = .037). “These are preliminary data, but I think the message is clear in that the proportion of residual neoplasms is higher in the cold snare group,” Steinbrück said.
The technical success rate was also lower in the cold snare group than in the hot snare group, at 92.2% and 97.5%, respectively (P = .02).
As a result of the subgroup analysis, the researchers concluded that suspected sessile serrated lesions were good candidates for cold snare treatment, as residual neoplasm was similar at approximately 5% for cold and hot snare treatments. discovered. LST nodular mixed lesions were considered unsuitable for cold snare EMR as the tumor residual rate was much higher than hot snare EMR, 43.8% vs. 16.7%, respectively (P = .01). And selected lesions, LST granular homogeneous and LST nongranular, may be candidates because the difference in outcome is less clear, Steinbrück added.
Cold snare EMR and traditional EMR
The second summary compared the effectiveness of complete resection of cold snare and conventional EMR in large nonpedunculated colonic lesions and determined the presence or absence of recurrence after 6 months. The open-label RCT was conducted in 15 hospitals in Spain and included adenomas ≥20 mm in size or contiguous nonpedunculated lesions of homogeneous type with serrated histology. A total of 229 patients (mean age 68 years) were included. Median lesion size was 25 mm (mainly adenomas), and almost 79% of lesions were found in the proximal colon.
Nogales reported that the recurrence rate was significantly higher in the cold snare group compared to the traditional EMR group, 33.6% vs. 16.7%, respectively (P = .007).
“Colonic lesions larger than 30 mm in diameter are more likely to recur,” he reported, with recurrence rates of 44% and 19% for cold snare and conventional EMR, respectively (P = .05). “Also, especially for serrated lesions, the recurrence rate was higher at 34.4% versus 4.2% with cold snare and conventional EMR.” Adenomas had similar rates.
“Adverse events were low overall, with no differences between groups, and there was a trend toward slightly more complications in traditional EMR patients,” Nogales said. all at once R0 resection rates were higher in the conventional arm, as was the use of clips for closure of mucosal defects, but the numbers were lower; [the results] Be careful,” he added.
Appropriate lesion selection is the key
Session co-chairs Nastja Pironis, MD, Department of Oncology and Gastroenterology, Maria Sklodowska Curie Institute of Oncology, Warsaw, Poland, and Marco Spadaccini, MD, Biomedical Sciences, Humanitas University, Milan, Italy, commented on the study. . Results of joint interview with Medscape Medical News.
Regarding cold snare and hot snare EMR techniques, Pironis said, “I think the price we have to pay for low event rates is recurrence, but overall I think these data provide great evidence.” said.
“Every new technology seems revolutionary, but despite its appeal, we need to be aware that it has some significant limitations,” she noted. “We need to select the appropriate lesions that are best suited for these techniques. If the patient is compliant with the following monitoring: colonoscopy, then that’s fine, but if you feel like you might never see them again, you might reconsider using the cold snare technique. ”
Spadaccini agreed, saying it’s important to choose the right lesions to cool, and it’s also important to choose lesions with a low risk of recurrence. “Most residual tumors can be removed relatively easily with endoscopy, but the problem is that there is usually an opportunity to see the patient again, not just to detect recurrence,” he added.
Steinbrück declares speaking fees and travel expenses from Olympus Medical and Falk Pharma. Nogales, Pironis and Spadaccini report no relevant financial relationships.
Unified European Gastroenterology (UEG) Week 2023: Summary of LB06. Announced on October 16, 2023.
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