Cold Snare Polypectomy for Colorectal Polyps: Current Uses and Development
Cold snare polypectomy (CSP) is a significant advancement in endoscopic resection technologies, particularly for the removal of diminutive colorectal polyps. This technique has been increasingly recommended for polyps less than 5 mm in size and even for noncancerous polyps up to 10 mm, playing a crucial role in reducing the incidence and mortality rate of colorectal cancer. The European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline endorses CSP as the preferred method for removing diminutive polyps, citing its high complete resection rate, low complication rates, and adequacy for histological sampling. The guideline is based on high-quality evidence and carries a strong recommendation.
For small polyps less than 10 mm, multiple randomized, single-center trials have demonstrated that CSP meets the necessary criteria for histological eradication, safety, and efficiency. ESGE also suggests the use of CSP for sessile serrated polyps (SSPs) measuring 6 to 9 mm, due to its superior safety profile, although this recommendation is based on moderate-quality evidence and is considered weak.
Recent studies have extended the application of CSP to larger polyps, those 10 mm and above. These studies have shown that CSP does not increase the risk of adverse events and achieves a complete removal rate of 99.3%. Follow-up colonoscopies have revealed acceptable rates of residual polyps (4.1%) and recurrence (12.2–13.8%). Moreover, wide-field piecemeal CSP has been applied for nonpedunculated large colon polyps, indicating that CSP is a safe and effective method for resecting colorectal polyps larger than 10 mm, despite the limited evidence.
CSP has also been considered as a less invasive option for patients with familial adenomatous polyposis (FAP) who choose to delay colectomy to avoid complications. A study involving 79 FAP patients who underwent CSP reported no complications post-polypectomy, with a decrease in the number of polyps in 77 patients and no development of colorectal cancer. This suggests that CSP could be a viable option for managing FAP.
Additionally, CSP has been used to remove small polyps in patients on antithrombotic therapy without stopping their medication, yielding better results compared to conventional polypectomy. This positions CSP as a potential option for patients receiving anticoagulation therapy.
Looking ahead, CSP may be used for the piecemeal resection of extensive or even circular SSPs, or for lesions in other locations such as the anal verge and duodenum, where post-polypectomy bleeding is more frequent. For patients on anticoagulant/antiplatelet agents or those who cannot tolerate electrocautery complications, CSP is a preferable choice.
The efficacy of CSP is primarily evaluated based on complete resection (R0 resection), as incomplete polypectomy may lead to interval colorectal cancer occurrences. Although CSP has a lower complete resection rate compared to endoscopic mucosal resection (EMR) (91.5% vs. 98.5%), its performance is acceptable when compared to other polypectomy methods. Studies have shown no significant difference in complete resection rates between CSP and hot snare polypectomy (HSP) (77.3–98.2% vs. 85–98.5%, P = 0.410). CSP is superior to hot forceps biopsy (91% vs. 77%) and cold forceps polypectomy (CFP) (93.2% vs. 75.9%, P = 0.009), and similar to cold biopsy forceps (CBF) and suction pseudopolyp technique (SPT), but inferior to EMR in terms of complete resection rate.
CSP reduces endoscopic operation time, thereby potentially reducing patient discomfort. The total colonoscopy time for CSP is significantly shorter than for EMR (4.7 min vs. 5.5 min) and HSP (16–23 min vs. 25–29.6 min, P < 0.001). This is attributed to the absence of electrocautery and the omission of submucosal saline injection during CSP. Although snaring can be more time-consuming than using forceps, the polypectomy duration is shorter for CSP than for CFP (14.29 s vs. 22.03 s).
The recurrence rate is a critical concern, with studies indicating a significantly lower residual neoplastic rate in the CSP group compared to EMR (6.2% vs. 29.7%, P = 0.013). Additionally, no recurrence was observed at the 1-year follow-up after CSP, suggesting a low rate of residual adenoma recurrence.
Bleeding is the most common complication of endoscopic operations, categorized as delayed or immediate. Delayed bleeding, usually occurring 5 to 21 days post-surgery, is less common with CSP due to the absence of electrocautery, which eliminates the risk of eschar detachment. Immediate bleeding, caused by capillary and venule injury, is more frequent with CSP, especially as polyp size increases. Protruding lesions and anticoagulation use are independent risk factors for immediate bleeding. A multicenter randomized trial showed a higher rate of immediate bleeding with CSP than with HSP (54% vs. 14%). However, self-hemostasis is usually achieved without special treatment, and argon plasma coagulation or hemostatic clips can be used to stop bleeding.
Perforation is a rare complication with CSP, as deep resection beyond the superficial submucosa is unnecessary, and the probability of cutting through the intrinsic muscularis of the intestinal mucosa is almost zero. No perforations have been reported in clinical trials involving CSP.
Post-polypectomy electrocoagulation syndrome is eliminated with CSP, reducing the likelihood of abdominal pain, muscle tension, fever, and other clinical manifestations. Although mild adverse events have been reported, they typically do not require special treatment.
The type of snare used in CSP can influence the procedure’s difficulty and outcomes. Studies comparing conventional CSP to dedicated cold snare polypectomy (DCSP) have shown that dedicated snares improve the complete resection rate, especially for polyps 8 to 10 mm in diameter. DCSP also slightly reduces the rate of immediate bleeding (24% vs. 28%, P = 0.700, 1% vs. 5%, P = 0.410) without increasing the risk of perforation or delayed bleeding. The thin braided wire and special shield shape of dedicated snares increase mucosal surface pressure, facilitating easier polyp tissue capture and cutting. DCSPs designed to support electrocautery can reduce operation time by eliminating the need to change snares for large polyps requiring HSP. However, more studies are needed to explore DCSP’s indications for polyps larger than 10 mm and its use in FAP patients.
In conclusion, CSP is a standard method for removing diminutive colorectal polyps, offering time-saving benefits and comparable efficacy and safety to traditional methods for polyps less than 10 mm. Its application for larger polyps, SSPs, and FAP patients shows promise, and the use of dedicated snares can enhance complete resection rates. Further research is needed to determine CSP’s upper limit for polyp diameter and its recurrence rate post-polypectomy.
doi.org/10.1097/CM9.0000000000001880
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