Clinical analysis of cold vs hot snare polypectomy for 10-19 mm non-pedunculated colorectal polyps

Abstract

BACKGROUND

Cold snare polypectomy (CSP) is comparatively safe and effective for removing polyps less than 10 mm in size with lower rates of postpolypectomy syndrome and delayed postpolypectomy bleeding compared with hot snare polypectomy (HSP). Recently, CSP is also expanded for removing polyps larger than 10 mm in size.

AIM

To compare the efficiency and safety of CSP and HSP in the management of 10-19 mm non-pedunculated colorectal polyps.

METHODS

A total of 1686 inpatients with at least one 10-19 mm non-pedunculated colorectal polyp, who underwent CSP (study group, n = 843) or HSP (control group, n = 843) at our Digestive Endoscopy Center between February 2020 and February 2024 were enrolled. The outcome measures including complete resection rate, intraoperative bleeding rate, and healthcare expenses such as procedure time and treatment cost were compared between the CSP vs HSP groups.

RESULTS

No statistically significant intergroup difference was observed in histological complete resection rates (P > 0.05). Polyp resection time in the study group (76.5 ± 23.6 seconds) was notably shorter than that in the control group (91.24 ± 32.06 seconds; P < 0.05). The immediate intraoperative bleeding rate was significantly higher in the study group than in the control group (12.7% vs 4.9%, P < 0.05). No instances of delayed bleeding or perforation were documented in either group. Hospitalization duration was significantly reduced in the study group (2.42 ± 0.61 days) compared to the control group (3.21 ± 1.02 days; P < 0.05).

CONCLUSION

For 10-19 mm non-pedunculated colorectal polyps, CSP demonstrates operational efficiency advantages over HSP in terms of procedure time, treatment cost, and length of hospital stay. Both techniques demonstrate robust safety profiles; however, CSP is associated with a higher intraoperative bleeding rate. Clinical decision-making should incorporate individualized assessment of these factors.

Key Words: Non-pedunculated colorectal polyps; Cold snare polypectomy; Hot snare polypectomy; Polypectomy

Core Tip: This study compares the clinical efficiency and safety of cold snare polypectomy (CSP) vs hot snare polypectomy (HSP) in the management of 10-19 mm non-pedunculated colorectal polyps. The results suggested that complete resection rate was comparable between the two groups. Procedure time, treatment cost, and length of hospital stay were lower in the CSP group than in the HSP showing the advantages of CSP. Notably, intraoperative bleeding rate is a little higher for CSP, which is essential to consider when choosing the surgical procedure.

INTRODUCTION

Colorectal cancer (CRC), a preeminent malignancy of the digestive system, exhibits a pronounced age-dependent incidence pattern, with risk escalating significantly after age 50[1,2]. Early detection and intervention are critical for optimizing the prognosis. Screening colonoscopy has been unequivocally proven to reduce the incidence of CRC[3,4]. As most CRCs evolve via the adenoma-carcinoma sequence, polyp resection serves as a cornerstone strategy to mitigate cancer progression[5]. Current primary polypectomy techniques encompass cold snare polypectomy (CSP), hot snare polypectomy (HSP), endoscopic mucosal resection (EMR), and endoscopic submucosal dissection[2]. Due to its superior efficacy and safety with negligible risk for thermal injury, CSP is recommended by the European Society of Gastrointestinal Endoscopy (ESGE) and the United States Multi-Society Task Force on Colorectal Cancer for sessile polyps ≤ 10 mm[3,6].

Non-pedunculated polyps (Paris Is/Isp/IIa) lack a stalk, presenting technical challenges for complete resection. CSP employs mechanical transection without electrocautery, minimizing thermal injury but potentially increasing immediate bleeding risk. Conversely, HSP utilizes high-frequency current for simultaneous cutting and coagulation, reducing intraoperative bleeding but carrying risks of delayed complications from thermal damage. The selection between CSP and HSP requires balancing procedural efficiency, safety profiles, and lesion characteristics.

CSP demonstrates comparable complete resection and complication rates to HSP, alongside shorter procedure durations and reduced reliance on hemoclips[7]. Larger polyps (> 15 mm) often necessitate adjunctive techniques such as submucosal injection or EMR to ensure complete excision. CSP is well-established as a safe and effective technique for small polyps, characterized by minimal adverse events and rare occurrences of perforation or delayed bleeding, with complete resection rates comparable to hot snare techniques[8,9]. ESGE designates HSP as the standard of care for resecting 10-19 mm sessile adenomatous polyps, while advocating for piecemeal CSP in 10-19 mm sessile serrated lesions without dysplasia[3,10]. This prospective study aimed to systematically evaluate the clinical utility of CSP for 10-19 mm non-pedunculated colorectal polyps, specifically to validate its complete resection rate and safety parameters within this intermediate size cohort, with an aim to provide high-quality evidence for clinical practice.

MATERIALS AND METHODS

Participants

A total of 1686 inpatients with at least one 10-19 mm non-pedunculated colorectal polyp, resected at our Digestive Endoscopy Center between February 2020 and February 2024, were included. Patients were allocated to two groups according to the resection therapies: A study group (treated with CSP) and a control group (treated with HSP).

The inclusion criteria were: (1) Confirmed 10-19 mm colorectal polyps by colonoscopy, morphologically classified as Paris type Isp, Is, or IIa[4]; (2) Aged between 18-80 years; and (3) Treated with either CSP or HSP.

The exclusion criteria included: (1) Sessile colorectal polyps < 10 mm or > 19 mm; (2) Coagulopathy (hereditary or acquired); (3) Dysplasia in the context of inflammatory bowel disease, suspicion of polyp malignancy, gastrointestinal bleeding, or active intestinal inflammation[11,12]; and (4) Poor general health precluding polypectomy tolerance.

At last, the study group included 843 eligible patients (1206 polyps) and the control group included 843 eligible patients (1317 polyps). The study protocol was approved by the local institutional ethics committee, and written informed consent was obtained from all patients prior to enrollment.

Preoperative preparation

All endoscopic procedures in the present study were performed or directly supervised by senior endoscopists with over 7 years of clinical expertise. Antithrombotic medication management strictly adhered to international consensus guidelines: (1) Thienopyridine antiplatelet agents were discontinued 5-7 days pre-procedure; (2) Anticoagulant regimens were adjusted based on thromboembolic risk stratification; (3) Bowel preparation was achieved via a split-dose polyethylene glycol electrolyte solution, with the final dose administered 4-6 hours prior to the procedure; and (4) Intravenous sedation comprised a combination of remifentanil hydrochloride (1-2 μg/kg), midazolam (1-2 mg), and propofol (0.5-1.5 mg/kg).

Detailed assessment of polyp surface architecture was performed. Polyp size was measured using a fully opened biopsy forceps or a fully expanded snare as reference standards[13,14].

Procedures

A mixture of indigo carmine and normal saline was administered via submucosal injection around the polyp periphery at multiple sites. The snare was positioned to encircle the polyp, extending 2-3 mm beyond the margin to ensure a safety margin.

Study group (CSP): The snare was gradually tightened to apply sustained mechanical pressure to the bowel wall for 10-15 seconds before transection was completed purely mechanically. Specimens were immediately retrieved by suction. The resection site was systematically irrigated with saline and evaluated from multiple angles to assess margin integrity, with indigo carmine staining used as an adjunct if required[15,16]. Supplementary resection was performed for any visible residual tissue.

Control group (HSP): Following adequate snare tightening and gentle traction to create a resection plane, excision was completed using a high-frequency electrosurgical unit. Electrosurgical unit was set to Endocut mode (Effect 3, duration 2 seconds, interval 1 second). Specimen retrieval was performed identically to the study group. In cases of challenging en bloc snare resection, piecemeal removal with biopsy forceps was employed. For all cases, after confirming the absence of macroscopic residual tissue, multiple biopsies were obtained from the resection margins and base for histological assessment of complete resection. Standardized irrigation of the resection site was performed in both groups. Active bleeding persisting for > 30 seconds was managed by immediate endoscopic hemostasis (primarily hemoclip placement) after pathological sampling. All resected specimens and biopsies underwent systematic histopathological evaluation.

Outcome measures

Our outcomes of interest primarily included intraoperative outcomes, which were histological complete resection rate (absence of neoplastic tissue in margin/base biopsies), polyp resection time, immediate intraoperative bleeding (persistent bleeding ≥ 30 seconds post-resection), delayed bleeding (requiring endoscopic hemostasis within 2 weeks), and perforation. In addition, health expenses such as treatment cost and hospitalization duration were also compared between the two groups.

Statistical analysis

Data analyses were conducted using SPSS 25.0. Normally distributed continuous variables were analyzed via independent samples t-tests; non-normally distributed data were evaluated using Mann-Whitney U tests. Categorical data are presented as frequencies (percentages), with intergroup differences assessed via χ² or Fisher’s exact tests. The significance threshold (α) was set at 0.05. All tests were two-tailed, with a P value < 0.05 considered statistically significant.

RESULTS

Baseline characteristics and polyp pathology

Comparison of baseline demographics (sex and age) and polyp characteristics (number, size, location, and morphology) between the two groups presented no statistically significant differences in terms of these characteristics (P = 0.123), which revealed that the two groups were comparable at baseline (Table 1).

Table 1 Comparison of baseline characteristics and polyp pathology between the two groups.

	Study group (n = 843)	Control group (n = 843)	χ2/t value	P value
Sex (male/female)	562/281	534/309	χ2 = 2.046	0.153
Age (years)	61.12 ± 21.09	60.75 ± 23.24	t = 0.34	0.734
Number of polyps	1206	1317
Maximum polyp diameter (mm)	12.49 ± 2.64	12.35 ± 2.42	t = 1.386	0.165
Polyp location, n (%)			χ2 = 1.52	0.912
Cecum	60 (5.0)	64 (4.9)
Ascending colon	241 (20.0)	270 (20.5)
Transverse colon	192 (15.9)	207 (15.7)
Descending colon	229 (19.0)	267 (20.3)
Sigmoid colon	428 (35.5)	443 (33.6)
Rectum	56 (4.6)	66 (5.0)
Paris classification, n (%)			χ2 = 2.11	0.348
0-Isp	354 (29.4)	345 (26.2)
0-Is	396 (32.8)	452 (34.3)
0-IIa	456 (37.8)	520 (39.5)
Histology			χ2 = 0.73	0.867
Tubular adenoma	735 (60.9)	806 (61.2)
Tubulovillous adenoma	229 (19.0)	248 (18.8)
Hyperplastic polyp	183 (15.2)	207 (15.7)
Serrated polyp/adenoma	59 (4.9)	56 (4.3)

Intraoperative outcomes

No statistically significant difference was detected in histological complete resection rates between the groups (P > 0.05; Table 2). However, polyp resection time was significantly shorter in the study group (76.5 ± 23.6 seconds) vs the control group (91.24 ± 32.06 seconds; P < 0.05). Notably, the immediate intraoperative bleeding rate was higher in the study group (12.7%) than in the control group (4.9%; P < 0.05). No perforation was recorded in either group. Occasional delayed bleeding was observed (specific rates/data omitted from results table).

Table 2 Differences in intraoperative outcomes between the two groups.

	Study group (polyps = 1206)	Control group (polyps = 1307)	χ2/t value	P value
Histological complete resection rate, n (%)	1155 (95.8)	1276 (97.6)	χ2 = 2.372	0.123
Polyp resection time (seconds)	76.52 ± 23.67	91.24 ± 32.06	t = 13.19	< 0.001
Immediate intraoperative bleeding, n (%)	153 (12.7)	64 (4.9)	χ2 = 49.08	< 0.001

Health expenses

Treatment costs in the study group (4708.33 ± 809.25 CNY) were significantly lower than those in the control group (8704.91 ± 762.30 CNY; P < 0.05; Table 3). Meanwhile. The hospitalization duration was substantially shorter in the study group (2.42 ± 0.61 days) than in the control group (3.21 ± 1.02 days; P < 0.001).

Table 3 Differences in health expenses between the two groups.

	Study group (polyps = 1206)	Control group (polyps = 1307)	χ2/t value	P value
Treatment cost (CNY)	4708.33 ± 809.25	8704.91 ± 762.30	127.3	< 0.001
Hospital stays (day)	2.42 ± 0.61	3.21 ± 1.02	23.72	< 0.001

DISCUSSION

Non-pedunculated colorectal polyps sized 10-19 mm are predominantly advanced adenomas (tubular or tubulovillous) or serrated lesions, carrying a substantial risk for malignant transformation, with some potentially harboring high-grade dysplasia. These polyps are closely linked to colorectal carcinogenesis, underscoring the critical need for early endoscopic resection to interrupt tumorigenesis[3]. International guidelines endorse CSP, HSP, or EMR as primary treatment modalities, prioritizing curative resection while minimizing complications[3,17].

Our findings demonstrated that CSP, achieved through mechanical transection with or without submucosal injection, is suitable for superficial mucosal lesions (Paris Is, Isp, or IIa). Its histological complete resection rate (95.8%) was comparable to that of HSP (97.6%; P > 0.05). However, CSP was associated with a significantly elevated immediate intraoperative bleeding rate (12.7% vs 4.9%), though this bleeding was effectively managed via hemoclip placement. Notably, CSP demonstrated superior operational efficiency (P < 0.05), with shorter procedure times, reduced hospital stays, and treatment costs amounting to only 54% of HSP (4708 CNY vs 8704 CNY). In this study, both groups revealed low rates of postoperative delayed bleeding or perforation. However, evidence from other studies[14] suggested that HSP, due to thermal injury from high-frequency coagulation, might carry a higher risk of delayed bleeding and potential perforation. Conversely, en bloc resection of sessile polyps > 15 mm with CSP can be technically challenging, often requiring piecemeal resection and potentially increasing the risk of residual tissues[3].

CSP offers significant advantages in cost-effectiveness and operational efficiency, making it a preferred approach for 10-19 mm sessile polyps, particularly in superficial lesions and patients not requiring anticoagulation[18]. HSP remains valuable in specific scenarios, such as deeply infiltrative lesions or complex cases requiring submucosal lifting[19]. Future research should focus on optimizing cold resection instruments and procedural protocols to establish CSP as the standard of care for the polyp category of this size. Concurrently, enhanced operator training is essential to mitigate intraoperative bleeding risks, and long-term follow-up studies are warranted to validate sustained efficacy[20].

CONCLUSION

In conclusion, for 10-19 mm non-pedunculated colorectal polyps, CSP outperforms HSP in terms of operative time, treatment cost, and hospitalization duration. Both techniques display high safety profiles; however, CSP’s higher intraoperative bleeding rate necessitates careful consideration. Clinical decision-making should require comprehensive consideration of these factors to tailor the treatment to individual patients.