Keywords Polyps / adenomas / ... - CRC screening - Endoscopic resection (polypectomy, ESD,
EMRc, ...)
Introduction
The effectiveness of colonoscopy in preventing colorectal cancer (CRC) and associated
death is dependent on the identification and complete removal of pre-cancerous polyps
[1 ]. For small (≤10 mm) colorectal polyps, cold snare polypectomy (CSP) has emerged
as the standard of care for resection [2 ]
[3 ]. CSP is effective and carries a low risk of adverse events compared with hot snare
polypectomy (HSP) [4 ]
[5 ]
[6 ].
Incomplete resection of polyp tissue can occur following both CSP and HSP which is
an important contributor to the development of post-colonoscopy CRC [7 ]. Higher success of complete resection (CR) with CSP has been theorized to be dependent
upon both operator technique and snare type. Early studies of CSP have reported incomplete
resection rates (IRRs) ranging from 5% to 35% [7 ]
[8 ]
[9 ]. In contrast, more recent studies have determined that complete resection rates
of greater than 98% are attainable when endoscopists aim to capture a 2-mm margin
of normal tissue and subsequently examine the cold snare defect margin for residual
polyp [10 ]
[11 ]
[12 ]. In addition to improved endoscopic techniques, dedicated thin-wire cold snares
with no current-carrying capacity have been designed in an attempt to improve complete
resection rates. The caliber of these snares ranges from 0.18 mm to 0.30 mm and are
composed of monofilament or braided wires [13 ]
[14 ]
[15 ]
[16 ]
[17 ], whereas traditional thick-wire current-carrying snares have calibers ranging from
0.40 mm to 0.47mm [13 ]
[18 ]
[19 ]. Data on the efficacy derived from randomized trials and the effectiveness from
real-world observational studies comparing thin- and thick-wire snares for CSP are
conflicting [9 ]
[20 ]
[21 ]
[22 ].
Given the lack of consistent supporting evidence and an absence of CSP snare choice
recommendations made by endoscopy societies, we performed a systematic review and
meta-analysis (MA) of studies comparing completeness of resection and adverse event
(AEs)
rates of CSP using thin-wire and thick-wire snares for colorectal polyps ○ 10 mm.
Methods
We conducted this systematic review and MA according to the Preferred Reporting Items
Systematic Reviews and Meta-analyses (PRISMA) statement [23 ]. Our protocol was registered a priori on PROSPERO (CRD42022357424). Ethics approval
was not required for this study given the lack of patient-specific data being collected.
Eligibility criteria
We included observational or interventional studies that met all of the following
criteria:
Patients were adults (age ≥18) undergoing colonoscopy and found to have one or more polyp(s)
≤10 mm.
The intervention was polypectomy (en bloc or piecemeal) with a thin-wire braided or monofilament snare
dedicated for CSP (thickness 0.18 mm-0.30 mm). Examples include the 0.18-mm LESIONHUNTER
and 0.23-mm Diamond Cut snares (Micro-Tech Endoscopy, Nanjing, China), 0.30-mm Exacto
cold snare (Steris Healthcare, Dublin, Ireland), and the 0.30-mm Captivator cold snare
(Boston Scientific, Marlborough, United States).
The comparator was polypectomy (en bloc or piecemeal) with a thicker current-carrying snare (thickness
0.40 mm or 0.47 mm). Examples include the 0.47-mm SnareMaster oval snare and the 0.40
mm SnareMaster soft snare (Olympus, Tokyo, Japan).
The outcomes included any of the following:
Complete resection rate,
Polyp retrieval rate,
Intraprocedural bleeding (IPB),
Delayed post-polypectomy bleeding (DPPB) up to 30 days,
Deep mural injury (DMI) including perforation,
Patient discomfort scores,
Total sedation used, or
Procedure time.
We excluded studies from the final review that met any of the following criteria:
(1) the comparator was either unclear or not considered to represent a thick snare;
(2) the comparator was HSP; (3) the study assessed outcomes exclusively in trainees
or described CSP learning curves; (4) the study included patients who underwent CSP
for upper gastrointestinal lesions.
Search strategy and terms
We designed a comprehensive search strategy with a health research librarian to query
the electronic databases MEDLINE (Ovid), EMBASE, PubMed, CINAHL, MEDLINE (Ebsco),
Web of Science, TRIP (Turning Research into Practice) and Cochrane Library, from inception
through September 15, 2022. We used a combination of free-text and Medical Subject
Heading (MeSH) terminology in the search strategy, along with appropriate synonyms
and spelling variations. The full electronic search strategy is provided in the Supplementary
Materials. We also hand-searched the conference abstracts from 2015–2022 from Digestive
Diseases Week, The American College of Gastroenterology Annual General Meeting, and
United European Gastroenterology Week.
Study selection and data abstraction
We imported all citations into Covidence (Melbourne, Australia). Two reviewers (RK,
SSS) performed initial screening and full-text exclusion and a third author (NF) resolved
all discrepancies. Two authors (RK, SSS) then abstracted data in duplicate into standardized
forms containing: (1) study identification (e.g., authorship, year of publication,
country of origin); (2) study design parameters and risk of bias assessments; (3)
endoscopist demographics; (4) patient demographics (e.g., age, sex, comorbidities);
(5) descriptions of the intervention and comparators; (6) bowel preparation regimens;
and (7) outcomes. We also collected data on relevant subgroups where available. For
included abstracts, we attempted to contact study authors to obtain additional information.
We emailed first and last authors up to two times, one week apart.
Outcome definitions
Our primary outcome was the CR rate, as we considered complete resection to be the
most important clinical outcome with respect to CSP. We defined CR as the absence
of any adenomatous tissue on histopathologic examination after CSP, either based on
post-polypectomy site margin biopsies or en-bloc specimen examination [20 ]
[22 ]. Secondary outcomes included polyp retrieval rate, IPB (defined as visible oozing
or spurting of blood for >30 seconds or use of a haemostatic agent to control bleeding),
DPPB (defined as a bleeding event reported by the patient leading to presentation
to a healthcare setting for up to 30 days after the procedure), Sydney classification
DMI grade III-V (visible target sign or full-thickness hole) [24 ], radiographically or surgically confirmed perforation, total sedation used, and
procedure time. The secondary outcome of polyp retrieval rate was not included in
the initial study protocol but added post hoc.
Risk of bias
Two authors (RK, SSS) conducted risk of bias assessments in parallel for all studies
included in the final review. We used the Cochrane Risk of Bias version 2 (RoB 2)
and Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tools [25 ]
[26 ] for randomized trials and observational studies, respectively. Discrepancies were
resolved by consensus. We created risk of bias figures using the Risk-of-Bias Visualization
(robvis) tool [27 ].
Statistical analyses and certainty of the evidence
We conducted the MA using DerSimonian and Laird random effects models [28 ]. We calculated risk ratios (RRs) from pooled data from observational and interventional
studies separately and generated forest plots with RRs and corresponding 95% confidence
intervals (CIs). We used the I2 test to measure and report statistical heterogeneity. To assess publication bias,
we performed visual inspection of funnel plots. We planned to conduct sensitivity
analyses by (1) removing each study individually; (2) only including studies without
high risk of bias; and (3) only including studies where endoscopists took biopsies
from margins of resected polyps to assess for incomplete resection. We planned to
perform subgroup analyses where possible on patient subgroups (e.g., age, sex, comorbidity),
presence or absence of endoscopist training for CSP, presence of trainees at the time
of the procedure, polyp size and polyp histology (adenomatous and sessile serrated
lesions [SSLs]). Finally, we assessed the certainty of evidence using the Grading
of Recommendations Assessment, Development, and Evaluation (GRADE) framework.
Results
Study selection
We identified 2901 records through an electronic database search and an additional
seven records from hand-searching, 1558 of which remained after de-duplication. After
title and abstract screening, there were 38 articles retrieved for full-text review,
six of which were included in the MA ([Fig. 1 ]).
Fig. 1 Study flow diagram.
Characteristics and quality of included studies
Of the six included studies, four were randomized controlled trials (RCTs) [20 ]
[22 ]
[29 ]
[30 ] and two were observational (cohort) studies [9 ]
[21 ]. Three randomized trials were published in full manuscript form [20 ]
[22 ]
[29 ]. One randomized trial was published in abstract form, for which supplemental information
was gathered through email correspondence with study authors [30 ]. All studies were published in 2015 or later ([Table 1 ]). There were 1316 unique patients with 1679 polyps included, 853 of which underwent
thick-wire CSP and 826 of which underwent thin-wire CSP ([Table 2 ]). For thick-wire snares, three studies used a 0.47-mm snare [9 ]
[20 ]
[22 ], one study used 0.40-mm and 0.47-mm snares [21 ], 1 study used a 0.43-mm snare [30 ], and one study used a 0.40-mm snare [29 ]. For thin-wire snares, five studies used a 0.30 mm snare [9 ]
[20 ]
[21 ]
[22 ]
[30 ] and one study used 0.23 mm snare [29 ]. Study quality varied from a low risk of bias to some concerns for RCTs and from
a low to moderate risk of bias for observational studies (Supplementary Materials).
Summaries of findings and the overall certainty of evidence using GRADE are available
in [Table 3 ] for RCTs and [Table 4 ] for observational studies.
Table 1 Summary of baseline characteristics of studies included in the meta-analysis.
Study ID
Study design
Country
Multicenter
Snares (brand, wire thickness)
Patients, male n (%)
Definition of complete resection
Risk of bias*
Thick-wire
Thin-wire
M, male; F, female; P, proximal; L, left; RCT, randomized controlled trial; H, hyperplastic;
S, sessile serrated lesion; A, adenoma; N, not stated
*Risk of bias assessed using the Cochrane Risk of Bias version 2 (RoB 2) and Risk
of Bias in Non-randomized Studies of Interventions (ROBINS-I) tools 25,26 for randomized
trials and observational studies, respectively.
Din 2015
Observational
United Kingdom
No
Olympus, 0.47 mm
Steris, 0.3 mm
74 (66)
Resection bed margin histology
Moderate
Dwyer 2017
Observational
Australia
No
Olympus, 0.40 and 0.47 mm
Steris, 0.3 mm
115 (64)
Resection bed margin histology
Low
Horii 2023
RCT
Japan
Yes
Boston Scientific, 0.4 mm
Micro-Tech, 0.23 mm
132 (69)
Resected polyp margin histology
Some concerns
Horiuchi 2015
RCT
Japan
No
Olympus, 0.47 mm
Steris, 0.3 mm
41 (54)
Resected polyp margin histology
Some concerns
Jung 2018
RCT
Korea
No
Boston Scientific, 0.43 mm
Steris, 0.3 mm
Not stated
Resected polyp margin histology
Some concerns
Sidhu 2022
RCT
Australia, Canada
Yes
Olympus, 0.47 mm
Steris, 0.3 mm
379 (57)
Resection bed margin histology
Low
Table 2 Summary of polyp characteristics of studies included in the meta-analysis.
Snare
Polyps, n
Size >5 mm, %
Proximal location*, %
Morphology, % (Ip/Isp/Is/IIa)†
Histology, %
Hyperplastic
SSL
Adenoma
SSL, sessile serrated lesion.
* Polyp location proximal to the splenic flexure.
† The Paris Classification [31 ] for gastrointestinal polyps: Ip, pedunculated; Isp, subpedunculated; Is, sessile;
IIa, slightly elevated.
Din 2015
Thick-wire
72
–
68
0/0/91.7/8.3
30.6
54.2
Thin-wire
89
–
57
0/0/87.6/12.4
21.3
2.2
81.6
Dwyer 2017
Thick-wire
173
51
43
–
13
9
78
Thin-wire
126
41
29
–
17
17
66
Horii 2023
Thick-wire
128
54.7
50
0/19.5/67.2/13.3
–
Thin-wire
126
54.8
50.8
0/16.7/70.6/12.7
–
Horiuchi 2015
Thick-wire
112
59.8
43.7
10.7/0/72.3/17
9.8
5.4
84.8
Thin-wire
98
66.1
40.8
8.2/0/68.4/23.4
9.2
5.1
85.7
Jung 2018
Thick-wire
47
–
–
–
–
–
–
Thin-wire
48
–
–
–
–
–
–
Sidhu 2022
Thick-wire
321
36.1
30.5
–
14.1
10.3
58.2
Thin-wire
339
40.7
29.2
–
12.1
10.3
64
Table 3 Summary of findings table for outcomes among randomized trials.
Certainty assessment
N
Effect
Certainty
No. studies
Study design
Risk of bias
Inconsistency
Indirectness
Imprecision
Other considerations
Thin-wire snare
Thick-wire snare
Relative (95% CI)
Absolute (95% CI)
CI, confidence interval; RR, risk ratio.
*One study which favors thick-wire snare, one study which favors thin-wire snare,
and two studies found no difference between thin-wire snare and thick-wire snare
† Endoscopist participants in all studies were not blinded to group.
‡ Few events of intraprocedural bleeding and very wide confidence intervals.
Complete resection rate
4
Randomized trials
Not serious
Serious*
Not serious
Not serious
None
563/611 (92.1%)
533/608 (87.7%)
RR 1.05 (0.94–1.16)
44 more per 1,000 (from 53 fewer to 140 more)
⨁⨁⨁◯ Moderate
Polyp retrieval rate
3
Randomized trials
Very serious†
Not serious
Not serious
Not serious
None
513/513 (100.0%)
495/496 (99.8%)
RR 1.00 (1.00–1.01)
0 fewer per 1,000 (from 0 fewer to 10 more)
⨁⨁◯◯ Low
Intraprocedural bleeding
4
Randomized trials
Not serious
Not serious
Not serious
Very serious‡
None
17/550 (3.1%)
13/535 (2.4%)
RR 1.28 (0.51–3.20)
7 more per 1,000 (from 12 fewer to 53 more)
⨁⨁◯◯ Low
Table 4 Summary of findings table for outcomes among observational studies.
Certainty assessment
N
Effect
Certainty
No. studies
Study design
Risk of bias
Inconsistency
Indirectness
Imprecision
Other considerations
Thin-wire snare
Thick-wire snare
Relative (95% CI)
Absolute (95% CI)
CI, confidence interval; RR, risk ratio.
*One study at moderate risk of bias, one study at low risk of bias.
† One study favors thick-wire snare, one study found no difference between thin-wire
snare and thick-wire snare.
‡ Few events of intraprocedural bleeding and very wide confidence intervals.
Complete resection rate
2
Observational studies
Very serious*
Serious†
Not serious
Not serious
None
168/215 (78.1%)
195/245 (79.6%)
RR 1.03 (0.99–1.08)
24 more per 1,000 (from 8 fewer to 64 more)
⨁◯◯◯ Very low
Polyp retrieval rate
2
Observational studies
Very serious*
Not serious
Not serious
Not serious
None
201/215 (93.5%)
230/245 (93.9%)
RR 1.00 (0.99–1.01)
0 fewer per 1,000 (from 9 fewer to 9 more)
⨁◯◯◯ Very low
Intraprocedural bleeding
2
Observational studies
Very serious*
Not serious
Not serious
Serious‡
None
1/215 (0.5%)
5/245 (2.0%)
RR 0.27 (0.03–2.32)
15 fewer per 1,000 (from 20 fewer to 27 more)
⨁◯◯◯ Very low
Complete resection rate
Endoscopists were explicitly instructed to position the polyp near the bottom of the
screen (approximately 5–8 o’clock) in five studies [9 ]
[20 ]
[21 ]
[22 ]
[29 ], to capture a rim of normal tissue in five studies [9 ]
[20 ]
[21 ]
[22 ]
[29 ], and to inspect the resection bed after CSP to ensure removal of any endoscopically
visible residual tissue in four studies [9 ]
[20 ]
[21 ]
[22 ]. CR was assessed based on histological examination of the resected polyp sample
in three RCTs [20 ]
[29 ]
[30 ], and based on histological examination of biopsies from polyp resection sites in
one RCT and two observational studies [9 ]
[21 ]
[22 ]. The pooled estimates from included RCTs showed no significant differences between
the CR rate for thin- and thick-wire snares, at 92.1% versus 87.7%, respectively (relative
risk [RR] 1.05, 95% CI 0.94–1.16). Heterogeneity was considerable, with an I2 of 75%. The pooled estimates from included observational studies showed no significant
differences between the CR rate for thin- and thick-wire snares, at 78.1% versus 79.6%,
respectively (RR 1.03, 95% CI 0.99–1.08). Results for the primary outcome of CR rate
are shown in [Fig. 2 ].
Fig. 2 Forest plots of primary and secondary outcomes. a Complete
resection rate for randomized trials. b Complete resection rate
for observational studies. c Polyp retrieval rate for
randomized trials. d Polyp retrieval rate for observational
studies. e Intraprocedural bleeding for randomized trials.
f Intraprocedural bleeding for observational studies.
Secondary outcomes
For the secondary outcome of polyp retrieval rate, pooled estimates from included
RCTs showed no significant differences between thin- and thick-wire snares (100.0%
versus 99.8%, RR 1.00, 95% CI 1.00–1.01). There was also no significant difference
between thin- and thick-wire snares for polyp retrieval rate among observational studies
(93.5% versus 93.9%, RR 1.00, 95% CI 0.99–1.01). For IPB rates, there were no differences
between thin-wire snares and thick-wire snares among RCTs (3.1% versus 2.4%, RR 1.28,
95% CI 0.51–3.20) or observational studies (0.5% versus 2.0%, RR 0.27, 95% CI 0.03–2.32).
We did not conduct meta-analyses for DPPB, DMI, or perforation, given all six included
studies reported no events meeting these criteria. We did not conduct meta-analyses
for the outcomes of total sedation used or procedure time given only one study reported
on procedure time and none reported on total sedation used [20 ].
Subgroup and sensitivity analyses
Three of four RCTs [20 ]
[22 ]
[29 ] instructed endoscopists on optimal CSP technique. In this subgroup, there were no
differences between the thin-wire and thick-wire arms in terms of pooled CR rates
(93.6% versus 87.5%, RR 1.09, 95% CI.98–1.22), polyp retrieval rate (100% versus 99.8%,
RR 1.00, 95% CI 1.00–1.01), or IPB (1.6% versus 2.0%, RR 0.85, 95% CI 0.36–1.98),
with forest plots provided in the Supplementary Materials. For the subgroup analysis
based on polyp histology, we could not perform MA as only one RCT [20 ] presented outcomes data stratified by polyp histology. Horiuchi et al. reported
CR rates of 89% (n=75/94) for thin-wire snares versus 78% (n=73/94) for thick-wire
snares for adenomas, and 100% (5/5) for thin-wire snares versus 50% (3/6) for thick-wire
snares for SSLs [20 ]. Variable ways in which patient demographics, comorbidities, and polyp size were
presented precluded meaningful subgroup analyses for these characteristics. We also
could not perform subgroup analyses for the presence of a trainee because none of
the RCTs reported trainee involvement, and both observational studies reported trainee
involvement.
Removing each study individually did not significantly alter the observed effect on
the primary or secondary outcomes. Sensitivity analysis was not done by (a) excluding
high risk of bias studies, as none of the four RCTs had high risk of bias or (b) by
only including studies where endoscopists took biopsies from margins of resected polyps
to assess for incomplete resection, as only one RCT reported doing this [22 ]. Visual inspection of a funnel plot showed no evidence of small study effects (Supplementary
materials).
Discussion
CSP is the standard of care for resection of small (≤10 mm) colorectal polyps [2 ]
[3 ] due to its superiority over forceps polypectomy and lower risk of adverse events
compared to HSP [4 ]
[5 ]
[6 ]. In this MA of six studies that included 1316 patients and 1679 polyps, there were
no differences between thin-wire and thick-wire snares with respect to CR rate, IPB,
or polyp retrieval rate. Completeness of histologic resection was high in RCTs, with
pooled CR rates of 92.1% and 87.7% for thin- and thick-wire snares respectively. Our
results also confirm the safety of this technique, with no reported cases of DPPB
or perforation with either type of wire.
The thin-wire design and diamond shape of some dedicated cold snares are hypothesized
to enable more effective tissue capture compared to traditional snares capable of
both CSP and HSP [3 ]
[15 ]
[17 ]. Data with respect to CR rate are conflicting among individual studies in our MA.
Horiuchi et al. [20 ] (91% vs. 79%) and Horii et al. [29 ] (81% vs. 70%) both reported higher CR rates with a dedicated thin-wire cold snare
compared with a traditional thick-wire snare. The rates of CR for these studies are
in keeping with historical rates ranging between 7% to 35% [9 ]
[32 ]. Newer studies, however, suggest that a CR rate of >98% is possible with CSP [33 ]. While the use of a thin-wire snare may contribute, it is possible that technical
factors such as a focus on the acquisition of a margin of at least 2 mm of normal
tissue and endoscopic examination of the cold snare defect after resection may be
more important contributors [10 ]
[12 ]. While endoscopists in the majority of RCTs assessing this question were instructed
to follow optimal techniques, only those in the study by Sidhu et al. received a standard
education package and were initially supervised by senior endoscopists to ensure a
systematic and uniform approach to CSP, subsequently achieving CR rates of >97% for
both the thin-wire and thick-wire groups [22 ].
Differences in CR rate may also be due to methods of determining histological excision.
The studies with resection rates > 95% both determined complete histological excision
based on biopsies taken from the polypectomy margin immediately following resection
[21 ]
[22 ]. While margin site biopsies are superior to endoscopic evaluation of completeness
of resection [34 ], they are nevertheless prone to sampling bias. In contrast, studies where histological
resection was determined to be complete if the lateral and vertical margins of the
en-bloc specimens were free of polyp tissue had lower reported CR rates [20 ]
[29 ]. This method avoids sampling bias but is potentially affected by an inability to
pathologically examine lateral margins due to polyp fragmentation in the endoscope
channel [35 ]
[36 ]. One recent report found that more than two-thirds of polyp margins from CSP samples
had lateral margins that could not be assessed [35 ]. The optimal method of CR assessment remains unclear, as resection margin biopsy
and en-bloc specimen evaluation have not been compared directly. Future studies should
aim to compare these methods to more definitive assessments of incomplete resection,
such as endoscopic mucosal resection of polyp margins [35 ] or assessment of recurrence on repeat colonoscopy.
We also observed significantly higher CR rates in RCTs compared to those observed
in observational studies, regardless of snare type. One factor that potentially explains
these differences is the Hawthorne effect, wherein an endoscopist’s knowledge of being
observed results in a change in behavior. This effect is commonly observed in endoscopic
studies, with it potentially being implicated as a mechanism of observed benefit for
some endoscopic interventions [37 ]
[38 ]. In this case, the potential contribution of the Hawthorne effect reinforces the
notion above that when one is mindful of optimal CSP technique, high CR rates well
above 90% are achievable regardless of snare type. Higher CR rates in RCTs could also
be partially explained by the fact that endoscopy experts at tertiary centers are
often those recruiting for such studies, with this expertise and cumulative experience
potentially separating these performers from those performing CSP in observational
studies.
There are several strengths of our study. First, we used a rigorous approach to our
MA with robust results with sensitivity analysis. Second, we performed separate meta-analyses
for randomized trials and observational studies, identifying important differences
in findings between study designs. Combining randomized and non-randomized studies
increases statistical heterogeneity and the risk of confounding bias that arises from
observational studies [39 ] and is generally advised against [40 ]. As an example, a MA on this topic was limited due to the pooling of data from randomized
and non-randomized studies [41 ]. Third, our study includes the most recent studies on this topic, which was not
included in prior analyses [41 ]
[42 ]. Fourth, we performed rigorous quality and risk of bias assessments for both randomized
and observational studies.
Our study also has several limitations. First, one study lacked methodological details
such as endoscopist training as it was in conference abstract form [30 ]; however, we were able to obtain additional information directly from study authors,
so we decided on including this abstract. Second, statistical heterogeneity was considerable
between randomized studies, suggesting that important differences in study populations
and/or methodology could have existed between. Indeed, as discussed above, different
definitions of histologically complete resection may explain much of the variation
in CR rates among studies. Given the relatively small number of studies, we were unable
to perform additional analyses to explore this question. Third, we were unable to
perform subgroup analysis based on polyp histology (adenomas and SSLs), location (right
colon vs. elsewhere), polyp size (< 5 mm, 5–10 mm), or en-bloc resection rates by
individual endoscopist, as most studies did not report outcomes stratified by these
variables. Fourth, a source of bias within the primary studies is the lack of endoscopist
blinding for RCTs. Despite randomization, endoscopist awareness of snare type may
systematically introduce bias into the results. Finally, risk estimates for observational
studies were not adjusted for potential confounders are sources of bias arising from
lack of randomization, allocation concealment, and blinding. Therefore, though these
results should be interpreted with some caution overall, we did not identify any significant
differences between both thin- and thick-wire snares for CR in CSP.
Our study has important implications for CSP of small colorectal polyps. Despite the
hypothesis that thin-wire snares lead to superior CR rates, operator technique and
endoscopic evaluation for completeness of resection may be more important, with the
available data suggesting this is likely. Using traditional current-carrying snares
exclusively may allow endoscopists and assistants to optimize polypectomy technique
and become more comfortable with their equipment. In addition, purchasing a smaller
range of snares for an endoscopy unit and using fewer individual snares during a procedure
may incur cost savings. On the other hand, dedicated thin-wire CSP snares could serve
an important role for those first learning the technique. Future studies comparing
thin-wire and thick-wire snares should explore factors such as polypectomy learning
curves, endoscopist assessments on ease of use and satisfaction, procedure time, and
cost. Additionally, different methods of histologic assessment should be compared
as they related to recurrence of polyps at surveillance colonoscopy.
Conclusions
In conclusion, in our systematic review and MA of four randomized trials and two observational
studies, we found no differences in CR rates, polyp retrieval, and intraprocedural
bleeding when comparing thin-wire and thick-wire snares. Importantly, there were no
cases of clinically significant delayed bleeding or DMI in any of the included studies.
Therefore, our findings confirm that CSP, regardless of snare type, is safe and effective
overall for the endoscopic resection of small colorectal polyps.
Effectiveness and safety of thin vs. thick cold snare polypectomy of small colorectal
polyps: Systematic review and meta-analysis
Rishad Khan, Sunil Samnani, Marcus Vaska et al. Endoscopy International Open 2024;
12: E99–E107. DOI: 10.1055/a-2221-7792
In the above-mentioned article an author's name was corrected. This was corrected
in the online version on 20.02.2024.