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CLINICAL GASTROENTEROLOGY AND HEPATOLOGY 2011;9:102–105

DUCATION PRACTICE

olonoscopy and Diminutive Polyps: Hot or Cold Biopsy or Snare? Do Iend to Pathology?

AVID G. HEWETT,*,‡ and DOUGLAS K. REX*

Indiana University School of Medicine, Indianapolis, Indiana; ‡University of Queensland School of Medicine, Brisbane, Australia

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Clinical Scenario63-year-old woman with a 30-pack-year history of cigarettesmoking presents for her first screening colonoscopy. She

as delayed undergoing colonoscopy because her father had aerforation after removal of a 5-mm tubular adenoma from theecum during colonoscopy. She takes 81 mg aspirin per day forhistory of hypertension. At colonoscopy, 6 diminutive lesions,

ll �5 mm in size and with narrow band imaging features ofdenomas, are found scattered through the ascending andransverse colon; several are flat and the remainder sessile. Howhould they be removed, and should they be sent to pathology?

The ProblemSmall (6–9 mm) and diminutive (1–5 mm) colorectal

olyps are commonly encountered during colonoscopy. Polypec-omy is the fundamental mechanism by which colonoscopy pre-ents colorectal cancer and is arguably the most valuable ther-peutic procedure in gastroenterology. Studies in high leveldenoma detectors have demonstrated that adenoma preva-ence is approximately 50% in patients undergoing first timecreening examinations. However, a vast majority of adenomasetected during colonoscopy are small or diminutive, with aery low risk for progression to colorectal cancer.

Two specific questions are discussed here regarding the man-gement of polyps �5 mm in size found during colonoscopy.irst, what endoscopic techniques are most safe and effectiveor removing these lesions? Second, once resected, should theseesions be sent for pathological assessment?

Most colonoscopic complications are related to polypec-omy. Given the prevalence and limited clinical significance ofolyps �5 mm detected at colonoscopy, the risks of theiremoval should be minimized.1 These risks include hemorrhagend perforation, which are related to the method of removal.pecifically, the use of electrocautery increases the risk of trans-ural colonic injury and delayed postpolypectomy bleeding.Polypectomy involves costs related to the use of disposable

olypectomy and retrieval devices, time costs, and the costs ofathology processing and histologic interpretation. New imag-

ng technologies have the potential to redefine our approach toolyp diagnosis, and substantially reduce the costs and risks of

olypectomy.2

Management Strategies and SupportingEvidenceThe goals of management in this 63-year-old patient are

o: (1) completely remove the polyps/lesions; (2) avoid compli-ations; and (3) determine histology for the purposes of recom-ending an appropriate surveillance interval.

Removing the PolypsDiminutive polyps can be removed using biopsy forceps

r snares. Each technique can be combined with electrocauteryhot forceps or hot snare) or used alone (cold forceps or coldnare). All techniques yield tissue for histologic evaluation,hough the tissue provided by hot forceps can be suboptimal inhis regard.3 The efficacy and safety of forceps versus snare withr without electrocautery have not been well studied, and evi-ence derives from limited observational studies. In our view,he technique of choice for removing most diminutive (1–5

m) and all small (6 –9 mm) lesions is the snare.However, forceps are sometimes more easily applied than

nares for the removal of tiny, flat lesions, especially when in theeft side of the endoscopic field of view. Large capacity forcepsan help ensure that small polyps are completely engulfed. Hotiopsy forceps offer the application of electrocautery which inheory helps to ensure complete destruction of polyp tissue, butn practice frequently fails to achieve this. Further, use of hotorceps results in significant risk.

Cold and hot forceps are both associated with a risk ofesidual polyp tissue after resection. Recurrence rates of almost0% have been reported for both hot and cold forceps.4 Hotorceps should not be used for polyps greater than 5 mm, givenhe risks of residual polyp tissue after resection.5

Cold snaring is readily applied for diminutive and even manymall polyps, particularly with the availability of very smallnares. Suction to create a pseudopolyp can assist in snareesection of flat lesions, although we prefer to use suction onlyor lumen deflation, which itself can facilitate snaring (withoutirect suction on the lesion). The efficacy and safety of coldnaring have been established for polyps up to 7 mm in size.here is emerging yet preliminary evidence suggesting a lower

ate of residual polyp tissue with cold snaring versus coldorceps.

© 2011 by the AGA Institute1542-3565/$36.00

doi:10.1016/j.cgh.2010.09.024

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February 2011 COLONOSCOPY AND DIMINUTIVE POLYPS 103

There are no published data on the efficacy of hot versusold snaring. Most endoscopists tend to convert to hot snarings polyp size increases, and some endoscopists utilize electro-autery for all snare applications. Consistent with the lack oftudy evidence, a survey of US gastroenterologists in 2004evealed widely disparate practices for removal of polyps �10

m in size.6 For polyps measuring 1–3 mm in size, 50% ofhysicians reported using cold forceps, and 33% reported usingot forceps. For polyps measuring 4 – 6 mm, 19% reported usingold forceps, 21% hot forceps, 59% hot snare, and 15% coldnare.

Avoiding ComplicationsGiven that the overwhelming majority of diminutive

olorectal polyps will never develop into colorectal cancer, theafety of endoscopic resection should be a priority. Cold biopsynd cold snaring are nearly without risk. Any bleeding thatccurs is immediate (not delayed), minor (not requiring inter-ention), and not clinically significant. We regard cold snarings safe even for patients taking antiplatelet agents or withherapeutic levels of anticoagulation, as any bleeding can bemmediately visualized and treated.

The risks of polypectomy are almost entirely related to elec-rocautery. Numerous reports attest to the hazards of hotiopsy forceps, particularly in the right colon, no doubt relatedo the extent of tissue injury produced.4 The electrocauteryurn can be uncontrolled, asymmetric, deep, and affect trans-ural injury, or perforation. In our view, these potential risks

ombined with evidence of ineffective resection make hot bi-psy polypectomy suboptimal for routine diminutive polypec-omy.

Hot snaring is the established method for larger sessile andedunculated polyps; however, it is also associated with elec-rocautery-related complications. A risk-benefit analysis for hotnaring of diminutive polyps would likely not be favorable,iven the high efficacy and negligible risks of cold snaring.here is no evidence-based consensus for the optimal type ofurrent to use for electrocautery. The use of blended current isssociated with immediate postpolypectomy bleeding, and pureoagulation current with delayed hemorrhage.1

Our Approach to Diminutive LesionsWe acknowledge the paucity of evidence to support

ecommendations about polypectomy, particularly for diminu-ive lesions.7 Our approach to diminutive polypectomy centersrst on eliminating cautery-related complications. We preferold snaring in most cases because we consider it more effectivend efficient than cold forceps.

Our choice of technique is, however, flexible, and is deter-ined by the size and shape of the lesion and its location in the

ndoscopic field. We use large capacity, cold forceps for normalissue, leading to postpolypectomy bleeding, very flat, diminu-ive lesions measuring 1–3 mm in diameter, particularly if theesion is in the left endoscopic field and cannot be moved to theight lower side of the field of view, as snares are more difficulto use than forceps in the left endoscopic field. Removal of anyoops or bends in the instrument shaft facilitates rotating thendoscopic field of view. In some cases, our approach is to onlyartly open the forceps so as to fully engulf the polyp but noto remove so much tissue that the pathologist has trouble

dentifying the tiny polyp. A randomized controlled trial has t

onfirmed that large capacity forceps are more efficient (fewerites required) than standard forceps for removing diminutiveolyps.8 Our preference is to utilize cold forceps only in those

nstances where we can engulf the entire polyp in a single bite.f that does not appear feasible, we prefer cold snaring foriminutive polyps.

We use cold snaring for most diminutive lesions and some-imes for 6 –9-mm polyps, depending on their shape. Thus,lectrocautery is generally used for pedunculated and bulkyessile polyps in the 6 –9-mm size range, while flat lesions in thisange may be resected cold, including cold piecemeal resectionn occasion. We do not use hot forceps under any circum-tances.

The technique of cold snaring is important to ensure efficacynd minimize the risk of residual polyp.4 Most experts preferiminutive snares for cold snaring, and some endoscopists haveurther preferences for nonbraided versus braided devices, etc.uch preferences are anecdotal, as these differences have noteen subjected to controlled evaluation. As demonstrated inigure 1 and Supplementary Video 1, there are critical differ-nces in the technique of cold snaring compared with snaringsing electrocautery. First, in cold snaring the snare captures amall (1 to a few mm) rim of normal mucosa around the polyp

argin. This may require some deflation. Importantly, thenare sheath should be pushed or angulated (via steering) intohe colonic wall while closing the snare, with the snare sheathositioned at least 2 mm distal to the polyp. As the snare islosed, the snare sheath remains embedded against the colonicall, without tenting or lifting the polyp away (as is done forot snare polypectomy). The snare is then fully closed to guil-

otine the polyp tissue. Tenting is not required because heat isot being applied, and further is best avoided to ensure that thenare does not slip off the rim of normal mucosa. Not tentinglso causes the polyp to remain on the defect for efficient andeliable retrieval. Retrieval has been achieved in 98% of coldnare polypectomies.9

Should Diminutive Polyps Be Sent toPathology?Histologic evaluation of diminutive colorectal polyps is

sed clinically to determine colonoscopic surveillance intervalsand for little else). Colonoscopic surveillance recommenda-ions are based primarily on the number (and size) of adeno-

atous polyps and presence of advanced histologic featureshigh grade dysplasia or villous elements).10 The current stan-ard of care is that all resected polyps are sent for histopatho-

ogic evaluation.However, the cost of routine pathologic evaluation of all

esected colorectal polyps is enormous, while the prevalence ofancer is negligible and the prevalence of advanced histologiceatures is very low in diminutive polyps.11

Endoscopists can use real-time imaging technologies (Table) to distinguish adenomatous from nonadenomatous histol-gy with very high levels of accuracy.12 Accuracies of over 95%ave been reported for the use of narrow band imaging withoutagnification, when predictions are made with high levels of

onfidence, suggesting that real time endoscopic diagnosis maye sufficiently accurate to obviate the need for formal histologicvaluation of diminutive polyps.2 Diminutive polyps could beesected and discarded, with the surveillance interval based on

he endoscopic assessment of histology.13,14 Such a “resect and

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104 HEWETT AND REX CLINICAL GASTROENTEROLOGY AND HEPATOLOGY Vol. 9, No. 2

iscard” policy could have a substantial impact on the costs ofolonoscopy. A further strategy would rely on endoscopic diag-osis alone for clinically insignificant polyps, such as diminu-ive hyperplastic lesions in the distal colon and rectum, whichould be left in place without resection.

However, this approach cannot be currently recommended.everal steps must first be accomplished before such a clinicalpproach is appropriate, including endorsement by profes-ional gastrointestinal societies.2

Areas of UncertaintyGiven the importance of polypectomy to the effective-

ess of colonoscopy for colorectal cancer (CRC) prevention, andts centrality to gastroenterology practice, the body of evidenceor polypectomy techniques is thin.7 Very few randomized clin-cal trials of polypectomy techniques have been reported, and

ost studies of polypectomy are observational and uncon-rolled.

igure 1. Consecutive endoscopic images demonstrating the techniqanding imaging shows typical features of an adenoma (brown color, thi

s rotated for polypectomy, to align the polyp with the instrument channeo be ensnared and resected. The scope is angled into the colon wall wolyp and small rim of normal tissue is snared and guillotined, while the s

G) Without tenting, the polyp tissue remains in the polyp defect for ret

able 1. Available Imaging Technologies for Real-TimeEndoscopic Diagnosis of Colorectal Polyps

Technology Company

ICE with optical magnification Fujinonrobe-based confocal imaging Mauna-Kea TechnologiesBI with (Lucera) or without (Exera)optical magnification

Olympus

ndocytoscopy Olympus-scan Pentaxonfocal laser microscopy Pentax

OTE. Fujinon (Wayne, NJ); Mauna-Kea Technologies (Paris, France);lympus (Center Valley, PA); Pentax (Montvale, NJ).

ICE, Fuji Intelligent Chromo Endoscopy; NBI, narrow band imaging.

A large number of research questions remain unansweredTable 2). For example, it remains unproven whether the effi-acy and safety of cold snare polypectomy is superior to hotnaring. The optimal electrocautery current for hot snaring islso unknown. There have been no randomized trials evaluatinghe risks of polypectomy techniques with concurrent anticoag-lation or antiplatelet therapy.

Published GuidelinesThere are few society guidelines dealing specifically with

olypectomy techniques. The American Society for Gastrointes-inal Endoscopy (ASGE) has recommended that hot biopsyorceps not be used for polyps larger than 5 mm.5

Guidelines are also available for the management of antico-gulation for endoscopic procedures15,16 and the timing ofostpolypectomy surveillance.10 The American Society for Gas-rointestinal Endoscopy recommends that aspirin does noteed to be discontinued for polypectomy. Recommendationsbout clopidogrel and warfarin are dependent on dual consid-ration of the procedure risk for bleeding and condition risk forhromboembolic events. If discontinued, clopidogrel should betopped 7 to 10 days before the colonoscopy. According to

able 2. Candidate Research Questions for RandomizedTrials of Diminutive Polypectomy Techniques

. Are cold snaring and hot snaring comparable for eradicationof small polyps?

. What are the relative efficacy, efficiency, and retrieval rates ofcold forceps vs cold snaring?

. For hot snaring, how does current selection affect thecomplication rate or eradication success of polypectomy?

. Are imaging technologies sufficiently accurate in routine clinical

cold snaring. (A) A diminutive polyp in the ascending colon. (B) Narrowown vessels, white oval and tubular surface pattern). (C) The instrumento’clock. (D) The snare is opened enough to allow a rim of normal tissuee snare is pushed forward. (E) Deflation can assist with snaring. (F) Theheath remains embedded in the wall (through gentle forward pressure).(H) A small amount of minor bleeding is typical.

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February 2011 COLONOSCOPY AND DIMINUTIVE POLYPS 105

urrent recommendations from the US Multi-Society Taskorce on Colorectal Cancer and the American Cancer Society,10

his patient with 3–10 adenomas should undergo repeatolonoscopy in 3 years (assuming the colonoscopy was com-lete and bowel preparation was adequate).

SummaryThe clinical scenario we have described is commonly

ncountered by colonoscopists who are high level adenomaetectors and who perform high quality mucosal inspection. Inhis 63-year-old female screening colonoscopy with multiple�10) diminutive colonic polyps, we recommend: (1) resectionf all polyps with cold snare polypectomy, using cold forceps ifold snaring is not feasible; (2) continuation of aspirin duringnd after the colonoscopy; (3) sending all polyps for pathologicvaluation; and (4) surveillance colonoscopy in 3 years time.

The concurrent administration of clopidogrel or warfarinould not change our approach. Until professional societiesssist in changing the standard of care to enable real-timendoscopic diagnosis, our current practice is to send all resectedolyps for pathologic evaluation.

Supplementary MaterialNote: To access the supplementary material accompa-

ying this article, visit the online version of Clinical Gastroenter-logy and Hepatology at www.cghjournal.org, and at doi:10.1016/.cgh.2010.09.024.

Suggested Reading

1. Fatima H, Rex DK. Minimizing endoscopic complications: colono-scopic polypectomy. Gastrointest Endosc Clin N Am 2007;17:145–156.

2. Rex DK, Fennerty MB, Sharma P, et al. Bringing new endoscopicimaging technology into everyday practice: what is the role ofprofessional GI societies? Polyp imaging as a template for mov-ing endoscopic innovation forward to answer key clinical ques-tions. Gastrointest Endosc 2010;71:142–146.

3. Monkemuller KE, Fry LC, Jones BH, et al. Histological quality ofpolyps resected using the cold versus hot biopsy technique.Endoscopy 2004;36:432–436.

4. Tolliver KA, Rex DK. Colonoscopic polypectomy. GastroenterolClin North Am 2008;37:229–251.

5. ASGE, Standards of Practice Committee. Hot biopsy forceps.

Gastrointest Endosc 1992;38:753–756. A

6. Singh N, Harrison M, Rex DK. A survey of colonoscopic polypec-tomy practices among clinical gastroenterologists. GastrointestEndosc 2004;99:414–418.

7. Rex DK. Have we defined best colonoscopic polypectomy practicein the United States? Clin Gastroenterol Hepatol 2007;5:674–677.

8. Draganov P, Chang MN, Lieb J, et al. Randomized controlled trialof two types of biopsy forceps for polypectomy of small sessilecolorectal polyps. Gastrointest Endosc 2010;71:AB194.

9. Deenadayalu VP, Rex DK. Colon polyp retrieval after cold snaring.Gastrointest Endosc 2005;62:253–256.

0. Winawer SJ, Zauber AG, Fletcher RH, et al. Guidelines forcolonoscopy surveillance after polypectomy: a consensus updateby the US Multi-Society Task Force on Colorectal Cancer and theAmerican Cancer Society. Gastroenterology 2006;130:1872–1885.

1. Rex DK, Overhiser AJ, Chen SC, et al. Estimation of impact ofAmerican College of Radiology recommendations on CT colonog-raphy reporting for resection of high-risk adenoma findings. Am JGastroenterol 2009;104:149–153.

2. Rex DK. Update on colonoscopic imaging and projections for thefuture. Clin Gastroenterol Hepatol 2010;8:318–321.

3. Rex DK. Narrow-band imaging without optical magnification forhistologic analysis of colorectal polyps. Gastroenterology 2009;136:1174–1181.

4. Ignjatovic A, East JE, Suzuki N, et al. Optical diagnosis of smallcolorectal polyps at routine colonoscopy (Detect InSpect ChArac-terise Resect and Discard; DISCARD trial): a prospective cohortstudy. Lancet Oncol 2009;10:1171–1178.

5. Kwok A, Faigel DO. Management of anticoagulation before andafter gastrointestinal endoscopy. Am J Gastroenterol 2009;104:3085–3097.

6. ASGE, Standards of Practice Committee. Management of anti-thrombotic agents for endoscopic procedures. Gastrointest En-dosc 2009;70:1060–1070.

eprint requestsAddress requests for reprints to: Douglas K. Rex, MD, Indiana Uni-

ersity Hospital 4100, 550 N. University Boulevard, Indianapolis, Indi-na 46202. e-mail: drex@iupui.edu; fax: (317) 944-5449.

onflicts of interestThe authors disclose the following: Drs Hewett and Rex disclose a

onsultant relationship with Olympus Medical Systems Corporation,okyo, Japan. Dr Rex has received research support from Olympus

merica Inc, Pennsylvania.