ttvir(iat

1pt

r

Gastroenterology in MotionRalf Kiesslich and Thomas D. Wang, Section Editors

Retroflexion in Colonoscopy: Why? Where? When? How? What Value?DOUGLAS K. REX and KRISHNA C. VEMULAPALLI

Department of Medicine, Division of Gastroenterology, Indiana University Health, Indianapolis, Indiana

smiiAnmrta

Scan the quick response (QR) code to the left withyour mobile device to watch this article’s videocontent. Don’t have a QR code reader? Get one bysearching ‘QR Scanner’ in your mobile device’sapp store.

In this report, the term “retroflexion” refers to making aU-turn with the bending section of the colonoscope, so

hat the viewing lens is looking backward and the insertionube is visible to the endoscopist. Separate devices for retroiewing such as the “Third-Eye Retroscope” (Avantis Med-cal Systems, Sunnyvale, CA) are not reviewed here. Threeoles have been described for retroflexion in colonoscopy:1) Improved detection of neoplasia in the distal rectum, (2)mproved detection in the proximal colon, especially thescending colon, and (3) removing lesions that are difficulto access in the forward view.

Description of TechnologyRetroflexion in the RectumEarly studies reported a substantial gain in polyp

detection with retroflexion, including detection of largelesions.1,2 Recent prospective studies in which the rectumis first systematically examined in the forward view, havereported much lower polyp yields from retroflexion.3,4 In

series, retroflexion resulted in 4 perforations in 40,000atients, accounting for 10% of all colonoscopy perfora-ions.5 Retroflexion can provide valuable information

and photodocumentation regarding benign disease at therectal outlet (eg, hemorrhoids).

RecommendationsThe value of rectal retroflexion for neoplasia de-

tection is often overstated, but retroflexion should beattempted whenever there is adequate luminal diameter.The rectum is first examined carefully in the forward viewto the dentate line and the luminal caliber is assessed. Ifthe rectum is narrow and the distal rectal walls are visiblecircumferentially, then a photograph is taken and anattempt at retroflexion may not be warranted. Thiscourse was taken in 5% of colonoscopies in 1 series.4 The

etroflexion technique is to advance most of the bending

GASTROENTEROLOGY 2013;144:882– 883

ection into the rectum, deflect the instrument maxi-ally in the up direction (or both up and left), grasp the

nsertion tube with the palm facing up, and advance thensertion tube forward while rotating counterclockwise.n effective retroflexion visualizes the proximal anal ca-al and the distal 3– 4 cm of rectal mucosa. The instru-ent is rotated to see the full circumference of the distal

ectum and photodocumentation is performed. Perfora-ion is avoided by never turning the bending section ordvancing the scope against resistance.

Retroflexion in the Right ColonColonoscopy is less effective in preventing right-

sided compared with left-sided colon cancer. This findinghas led to discussion of potential methods to improvedetection during right colon examination. Split-dosebowel preparation is increasingly accepted as essential forthe right colon. Technical steps under consideration in-clude a separate withdrawal time target for the rightcolon, examination of the right colon twice, and perfor-mance of right colon retroflexion after a careful forwardexamination. A randomized trial of patients who firstunderwent a forward viewing examination from the ce-cum to splenic flexure compared a second examination inthe forward view with one in retroflexion.6 The calculatedmiss rate for adenomas was 33% in both arms, indicatingthat a second examination in the forward view was aseffective as one in retroflexion. In a feasibility study, rightcolon retroflexion was attempted in 1000 routine colono-scopies after a forward examination from the cecum tohepatic flexure.7 The success rate in achieving retroflex-ion was 94%, with the main cause of failure being a loopin the insertion tube. Predictors of detecting more polypsduring retroflexion included male gender, older age, anddetection of polyps during the forward examination.

RecommendationsParticularly when polyps are detected in the for-

ward examination from cecum to hepatic flexure, con-sider a second examination of the right colon. A secondforward viewing examination is just as effective as a

© 2013 by the AGA Institute0016-5085/$36.00

http://dx.doi.org/10.1053/j.gastro.2013.01.077

Gastroenterology in Motion, continued

retroflexed examination. I decide on retroflexion versusforward for the second examination based on whetherthe insertion tube is straight, in which case retroflexion istechnically easier. First, reintubate the cecum and exam-ine it in the forward view. Retroflexion is initiated withthe scope tip facing forward at a location where there isplenty of room to form the U-turn. The bending sectionis turned maximum up and left and the insertion tube isrotated counterclockwise without advancement of theinstrument. Once retroflexion is achieved, the scope ispulled slowly to the hepatic flexure or the proximaltransverse colon while inspecting. Polypectomy is per-formed in retroflexion as needed. Retroflexion is endedbefore the splenic flexure is reached when either standardor pediatric colonoscopes are used. As inspection pro-ceeds, the endoscopist looks for an open section of bowelin which to unwind from retroflexion. Once the locationis selected, unwinding is achieved by releasing the direc-tional controls and pulling back on the insertion tube.To make certain all is seen, I then readvance 10 –15 cmbefore resuming withdrawal in the forward view.

Polypectomy in RetroflexionSome polyps are difficult to access during colono-

scopy because of location on the proximal sides of foldsor flexures. The forward view demonstrates only a por-tion of the polyp. Retroflexion typically exposes the entirepolyp surface that could not be seen in the forwardview.8,9 The endoscopist advances proximal to the polypto find an open section of colon in which to form theU-turn. Once in retroflexion, the instrument is with-drawn until the lesion is seen. Retroflexion may beneeded only to perform submucosal injection precisely atthe proximal edge of the lesion. If a large submucosalmound is created, the polyp may become accessible forresection in the forward view, or the entire resection maybe best performed in retroflexion.

RecommendationsUse a standard or pediatric colonoscope to ap-

proach difficult to access polyps in the ascending andtransverse colon, and rectum in retroflexion. In the de-scending and sigmoid colons, use an upper endoscope toeliminate the risk of perforation when unwinding. If theinsertion tube is in the way of polypectomy despite ma-neuvering, perform the injection in retroflexion and re-

section in the forward view. Use of a soft cap on the

instrument tip can be preferable to retroflexion for dif-ficult to access lesions on the medial wall of the cecumand on the ileocecal valve. Small cecal anatomy some-times makes retroflexion proximal to the ileocecal valveimpossible with a colonoscope.

Video DescriptionThe video demonstrates retroflexion in the prox-

imal colon, in the rectum, and for performance ofpolypectomy in the ascending colon. Audio accompani-ment explains the video.

Take Home MessageRetroflexion in the proximal colon is a recently

described adjunct to proximal colon examination as wellas to endoscopic resection of difficult-to-access polypsproximal to the rectum. The technique can be safelyapplied using colonoscopes in the right and transversecolons and upper endoscopes in the descending andsigmoid colon. A second examination of the proximalcolon should be considered when the first examination inthe forward view reveals lesions. A second examination inthe forward view is as effective as a second examinationthat is performed in retroflexion.

Supplementary Material

Note: To access the supplementary materialaccompanying this article, visit the online version ofGastroenterology at www.gastrojournal.org, and at http://dx.doi.org/10.1053/j.gastro.2013.01.077.

References

1. Hanson JM, et al. Dis Colon Rectum 2001;44:1706–1708.2. Varadarajulu S, et al. J Clin Gastroenterol 2001;32:235–237.3. Cutler A, et al. Am J Gastroenterol 1999;94(6):1537–1538.4. Saad A, et al. World J Gastroenterol 2008;14:6503–6505.5. Quallick MR, et al. Gastrointest Endosc 2009;69:960–963.6. Harrison M, et al. Am J Gastroenterol 2004;99:519–522.7. Hewett DG, et al. Gastrointest Endosc 2011;74:246–252.8. Rex DK, et al. Gastrointest Endosc 2006;63:144–148.9. Pishvaian AC, et al. Am J Gastroenterol 2006;101:1479–1483.

Reprint requestsAddress requests for reprints to: Douglas K. Rex, MD, 550 N.

University Boulevard, Indiana University Hospital #4100,Indianapolis, Indiana 46202. e-mail: drex@iupui.edu.

Conflicts of interest

The authors disclose no conflicts.

883