Christopher B Williams

Crossref

SIXTH INTERNATIONAL COURSE ON THERAPEUTIC ENDOSCOPY The fastest way to the cecutn OtRJSTOPHER B W ILLIAMS, BM, FRCP CB WILLIAMS. The fastest way to the cecum. Can J Gastroenterol 1993; 7 ( 6): 482-484. Successful colonoscopy requires both an understanding of the common problems encountered in the process of routine examinations and the various solutions to ensure a thorough, quick and painless examination. The colonoscopist is encouraged to be flexible in his approach to advancing the colonoscope and to use the patient's response, as well as the 'feel' of the colonoscope in the patient. Specific anatomical considerations of the colon are discussed with regard to successful passage of the colonoscope. Strategies for straightening and torquing the colonoscope, application of abdominal pressure and patient positioning are detailed. The methods of a forceful versus a technical approach are compared and contrasted. The need to attempt several manoeuvres rapidly, rather than persist in repeated unsuccessful attempts, is stressed. Key Words: Colonoscopy, Sigmoid colon, Technique Acces rapide au caecum RESUME: Pour reussir la colonoscopie, ii faut bien comprendre les problemes susceptibles de survenir frequemment !ors des examens de routine et leurs solutions diverses pour assurer un examen le plus complet, rapide et indolore possible. Le medecin qui pratique la colonoscopie doit preferablement exercer une certaine souplesse lorsqu'il pousse le colonoscope, bien interpreter Jes reac-tions du patient et "sentir" la progression de son instrument. Certaines considera-tions anatomiques du colon sont abordees relativement au passage sans heurt du colonoscope, appliquer une pression sur !'abdomen, et positionner le patient. Les methodes vigoureuses sont comparees aux method.es plus techniques. On insiste sur le manoeuvres successives rapides qui sont privilegiees, au detriment d'une approche repetee et plus insistante. SPEED lN PASSING THE COLONO-scope isn't everything, but it helps. It helps the patient by staying within the 4 to 5 min plateau of the maximum effects of intravenous medication and minimizes the autonomic side effects of prolonged endoscopic struggle. Rea-sonable speed helps in schedul ing pa-tient throughput, while minimizing the mechanistic parts of the examination allows more nme for care in diagnosis or performing multiple polypectomies. Personally speaking, I am more inter-ested in patient comfort while using modest sedation (intravenous midazo-lam 2.5 mg with intravenous pethidine 25 to 50 mg) than in absolute speed, although a quick, painless, accurate ex-amination is the obvious ideal. BE RELAXED - FEEL THE ENDOSCOPE, LISTEN TO THE PATIENT As in most mechanical or sport pur-suits greater success comes with opera-tor relaxation, reflex responses and sub-St Marks Hospital far Diseases of the Rectum and Colon, London, United Kingdom C01Tespondence: Dr CB Willia111.1, St Marks Hospital far Diseases of the Rectum and Colon, City Road, London EC JV 2PS, United Kingdom tie awareness, rather than with a tense or tough approach. Standing comfort-ably, holding the instrument shaft gen-tly (in the fingers rather than the fist) and train ing Lhe left hand to spin the control wheels easily and accurately to their maximum extent contributes sig-nificantly to a facile procedure. The endoscopist should he aware that a shaft that requires force to push or twist, or conLrols that feel stiff, indi-cate that the instrument is looped and should be straightened. A patient in pain is giving the same feedback; ignor-ing the protest or suppressing it with medication means that a loop is being ignored. An endoscopist who expects to use force gets in the habit of accept-ing such loop formation and so works at increasing mechanical disadvantage as the insertion continues. ANATOMIC CONSIDERATIONS IN THE SIGMOID The considerable variability of colon length and attachments means chat there is no one sLrategy for speedy insertion. In a patient with a capacious colon, as judged by the feel of the sigmoid colon during insertion or the results of a pre-vious endoscopic or barium contrast ex-amination, rhe best plan may be to accept formation of a sigmoid colon alpha loop (1), even encouraging such a loop by pushing in the shaft with simultaneous anticlockwise twist; the instnunent will run up through the descending colon to the splenic flexure at 90 cm before be-ing straightened back. The difficulty is that, as often as not, the wished for 'alpha' does not materialize and all that results is forceful bowing-up of the sig-moid into an 'n' loop, with a fearsome iatrogenic hairpin bend resulting at the sigmoid-descending colon junction. 482 CAN J GASTR0ENTER0l. VOL 7 No 6 jUL.Y/AUGU5 f 1993 In Western patients, the 'crash and dash' approach may sometimes work up to the splenic flexure but generally causes unacceptable pain or equiva-lently heavy sedation requirements. Oriental patients seem w have more permissive colon attachments and het-ter visceral pain threshold so that two-man insertion technique and well-tol-erated loop formation are the norm. The shorter, more muscular and less tolerant Western sigmoid colon is ide-ally passed with the instrument 'straight' into the sigmoid colon using repeated shortening withdrawals. The process starts once the instrument has reached the mid- or proximal-sigmoid colon, withdrawing before the tip reaches into the descending colon so that the mechanical disadvantage of trying to progress with a hooked or overangled tip is avoided. Since the sig-moid colon spirals clockwise round the pelvic brim into the descending colon, a clockwise corkscrew twist applied to the shaft often helps. Deflation and as-sistant hand pressure over the lower abdomen also contribute usefully to the shortening process (2). The main para-dox in this 'straight endoscope' ap-proach is that hurrying or aggression end up by re-forming the sigmoid loop and losing the subtlety, comfort and subsequent speed of keeping the instru-ment straight. Obsessional concentra-tion on the minutiae of the close-up view of the anatomy of a bend are par-ticularly necessary when the attach-ments are mobile and the endoscopist is chasing the mobile target of the approach to the descending. Flexible endoscopy requires a flex-ible approach, however, so that after three to four failed attempts to reach around the sigmoid-descending colon junction using subtlety and a straight endoscope (lasting perhaps 1 to 2 mins), it may be best to warn the patient of aggressive intent and then try to 'push through' into the distal descending co-lon. If this fails or is too painful I ask the patient to rotate to the right lateral position, as gravity sometimes favour-ably improves the anatomy and trans-forms the situation at the modest cost of the 30 s it may require for a sedated patient to rotate. SPLENIC FLEXURE -HALFWAY HOUSE Once in the proximal descending colon or at the splenic flexure, the en-doscope can always be straightened hack to 40 rn 50 cm, and it must be so straightened if the second part of the insertion is to be made easily and quickly. The splcnic flexure is a mo-ment of calm for the endoscopist, when the colonoscope cannot sl ip back ex-cessively (and can be reinserted and actively hooked around the splenic flexure if it scares to do so) and it repre-sents a perfect half-way stage in the procedure. Start the straightening rna-ncuvre by pulling back, then apply ac-tive twist to the shaft - usually clock-wise, less frequently anticlockwise if the attachments are mobile; occasion-ally rotation is needed first in one direc-t ion and then in the other according to feel and results. When properly straight the endoscope will respond as effort-lessly to in/out or twisting movements, as if it were a cue in the hands of a pool player. POSITION, PRESSURE AND PASSING PROXIMALLY -ALGORITHMS OF COLON OSCO PY Any tendency for the sigmoid colon to loop will be exaggerated if the instru-ment tip meets resistance, as is frequent in passing around the splenic flexure, the midcransverse colon or the hepatic flexure. Using aggressive force is there-fore a mistake; it simply loops the in-strument and causes pain while getting nowhere. On the other hand, some in-ward force muse be transmitted to the tip. The problem is to combine suffi-ciently gentle isometric inward pres-sure to progress without looping the sigmoid while simultaneously steering and coaxing the tip around any particu-lar bend. A useful contribution is made by prestraighcening the colon as far as possible by pulling back beforehand and by deflating excess air, particularly in the capacious proximal colon. Since flexurcs and bends are the main source of friction/resistance, flattening these out by gravity, can also be magical. The splenic flexure (and any fluid in it) al-most disappear when the patient is su-CAN J 0ASTR0ENTEROL VOL 7 No 6 JULY/AUGUS'T 1993 Fastest way to the cecum pine or in the right lateral position, whereas the hepatic flexure is best trav-ersed in left lateral. Providing the patient is only lightly sedated, and not too old or infirm, it takes only 20 co 30 s to roll over com-pletely before the enJoscopist passes the instrument shaft under the legs, the small amount of time lost usually being well rewarded by avoiding pain and prolonged attempts to pass a 'difficult' or poorly visualized bend. Adjunctive useful measures include simultaneously twisting the shaft to avoid sigmoid looping and avoidance of over-angling the controls with impaction of the acutely flexed bending section. Mose endoscopists ask for hand pres-sure by an assistant over the lower ab-domen to reduce the degree of sigmoid colon looping, reducing the anteropos-terior diameter of the abdominal cav-ity. Pressure in the upper abdomen to lift the transver~e colon or in the left hypochondrium to encourage a down-ward-looped colonoscope towards the hepatic flexure are also useful routine measures. When the tip will not quite reach to the hepatic flexure after all these efforts have been combined the endoscopist can use 'specific hand pres-sure' (2), feeling around the abdomen to determine empirically where the as-sistant can most usefully press. One of the essentials for rapid colonoscopy is rapidity in trying these various combinations (sometimes re-peated several times if necessary), start-ing with the most predictably logical but working quickly through the alter-native measures, picking out and main-tain mg those acLions found empirically to be useful. The number of possible endoscopic options is limited, but the complexity of the decision-making process is simplified and speeded if it is turned into an algorithm of additive, individually logical decisions, rather than thrashing around in an uncon-structive, increasingly frustrated and aggressive frenzy. If, after several attempts, one ap-proach does not work the endoscopist should be thinking of trying another, even its opposite, before resorting to the use of force. Thus, L wisting counter-clockwise may prove better than the 483 WII.LIAMS usual clockwise torque, especially in the proximal transverse colon, and the right lateral position can sometimes, surprisingly, prove best for passing around an awkward hepatic flexure -perhaps hecause the transverse colon flops downwards. The endoscopist who ib quickest, gentlest, safest and most sure of reach-ing the cecum needs to be truly a 'flex-ible' endoscopist, adaptable to circum-stance, interested in the minutiae of technique, determined hut able to abandon any predetermined scheme if difficulty occurs. The endoscope and the colon can almost invariably and rapidly be finessed into a workable and compatible configuration if the en-doscopist concentrates hard and works at it, slowly at first, but faster with ex-perience. There is a logic to colono-scopy but this often means snaking as gently as possible around each succes-sive bend and straightening for the next one without any case-iron ana-tomical hypothesis as to what is hap-pening. Speculating as to the position of the instrument tip or the probable configuration of the shaft is of some help in decision-taking, but often proves wrong. When 'lost' in the proximal co-lon the endoscope is usually in the splenic flexure - the implication being that it should be straightened back to 50 cm before progress can be made. PROXIMAL COLON AND ILEOCECAL VALVE Tomi colonoscopy in the l990s means reaching to the cecal pole, in-specting all of it with positive identifi-cation of appendix orifice and the ileocecal valve. Without this rigorous identification of these landmarks it is too easy mistakenly to identify the he-patic flexure as the cecum. Reaching around the hepatic f1exure is usually easy, often blindly cranking both con-trols fully in the appropriate direction, visually predetermined as the instru-ment first reaches the flexure. Repeated gentle deflation can he used synchro-nously to collapse and shorten the flex-ure without losing the view completely. With a view dnwn the ascending colon a slight asymmetry or inwarJ bulge on the ileocecal valve fold in the 484 distance signals the posnion of the valve, and this bulge can be accentu, ated or made to bubble hy further defla-tton. Trying to push may be the worst way of passing down the ascending co-lon and, as in the duodenum or sig-moid-descending colon, it is usually more productive to pull back the en, dosCl)pe. This straightens the inevita-ble transverse colon loop, flattens the hepatic flexure and often causes the instrument tip to sliJe satisfyingly in-wards. Deflation aids the process, posi-tion change (supine or prone) may help greatly in reaching the cecal pole and, very occasionally, hand pressure below it can raise the cecum up. Entering the ileum is mainly a ques-tion of identifying the valve, and hav, ing the instrument straight (for efficiency of angulation and control) and the colon partially deflated to keep it sh.on and malleable. Thereafter quite fine movements should be sufficient to dip the margin of the colonoscope tip onto the slit of the valve or between its soft lips (appearing as a red-out because of transillumination) then insufflating air to show the granular ilea! surface and find the lumen. It helps, as in en-doscopic retrograde cholangiopancrea-tography, co preadjust the instrument by rotation and angling it so that the instrument and valve are precisely aligned for efficient 'cannulation'. Placing the valve in the 6:00 position of the endoscope view is ideal since this results in the air nozzle at the lower margin of the instrument tip entering the valve first and facilitates angulation since only the up/down knob is needed for the manoeuvre. THE 'DIFFICULT' COLON Ignoring the obvious problems caused hy adhesions after surgery, in-flammatory disease or diverticulitis -which can occasionally require the use of a pediatric colonoscopc (3) or gastro-scope - difficulties encountered arc usually either the fault of a too rigid and aggressive endoscopist or a too mobile and swingy colon. Endoscopists com-plaining of regular 'difficulty ar the he-patic flexure' have usually not grasped the importance of straightening (to 50 cm) the instrument at the splenic flexure and are trying to forge ahead encum-bered by a persistent sigmoid colon loop. A mohile colon can, however, hum-ble the most skilful endt)scopist as he, hb instrument and the colon thrash around ineffectively. Normal straight-ening an<l rotation movements depend on the fulcrum effect of fixed points such as the sigmoid-descending Junc-tion or the phrenicocolic ligament which tethers the splcnic flexure. l n the 5 tn 15% of individuals where intra-uterine fusion of the mesocolon or mes-entery onto the abdominal wall fails to occur ( 4) or fixes in odd locations, frus-tratingly uncontrollable loops may re-sult and 1Kme of the 'tricks of the trade' arc effective. Nonetheless the cecum can always be visualized ( 5 ), even if the instrument will not reach right down into it and the ileocecal valve cannot be entered. It can be a matter of trial and error, rapidly undertaken, as LO whether the more aggressive looping 'get it over with' approach is better or whether, as is usually the case, 'shorten-ing and subtlety' are the preferred ap-proach. The reality of colon mobility is reflected in the fact that a colon which proves horrendous to intubate can often, on straightening by withdrawal, be reduced ro only 50 to 60 cm in length. A long but conventionally fixed colon or a short mobile colon can he rapidly examined hut a long and mobile colon may be a nightmare even in the best of hands. REFERENCES I. Cotton PB, Williams CB. Practical Gascromtestinal Endoscopy, 3rd cdn. Oxford: Blackwell Scicnrific Publications, 1990. 2. Waye JD, Ycssayan SA, Lewi, BS, Fabry TL. The techmque of abdominal pressure in torn! colonosct1py. Gastrointest EnJosc 199 l ;17: 147-51. 3. Bat L, Williams CB. Usefulness of pediatric colonoscopcs in adult colnnoscopy. Gastroinresr Endosc l 989;35:129-32. 4. Morgenstern L. Persistent descending mcsoculon. Surg Gynccol Oh,tet 1960;110:197-202. 5. Waye Jl), Rm,hkoff E. Tntal colonoscopy: ls n always possihle1 G,1strointcsi Endosc 1991;37:152-4. CAN J GASTROENTEROL Vo, 7 No 6 JUI Y/AlK,U..,, 1993 Submit your manuscripts athttp://www.hindawi.comStem CellsInternationalHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014MEDIATORSINFLAMMATIONofHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Behavioural NeurologyEndocrinologyInternational Journal ofHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Disease MarkersHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014BioMed Research InternationalOncologyJournal ofHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Oxidative Medicine and Cellular LongevityHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014PPAR ResearchThe Scientific World JournalHindawi Publishing Corporation http://www.hindawi.com Volume 2014Immunology ResearchHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Journal ofObesityJournal ofHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014 Computational and  Mathematical Methods in MedicineOphthalmologyJournal ofHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Diabetes ResearchJournal ofHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Research and TreatmentAIDSHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Gastroenterology Research and PracticeHindawi Publishing Corporationhttp://www.hindawi.com Volume 2014Parkinson’s DiseaseEvidence-Based Complementary and Alternative MedicineVolume 2014Hindawi Publishing Corporationhttp://www.hindawi.com

The Fastest Way to the Cecum

Abstract

Similar works

Full text

Available Versions

Crossref

Directory of Open Access Journals