colorectal

Colorectal-anus short note by S.Wichien (SNG KKU)

Anatomy

Histology -mucosa

-submucosa -inner cir : int anal sphinc -outer long : 3 tenia coli

-serosa Embryology -primitive gut derived from endoderm Midgut -small intestine,asc.colon,prox T.colon

-SMA Hindgut -distal Transverse colon, descending colon,

rectum, prox.anus -IMA

-distal anus from ectoderm -int pudendal a. -dentate line use to divide Colon Landmark -3-5 feets -rectosigmoid:sacral promontary

-caecum diameter 7.5-8.5 cm,thinest -sigmoid :narrowest>>most to obstruct :extremely mobile>>most vulvulus :diverticulitis -marginal a.of Drummond :anastomosis at terminal br SMA -ileocolic:terminal ilium,asc.colon

-rt colic a:asc.colon -middle colic:T.colon IMA

-lt colic a:des.colon -sigmoid br:sigmoid colon -sup rectal:prox rectum Lymp drainage -network in m.mucosa -epicolic(bowel wall),paracolic intermediate(vv),main(SMA,IMA) Nerve -sympathetic(inhi):T6-12,L1-3 -parasym(sti):vagus n.,sacral n(S2-4)

Anorectal Landmark -rectum 12-15 cm -sx anal canal 2-4 cm

-3 valve of Houston -presacral fascia -waldeyer fascia :post

-denovillier fascia :ant -lateral lig support lower rectum Dentate/pectinate line -2cm of mucosa just prox to dentate share histo (colum,cuboi,squa) :Anal transitional zone -long.m.fold:column of Morgagni -anal crypt Sphincter

-int:smooth m. -ext :subcutaneous

:superficial :deep sphincter(puborectaris m.) -levator ani :puborecta,iliococcygeus,pubococcyg Artery -sup rectal = IMA -mid rectal = int illiac

-inf rectal = int pudendal > int iliac Lymphatic -upper,middle = inf mesen LN -lower = inf mesen LN,int iliac LN -anal prox dentate = inf mesen,int iliac LN distal dentate = inguinal LN Nerve plexus -sym = L1-3

-parasym = S2-4 -int sphinc = sym,para :both inh sphincter contraction

-ext sphinc = inf rectal br of int pudendal n. -levator ani = int pudendal n.+ S3-5


Physiology

Fluid/elyte -90% water in ileum :absorb in colon

-1000-2000cc/d -Na absorb via Na-K ATPase -can absorb Na 400 mEq/d

-K absorb by passive diffusion -Cl absorb via Cl-HCO3 exchange -protein,urea --bact--ammonia -amonia to liver due to intraluminal pH -dec bact/pH>>dec absorb ammonia (lactulose administration )

Short chain fatty a. -acetate,butyrate,propionate -produce by bact ferment of carbo

-energy for colonic mucosa,transport -lack of dietary,diversion fecal stream result in m.atrophy=Diversion colitis

Microflora -bacteroides=most common anaerobe -e.coli=most common aerobe -breakdown carbo,prot -metabolism of bili,bile a,estro,chol -produce vit k -suppress patho organism--c.difficile

-gas=n2,o2,co2,h2,methane (bact=h2,methane) Motility -not cyclic motor activity character of migratory motor complex in small b. -intermittent contraction low amplitude -short duration contraction -burst,move content ante/retrograde

-delay colonic transit :absorp water,elyte Hi amplitude -mass movement Defecation -colonic mass movement -inc intraabdo/rectal p. -relax pelvic floor -rectum distend--reflex relax sphincter (rectoanal inhibitory reflex) -sampling reflex--sensory epi to distinguish solid stool from liquid/gas Continence

-puborectalis--sling around distal R. -rectal wall compliance -ext/int sphincter -n=br of int pudendal n

S+S

1.Pain -abdominal pain

-pelvic pain -anorectal pain :proctalgia fugax-levator spasm

2.LGIB -NG tube r/o UGIB -proctoscope r/o hemorrhoid -rbc scan detect bleeding 0.1 cc/hr If +ve

:angiography to localized bleeding :vasopressin iv :angioembolization

-if stable pt,rapid bowel preparation (4-6hr) to allow colonoscopy -colonoscopy identify cause bleeding,

cautery or inject epi may control bl. -if persist bleeding = colectomy :segmental resection 3.constipation 4.diarrhea/IBS 5.incontinence

-neurogenic -anatomic :procidentia :overflow inconti 2nd to impaction :trauma >>vg.delivery,sx


Lab+imaging

FOBT Advantage

-non invasive -low cost -good sens c repeat testing

Disadvantage -low spec -colonoscopy require for test+ve BE Advantage

-entire colon -good sene in polyps >1cm Disadvantage

-required bowel prep -less sens in <1cm -may miss lesion in sigmoid

-colonoscopy if test +ve Endoanal/rectal ultrasound -dept of invasion in rectum -normal = 5 layer :mucosal surface,m.mucosa, submucosa,m.propia,perirectal fat

-perirectal LN CT -extraluminal lesion -insensitive for detect intraluminal Positron emission tomography -PET -tissue c high level of anaerobic

glycolysis(tumor) -F-fluorodeoxyglc(FDG) is tracer, metabolism of it = positron emission

-as an adjunct to CT in staging -distinguish recurrent vs fibrosis Anoscope -anal c. -8 cm in length -rubber b.ligation,sclerotherapy Proctoscope -rectum,distal sigmoid

-25 cm in length

Sigmoidoscope -60 cm in length -see high as splenic flexor

-enema is adequate for scope Advantage -bowel prep=enema only

-exam most risk(sigmoid) Disadvantage -invasive -risk perforate -miss proximal lesion -colonoscopy if polyps identify

Colonoscopy -100-160 cm in length

-require oral bower preparation -require sedation -electrocautery not in absence bowel

preparation=risk of explosion Advantage -entire colon -hi sens,spec Disadvantage -most invasive -require sedation/bowel prep

-risk perforate CT colonography/ virtual colonoscopy Advantage -entire colon -noninvasive -sens as colonoscopy Disadvantage

-require bowel prep -insen for small polyps -colonoscopy if test +ve

-costly

Pelvic floor ix

Manometry -resting pressure = int sphincter (normal 40-80mmhg) -squeez pressure = ext sphincter (max p-resting p) (normal 40-80mmhg)

Neurophysiologic testing -assess pudendal n Rectal evacuation study -ballon expulsion test -video defecography


Anal fissure -tear in anoderm distal to dentate line -related to trauma from passage hard

stool or prolong diarrhea -cause spasm of int anal sphincter :pain--spasm--dec bl.supply

:this cycle develop chronic fissure -major in posterior midline 10-15% in ant middle Sign/symptom -tearing pain c defecation

-hematochezia:bl on toilet paper -anal spasm lasting several hours after bowel movement

-seen by gently separate buttock -too tender on PR/proctoscope

Tx Medical Tx--is effective in acute but only 50-60% in chronic fissure -bulk agent -stool softener -warm sitz baths -2%lidocain jelly

-0.02%nitroglycerine ointment :improve bl.flow :but often severe headache -ca channel blocks :diltiazem,nifedipine -newer agent :arginine :topical bethanechol (muscarinic ago) -injection of botulinum toxin

:inhi Ach release from presynap :cause temporary m.pararlsis :alternative to sx sphincterotomy

Sx

-in chronic fissure that fail medical lateral sphincterotomy -procedure of choice -divide 30% of internal sphincter fiber -open or closed technique -risk of incontinence (flatus)

Anorectal abscess

-Cryptoglandular infection -infect of anal glands

-intersphincteric plane -ducts traverse int sphincter into crypts at level of dentate line

Space

-Perianal space -Intersphincteric space -Ischiorectal space -Pelvic/supralevator space

Dx -severe anal pain

-inc by walking,coughing,straining -fever,uri retention -life threatening abscess

Treatment

-drainage as soon as dx -ATB alone ineffective Perianal abscess

-cruciate skin and subcu incision

-no packing is necessary -sitz baths in nextday Ischorectal abscess

-diffuse swelling in ischorectal fossa -incision in overlying skin -both=horseshoe abscess :drainage of deep postanal space :often require counterincision over

one/both ischorectal space Intersphincteric abscess

-difficult to dx -few perianal signs -pain deep and up inside anal area -posterior internal sphincterotomy Supralevator abscess

-uncommon,difficult to dx -mimic intraabdo condition -PR=indurated bulging mass -identify origin of abscess prior to tx

-if 2nd to extension of intersphincteric, should be drained through rectum -if from ischorectal,should be drained through ischorectal fossa -if from intraabdo ds,should drain via most direct route


Fistula in ano

-50%of drainage of anorectal abscess -internal opening : infected crypt

-external opening: site of prior drain -non-healing fistula should aware :crohn disease,malignancy,radiation,

TB,actinomycosis,chlamydia Diagnosis

-persist drainage from int/ext opening -indurated tract is often palpable

Goodsall rules

-determine locate of internal opening 1.external opening anteriorly

-short-radial tract -except this rule if >3cm--post midline 2.external opening posteriorly

-curve to post midline Type

1.intersphincteric fistula 2.transphincteric fistula 3.suprasphincteric fistula 4.extrasphincteric fistula:rare

Treatment

-locate int/ext opening -external opening usually visible -injection of hydrogen peroxide or dilute methylene blue may be helpful 1.Simple intersphincteric fistula -fistulotomy/curettage

-wound healing by2nd intention 2.Transphincteric fistula

:depend on location in sphincter <30% of sphincter -sphincterotomy -without signi risk of major incontine >30% of sphincter -initial placement of seton 3.Suprasphincteric fistula -seton placement

4.extrasphincter fistula -fistula outside sphinc--drain+open -1°tract at level of dentate line

:may opened if present -seton Failure to heal

-require fecal diversion -may from malignancy,crohn,radiate -proctoscope assess rectal mucosa -bx can r/o malignancy Seton

-drain placed through fistula -maintain drainage/induced fibrosis Cutting seton

-suture or rubber band placed through fistula and intermittent tightened -tightening the seton results in fibrosis

and gradual division of sphincter Noncutting seton -soft plastic drain,often vv loop -placed in to maintain drainage -tract may be laid open with less risk of incontinence because scarring prevent retraction of sphincter


Hemorrhoids

-cushions of submucosa containing venule,arteriole,smooth m.

-3 hemorrhoidal cushion in lt lateral,rt ant,rt post -fxn as continence mechanism

-complete closure of anal canal External hemorrhoid

-located distal to dentate line -are covered c anoderm -richy innervate

-thrombosed=painful skin tags -often confused c symp hemorrhoid

-redundant fibrotic skin at anal verge -residual of thrombosed ext hemorr Tx-only indicated for symptom relief

Internal hemorrhoid

-proximal to dentate line -covered by insensate anorectal muco -rarely pain,unless thrombo/necrosis -may prolapsed,bleeding Grading

1st =may prolapse on straining 2nd=reduced spontaneous 3rd=require manaul reduction 4th=can't reduce,risk for strangulation Portal HT pt -Hemorrhoida = normal popu -risk bleeding > normal popu Hemorrhoid Tx

Medical

-bleeding 1st,2nd degree -diet fiber,stool softener,water

-avoid straining Rubber band ligation

-persist bleeding 1st,2nd,3rd -graped and pulled mucosa 1-2 cm proximal to dental into a rubber band -1,2 quadrants are banded -severe pain--placed distal to dentate c/p 1.urinary retention -1% of pt -ligate int sphincter

2.infection -necrotizing infection -rare but life threatening -severe pain,fever,chill,uri.retention Tx -debride,drainage abscess,ATB

3.bleeding -may 7-10 after rubber band -usually self limit

-may require suture ligation Infared photocoagulation

-small 1st,2nd degree

-apply to apex of each hemorrhoid -coag underlying plexus -all 3 quadrant may be tx in same visit -large,prolapsed not effective Sclerotherapy -sclerosing agent

:5-phenol in olive oil :sodium morrhuate :quinine urea

-inject bleeding hemorrhoid -1st,2nd and some 3rd -1-3 ml of agent inject to submucosa

Excision of thrombosed Ext H -24-72 hr -elliptical excision under LA -usually loculated--I$D--ineffective -72hr--begin resorb--not excision Hemorrhoidectomy

Closed submu hemorrhoidectomy Park or Ferguson -prone/lithotomy -fansler anoscope -elliptical incision distal to anal verge and extended proximally -ligated apex of hemorrhoid plexus -resect hemorrhoid tissue -closure c running absorb suture -must identify fiber of int sphincter

-avoid resect large area--stenosis Open hemorrhoidectomy Milligan and Morgan

-as above but wound are left open -allow to heal by 2nd intention Whitehead hemorrhoidectomy

-circumferential excision of H -proximal to dentate line -most don't use this method because risk of ectropion (whitehead deform) Stapled hemorrhoidectomy -alternative sx -remove short circum segment of

rectal mucosa proximal to dentate line using circula staple -for large,bleeding int hemorrhoid -not in ext/combined hemorrhoid


Diverticular disease

-major=false diverticula -true diverticula=congenital

-between tenia coli -hi abdo.pressure=pulsion diverticula

Diverticulosis -diverticula without inflam -sigmoid=most common -lack of dietary fiber -most=asymptom

Diverticulitis

-10-25% of diverticulosis -lt side abdo.pain,leukocytosis,fever

1.uncomplicated diverticulitis

-LLQ pain

-CT:pericolic soft tissue stranding, colonic wall thickening,phlegmon -Rx=ATB -most=recovery without sx Sx--elective sx -sigmoid colectomy c 1°anas (procedure of choice)

-recommend after 2nd episode -resect extend to rectum -recurrence if retain sigmoid colon 2.complicated diverticulitis

Hinchey staging system

1-colonic inflam c pericolic abscess 2-retroperitoneal or pelvis abscess 3-purulent peritonitis

4-fecal peritonitis Rx -abscess<2cm--iv ATB

-larger--CT guide percu.drain--best Emer laparotomy -can't percu.drain -free air / peritonitis Stage1,2 -sigmoid-colectomy c 1°anas (one stage operation) Stage3,4

-sigmoid-colectomy c end colostomy c Hartman pouch (most common) Others -sigmoid-colectomy c 1°anas +/- on table lavage c prox.diversion (loop ileostomy)

Obstruction -67% of diverticulitis -10% complete obstruction

-sigmoid colectomy c end colostomy Fistula

-5%of complete diverticulitis -1st--colovesical--most common 2nd--colovg,coloenteric Rare--colocutaneous 2 key point 1.defined anatomy of fistula

2.exclude other dx -DDx--malignancy,crohn,RTX induce -barium enema, CT, colonoscopy

-Hx RTx--1st--should r/o recurrent ca Rx -resection of affected segment

(usually 1°repair) and simple repair of involved organ Hemorrhage

-erosion of peridiverticula arteriole -may massive -elderly

-80% spon.stop Rx -colonoscopy+epi injection/cautery -angiography--dx+therapeutic -laparotomy--segmental colectomy Giant colonic diverticula

-rare -antimesen of sigmoid colon

-pain,nausea,constipation -Ix--BE -c/p--perforate,obstruct,volvulus

Rt side diverticula

-cecum,asc.colon -young pt -most--asymptomatic -ddx=appendicitis -dx in operating room Tx--diverticulectomy/ileocolic resect


Pruritis ani

Sx correctable -prolapsed hemorrhoid

-ectropion -fissure -fistula

-neoplasm Infection -fungus=candida,monilia -parasite=enterobius,scabies,louse -bact corynebac.minutissimum(erythrasma)

treponema pallidum(syphylis) -virus=HPV Noninfectious

-seborrhea -psoriasis -contact dermatitis

-jx -DM Hidradenitis suppurative

-infect of cuta.apocrine sweat gl. -infect gl.rupture>form subcu.sinus T -mimic complex fistula

-stop at anal verge, because no apocrine gl.in anal canal Tx -I&D in acute abscess -unroof fistula,debride granulation Pilonidal dz

-hair containing sinus/abscess -in intergluteal cleft

-unknown etiology -cleft suct hair into midline when sit -ingrown hair=infect

Tx acute -incised and drain ¤midline w--heal poorly ¤incision--lateral to gluteal cleft chronic -unroof tract -curetting base -marsupializing wound -free of hair

Complex/recurrent sinus -more extensive resection -Z plasty/advancement flap/ Rotational flap

STD

Bacteria : proctitis -n.gonorrhea=most common

-c.trachomatis -t.pallidum=chancre -h.ducreyi

:chancroid :inguinal lymphadenopathy -donovania granulomatis :granuloma inguinale :red mass on perineum

Parasite -e.histolytica :ulcer in GI mucosa

-giardia lamblia Viral

HIV HSV T.2 HPV -anogenital wart,condy.accuminata -asso AIN,sq.cell ca -HPV T.6,11--no ca -HPV T.16,18--ca

Tx -topical podophyllin--small lesion -imiquimod (Aldara)--severe lesion -excision in large lesion + can r/o dysplasia


Megacolon

-chronic dilate,elongate,hypertrophy -congenital vs acquire

-asso chronic Mechanical or fxn obstr -exclude correctable mecha.obstr Congen.

-Hirschprung dz -no GG cell in distal colon -failure of relaxation -fxn obstruction -resect aganglion segment -can later in childhood

:ultrashort-srgment hirschprung dz Acquired Infection

-T.cruzi (chagas dz) :destroy GG cell :megacolon/eso

chronic constipation -from slow transit -med--anti cholinergic -neurologic--paraplegia Tx -diverting ileostomy or subtotal colectomy c ileorectal anas

Colonic pseudo-obstruction

-Ogilvie syndrome -fxn disorder -absent mech.obstruction -massive colon dilate (esp.rt and transverse colon) -common in hospitalized pt

-narcotic,anticholi,bed rest comorbid -autonomic dysfxn -adynamic ileus

Tx -r/o mech.cause -stop drugs -strict bowel rest -iv -neostigmine(Achesterase inh) :s/e=bradycardia :not in CVS ds -if fail--colonoscopic decompression :caution perforate

-rectal tube=rarely effective :greatest dilate=prox.colon

Solitary rectal ulcer syndrome

-asso internal intussusception -pain,bleeding,mucus d/c,obstruc

-one or more ulcer in distal rectum -ant.wall

colitis cystica profunda -nodule/mass in similar location Ix -bx r/o malignancy -colonoscopy /BE

Tx Nonsx -hi-fiber diet

-defecation to avoid straining -laxative/enema Sx

-as prolapsed -in symptomatic pt,fail med Typhlitis -neutropenic enterocolitis -life-threatening

-abdo.pain/distend,fever, diarrhea()bloody),n/v -neutropenia -difficult dx due to lack inflam rxn -CT :dilate cecum c pericolic stranding :normal not r/o ds -perianal pain Rx

-bowel rest -ATB -parenteral nutrition

-granulocyte infusion -perforate >> sx


Rectal prolapse

-circum,full thickness protusion -1st degree/complete/procidentia

-internal prolapse=intuss -female:male=6:1 -women:inc with age

-men:unrelated with age Mucosal prolapse -partial thickness protusion -often asso hemorrhoid Tx--banding/hemorrhoidectomy

Clinical -tenesmus

-tissue protuding -incomplete evacuation -mucus d/c,leakage

-fxn complaint--incontinence/constipa Ix

-colonic transit study -anorectal manometry -colonoscope/BE--exclude ca/diverti

Tx 1.Abdominal approach

1.Moschowitz repair -reduction of perineal hernia and closure of cul-de-sac 2.fixation of rectum 2.1 Ripsten and Well rectoplexy) -with prosthetic sling

2.2 suture rectoplexy 3.resection rectoplexy

-resection of redundant sigmoid colon may combine c rectal fixation 2.Peritoneal approach

1.Delorme procedure -tightening the anus c prosthetic 2.Perineal rectosigmoidectomy or Altemeier procedure

Volvulus

-twisted it mesentery -sigmoid 90% -caecum<20% -may reduce spontaneous -gut obstruction ,strangulate,

gangrene,perforation -constipate--large redundant colon (chronic megacolon)--volvulus Clinical -acute bowel obstr -intermittent chronic volvulus

Sigmoid volvulus X-ray

-bent inner tube or coffee bean -BE=bird beak--(pathognomonic) Tx

1.not emer -resus -rectal tube to decompress -endoscopic detorsion :rigid proctoscope or flex.sigmoido/colonoscope -if suggest strangulate=sx

-hi recurrent (40%) -elective sigmoidectomy 2.emer -gangrene,perforate -sx exploration -end colostomy (Hartman procedure) :safest operation Cecal volvulus

-non-fixed of rt colon -rotate around ileocolic vv -early vascular compromise

X-ray -kidney shape/air fill structure LUQ Tx -most can't endoscopic detorsion -rt hemicolectomy c 1°ileocolic anas -simple torsion may cecoplexy :hi recurrence Transverse colon volvulus

-rare

-predispose--chronic consti--megaco -x-ray as sigmoid but BE show more proximal obstruction


Rectovaginal fistula

-connection between vagina and rectum or anal canal proximal to dentate line Classified

Low -rectum--close to dentate line -vagina--fourchette cause -common caused by OB inj -trauma from FB

Middle -vagina--between fourchette and cx

cause -after sx resect of midrectal neoplasm -radiation inj

-more severe OB inj -extension of undrain abscess High

-vagina--near cervix cause -operative

-radiation inj complicated diverticulitis -may cause colovaginal fistula crohn dz -cause RV fistula all level -colovaginal, enterovaginal fistula

Dx

-pass flatus from vagina to -pass solid stool from vg

-some degree of fecal incontinence -contaminate result in vaginitis -anoscope/vaginal speculum may dx -BE or vaginogram may identify -methylene blue into rectum while tampon in vagina may dx

Tx

OB inj -50%heal spon--wait 3-6mo

Cryptogl abscess -drainage allow spon closure

low+mid rectovaginal fistula -endorectal advancement flap (best Tx) -healthy mucosa,submu,cir muscle

if sphincter inj -overlapping sphincteroplasty -fecal diversion =rare

hi fistula -best tx via trans-abdo pproach

-bowel is resected -closed hole in Vg -omentum interposed Crohn -adequate drain of perianal sepsis -advancement flap may performed if

spare from active dz Radiation -can't flap -bx--r/o ca


1.Ischemic colitis

-intes colitis--most com=colon :splenic flexure

-from low flow/small vv occlusion -rarely asso major a/v occlusion -splenic flexure=most site

-rectum=spare(rich collateral br.) Risk factors -vascular dz -DM -vasculitis

-hypoT -ligate IMA in aortic sx

Ix Film -thumb printing

(mucosal edema,submu.hmg) CT -nonspecific colonic wall thickening -pericolic fat stranding Angiography -not helpful -rare major a.occlusion

Sigmoidoscope -dark,hmg mucosa -hi-risk to perforate -relative C/I BE -C/I in acute phase Tx -major can medical tx

-rest bowel,broad ATB -correct low flow stage -colonoscopy after recovery

:evaluate stricture :r/o other cause -fail med=sx exploration :resect necrotic bowel :avoid primary anas :may be 2nd look operation Sequele -stricture 10-15% -chronic segmental ischemia 15-20%

2.Infectious colitis

2.1 Pseudomembranous colitis -c.difficile

-nosocromial diarrhea -give ATB=deplete normal flora :clindamycin

-2 toxins :toxin A-enterotoxin :toxin B-cytotoxin -ulcer plaque,pseudomembranous Ix -stool c/s

-immunoassay for toxins Tx -stop ATB

-oral metro=1st line (10 d) -oral vanco=2nd line -vanco enema

-recurrent=longer (up to 1 mo) Fulminant colitis -total colectomy c end ileostomy Others infectious colitis Common -e.coli,campylobacter jejuni,yersinia,

samonella,shigella,gonorrhea -ameba,cryptosporidium,giadia -HIV,HSV,CMV Uncommon -TB,syphilis,actinomycosis -fungi


Colon inj Tx depend on 1.size perforation

2.duration of time since inj 3.condition of pt

1.Prenetrating colorectal inj 1.1 Primary repair -hemodynamic stable -minimal contaminate C/I -shock

-inj>2 organs -mesen.vascular damage -extensive fecal contaminate

Relative C/I ->6hr

1.2 Ostomy (fecal diversion) Inj factor -hi-velocity bullet w. -shotgun w. -blast w. -crush inj Pt factor -tumor -radiate tissue -age -med condition

Inj factor -inflam tissue -infection -distal obstr -local FB -impaire bl.supply -mesen.vv damage -shock -hmg>1000cc ->2organ inj ->6hr prox.fecal diversion :distal rectal washout

:+/-presacral drain placement 4D

1.debridement 2.prox.fecal diversion 3.distal rectal washout 4.presacral drain placement

2.Blunt colorectal inj

-less than penetrating inj -colon perforate -shear inj to mesentery -crush inj

:debride nonviable tissue :prox.fecal diversion :distal rectal washout :+/-presacral drain placement

3.Iatrogenic inj

1.intraop -pelvic operation

-must early recognition -little conta=primary repair -delay=sig.peritonitis,sepsis

:fecal diversion :repeat exploration 2.BE -rare -above petitoneal reflection=sx -extraperitoneal rectum=NOM

3.colonoscopy -perforation -<1%of procedure

Tx depend on 1.size perforation

2.duration of time since inj 3.condition of pt -If signi contaminate,delay dx hemodynamic unstable :prox.diversion+/-resection Anal sphincter inj

cause -obstetric traummost common -hemorrhoidectomy -sphincterotomy -abscess drainage -fistulotomy -penetrating/blunt inj Ix -anal manometry

-electromyography(EMG) -endoanal u/s Surgical repair

A wrap around sphincteroplasty -most common -mobilize divided sphincter m. -reapproximate without tension Postanal intersphincteric levatorplasty -levator ani m.is approximate to restore anorectal angle -puborectalis/ext sphincter are tighten with suture Gracilis m.transposition

-sig.loss sphincter m. -fail prior procedure Artificial anal sphincter -inflate silastic cuff Sacral n.stimulation


Polyps

Neoplastic polyps -adenomatous polyps

-dysplastic -risk ca--size + type of polyps Size--polyps<1cm--rare ca

Type -Tubular adenoma - ca 5% -Villous adenoma - ca 40% -tubulovillous - ca 22% Tx -snare excision--pedunculate P

-saline lift+piecemeal snare--sessile P Hamatomatous polyps

-juvenile polyps -not usually premalignancy -childhood

-common symptom :bleeding,intussus,obstruction A.familial juvenile polyposis

-AD -100 polyps in colon,rectum -may ca -anaul screening age 10-12 yr

Rx -spare rectum :total colectomy c ileorectal anastomosis -total proctocolectomy,ileal pouch, anal reconstruction B.Peut-Jeghers synd

-polyposis small bowel,colon,rectum -melanin spot on buccal mucosa,lips -may ca

Sx--symptom,develop adenomatous C.Cronkite-Canada synd -GI polyposis c alopecia,

cutaneous pigmentation, atrophy fingernail/toenail -diarrhea,n/v,malabsorp -prot-losing enteropathy -sx for c/p--obstruction D.Cowden synd

-AD -harmartomatous -facial trichilemmomas,breast ca, thyroid dz,GI polyps = typical synd

Inflammatory polyps

-pseudopolyps -inflam bowel dz

-amebic/ischemic/schisto colitis -not ca -but can't distinguished adenomatous

polyps,so should be removed Hyperplastic polyps

-usually <5mm -hyperplasia ,without dysplasia -large polyps >2cm--slightly risk ca


Pre-op evaluation

-colonoscopy :synchronous lesion

:up to 5% of pt -PR -proctoscope c bx

-endorectal u/s -CXR -abdo./pelvis CT -obstructive symp :avoid mech.bowel preparation -PET

-CEA = follow up Pre-op preparation

1.Bowel preparation -mechanical bowel preparation :polyethylene glycol (PEG) solution

:sodium phosphate solution :drink large volume -antibiotic prophylaxis :neomycin 1 gm :erythromycin 1 gm/metro 500mg 2.stomal planning

-consult enterostomal(ET)nurse -educated -stoma siting : pre-op mark 3.ureteral stent -identify ureter intraop -inflam/phlegmon inc risk of ureter inj during mobllize sigmoid colon

Anastomoses

-highest risk of leak/stricture in :distal rectal or anal canal

:irradiated/disease bowel Configuration

End to end -same caliber -colocolostomy,small bowel anasto End to side -one limb of bowel larger than other -in chronic obstruction

Side to end -prox.bowel smaller than distal -ileorectal anastomosis

-less bl.supply than end to end Side to side -antimesen of two segment

-ileocolic,small bowel anas Technique

Hand suture -single layer :running or interrupt -double layer

:inner=continue :outer=interrupt -permanent or absorb suture Stapled technique -linear cutter stapling device :end to end anastomosis -circular stapling device :end to end,end to side,side to end -useful in low rectal/anal canal anas

that hand sew difficult due to pelvis


Colectomy

Ileocolic resection -resect terminal ilium,cecum,appendix

-ileocolic crohn dz -benign lesion or incurable ca -if curable ca,more radical resection,

such as rt hemicolectomy -ligated ileocolic vv -1°anastomosis between distal small bowel and ascending colon Rt colectomy

-for curative intent resection of proximal colon ca -ligated ileocolic,rt colic,

rt br of middle colic vv -10 cm of terminal ilium are resected -primary ileal transverse colon anas

Extend rt colectomy

-for curative intent resection of hepatic flexure/prox transverse colon -ligate middle colic vv at their base -rt colon,prox tv colon are resected -primary anas at ilium-distal tv colon

Transverse colectomy

-lesion in mid,distal tv colon -ligate middle colic vv -colocolonic anastomosis Lt colectomy

-lesion confined to distal tv colon, splenic flexure,descending colon

-ligated lt br of middle colic vv, lt colic vv,1st br sigmoid vv -colocolonic anastomosis

Extended lt colectomy

-lesion in distal tv colon -lt colectomy+extend include rt br of middle colic Sigmoid colectomy -sigmoid lesion -ligated sigmoid br of IMA -resected to level of peritoneal reflect

-anas at descending c./upper rectum -full mobilization of splenic flexure to create tension free anastomosis

Total Colectomy

-fulminant colitis -FAP

-peserved sup rectal a. -ileorectal anastomosis -if anas is contraindicate,an end

ileostomy is created and remaining sigmoid or rectum as mucus fistula or hartmann pouch Subtotal colectomy -distal sigmoid vv are left

-anas ilium-distal sigmoid colon Proctocolectomy

Total protocolectomy -colon,rectum,anus are removed -ileum to skin=ileostomy

Restorative proctolectomy -ileal pouch anal anastomosis -preserve anal sphincter m,anal canal -anastomose of ileal reservoir to anus -neorectum by anastomosis of terminal ileum aligns to J,S,W

-J puch is simplest=most used -most perform proximal ileostomy to divert succus from create pouch to minimize leak and sepsis -ileostomy closed 6-12 wk later


Anterior resection

resect rectum from abdo approach

High AR -resect distal sigmoid,upper rectum -benign lesion and dz at rectosig jxn such as diverticulitis -mobilize rectum,not fully from concavity from sacrum -ligated IMA at its base -ligated IMV -1°anastomosis :end to end

Low AR -lesion at upper/mid rectum

-mobilize rectosigmoid -open pelvic peritoneum -mobilize rectum from sacrum

-dissection anorectal ring -Post : through rectosacral fascia Ant : through Denonvilliers fascia to vagina in women or seminal vesicle and prostate in men -anastomosis require mobilize of splenic flexexure

Extend low AR

-lesion in distal rectum,but several cm above sphincter -moblize rectum as low AR -but ant dissection is extended along rectovaginal septum in women,distal seminal vesicle/prostate in men -risk of leakage is hi when

anastomose in distal rectum or anal canal,temporary ileostomy should perform

-anastomosis may feasible very low in rectum or anal canal,post operative fxn may be poor. Because des colon lack distensibility,reservoir fxn may compromise. Create colon J-pouch or coloplasty may improve fxn -Hx of sphincter damage or any degree of incontinence is relative C/I for coloanal anastomosis :End colostomy should perform

APR

-abdomioperineal resection -remove entire rectum,anal,anus

-permanent colostomy -procedure as extend low AR -peritoneal dissection

:2nd surgeon :excise anal c. c wide circum margin Pouchitis -inflam affect both ileoanal pouch and

continent ileostomy reservoir -incidence 30-55% -diarrhea,hematoczia,abdo.pain,fever

-dx=endo+bx -ddx=infection,undx crohn dz -etiology=unknown

-fecal stasis -ATB=metro+/-ciprofloxacin -some develop chronic pouchitis :salicylate/steroid enema :pouch excision


Ostomy

-temporary vs permanent -end on vs loop

-located in rectus m.to minimize risk of parastromal hernia -pt can see,easily manipulate

-abdo should flat to prevent leak -circular skin incision -subcu.dissected to ant rectal sheath -sheath is incised in cruciate fashion -separated m. -incised post sheath

-size of defect depend on bowel size -should be as small as possible, without compromise bl.supply

-usually width of 2-3 finger -closed incision and dress prior maturing stoma to avoid contaminate

-3-4 interrupt absorb suture are placed through edge of bowel then through serosa then through dermis (Brooke technique) 1.Ileostomy

Temporary ileostomy

-protect anastomosis for leakage -loop ileostomy -with or without rod -divided loop prevent incomplete diversion that occur c loop ileostomy -advantage=closure can be accomplished without laparotomy,handsewn or stapled anastomosis can be created and

return bowel to peritoneal cavity Permanent ileostomy

-require after total proctocolectomy or in pt c obstruction -end ileostomy :Brooke end ileostomy :Continent ileostomy (by Kock) internal ileal reservoir nipple valve construct :continence m.

Complication -stoma necrosis (early post op) :tight fascial defect or

:skeletonizing the distal small bowel -stoma retraction :in obesity

-skin irritation -obstruction -parastomal hernia :less than colostomy :resiting the stoma to contralat side -prolapse

:rare,late c/p :asso parastomal hernia -Continent ileostomy = valve slippage

2.Colostomy

-most as End colostomy > loop colos

-loop colostomy >>more prolapse -most = in left side -mature by Brooke fashion -distal bowel as :mucus fistula :Hartman pouch -closure of colostomy require

laparotomy : end to end anas Complication -colostomy necrosis :skeletonize distal colon :tight fascial defect Tx :suprafascia--expectant :below fascia--sx

-retraction -obstruction -parastomal hernia

:most common late c/p -prolapse -less skin irritation than ileostomy -less dehydrate than ileostomy


Adenocarcinoma

Incidence -most common malignancy in GI

-men=female -adenoma-carcinoma sequence Risk factor 1.aging > 50yr 2.hereditary -80%sporadic 20%fam.hx -APC gene defect 3.environments

-animal fat diet,low fiber -hi-sat or polyunsaturated fat -alcohol

-vit A,E,C,ca,selenium=dec risk 4.inflammatory bowel -10yr--inc 2%

20yr--inc 8% 30yr--inc 18% 5.other -smoking,ureterosigmoidotomy acromegaly,pelvis irradiation Genetic defect

Normal epi>>APC>>dysplastic epi>>early adenoma>>K-ras>>intermediate adenoma>>DCC/DPC4>>late adenoma>>p53>>carcinoma>>other change>>metas APC-tumor suppressor gene K-ras-proto-oncogene DCC-tumor suppressor gene

p53-tumor suppressor gene Genetic pw--2 major pw

1.LOH pw--80% -chromosome deletion and tumor aneuploidy 2.RER pw--20% -Replication Error pw -missmatch repair pw -asso microsatellite instability--MSI Familial colorectal ca

Risk of ca

-no fam.hx 6% -one 1st degree 12% -two 1st degree 35%

Spreading

1.Regional LN -most common

-node metas inc with tumor size, poorly diff,dept of invasion, lymphovascular invasion

-dept of invasion (T) :most signi predictor of LN spreading :Tis = no node metas :T1,2 = node metas 5-20% :T3,4 = node metas >50% -number of node asso.distant ds

->=4 node : poor prog -upper rectum :along sup.rectal vv to IMA

-lower rectum :middle rectal vv :inf rectal vv to int illiac node

2.Hematogenous -most common = liver -via portal venous system -risk of hepatic metas :tumor size :tumor grade

-pulmo.metas rarely occur in isolate Staging

T1-invade submucosa T2-invade mucularis mucosae T3-invade subserosa or nonperitoneal pericolic/perirectal T4-other organ or perforate viscer peritoneum

N1-1-3 pericolic/perirectal LN N2->=4 pericolic/perirectal LN

N3-any LN along major vv *node involve is single most important prog.factor M1-metas Stage TNM prog l T1-2,N0,M0 70-95% lla T3,N0,M0 54-65%

llb T4,N0,M0 llla T1-2,N1,M0 39-60% lllb T3-4,N1,M0 lllc anyT,N2,M0 lV anyT,N M1 0-16%


Ca colon.Tx

Pre-op -Colonoscopy

:synchronous lesion--5% of pt -endorectal u/s :assess T N

-CT chest/abdo/pelvis -CEA Objection -remove 1°tumor along with its lympovascular supply

:lymph along a. :bowel resection depends on vv are supplying segment involved with ca

-resect adjacent organ :omentum -if can't remove all tumor

:palliative procedure Stage 0 (TisN0M0) -no node metas -completely remove endoscopic -follow colonoscopy

Stage1 (T1 N0 M0) (malignant polpys) Pedunculate polyps -in head polyp--can endoscopic tx -lymphovas.invasion,poorly diff, tumor within 1mm msrgin, invade submu :segmental colectomy

Stage1 and 2 (T1-3 N0 M0) (localized colon ca) -major=cure c sx

-adjuvant CMT for select pt c stage2 :young pt,tumor c hi-risk histo.finding Stage3 (anyT N1 M0) (LN metastasis ) -recommend adjuvant CMT -5-FU base regimen c leucovorin Stage4 (anyT anyN M1) (distant metas)

-all require adjuvant CMT -can't cure by sx -palliative

Follow up

-most recur within 2yr -colonoscopy within 12 mo

if normal,repeat q 3-5 yr -CEA q 2-3 mo for 2 yr -CT scan in CEA elevate,not routine

Screening

Average risk -50yr -annual FOBT -flex.sigmoidoscope q 5yr or

BE q 5 yr or Colonoscopy q 10 yr

Adenomatous polyps -50yr -colonoscopy at 1st dx then in 3yr

Colorectal ca -at dx -pre tx colonoscope then 12 mo after curative resection then colonoscopy after 3yr then q 5yr

FAP -10-12yr -annual flex.sigmoidoscope -EGD q 1-3yr after polyps appear Attenuated FAP -20yr -annual flex.sigmoidoscope -EGD q 1-3yr after polyps appear

HNPCC -20-25yr

-colonoscopy q 1-2 yr -endometrial aspi.bx q 1-2yr Fam.colorectal.ca (1st degree relative) -40 yr or 10 yr before the age of youngest affect -colonoscopy q 5yr


Ca rectum.Tx

-more difficult to resect neg margin -because anatomic limit of pelvis

-local recurrence higher than colon Local tx

¤distal 10 cm of rectum can transanal Transanal excision -noncircum,benign,villous adenoma -can T1,some T2 -can't LN--may understage pt Transanal Endoscopic microsx(TEM)

-higher lesion(up to 15cm) Ablative technique -electrocautery,radiation

-disvantage=no patho specimen Radical resection

-remove involve segment, lymphovascular supply -2cm distal margin Total mesorectal excision(TME) -sharp dissection anatomic plane -complete resection rectal mesentery -upper rectum/rectosigmoid

:partial mesorectal excision :5cm distal tumor=adequate -extensive involvement of pelvic organ may require pelvic exenteration :APR :en bolc resection (ureter,BD,prostate or uterus/vg) :colostomy,ileal conduit :sacrectomy upto S2-3 jxn

stage0(Tis N0 M0) -Transanal excision -1 cm margin

stage1(T1-2 N0 M0) -localized rectal ca

-local excision:local recur hi(20-40%) -radical resection:recommend -in refuse radical sx :local excision :adjuvant chemoradiation :improve local recurrence

stage2(T3-4 N0 M0) -localized rectal ca

2 thought 1.TME -not need adjuvant chemradiation

2.chemoradiation:reduce local recur 2.1 preop -tumor shrinkage -impair wound healing,pelvis fibrosis 2.2 postop -accurate patho staging -avoid wound healing problem

-but if large tumor,difficult to resect stage3(anyT N1 M0) -node metas -chemoradiation pre or post op for node+ve rectal ca -neoadjuvant>>sx stage4(M1)

-palliative procedure -avoid morbid procedure -intraluminal stent

-diverting colostomy


Anal tumor

-uncommon -2%of colorectal malignant

Divided into 1.anal canal

-prox.to anal canal -lymph drainage :sup.rectal >> IM node :middle,inf.rectal >> int.illiac node 2.anal margin -distal to dentate line

-lymph drainage :inguinal node :if 1°are block >> sup.rectal

Anal intraepi.neoplasia(AIN) -bowen ds -hi-grade squa. intraepi lesion--HSIL -sq.cell ca in situ -precursor to invasive sq.cell ca -plaque like lesion -as CIN : acetic acid,Lugol solution -asso HPV 16,18 -asso HIV,homosexual men

-hi-reso anoscopy--abnor telangiec Tx -resection or ablation -hi recurrent,require closed f/u :pap smear q 3-6 mo Epidermoid carcinoma -1.sq.cell ca 2.cloacogenic ca, 3.transitional ca 4.basaloid ca

-slow growing -anal/perianal mass -pain,bleeding

-inguinal node=poor prog Tx -as sq.cell ca in skin -wide local excision -in can't excise=CMT+RTX :Nigro protocal(5FU,MMC,3000cGy) Verrucous ca -Buschke-Lowenstein tumor or Giant condyloma accuminata

-aggressive of condy.accuminata -not metas -Tx of choice--wide local excision

Basal cell ca -rara of anus -as skin

-raise,pearly edge,central ulcer -slow growing tumor -rare metas

-wide local excision -large lesion=radical resection,RTX Adenocarcinoma -extremely rare -spread from lower rectal ca

-may from anal gland/chronic fistula -radical resection +- adjuvant CMT Paget dz

-adenocarcinoma in situ -apocrine gl. -plaque like

-indistinguish from Bowen dz -paget cell -asso synchronous GI adenoca :complete assess GI tract -wide local excision Melanoma

-rare -1-2% of melanoma -5yr survive <10% -at dx,often deep invade,metas -in resectable :radical resection (APR) or wide local excision


Rare colorectal tumor Carcinoid -25% in rectum

-risk malignancy inc with size -tumor>2cm :60% have metas -less vasoactive in other location

-have syndrome--have liver metas -in prox.colon :less common :more likely to be malignancy -med=somatostatin(octreotide),INF Small

-locally resect Large/invade muscular -more radicak sx

Carcinoid carcinoma

-adenocarcinoid

-both carcinoid and adenoca -hx=more closely adenoca -common regional/systemic metas -tx as adenoca Lipoma

-most common in submucosa

-benign -<2cm=rarely cause bleed,obstr,intus -small asymp=not sx -larger :colonoscopic resection :colotomy c enucleation Lymphoma -10%of GI lymphoma

-rare in colon/rectum -cecum is most involve (spread from terminal ileum)

-bleeding,obstruction -Tx of choice = bowel resection -adjuvant cmt upon stage Leiomyoma

-smooth m.tumor -most common in upper GI -most=asymp -large lesion=bleed,obstruct -difficult to distinguished from

leiomyosarcoma,should resect ->5cm--radical resection, (because risk of malignancy)

Leiomyosarcoma

-rare in GI -rectum is most common

-radical resection Retrorectal tumor

-presacral tumor -ant--rectum post--presacral fascia lateral--endopelvic fascia -upper 2/3 of rectum and sacrum -contain embryologic remnant (neuroectoderm,notocord,hindgut)

-most common=congenital -lower back/pelvic/leg pain -GI symptom

-PR=palpable lesion -MRI pelvis=most sense/spec -myelogram in CNS involve

-bx not indicate,if lesion resectable :infection,seeding Cyst -dermoid/epidermoid--ectoderm -enterogeneous cyst--primitive gut -ant meningocele/myelomeningocele :scimitar sign = pathognomonic

(sacrum c round, concave border without bony destruction) Solid -teratoma--germ cell -chordoma--notochord :most common malig in this region :bony destruction -neurofibroma,neurilemoma ependymoma,ganglioneuroma

-osteoma,bone cyst osteogenic sarcoma ewing sarcoma,giant cell T

chondromyxosarcoma Tx -sx resection Hi-lesion--transabdo approach Low-lesion--transacral


Familial Adenomatous Polyposis

-1% of colorectal adenoca -AD

-APC gene mutation -APC gene testing (+ve in 75%) -located on chrom 5q

-risk ca 100% by age 50 yr Screening -flex.sigmoidoscope :1st degree relative--age 10-15 yr :q 2 yr until 34 yr :q 3 yr until 44 yr

:then 3-5 yr -EGD :at 25-30yr q 1-3yr

:adenoma anywhere in GI :duodenum >> periampullary ca

Rx 4 factors affect choice of Sx -age -severity of symptom -extend of rectal polyposis -location of ca,desmoid tumor

1.total abdo.colectomy -ileorectal anastomosis -¤surveillance rectum 2.total proctocolectomy -end ileostomy (Brooke) or continent ileostomy (Kock) -large abandon--success of 1 3.restorative proctocolectomy -ileal pouch anal anastomosis

+/- temporary ileostomy Med

-admin cox-2 inh (celecoxib,sulindac) may slow develop polyps Extraintes manifestation

-congen.hypertrophy of retinal pigment epithelium -desmoid -epidermal cyst -mandibular osteoma (Garder synd) -CNS tumor (Turcot synd)

FAP attenuated

-AFAP -later in life age

-variant FAP -mutation APC---AD--30% of pt mutation MYH--AR

-10-100 polyps--dominant rt colon ->50%--ca clon--average 50yr -duodenal polyposis HNPCC -Hereditary Nonpolyposis Colon ca

-Lynchs synd -AD -error in mismatch repair -develop ca at early age--40-45 yr -synchronous lesion = 40%

Extracolonic malignancy -endometrial--most common -ovarian,pancrease,stomach small bowel,biliary,uro 3-2-1-0 rules Amsterdam criteria ->=3 relative dx--HNPCC

one of whom is 1st degree relative -at least 2 generations -at least 1--dx <50yr -no FAP Screening -screening colonoscopy 20-25yr or 10yr younger than youngest age at diagnosis in family

-hi risk of endometrial ca :TVS or endometrial aspiration bx :after 25-35yr

Sx -40% risk of develop 2°colon ca :total colectomy c ileorectal anas in adenoma or colon ca :anaul proctoscope >> risk ca rectum -prophylactic hysterectomy c BSO :in complete childbearing

colorectal

Documents

sigmoid colon

colon landmark

inf rectal br of int

descending colon

transphincteric fistula

colon sigmoid br

int illiac inf rectal

anal crypt sphincter