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