1、AnatomyLevator ani muscleDeep external sphincter andPuborectalis muscleConjoined longitudinal muscleSubcutaneous external sphincterAnorectal ringArterial supply of the rectum Superior rectal artery Middle rectal artery Inferior rectal arteryVenous drainage of the rectum Internal hemorrhoidal plexus
2、External hemorrhoidal plexusReservoir Function Mechanical adaptive compliance,lateral angulation of the valves of Houston Physiological contractile waves more frequent and higher amplitude in rectum than sigmoidSensory ComponentsNeuro pathways Sympathetic+parasympathetic pathways to internal sphinct
3、er(hypogastric)Somatic to external sphincter(pudendal)Sphincter factorsBasal tone Pressure zone anal canal 25120 mmHg rectum 5 20 mmHg Continuous tone of int.and ext.sphincter increases with increased abdominal pressureMechanism of Anal ContinenceStructural considerations Anorectal angle between rec
4、tum and anal canal Flap valve angle of the anterior rectal mucosa caused by puborectalis causes occlusion Internal sphincter in continuous tonic state with external sphincter engaged during VasalvaAnal Fissure Ulcer in the lower portion of the anal canal Acute/chronic primary/secondary Sx:anal pain,
5、during and after BMsAnal FissureTriade of anal fissure anal papilla hypertrophy fissure in ano sentinel pileAcute FissureTreatment inspection,usually increased anal tone can be appreciated on rectal exam if tolerated cleansing measures typically resolve in 6 weeks without surgical interventionChroni
6、c Fissure sentinel tag,ulcer,hypertrophied anal papilla Form because of swelling,edema,and low grade inflammation may go on to fibrosis Extends from the dentate line to the anal vergeChronic FissureTeatment nitroglycerin ointment 0.2%-0.4%BID Topical diltiazem(50%resolution at 6 weeks)Botulinum toxi
7、n A injection 42%recurrence at 42 months side effects Surgery:lateral internal sphincterotomyLateral internal sphincterotomySecondary anal fissure Crohns disease Non-midline or abnormal appearing fissure should undergo margin biopsy Avoid surgery in neutropenic patients treat with perineal hygine an
8、d pain reliefAnorectal AbscessAnorectal Abscess Infection in one of the anal glands May be asymptomatic or cause severe throbbing pain that resembles a fissure Abscess should be drained when diagnosedAnorectal Abscess Sx:severe pain(aggravated by walking,straining)Swollen mass may be appreciatedAnor
9、ectal AbscessTreatment drainage,avoid packing,no abscess typically Crohns disease oral metronidazole or ciprofloxacin seems to have a mitigating effectFistula Chronic form of perianal abscess Evaluation with anoscopy,endoanal ultrasound ClassificationFistulaintersphincterictranssphinctericsuprasphin
10、ctericextraspinctericGoodsalls ruleFistulaTreatment Unroofing the fistula,eliminating the internal opening,and establishing adequate drainage Older patients use loosely tied setons to allow for adequate drainageAnal fistulotomy Thread-drawingHemorrhoidsHemorrhoids Varices of hemorrhoidal plexus A-V
11、communication in anal mucosa Vascular cushions thick submucosa with blood vessels,smooth muscle,elastic and connective tissueHemorrhoid Classification External skin tags External hemorrhoids(below the dentate line)Internal hemorrhoidsInternal hemorrhoids Bleeding Prolapse Pain usually associated wit
12、h other anal diseaseInternal hemorrhoidsTreatment Bulking agents for first and second degree hemorrhoids Sclerotherapy Infrared Photocoagulation Banding 2 3 ligations at 4 to 6 week Hemorrhoidectomy Stapled Circular Hemorrhoidectomy for prolapsed hemorrhoidsProcedure for prolapsed hemorrhoidsCircumcise for hemorrhoidsNeoplasms of the Anal Canal Squamous cell carcinoma Basaloid Carcinoma Mucoepidermoid Carcinomas AdenocarcinomasThank you
