ACUTE APPENDICITIS

ACUTE APPENDICITISResident: Dr SD SanyalModerator: Brig SR Ghosh Consultant Surgery and GI Surgeon

IntroductionVestigeal organSurgical importance: Propensity for inflammationMost important cause of Acute Abdomen in young adults

AnatomyPresent only in humansAt birth: Short & broad at its jn with the Caecum Typical tubular structure produced by 02 years of ageResults from differential growth of caecum

AnatomyPosition: constant at the confluence of the 03 taenia coli of caecumMesoappendix : Arises from the lower surface of the mesentery of terminal ileumAppendicular Artery: Branch of Ileo-colic artery End Artery04-06 Lymphatic channels traverse Mesoappendix ----------> Ileo-caecal LNs

Microscopic anatomyLayers: - Mucosa - Submucosa - Muscularis - Serosa

Microscopic anatomyLumen has longitudinal folds of mucous membraneLining: Columnar cells of colonic typeCrypts: Argentaffin ( Kulchitsky cells )Submucosa: Lymphatic aggregations/Follicles

Anatomical Positions

RETROCAECAL74%PELVIC21%PARACAECAL2%SUBCAECAL1.5%PREILEAL1%POSTILEAL0.5%

Anatomical positions

EtiologyLow dietary fibre FaecolithsStrictureWorm infestations: Oxyuris vermicularisNeoplasms: Ca caecum, carcinoidsViral

Pathology Lymphatic hyperplasia

Luminal obstruction

Increased intra-luminal pressure

Edema, mucosal ulceration

Bacterial translocation to submucosa

Pathology

Resolution Venous obstruction

Ischaemia of appendix wall

Invasion of muscularis propria, submucosa

Pathology

Acute Appendicitis Lump/mucocele

Gangrenous appendicitis

Peritonitis

Bacteriology of perforated appendicitis

TYPE OF BACTERIAPATIENTS (%)ANAEROBICB. fragilis80B. thetiaotaomicron61Bilophila wadsworthia55Peptostrptococcus spp46AEROBICE.coli77 S.viridans43Group D streptococcus27P.aeruginosa18

Clinical featuresSymptoms:Periumbilical pain 50% casesPain shifts to RIFAnorexiaNausea/vomiting

Clinical featuresSigns:Pyrexia Localized tenderness in RIFMuscle guardingRebound tendernessRovsings signPointing signPsoas signObturator sign

Clinical featuresRisk factors for perforation:Extremes of ageImmunosuppressionDiabetes mellitusPelvic appendixPrevious abdominal surgery

Special clinical scenariosAccording to position:Retro-caecal - Silent appendix - Quadratus lumborum rigidity - Psoas sign - Loin tenderness

Special clinical scenarios2. Pelvic - Early diarhoea - Increased urinary frequency - Deep tenderness over symphysis pubis - DRE: Rectovesical pouch/POD tenderness - Obturator/Psoas sign +ve

Special clinical scenarios3. Post-ileal - Diarrhoea - Marked retching - Ill defined tenderness to rt of umbilicus

Special clinical scenariosAs per age:Infants - Uncommon 7 : Strongly s/o appendicitisModified Alvorado Score: - 9 points - Differential count not donePAS: - Total : 10 - Rebound tenderness excluded - Cough/percussion/hopping tendeness = 2 - Leucocytosis > 10,000 1

Tzanakis Score1. Rt lower abdominal tenderness = 42. Rebound tenderness = 3 3. WBCs> 12,000 in the blood = 2 4. Positive USS findings of appendicitis = 6 Total score = 15> 8 = 96% chances

Computed TomographyCommonly used in the West5mm slices : - Sensitivity: 90% - Specificity: 80 90%RCT for 64-MDCT: 95% accuracySensitivity PROPORTIONATE TO SeverityFaecoliths/Appendicoliths detected in 50% pts of appendicits ???

Computed TomographyClassical findings: - Distended appendix > 7mm diameter - Halo/ Target sign - Periappendiceal fat stranding - Edema - Peritoneal fluid - Phlegmon - Periappendiceal abscess

Computed TomographyRational use: - Elderly - Atypical presentations - Neoplasms - Acute diverticulits - Intestinal obstruction MRI: ??

US ScansSensitivity = 85% Operator basedSpecificity > 90%AP dia appendix > 7mm CROSS SECTIONAL VIEW: - Thick walled - Non compressible luminal structure : Target LesionPeriappendiceal fluid/ Mass

Plain Abdominal X-RaysLow sensitivityAppendicoliths picked up in only 10-15% casesCan be combined with Barium enemaFailure of appendix to Fill upLow specificity 20% of normal Appendices do not fill up

Diagnostic LaparoscopySmall fraction of ptsWomen of child bearing agePrompt intervention ------- Implications on future fertility

Laboratory ExaminationsWBCs elevatedNormal in 10% casesTLC > 20,000 s/o PERFORATIONPolymorphs > 75%Minimal pyuria CommonMicroscopic haematuria

Diagnostic algorithm Surgical consultation for acute abdomen

Clinical probability of Ac appendicitis

High Intermediate Low Elderly/ unreliable/ farOperate CT/USG & reassess Local/reliable

Diagnostic algorithm

+ ve Uncertain - ve

Operate DL/admit Disc/alt

Diagnostic algorithm Elderly/unreliable/far Reliable & local

CT re-examine Discharge/ follow up