HEPATIC ABSCESS

ACUTE APPENDICITIS

DR.SYED UBAID ASSOCIATE PROFESSOR OF SURGERY

IntroductionVestigeal organSurgical importance: Propensity for inflammationMost important cause of Acute Abdomen in young adultsAppendicectomy is most common surgery performed worldwide

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History Recognition as clinical entity Reginald Fitz perforating inflammation of the vermiform appendixCharles McBurney described the clinical manifestation the point of max. tenderness in the right iliac fossa

AnatomyPresent only in humans,At birth: Short & broad at its junction 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

AnatomyThe three taeniae coli converge at the junction of the cecum with the appendix and can be a useful landmark to identify the appendix.The appendix can vary in length from 30 cm; most appendices are 6 to 9 cm long.

ANATOMY

Microscopic anatomyLayers: - Mucosa - Submucosa - Muscularis - Serosa

Anatomy

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

Etiology No unifying hypothesis Bacterial proliferationInitiating event is controversialObstruction of appendix lumenFaecolith or fibrotic strictureWorm infestations: Oxyuris vermicularisNeoplasms: Ca caecum, carcinoidsViralNo luminal obstruction Low dietary fibre

A faecolith (sometimes referred to as an appendicolith) is composed of inspissated faecal material, calcium phosphates, bacteria and epithelial debris

Pathological sequence

Pathological sequence

Pathological sequence

Pathology Continued mucous secretion and inflammatory exudation intraluminal pressure obstructing lymphatic drainage. Edema and mucosal ulceration develop with bacterial translocation to submucosa . Further distention may cause venous obstruction and ischcemia of the appendix wall. Bacterial invasion through muscularis externea producing acute appendicitis. Ischaemic necrosis of appendicular wall gangrenous appendix bacterial contamination of peritoneal cavity.

Pathology cont. Greater omentum becomes adherent to inflamed appendix paracaecal abscess Extremes of age Immunosuppression Faecolith obstructionPelvic appendixPrevious abdominal surgery

Pathology cont.

Pictorial ExplanationAppendiceal obstruction/early appendicitis visceral peritoneal irritation

Appendiceal distension

Irritation of parietal peritoneum (localised)

Perforation, localised/generalised peritonitis, mass

obstructionDistentionmucusDistention causingIschemiaGangrene

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

Two clinical syndromes of acute appendicitis can be discerned, acute catarrhal (non-obstructive) appendicitis and acute obstructive appendicitis, the latter characterised by a more acute course.

The classical history

AnorexiaNausea

Abdominal painVisceral abdominal painSomatic abdominal painreferred abdominal

Visceral abdominal painVisceral abdominal pain, organs, visceral peritoneum, mesentery 1-distention of a hollow viscus 2-ischemia to a viscus 3-inflammation Referred to midline embryological development

Relevant Anatomy

costalmargin

umbilicusASISPubicsymphisisT6T10T12

unpairedPaired organs

4. Innervation of appendix & other organsForegut(inc. duodenum)Midgut(inc. appendix)HindgutLower urinary tractSexual organs

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3/4/201733Colicky painColicky pain form of visceral pain rhythmic pain resulting from smooth muscle spasm as a reaction to luminal obstructionintestinal obstruction, passage of gallstone in biliary ducts, ureteric colic Often thought to be indigestion, constipation and is frequently ignored. Lasts for a variable period, usually few hours / 2 or 3 days, rarely longer

3/4/201734Referred painThe vague referred pain in the periumblicalstretching of the lumen or spasm. The visceral innervation comes from the 10th thoracic spinal segment. Accompany the sympathetic nerves through the superior mesenteric plexus and the lesser splanchnic nerve If the visceral innervation is higher, then the mid-line pain will be higher. Testicular pain due to visceral referral of afferent nerve impulses to the same spinal segment

3/4/201735Somatic painSkin, fascia, muscle and parietal peritoneumSever and precisely localized Inflamed parietal peritoneum cutaneous hyperesthesia and tenderness The right iliac fossa pain is due to the irritation of parietal peritoneumsomatic pain as opposed to earlier visceral.

3/4/201736Guarding and rigidityGuarding is the protective phenomenon abdominal muscles increase in tone attempts to localize the inflammationThere is tenderness causing the patient to constantly tense the abdominal wall muscles in palpation Voluntary guarding /apparent guarding Involuntary guarding /true guardingMuscular spasm rigidity localized initially progressing to generalized with perforation or increasing peritonitis

3/4/201737Tenderness Tenderness: localised over McBurney's point not evident before later inflammation of serosa and parietal peritoneum often masked in obese due to inability to displace viscusBlumbergs sign The pain is elicited with pressing the abdominal wall deeply with fingers and abruptly releasing it.

3/4/201738ReflexesVisceral afferent fibers participate in reflex activities. Reflex sweating, salivation, nausea, vomiting and tachycardia may accompany visceral pain.Carried by autonomic nerve fibers

3/4/201739Signs lying still, with shallow breaths and reluctant to cough fever 37.5-38.5C, worsening with perforation Foetor oris - halitosis Furred tongue Flushedinfrequently, diarrhoea: early and transient as a result of visceral pain later if retroileal or pelvic involvement appendix; this is typically prolonged and mucoidconstipation - sometimes for a few days before the attack

3/4/201740Signs to elicit in appendicitisPointing signRovsings signPsoas signObturator sign

3/4/201741Pointing sign

3/4/201742Psoas sign

3/4/201743Obturator sign

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

Typical PresentationDull, crampy central abdo painMalaise/vomiting/anorexia/low grade feversPain worsens & localises to RIF with cough/movement tendernessSystemic symptoms

Early AppendicitisPain:Location: Periumbilical (T10)Character: DullOver time: ColickyAssociated symptoms:VomitingAnorexia

obstructionmucusdistention

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Later AppendicitisPain:Location: R Iliac FossaCharacter: LocalisedOver time: ConstantAggravating: going over bumps, coughing, walkingRelieving: hip flexion, staying stillExam findings:peritonismGuardingrebound tendernesspercussion tendernessRovsing, psoas, other signs

Distention causingischaemiaLocalised peritonealinflammation

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Late AppendicitisPain:Location: lower abdominal/generalisedCharacter: diffuse, severeOver time: constantAggravating: movement, coughing, palpation, reboundAssociated: FeverExam findings:Systemic features- fever, tachycardia, hypotensionAbdominal severe, generalised peritonismRIF mass (sometimes)

Gangrene

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Time Course

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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