Appendicitis

APPENDICITIS

APPENDICITISLazaro, GennieleneLlopis, ApleLoluquisen, RogelioAnatomy of AppendixAverage Length: Adult varies from 30 cm, average 6-9 cm. Outside diameter: 3-8 mm Luminal diameter:1-3 mm. Luminal Capacity: 0.1ml > Tip-located anywhere in the right lower quadrant of the abdomen or pelvis. > Base-located by following the longitudinally oriented taenia coli to their confluence at the cecum.Blood Supply:Arterial - from the appendicular branch of the ileocolic artery. It originates posterior to the terminal ileum, entering the mesoappendix close to the base of the appendix. A small arterial branch arises at this point that runs to the cecal artery. Lymphatics - flows into lymph nodes that lie along the ileocolic artery. Innervation-derived from sympathetic elements contributed by the superior mesenteric plexus (T10L1), afferents from parasympathetic elements brought in via the vagus nerve.

Histological features :Muscularis layer - not well defined; deficient in some locations.Submucosa and mucosa (+) lymphoid aggregates, (+) or (-) germinal center; Lymph vessels are prominent.Mucosa same like large intestine, except for the density of the lymphoid follicles. Crypts of Lieberkuhn - irregular sized and shape. Neuroendocrine complexes (ganglion cells, Schwann cells, neural fibers, and neurosecretory cells) positioned just below the crypts. Serotonin - prominent secretory product; mediating pain arising from the noninflamed appendix. These complexes may be the source of carcinoid tumors, for which the appendix is known to be the most common site of origin.

Function: may play a role in immune surveillance. The mucosa of the appendix, like any mucosal layer, is capable of secreting fluid, mucin, and proteolytic enzymes.Diseases of Vermiform AppendixAcute AppendicitisEtiology: low fiber diet (contribute to changes in motility, flora, or luminal conditions that predispose to development of fecaliths)Pathogenesis: OBSTRUCTION(+) fecalith(-) fecalith: hyperplasia of lymphoid tissue in the mucosa and submucosaNeoplasm (carcinoma/carcinoid tumor) or foreign body ~2%

Acute AppendicitisLocal Changes within the AppendixRIR - mediated by the mesothelium and blood vessels in the parietal peritoneum and serosa of nearby visceral structures formation of walled-off, periappendiceal abscess.8ROLE OF NORMAL COLONIC FLORA

Natural Hx and Complications24-36h average time from onset of symptoms to perforationComplications are observed in the very young and very old patients.

Complication ManagementSpreading peritonitisAntibiotics, appendectomy

Abscess Abdominal Retroperitioneal

Antibiotics, appendectomyPercutaneous drainage reserved for poor surgical risk patients; interval appendectomy in 6 weeksrecommendedIntestinal ObstructionAntibiotics, Appendectomy

Bacteremia/systemic Antibiotics, appendectomy, orsepsis percutaneous drainage of appendiceal abscess until acute episode resolvesFistula Abdominal WallAntibiotics until acute episode resolved, then bladder intervalappendectomy and closure ofFistula Liver AbscessBroad-spectrum antibiotics;percutaneous drainage of liverand appendiceal abscess;interval appendectomy PyelophlebitisBroad-spectrum antibiotics; systemicanticoagulation; percutaneousdrainage of liver and appendicealabscesses; interval appendectomyClinical Presentationonset - crampy (colicky) abdominal pain (attributable to the initial response of the muscularis of the appendix (or any hollow-lumen organ) to obstruction. >Pain--diffuse or perhaps centered about the umbilicus, because the appendix arises from the midgut, an embryonic midline structure that derives its innervation from autonomic afferents related to the spinal cord centered around T10.Pain does not radiate, nor do the patients describe it as being exacerbated by changes in body position, meals, urination, or defecation. As the response to luminal obstruction evolves to include luminal distension, intramural edema, and ischemia, the pain becomes constant. Fever (rarely occurs early in the appendicitis syndrome and usually appears after the time when localizing tenderness appears)Pain and tenderness localized to the area of parietal peritoneum overlying the inflamed tissue (phlegmon).Inflamed portion (usually the tip) is not located near the parietal peritoneumplace of maximal tenderness is not necessarily in the right lower quadrant.No localizing area of tenderness when the appendix is located in a retroperitoneal or retroileal position or in the true pelvis.

12Three Diagnostic ManeuversLaboratory Findings

Goalto exclude ureteral stones (hematuria); to evaluate the possibility of UTI(pyuria, bacteruria) as a cause of lower abdominal pain, particularly in elderly diabetic patients.

14Imaging StudiesDifferential DiagnosisInflammatory Bowel DiseaseMeckels DiverticulumEctopic PregnancyEndometriosisGastroenteritisPelvic Inflammatory DiseaseRenal CalculiUTI (both female and male)EP: R/O high HCG level and pelvic massIBD: r/o vomiting, nausea and anorexiaGE: hyperperistaltic abdominal cramps; no localized pain (diffuse)MD: rule of 2s17Treatment and MgtPreoperative: restore fluid balance, esp in the very young and in aged patients. Patient should be well hydrated, manifested by good urine output. NGT is passed for decompression of stomach to minimize vomiting during induction of anesthesia.Antipyretics and external cooling may be needed since hyperpyrexia may complicate anesthesia.

Perforated AP: IV fluid resuscitation and prompt appendectomy; all pus is drained with postoperative antibiotics continued for 3-7 days.Nonperforated AP: prompt appendectomy, 24 hours of antibiotics, discharge home usually on POD #1

Types of AppendectomyOpen vs LaparascopicPostoperative CareFluid balance maintained by IV administration of LRS.Patient is permitted to sit up for eating on the day of operation and may get out of bed on first postoperative day.Sips of water may be given as soon as nausea subsides. Diet is gradually increased.(+) evidence of peritoneal sepsis: frequent doses of Antibiotics. Constant gastric suction until all evidence of peritonitis and abd distention has subsided. Accurate estimate of fluid intake and output must be made.Possible ComplicationsAbscessWound infectionPerforationBowel obstruction

PrognosisOverall Mortality: 0.2-0.8%Mortality in children: 0.1-1%>17 y/o: > or = 20%Mortality of uncomplicated AP: 0.6%Attributable to complicationsSpecial ConsiderationsCorrect Preoperative Dx is difficult: elderly are susceptible to malignancy and other processes that are in the differential diagnosisIt is reasonable to be diagnostically aggressive (i.e., use CT scan) to establish the diagnosis or to identify other pathology and to move as quickly as possible to the appropriate intervention.

23Perforation is more common in the last trisemester, presumably because of delays in seeking treatment and delays in recognition of the need for surgery;

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