APPENDICITIS
Molly Chang, OMS-III
Photo by Ed Uthman from Houston, TX, USA / CC BY 2.0
• Anatomy Review
• Causes
• Signs and symptoms
• Physical Exam
• Differential Diagnosis
• Laboratory Studies & Imaging
• Management
• Complications
Contents
Anatomy
Review
Screenshot from Essential Anatomy 5
Anatomical Position
• Tip of appendix may be found in retrocecal, subcecal,
preileal, postileal or pelvic position
• Due to these anatomic variations, the location of referred
pain may not be of the classic right lower quadrant type
Image from UpToDate
Blood Supply &
Innervation
• Blood supply from the appendiceal artery
– Terminal branch of the ileocolic which arises from
the SMA
• As part of the midgut, its parasympathetic
innervation comes from the vagus nerve
• Its visceral afferent stimulates the spinal cord at
T8 through T10
– When irritated, these nerve fibers create a vague
Image from UpToDate
periumbilical pain.
Appendiceal
Function
What is appendicitis?
• Literally, inflammation of the appendix
• ”Appendix” [organ] + “-itis” [inflammation]
Gross pathology specimen from radiopaedia.org
• Common origin theory for this inflammation is
appendiceal obstruction
• Obstruction may be due to:
– Fecalith
– Appendicolith
– Lymphoid hyperplasia
– Infectious processes
– Benign or malignant tumor
Causes
Obstruction
Increases Luminal
and Intramural
Pressure
Intramural vessel
thrombosis
Appendiceal wall
ischemia &
necrosis
• Necrotic appendiceal wall is at risk of perforation
Appendicitis
• Perforation may lead to:
– Phlegmon
Complications
– Abscess
– Diffuse peritonitis
• Common organisms in gangrenous and perforated
appendicitis include:
Bacteroides Pseudomonas
fragilis
Pepto-
streptococcus
E. coli
Signs and
symptoms
• Nausea
• Vomiting
• Anorexia
• Periumbilical abdominal pain
which later localizes to his or her
right lower quadrant
– Migratory pain only occurs in 50
Screenshot from Dr. Google to 60 percent of patients
Physical Exam
Findings
• Early on:
– General appearance
– Low grade fever (<101℉)
– Early abdominal exam may be inconclusive
Mosby's Medical Dictionary, 8th edition • Possible periumbilical pain
• As conditions progresses:
– General appearance
– High grade fever (>101℉)
– Classically, RLQ abd TTP aka tenderness at McBurney’s point
• Only occurs after inflammation spreads to involve peritoneum
– Rovsing’s sign indicates peritoneal irritation
– Psoas sign seen with retrocecal appendicitis
– Obturator sign seen with pelvic appendicitis
– Perforated appendix
– Cecal diverticulitis
– Meckel’s diverticulitis
– Pancreatitis
– Hepatitis
– Acute ileitis
– Crohn’s disease
– Gynecological and obstetrical conditions
• Tubo-ovarian abscess
• PID
• Ruptured ovarian cyst
Differential • Ovarian and Fallopian tube torsion
• Ectopic pregnancy
Diagnosis – Urologic conditions
• Torsion of testicle or of appendix testis or appendix epididymis
• Epididymitis
• Renal colic
Laboratory
WBC
CBC ●Acute − 14,500±7300 cells/microL
●Gangrenous − 17,100±3900 cells/microL
Studies
●Perforated − 17,900±2100 cells/microL
BMP
LFTs
Amylase & Lipase
Beta HCG
UA
Imaging Studies
• CT
– First identify cecum or ileocecal valve (usually has fatty
lips)
– Most appendixes come out of the cecum between 2 and
6 o’clock
• Ultrasound
• MRI
>6 mm outer diameter is a reliable measurement to
characterize appendicitis in all imaging modalities
Photo by James Heilman, MD and UpToDate
Clinical vs. Surgical • Current recommendation is that
appendectomy is treatment of choice
Management – Study of 257 patients with acute
uncomplicated appendicitis treated via
antibiotics were followed to measure
incidence of recurrent appendicitis
• 27 percent within one year of initial
presentation
• 34 percent at two years
• 39 percent at five years
• Antibiotic therapy intended for
uncomplicated nonperforated
appendicitis patients ONLY
– However, there is no reliable way to
identify these patients based on clinical,
laboratory, or radiologic data
Screenshot from UpToDate
Open Appendectomy Laparoscopic Appendectomy
• Lower rate of intra-abdominal abscess • Lower rate of wound infection
• Shorter operative time • Less pain on postoperative day one
• Shorter hospital stays
• Fewer short-term and long-term adhesive bowel obstructions
Photos from UpToDate, gettyimages, and InfoEscola
• Bleeding
• Infection
• Recurrence of problem
• Injury to anything nearby
– Ureter
– Iliac vessels
– Small bowel
– Cecum
Complications
• Martin R. Acute appendicitis in adults: Clinical manifestations and differential diagnosis.
Retrieved October 3, 2018, from
https://www.uptodate.com/contents/acute-appendicitis-in-adults-clinical-manifestations-an
d-differential-diagnosis?search=appendicitis&source=search_result&selectedTitle=3~150&us
age_type=default&display_rank=3#H5345961
.
• Jaffe BM, Berger DH. The appendix. In: Schwartz's Principles of Surgery, 8th ed, Schwartz SI,
Brunicardi CF (Eds), McGraw-Hill Companies, New York 2005.
• Bennion RS, Baron EJ, Thompson JE Jr, et al. The bacteriology of gangrenous and perforated
appendicitis--revisited. Ann Surg 1990; 211:165.
• Birnbaum BA, Wilson SR. Appendicitis at the millennium. Radiology 2000; 215:337.
• Blackbourne LH. Surgical Recall,6th Ed, Lippincott Williams & Wilkins, Baltimore 2012.
• Guraya SY, Al-Tuwaijri TA, Khairy GA, Murshid KR. Validity of leukocyte count to predict the
severity of acute appendicitis. Saudi Med J 2005; 26:1945.
• Choi D, Park H, Lee YR, et al. The most useful findings for diagnosing acute appendicitis on
contrast-enhanced helical CT. Acta Radiol 2003; 44:574.
• Salminen P, Tuominen R, Paajanen H, et al. Five-Year Follow-up of Antibiotic Therapy for
Uncomplicated Acute Appendicitis in the APPAC Randomized Clinical Trial. JAMA 2018;
320:1259.
References
• Jaschinski T, Mosch C, Eikermann M, Neugebauer EA. Laparoscopic versus open
appendectomy in patients with suspected appendicitis: a systematic review of meta-analyses
of randomised controlled trials. BMC Gastroenterol 2015; 15:48.
• Markar SR, Penna M, Harris A. Laparoscopic approach to appendectomy reduces the
incidence of short- and long-term post-operative bowel obstruction: systematic review and
pooled analysis. J Gastrointest Surg 2014; 18:1683.
• Awkwardyeti.com
• Radiopaedia.org
