Appendix Flashcards
What is the appendix?
blind muscular tube at the base of the cecum
base is fixed at confluence of the 3 tenia coli of the cecum
What is the most common position of the appendix?
- retrocecal (74%)
- pelvic (20%)
What is the function of the appendix?
- immunity
- gut flora regulation
- appendectomy protective against ulcerative colitis
What is the normal size of the appendix?
7.5-10cm
<6mm in diameter
What is the most common cause of acute abdomen in young adults?
appendicitis
- common in childhood & early adulthood
- peaks in teens & early 20s
What are the causes of appendicitis?
- decreased dietary fibers
- increased consumption of refined carbohydrates
- bacterial proliferation (E. coli)
- obstruction of lumen (ficolith, stricture, cecal carcinoma, intestinal parasite)
What is the pathogenesis of appendicitis?
aggregating factor -> mucosal inflammation & lymphoid hyperplasia -> obstruction of lumen -> edema & mucosal ulceration -> bacterial translocation to submucosa -> venous obstruction & ischemia -> bacterial invasion of muscularis propria -> ischemic necrosis -> gangrene & perforation -> peritonitis
how does an appendiceal mass form?
adherence of greater omentum
- leads to phlegmon, appendicial mass, paracecal abscess
What are the risk factors for appendiceal perforation & peritonitis?
- extremes of age
- immunosuppression
- diabetes mellitus
- fecolith obstruction
- pelvic appendix
- previous abdominal surgery
DO NOT DELAY SURGERY
what are the symptoms of appendicitis?
- periumbilical colicky pain
- pain shifting to right iliac fossa, sharper
- anorexia
- nausea +- vomiting
- suprapubic discomfort & tenesmus
- low grade fever (if high grade -> peritonitis)
- diarrhea
- RUQ pain in pregnancy
What are the signs of appendicitis?
- low grade fever
- RIF tenderness (McBurney’s point)
- rebound tenderness
- guarding
- Rovsing’s sign (push on one side pain felt on the other)
- Psoas sign (hip extension causes pain)
- obturator sign
Where is McBurney’s point?
between ASIS & umbilicus
lateral 1/3 & medial 2/3
What is the DD of appendicitis?
in children:
- gastroenteritis
- mesenteric adenitis
- Meckel’s diverticulitis
in adults:
- regional enteritis
- ureteric colitis
- perforated peptic ulcer (valentino sign)
- torsion of testis
- ectopic pregnancy
- pancreatitis
- pyelonephritis
in elderly:
- diverticulitis
- intestinal obstruction
- colonic carcinoma
What is the Alvarado score?
score of 7 or more is highly predictive of acute appendicitis Migratory pain 1 Anorexia 1 Nausea & vomiting 1 Tenderness RIF 2 Rebound tenderness 1 Elevated temperature 1 Leucocytosis 2 Shift to left 1
What are the investigations that should be done for suspected appendicitis?
- CBC
- urinalysis
- pregnancy test
- urea & electrolytes (hypokalemia hypochloremia)
- ULTRASOUND
- CT with contrast
When should an ultrasound be preformed & what will be its findings?
- in young females
- in children
- in low Alvarado score
findings:
- non compressible distended (>6mm) appendix
- fluid around appendix
- target sign
When should CT be preformed & what are its findings?
- obese
- elderly
- urgent cases iff <18 year olds
findings:
- distended edematous appendix
- periappendiceal fat stranding
- perforation
- abscess
How should appendicitis be treated?
- if an appendicial mass is felt -> conservative & antibiotics till mass gets smaller
(cephalosporin & metronidazole) for 1-2 weeks then surgery after 3 months - appendectomy
What are the post-op complications?
- wound infection
- intra-abdominal abscess
- ileus (esp after peritonitis)
- portal pyemia/pylephlebitis
- fecal fistula (V. common in Crohn’s so do right hemicolectomy instead)
- DVT, adhesions…..
where do carcinoid tumors most commonly arise in GI tract?
- in terminal ileum & appendix
- rarely metastasize
- asymptomatic due to hepatic metabolism of serotonin
What are the signs of metastatic carcinoid tumors?
Carcinoid syndrome
- diarrhea & abdominal cramps
- cutaneous flushing
- tachycardia & fluctuating blood pressure if severe
- dyspnea, wheezing (asthma like due to histamine)
- palpitations
What investigations should be done to confirm presence of carcinoid tumor?
- CHROMOGRANIN-A (hallmark)
- 24h-urinary 5 HIAA
- octreotide scan
- CT/MRI abdomen
How is an appendiceal carcinoid tumor treated?
appendectomy UNLESS: - cecum is involved - >2cm - lymph node is involved do right hemicolectomy
What is the classification of epithelial neoplasia of the appendix?
ADENOMA
- tubular -> benign
- tubulovillous -> borderline
- villous -> precancerous
NON-MUCINOUS ADENOCARCINOMA -> right hemicolectomy
MUCINOUS NEOPLASM
- low grade (LAMN) -> benign
- if it perforates -> pseudomyxoma peritonei (PMP)
- high-grade (HAMN)
- mucinous adenocarcinoma
ADENOCARCINOMA with <50% Signet rings
SIGNET RING CARCINOMA >50% (worst)
What is the pathophysiology of PMP?
slow leak or sudden release of mucus -> free mucinous epithelial tumor cells in peritoneal cavity -> cells continue to proliferate -> mucinous ascites
- progressive peritoneal tumor deposits
- mucinous ascites
- omental cake
- ovarian involvement in females
How does PMP present?
- progressive massive abdominal distension JELLY BELLY
- anorexia
- symptoms of bowel dysfunction or intestinal obstruction
- ovarian mass causing lower abdominal/pelvic pain
What investigations should be done for epithelial appendiceal tumors?
- colonoscopy
- CA 125, CA 19-9, CEA
- CT abdomen & pelvis
How should epithelial appendicial tumors be managed?
NO PMP
- low grade, non-mucinous, localized to appendix -> appendectomy + surveillance for 5 years
- high grade, invasive adenocarcinoma, goblet cell tumor, mucinous -> right hemicolectomy + prophylactic regional peritonectomy, omentectomy +/- HIPEC +/- prophylactic bilateral oophorectomy
PMP:
- cytoreductive surgery (CRS) + HIPEC
