Appendix Flashcards
What vessel provides blood supply to the appendix?
Appendiceal artery (branch of the ileocolic artery)
Name the mesentery of the appendix. What does it contain?
Mesoappendex (contains the appendiceal artery)
How can the appendix be located if the cecum has been identified?
Follow the teniae coli down to the appendix; the teniae converge on the appendix
What is appendicitis?
Inflammation of the appendix caused by obstruction of the appendiceal lumen, producing a closed loop with resultant inflammation that can lead to necrosis and perforation
Causes of appendicitis?
Lymphoid hyperplasia
Fecalith (aka appendicolith)
Lifetime incidence of acute appendicitis in the US?
~7%
Most common cause of emergent abdominal surgery in the US?
Acute appendicitis
Classical presentation of appendicitis?
Periumbilical pain (intermittent and crampy) -> N/V -> anorexia -> pain migrates to RLQ (constant and intense), usually in <24 hours
Why does periumbilical pain occur?
Referred pain
Why does RLQ pain occur?
Peritoneal irritation
What are the signs/symptoms of appendicitis?
Signs of peritoneal irritation may be present (guarding, muscle spasm, rebound tenderness, obturator, psoas signs), low-grade fever (high grade if perf occurs), RLQ hyperesthesia
Define - obturator sign.
Pain upon internal rotation of the leg with the hip and knee flexed; seen in patients with pelvic appendicitis
Define - psoas sign.
Pain elicited by extending the hip with the knee in full extension or by flexing the hip against resistance; classically seen in retrocecal appendicitis
Define - Rovsing’s sign.
Palpation or rebound pressure of the LLQ results in pain in the RLQ; seen in appendicitis
Define - McBurney’s point.
Point 1/3 from the ASIS to the umbilicus (often the point of max tenderness)
DDx for appendicitis? (everyone)
Everyone: Meckel’s, Crohn’s disease, perforated ulcer, pancreatitis, mesenteric lymphadenitis, constipation, gastroenteritis intusussception, volvulus, tumors, UTI (eg., cystitis), pyelonephritis, torsed epiplociae, cholecystitis, cecal tumor, diverticulitis (floppy sigmoid)
DDx for appendicitis? (females)
Ovarian cyst, ovarian torsion, tuboovarian abscess, mittelschmerz, PID, ectopic pregnancy, rupture pregnancy
What labs should be performed in suspected appendicitis?
CBC: increased WBC (>10000 in >90% of cases), most often with a “left shift”
UA to evaluate for pyelo or renal calculus
Can you have an abnormal UA in appendicitis?
Yes; mild hematuria and pyuria are common in appendicitis with pelvic inflammation, resulting in inflammation of the ureter
What additional tests can be performed if the dx of appendicitis is not clear?
Spiral CT, U/S (may see a large, non-compressible appendix or fecalith)
In acute appendicitis, what classically precedes vomiting?
Pain (in gastroenteritis, the pain classically follows vomiting)
What radiographic studies are often performed?
CXR to rule out RML or RLL pneumonia, free air
AXR: abdominal films are usually non-specific, but calcified fecalith present in ~5% of cases
What are the CT scan findings with acute appendicitis?
Periappendiceal fat stranding, appendiceal diameter >6 mm, periappendiceal fluid, fecalith
Preoperative prep for appendicitis?
Rehydration with IV fluids (LR)
Preoperative ABX with antibiotic coverage (appendix is considered part of the colon)
Rx for non-perforated acute appendicitis?
Prompt appendectomy to prevent perforation, 24 hours of ABX, discharge home usually on POD #1
Rx for perforated acute appendicitis?
IV fluid resuscitation
Prompt appendectomy
All pus is drained with post-op ABX continued for 3-7 days; wound left open in most cases after closing the fascia (heal by secondary intention or delayed primary closure)
How is an appendiceal abscess that is diagnosed pre-operatively treated?
Percutaneous drainage of the abscess, antibiotic administration, ad elective appendectomy ~6 weeks later
If a normal appendix is found upon exploration, should you take out the normal appendix?
Yes
How long after removal of a non-ruptured appendix should ABX continue post-operatively?
24 hours
Which antibiotic is used for non-perforated appendicitis?
Anaerobic coverage -> cefoxitin, cefotetan, unasyn, cipro, flagyl
Which antibiotic is used for a perforated appendix?
Broad-spectrum ABX (eg, amp/cipro/clinda, Zosyn)
How long do you give ABX for perforated appendicitis?
Until the patient has a normal WBC count and is afebrile, ambulating, and eating a regular diet (usually 3-7 days)
What is the risk of perforation?
~25% by 24 hours from onset of symptoms, 50% by 36 hours, 75% by 48 hours
What is the most common general surgical abdominal emergency in pregnancy?
Appendicitis (~1/1750); appendix may be in the RUQ because of the enlarged uterus
Possible complications of appendicitis?
Pelvic abscess
Liver abscess
Free perforation
Portal pylethrombophlebitis (very rare)
What % of negative appendectomies is acceptable?
Up to 20%
Who is at risk of dying from acute appendicitis?
Very old and very young patients
What bacteria are associated with mesenteric adenitis that can closely mimic acute appendicitis?
Y. enterocolitica
What are the layers of the abdominal wall during a McBurney incision?
Skin Subcutaneous fat Scarpa's fascia External oblique Internal oblique Transversus muscle Transversalis fascia Preperitoneal fat Peritoneum
If you find Crohn’s disease in the terminal ileum, will you remove the appendix?
Yes, if the cecal/eappendiceal base is not involved
If the appendix is normal, what do you inspect intraoperatively?
Terminal ileum: Meckel’s diverticulum, Crohn’s disease, intussusception
Gyne - cysts, torsion, etc
Groin - hernia, rectus sheath hematoma, adenopathy (adenitis)
What is the most common appendceal tumor?
Carcinoid tumor
What s the treatment of appendiceal carcinoid <1.5 cm?
Appendectomy (if not through the bowel wall)
Rx appendiceal carcinoid >1.5 cm?
R hemicolectomy
What percentage of appendiceal carcinoids are malignant?
<5%
DDx - appendiceal tumor?
Carcinoid
Adenocarcinoma
Malignant mucoid adenocarcinoma
What type of appendiceal tumor can cause the dreaded pseudomyxoma peritonei if the appendix ruptures?
Malignant mucoid adenocarcinoma
