|ECR 2018 / C-1597|
|Grading system for acute appendicitis using CT scan: imagenological characterization and its surgical and anatomopathological correlation.|
Acute appendicitis is the most common cause of acute surgical abdomen. It can affect all age groups, with a predilection for the population between 10 - 30 years old, and with greater risk for the male gender [1,2].
Anatomically, the cecalappendix is a blind intestinal loop measuring between 3-20 cm in length and less than 6 mm in transverse diameter. It usually originates in the posteromedial wall of the cecum, 2-3 cm inferior to the ileocecal valve . Its position has been described as retrocecal, subcecal, pelvic and peri-ileal; the first being the most common [3,4].
The primary pathogenic event is the intraluminal obstruction that can occur due to fecalith (appendicolith), lymphoid hyperplasia, foreign body, parasites or neo-formative processes [1,5]. This obstruction conditions the accumulation of fluid and secretions in the lumen of the appendix, with subsequent bacterial proliferation, and inflammation of the wall and the surrounding tissues that lead to an increase in endoluminal pressure, and at the same time, generates a decrease of blood perfusion that triggers ischemia, gangrene and, finally perforation .
The diagnosis of this pathology is clinical and has a variable accuracy between 71% -97%, according to the form of presentation and the experience of the attending physician . Currently, imaging techniques such as ultrasound and CT have substantially increased the precision in the diagnosis of atypical clinical pictures and are useful in the differential diagnosis of other pathologies. CT is considered the gold standard technique for the diagnosis of this entity with a high sensitivity (87-99%) and specificity (92-99%) [2,5,6] as well as a high positive (96%) and negative predictive value (95%) .
The main findings found in CT during an appendiceal process can be divided into 3 categories [1,5-8]:
1. Appendicular changes
a. Diameter> 6 mm
b. Presence of appendicolith
c. Thickening of the cecum wall> 2 mm
d. Reinforcement of the wall after intravenous contrast
e. Submucosal edema or stratification which configures the sign of the "target".
F. Alteration of peripendicular fat
g. Liquid collection or periappendiceal abscess
h. Intraluminal gas
2. Apical cecalchanges
a. Cecalfocal thickening
b. Arrowhead sign
3. Inflammatory changes in the lower right quadrant of the abdomen
a. Distal focal thickening of the ileal wall
b. Focal thickening of the sigmoid wall
c. Locoregional adenopathies
d. Extraluminal gas
e. Visualization of abscess
F. Extraluminal appendicolith
An important aspect of the diagnosis of acute appendicitis is the identification of any associated complication, such as perforation. This occurs in 19-35% of cases and is associated with an increase in morbidity and mortality before and after surgery [1,7]. Is because of this that preoperative identification is important to select an appropriate therapeutic approach.