During a 16-month period,
we retrospectively retrieved and reviewed sonographic examinations performed on 68 pregnant women with clinically suspected acute appendicitis.
(Sep.
2008 – Feb.
2010).
Study subjects' average age was 27.3,
with an average gestational age of 26 weeks.
All patients had abdominal pain.
Sonography was the first imaging modality employed.
Surgery or clinical follow-up was the gold standard for the evaluation of sonographic performance.
The scan was performed on a SIEMENS Acuson 2000 Diagnostic Ultrasound System with 4C1 & 9L4 transducers (Multi-D).
All examinations were performed using gray-scale graded compression in the left lateral decubitus position for detecting an enlarged appendix.
Since a report by Puylaert et al [4] of a graded compression sonographic technique to diagnose acute appendicitis,
several studies have validated the high sensitivity and specificity of sonography [5-6].
The normal appendix is a blind ended,
aperistaltic,
tubulal structure with wall thickness less than 2 mm and a diameter less than 6 mm,
originating from base of the cecum,
and is compressible and displasable (refer to Figure 1).
The sonographic criteria for acute appendicitis were: detection of a noncompressible,
blind-ended,
tubular,
multilayered structure measuring greater than 6 mm in maximal diameter (refer to Figures 2-4).
We considered the sonographic findings nondiagnostic if the cecum could not be adequately visualized or compressed,
due to significant enlargement of the gravid uterus or marked obesity. Additional relevant findings,
such as the presence of enlarged regional lymphatic nodes,
pericecal or periappendiceal free fluid, cecal wall edema with highly echogenic mesenteric fat,
an appendicolith that appears as echogenic focus with acoustic shadowing, were variably detected (refer to Figures 5-7).
If an appendix was not visualized and there were no secondary signs to suggest appendicitis,
the findings were considered negative
Technique of sonographic examination:
The area examined comprised the abdomen and the pelvis.
First,
a convex 3-5 MHz transducer was used for exclusion of alternative abnormalities of the liver,
gallbladder,
kidneys,
pelvic organs,
or presence of peritoneal fluid.
Then,
we swapped to a 5-12 MHz linear transducer,
with graded compression to the right abdomen,
directed to the site of maximal tenderness.
Transverse and longitudinal views were obtained on supine and left decubitus positions.
The examination of each patient took an average of 10 minutes.