The value of ultrasonography in the diagnosis and pathological classification of appendicitis

Abstract

Objective To assess the diagnostic value of ultrasonography in the diagnosis and pathological classification of appendicitis with pathological results. Methods The study included 111 cases confirmed by surgery and pathology in the Six Affiliated Hospital of Sun Yat-sen University from June 2012 to December 2013. The image characteristics of ultrasonic images performed before surgery were analyzed retrospectively. The cases were divided into five groups based on the pathology: 6 acute simple appendicitis, 45 acute suppurative appendicitis, 15 acute gangrenous appendicitis, 33 chronic appendicitis, and 12 acute attack of chronic appendicitis. The length, width and wall thickness of the appendicitis measured by preoperative ultrasound between various pathological type were compared with Kruskal-Wallis statistical method, and also used the same method to compared the one which had statistically significance between the five groups. As in the above case, Fisher exact test was used to compare the characters of ultrasonography included gradations of the appendix, the tube cavity expansion, stercorolith, the appendiceal abscess, mergering lymph node enlargement and the appendix around effusion, if there was statistically significance, the same method was used to compare between the five groups. Results Totally 90 of 111 cases were reminded appendicitis by preoperative ultrasound, the diagnostic accuracy rate was 81.08%, including acute suppurative appendicitis 91.11% (41/45), acute gangrenous appendicitis 93.33% (14/15), acute simple appendicitis 83.33% (5/6), chronic appendicitis 60.61% (20/33), chronic appendicitis onset acute 83.33% (10/12). There were no statistical differences of preoperative ultrasound measured between various pathological type of appendicitis in length, while the appendix width measured by preoperative ultrasound of acute gangrenous appendicitis was wider than the acute simple group and chronic group, and there were statistically significance between them (P<0.05), in the aspect of wall thickness, the acute suppurative appendicitis and the acute gangrenous appendicitis groups were thicker than the chronic group, and these differences had statistically significance (P<0.05). The stercorolith, lymph node enlargement and the appendiceal abscess in different types of appendicitis had no statistical difference. There were statistically differences (P<0.05) between the acute suppurative goup, acute gangrenous group and the chronic group respectively, both in gradations of the appendix and the tube cavity expansion. Also there were statistically difference (P<0.05) between the acute gangrenous appendicitis group and the chronic group in the aspect of the appendix around effusion. Conclusions Ultrasound is valuable in the diagnosis of appendicitis, especially for acute gangrenous appendicitis and acute purulent appendicitis. The measurement of appendix with wide diameter, wall thickness by ultrasond preoperatively, and the characteristics of the wall layers, lumen expansion degree and the appendix around effusion are valuable in identifying chronic appendicitis, acute suppurative appendicitis, and acute gangrene appendicitis. The ultrasonic measurement of appendix wide diameter could identify acute gangrenous appendicitis and acute simple appendicitis. Ultrasound had limited value in identifying acute suppurative, acute gangrenous appendicitis, acute simple appendicitis, chronic appendicitis, and chronic appendicitis onset acute. Key words: Appendicitis; Ultrasonography; Pathology