Outer Diameter of the Vermiform Appendix: Not a Valid Sonographic Criterion for Acute Appendicitis in Patients with Cystic Fibrosis

Abstract

The outer appendiceal diameter of 6 mm or more cannot be considered a reliable criterion for the diagnosis of acute appendicitis in patients with cystic fibrosis.

US examination of the appendix in children with suspected appendicitis: the additional value of secondary signs

“…Secondly, there are also entities that are known to give the appendix an abnormal appearance; for example, lymphoid hyperplasia in the appendix (one patient in this study) [3,13]. Additionally, in the majority of patients with underlying cystic fibrosis, the outer diameter of the appendix is also increased [20,21]. Another pitfall is the overlooked distal inflamed appendix, when the appendix is normal at its origin, as was the case in the only false-negative US diagnosis in this study [5,13].…”

Sonographic Appearance of the Normal Appendix in Adults

“…23,24 In evaluating the appendiceal wall, some studies have measured the outer appendiceal diameter rather than appendiceal wall thickness. 18,20,25 A few factors that may affect the outer appendiceal diameter are as follows: first, in the normal appendix with a thin wall, it may be difficult to identify the intraluminal limit of the mucosal layer; second, the shape of the normal appendix greatly changes depending on the intensity of pressure applied during examination, especially with the presence of loose feces in the lumen; and third, several studies, including this one, have reported outer appendiceal diameters of greater than 6 mm in healthy subjects 16,18,20 ; thus, the diameter of the appendix alone may not be a parameter for diagnosing appendicitis. In this study, intraluminal gas in the appendiceal lumen was revealed with sonography in 75% of cases, which is a rate close to the 86% reported for a control group in a previous study.…”

Colonic Wall Redundancy at CT in Patients with Cystic Fibrosis

“…Fibrosing colonopathy, characterized by mucosal fibrosis and stricturing, has been described in patients with cystic fibrosis, and in most cases, it is associated with high-dose pancreatic enzyme supplement treatment (2)(3)(4)(5)(6). Computed tomography (CT) can depict multiple colonic manifestations of cystic fibrosis, including distal intestinal obstruction syndrome, noninflammatory enlargement of the appendix, and Crohn disease (2,3,(7)(8)(9).…”