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Appendix in Children with Cystic Fibrosis: US Features¹

¹ From the Departments of Radiology (S.W.L., H.C.H.) and Pediatrics (M.J.S.), Juliana Children’s Hospital, Sportlaan 600, Den Haag, the Netherlands; and Department of Radiology, Medical Centre Haaglanden, the Netherlands (J.B.P.). From the 2002 RSNA scientific assembly. Received March 7, 2003; revision requested May 5; final revision received December 6; accepted January 5, 2004. Address correspondence to H.C.H. (e-mail: h.holscher@jkz-rkz.nl).

	ABSTRACT

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PURPOSE: To evaluate the ultrasonographic (US) appearance of the appendix in children with cystic fibrosis but who were asymptomatic for appendicitis.

MATERIALS AND METHODS: Between March 2001 and March 2002, 31 children (14 boys, 17 girls; mean age, 9.5 years; range, 2–16 years) with cystic fibrosis underwent graded-compression US of the appendix. The recordings were analyzed in consensus by two radiologists specialized in US. The overall appendiceal diameter and change in diameter during graded compression, wall dimensions, contents of material in the lumen, and periappendicular fat were evaluated. The exclusion criterion was abdominal pain at the time of investigation.

RESULTS: In all but one patient, the appendix was visualized with US. The diameter of the appendix ranged from 4.0 to 14.5 mm (mean, 8.3 mm). In 25 patients (83.3%), the appendix measured more than 6.0 mm. In six patients, the diameter of the appendix changed when graded compression was applied. Mucoid material was found in the lumen in 27 of 30 patients. No wall thickening occurred, and concentric layer structures of the wall were intact. No involvement of the neighboring mesenteric or omental fat was encountered.

CONCLUSION: The appendiceal diameter was enlarged in the majority of children examined. The lumen contained mucoid contents. Therefore, the diameter of the appendix alone may not be a parameter for diagnosing appendicitis in patients with cystic fibrosis.

© RSNA, 2004

Index terms: Appendicitis, 751.291 • Appendix, US, 751.12989 • Children, gastrointestinal tract, 751.291 • Fibrosis, cystic, 74.1496, 75.1496

	INTRODUCTION

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Cystic fibrosis is a lethal inherited disorder. It is a disease characterized by exocrine dysfunction with obstructive lesions throughout multiple organ systems and disturbance of electrolyte and mucus secretion. The majority of patients initially have malabsorption, meconium ileus, meconium plug, and pulmonary disease, although a diverse variety of symptoms has been reported (1).

Lower abdominal pain is a relatively common complaint in patients with cystic fibrosis. Differential diagnostic considerations are distal intestinal obstruction syndrome and constipation, intussusception, and volvulus (2). Appendiceal disease, including acute inflammation and abscess formation, is another potential cause of abdominal pain in patients with cystic fibrosis (3).

To diagnose acute appendicitis in this specific patient population by means of ultrasonography (US), a precise and detailed knowledge of US characteristics of the noninflamed appendix in patients with cystic fibrosis is paramount. Thus, the purpose of our study was to evaluate the US appearance of the appendix in children with cystic fibrosis but who were asymptomatic for appendicitis.

	MATERIALS AND METHODS

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Patients
In the Juliana Children’s Hospital, all patients with cystic fibrosis undergo routine physical, laboratory, and radiologic examinations once a year. The radiologic examination consists of standard chest radiography and US of the upper abdomen. In this prospective study, the routine US examination was extended to the right lower quadrant, with evaluation of the appendix and the surrounding area.

The study protocol was approved by the institutional review board, and informed consent was obtained from the parents or caretakers of all patients. From March 2001 until March 2002, 31 consecutive patients with a mean age of 9.5 years (range, 2–16 years) were included. The patient population consisted of 14 boys and 17 girls. Exclusion criterion was abdominal pain at the time of the examination.

US Examination and Interpretation
Transverse and longitudinal images of the appendix were obtained by using a scanner (ATL HDI 5000; ATL, Bothell, Wash) with a 5–12-MHz linear-array transducer. Video recordings were made. All US examinations were performed by one experienced radiologist (H.C.H.). The recordings were analyzed in consensus by two radiologists (H.C.H. and J.B.P.) specialized in US for more than 10 years.

The overall diameter of the appendix was measured on images with calipers in the transverse plane. A diameter exceeding 6 mm was considered abnormal. Graded-compression technique was applied to assess the compressibility of the appendix. The presence or absence of reduction in the overall appendiceal diameter during compression was registered. Wall thickness and preservation of wall layers (mucosal, submucosal, and muscularis) were evaluated. Luminal distention and the contents of the material in the lumen were judged. Echogenic luminal distention was diagnosed as mucoid material in the appendix. Furthermore, we evaluated the extent of the involvement of neighboring mesenteric or omental fat. An echogenic signal in the periappendicular surroundings was classified as fat infiltration.

	RESULTS

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In 30 of 31 patients, the appendix was depicted with US. The mean diameter of the appendix was 8.3 mm (range, 4.0–14.5 mm). In 25 patients, the appendix diameter measured more than 6 mm. The range of appendiceal diameters is depicted in the Table. In all of these patients, mucoid impaction in the appendix was observed. Mucoid material was found in 27 patients. In six patients, the diameter of the appendix was reduced when graded-compression technique was applied. The structure of concentric layers of the appendiceal wall was preserved in all 30 patients. Thickening of the appendiceal wall was not diagnosed in any of the patients. Infiltration of the neighboring mesenteric or omental fat was not observed. Representative transverse and longitudinal views of the appendix of two asymptomatic patients with cystic fibrosis are depicted in the Figure.

View larger version (125K): [in this window] [in a new window] [Download PPT slide]   Transverse (left) and longitudinal (right) US scans of the appendix in asymptomatic 9-year-old (top) and 10-year-old (bottom) female patients with cystic fibrosis. Note the thickened aspect of the appendix (arrows) (diameter, 9 mm) in both patients. The appendices are noncompressible (compression is demonstrated by contours of the abdominal wall), concentric wall layers are intact, and the lumen is filled with mucoid material.

	DISCUSSION

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Visualization of the appendix is primarily complicated by the overlaying intestinal structures filled with air and the pronounced mobility of the appendix. Varying results are encountered in the literature. Rioux (5) reported visualization of the appendix in 82% of cases in 125 asymptomatic children and adults. Vignault et al (6) identified an enlarged appendix (diameter >6 mm) in 50% of patients clinically suspected of having acute appendicitis. In our study, the appendix was depicted with US in 30 (97%) of 31 patients with cystic fibrosis, compared with US depiction in 20% of asymptomatic patients with cystic fibrosis in the prospective study performed by Hahn et al (7). A notable fact in our investigation is the increased diameter of the appendix in 25 of 30 patients, which resulted from mucoid impaction. Wilschanski et al (2) found an abnormal appendix in only 16% of cases in 50 asymptomatic patients with cystic fibrosis. To our knowledge, no further studies have described the appearance of the appendix during routine examination of patients with cystic fibrosis.

In the literature, acute inflammation has been mentioned as a principal cause of an increased appendiceal diameter. According to widely accepted standard US (8), as well as computed tomographic, criteria (9), the appendix can be considered pathologic if it exceeds 6 mm in cross-sectional diameter. However, authors of several studies have pointed out that appendiceal enlargement as the sole criterion for the diagnosis of acute appendicitis is not reliable and valid (10). In such studies, the outer diameters of noninflamed appendices of more than 6 mm due to inspissated faecal material are registered frequently (11–13).

As demonstrated in our study, many patients with cystic fibrosis had an increased appendiceal diameter of more than 6 mm. However, all of these individuals were asymptomatic at the time of the investigation. Therefore, to prevent misdiagnosing an enlarged appendix as acute appendicitis and performing unnecessary appendectomy, it is important to be aware of the contents of the noninflamed appendix in patients with cystic fibrosis, as well as of presence or absence of periappendiceal inflamed fat, tenderness at the site of the appendix, and hyperemia at power or color Doppler US.

A limitation of the present study is that the US appearance of the mucoid content, observed in almost all studied individuals, was not validated with histologic data. However, all patients were asymptomatic and did not undergo appendectomy. Furthermore, the two experienced radiologists who analyzed the US characteristics of the appendix in our study were not blinded to the fact that all patients had cystic fibrosis. However, the results of this study are so uniform that blinding the observers presumably would not alter the outcome of the study.

In conclusion, the appendiceal diameter on US scans in patients with cystic fibrosis and asymptomatic for acute appendicitis can be more than 6 mm. We believe that diagnosis of acute appendicitis in this specific patient population should be based on other signs of inflammation, including the correspondence of the point of maximal tenderness to the appendix itself, pain during compression of the appendix, distortion of the concentric layers of the appendiceal wall, infiltration of neighboring omental or mesenteric fat, and/or free intraperitoneal fluid.

	FOOTNOTES

 
Author contributions: Guarantor of integrity of entire study, H.C.H.; study concepts and design, H.C.H., J.B.P., M.J.S.; literature research, S.W.L.; clinical studies, H.C.H.; data acquisition, H.C.H., S.W.L.; data analysis/interpretation, H.C.H., S.W.L., J.B.P.; manuscript preparation, S.W.L., H.C.H.; manuscript editing, J.B.P., H.C.H., S.W.L.; and manuscript definition of intellectual content, revision/review, and final version approval, all authors

	REFERENCES

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1. Agrons GA, Corse WR, Markowitz RI, Suarez ES, Perry DR. Gastrointestinal manifestations of cystic fibrosis: radiologic-pathologic correlation. RadioGraphics 1996; 16:871-893.[Abstract]
2. Wilschanski M, Fisher D, Hadas-Halperin I, et al. Findings on routine abdominal ultrasonography in cystic fibrosis patients. J Pediatr Gastroenterol Nutr 1999; 28:182-185.[CrossRef][Medline]
3. McCarthy VP, Mischler EH, Hubbard VS, Chernick MS, di Sant’Agnese PA. Appendiceal abscess in cystic fibrosis: a diagnostic challenge. Gastroenterology 1984; 86:564-568.[Medline]
4. Coughlin JP, Gauderer MW, Stern RC, Doershuk CF, Izant RJ, Jr, Zollinger RM, Jr. The spectrum of appendiceal disease in cystic fibrosis. J Pediatr Surg 1990; 25:835-839.
5. Rioux M. Sonographic detection of the normal and abnormal appendix. AJR Am J Roentgenol 1992; 158:773-778.[Abstract/Free Full Text]
6. Vignault F, Filiatrault D, Brandt ML, Garel L, Grignon A, Ouimet A. Acute appendicitis in children: evaluation with US. Radiology 1990; 176:501-504.[Abstract/Free Full Text]
7. Hahn H, von Kalle T, Pfadler E, Franz R, Hilz B, Farber D. Ultrasound appendix imaging in mucoviscidosis patients. Rofo Fortschr Geb Rontgenstr Neuen Bildgeb Verfahr 1999; 170:181-184.[Medline]
8. Ramachandran P, Sivit CJ, Newman KD, Schwartz MZ. Ultrasonography as an adjunct in the diagnosis of acute appendicitis: a 4-year experience. J Pediatr Surg 1996; 31:164-167.[CrossRef][Medline]
9. Rao PM, Rhea JT, Novelline RA, et al. Helical CT technique for the diagnosis of appendicitis: prospective evaluation of a focused appendix CT examination. Radiology 1997; 202:139-144.[Abstract/Free Full Text]
10. Gwynn LK. Appendiceal enlargement as a criterion for clinical diagnosis of acute appendicitis: is it reliable and valid? J Emerg Med 2002; 23:9-14.[CrossRef][Medline]
11. Benjaminov O, Mostafa A, Hamilton P, Rappaport D. Frequency of visualization and thickness of normal appendix at nonenhanced helical CT. Radiology 2002; 225:400-406.[Abstract/Free Full Text]
12. Simonovsky V. Normal appendix: is there any significant difference in the maximal mural thickness at US between pediatric and adult populations? Radiology 2002; 224:333-337.[Abstract/Free Full Text]
13. Simonovsky V. Sonographic detection of normal and abnormal appendix. Clin Radiol 1999; 54:533-539.[CrossRef][Medline]

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