Distinct sonographic features of acute appendicitis in sickle cell disease

BACKGROUND AND OBJECTIVES: The purpose of this study was to report sonographic findings of appendicitis in patients with positive screening tests for sickle cell compared to normal control patients. DESIGN AND SETTING: A retrospective study of the medical records of 396 patients who underwent appendectomy during a 3-year period from March 2005–2008. PATIENTS AND METHODS: The study included 216 males and 180 females, whose ages ranged from 7 to 55 years. Four patients (0.9%) had sickle cell disease (SCD), 101 had sickle cell trait (SCT) (25%) and 291 (74%) patients were without sickle cell anemia (control group). RESULTS: Positive sonographic findings of appendicitis were identified in 95 (90%) SCT patients and in 253 (87%) control patients. The mean maximal mural thickness was higher in sickle cell patients (4.5 [1.4] mm) in comparison with the control group (3.0 [2.2] mm) (P<.0001). Appendicolith was significantly detected in 53% of the control group and in 8.5% of the sickle cell group (P<.0001). Color Doppler showed hypervascularity in 72% of patients with appendicitis in the control group with a significant difference compared to only 12 cases (11%) of SC patients (P<.05). Ultrasonography findings suggesting perforation were found in 35 sickle cell patients and in 75% (3 of the 4 patients) with SCD. Findings suggesting perforation were found only in 49 patients (17%) of the control group. Perforated appendix was significantly higher in sickle cell patients in preoperative US and intraoperatively ( P<.05) CONCLUSION: Positive sonographic findings of appendicitis in sickle cell patients are different from the general population. These findings include mural thickening with a low incidence of appendicolith and wall hypervascularity. Also sonographic features of perforation in sickle cell patients are more common suggesting a need for more urgent operative intervention.