[Radiological support for diagnosis of acute appendicitis: use, effectiveness and clinical repercussions]. / Empleo, eficacia y repercusión clínica del apoyo radiológico al diagnóstico de la apendicitis aguda.

ABSTRACT

OBJECTIVE: The aim of this study is to analyze the increasing need of radiological support in the diagnosis of acute appendicitis (AA), the clinical repercussions associated, and the parameters of diagnostic accuracy of ultrasound and computed tomography (CT) scan for AA. MATERIAL AND METHODS: Observational and analytical study. Cohort, patients operated on for suspected AA at a tertiary referral hospital. Pregnancy and <14 years were exclusion criteria. STUDY GROUP January 2010-December 2011 (n1=419). CONTROL GROUP set of patients aged 18 to 65 years old operated between October 2001-September 2003 (n2=237). Variables analyzed in both groups 1) percentage of radiological support for diagnosis of acute appendicitis; 2) sensitivity and positive predictive value (PPV) of ultrasound and CT scan; 3) rate of surgical explorations with negative result or with diagnosis other than acute appendicitis. STATISTICAL ANALYSIS: SPSS software, χ(2) test, statistical significance accepted with P<.05, 95% confidence interval (95% CI) for the odds ratio (OR). RESULTS: Age, gender, percentage of atypical locations and gangrenous/perforated episodes were similar in both groups. The number of radiological examinations needed for diagnosis was significantly higher in the study group (78.8% vs. 30.4%, P<.0,000). Sensitivity was significantly superior for CT than for ultrasound scan (97% vs. 86%), but PPV was similar in both tests (92% vs. 94%). Surgical exploration percent values with diagnosis of acute appendicitis was significantly higher in the study group (94.5% vs. 88.6%; P<.006, OR 2.2; CI 95% 1.25-4). CONCLUSIONS: CT and ultrasound scan are excellent diagnostic tools for acute appendicitis, and have contributed to a significant increase in surgical explorations with correct diagnosis.