Clinical implications of hepatobiliary scintigraphy and ultrasound in the diagnosis of acute cholecystitis.

Background: We assess the performance of ultrasound (US) and hepatobiliary scintigraphy (HIDA) as confirmatory studies in acute cholecystitis (AC) and demonstrate our current imaging protocol's impact on outcomes.

Study Design: Between January 2013 to July 2014, 117 patients were admitted through the emergency room with a preliminary diagnosis of AC. Overall, 106/117 (91%) of the patients received US preadmission and 34/117 (29%) received a HIDA post admission. Primary end points included: 1) diagnostic test reliability for AC, and 2) outcome and quality measures (time to surgery, LOS, costs, etc.).

Results: Laparoscopic cholecystectomy was performed in 96/117 (82%) and open cholecystectomy in 21/117 (18%) of the patients. Overall, histopathologic features consistent with AC was present in 46/117 (39%). AC alone was present in 23/117 (20%), and AC superimposed on chronic cholecystitis was present in 23/117 (20%). For AC, US had a sensitivity and specificity of 26% and 80%, respectively. HIDA scan had a sensitivity and specificity of 87% and 79%, respectively. Time to surgery (TTS) was 4 vs 2.3 days in patients who received HIDA vs US alone (p = 0.001), and length of stay (LOS) was 6.7 vs 4.3 days, respectively (p = 0.001). Age >50 years, glucose >140 (mg/dl), and WBC count >10 (×10 /L) were statistically significant independent variables associated with AC.

Conclusion: HIDA scan is superior to US as a diagnostic study in the setting of AC. Our current protocol of delayed HIDA (post-admission) was associated with increased TTS, LOS, and overall costs. Early confirmation with HIDA in high risk patients may hasten treatment allocation and improve outcomes in the setting of AC.