Association Between Hepatobiliary Scintigraphy and Delays in Operative Management in Acute Cholecystitis

Ultrasonography (US) is the first-line imaging modality for acute cholecystitis, while hepatobiliary scintigraphy (hepatobiliary iminodiacetic acid, or HIDA, scan) is often reserved for equivocal cases. Despite its diagnostic accuracy, HIDA requires more time and resources and is often an unnecessary and overutilized diagnostic test. Despite significant advancements in medical technology and efficiency, overutilization of these tests continues. This study aimed to determine if HIDA scans continue to cause delays in patient care, with the primary objective being to evaluate the effect of HIDA scans on time to surgery (TTS) and length of stay (LOS).

We conducted a retrospective cohort study of adult patients admitted through the emergency department to a community hospital, between January 2019 and December 2020, who underwent cholecystectomy. Patients were stratified by preoperative imaging pathway: US alone versus US and HIDA. The primary outcomes were TTS and LOS. Secondary outcomes included complicated gallbladder disease, which was defined by a dilated common bile duct, elevated bilirubin, or elevated lipase indicating choledocholithiasis or gallstone pancreatitis. Independent-samples t-tests were used for group comparisons, and multivariable linear regression was performed to identify predictors of TTS.

Of 159 patients, 84 (52.9%) received US only, and 75 (47.2%) underwent both US and HIDA. Mean TTS was significantly longer in the HIDA group (68.4 vs. 54.1 hours, p=0.039). Excluding patients with complicated gallbladder disease, the difference was more pronounced (59.5 vs. 31.2 hours, p=0.001). LOS did not differ between groups overall (135.4 vs. 133.7 hours, p=0.932) or in uncomplicated cases (126.8 vs. 118.7 hours, p=0.770). In regression analysis, HIDA scan (B=0.885, p=0.001) and elevated bilirubin (B=1.011, p=0.003) were independently associated with increased TTS, while ethnicity (Hispanic, B=-0.804, p=0.021) independently predicted shorter TTS.

In this community hospital cohort, HIDA scans were associated with a significant delay in the operative management of acute cholecystitis by more than 24 hours. Our findings suggest that HIDA scans continue to prolong surgical timing despite evolving hospital workflows and thus, ordering this diagnostic test should be reserved only for equivocal cases.