HIDA scan ejection fraction does not predict sphincter of Oddi hypertension or clinical outcome in patients with suspected chronic acalculous cholecystitis

Abstract

Hepatobiliary iminodiacetic scan with ejection fraction (HIDA EF) is used to evaluate chronic acalculous cholecystitis (CAC). A presumed etiology of CAC is sphincter of Oddi hypertension (SOH). In this study, we evaluated the value of HIDA EF to predict patient response to laparoscopic cholecystectomy and to identify SOH. A prospective study of 93 patients with biliary pain but without gallstones (CAC) who underwent preoperative HIDA EF was conducted. At laparoscopic cholecystectomy, transcystic antegrade biliary manometry was performed to determine the SO pressure. Patients were evaluated postoperatively for response to cholecystectomy. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. The outcomes were compared with the clinical impression. Of the 93 patients with both HIDA EF and SOP measurements, 50 had abnormal EF (< 35%); of these, 29 had SOH (SO pressure > or = 40 mmHg). Of the 43 patients with normal HIDA EF, 30 had SOH. The sensitivity was 49%, specificity 38%, PPV 58%, and NPV 30%. Eighty-six of the 93 patients returned for follow-up evaluation. Follow-up ranged from 0 to 99 months, with a mean of 26.4 months. Overall, 73 patients (85%) improved. Of the 46 with abnormal HIDA EF, 42 (91%) improved. Of the 40 patients with normal HIDA EF, 31 (77.5%) improved. The sensitivity was 57.7%, specificity 69.2%, PPV 91.3%, and NPV 22.5%. Although the PPV of abnormal HIDA EF is high, it is not much better than the clinical impression. The sensitivity and specificity are marginal. The NPV is poor. Based on the review of these 93 patients, HIDA EF is not reliable for identifying CAC. We recommend that patients with normal HIDA EF have additional testing or consultation before ruling out CAC. HIDA EF does not predict SOH.