Scintigraphy versus manometry in patients with suspected biliary sphincter of Oddi dysfunction

Abstract

Introduction: Sphincter of Oddi (SO) manometry is at present the "gold standard" investigation for patients with suspected biliary SO dysfunction. Non-invasive scintigraphy in cholecystectomised patients using a complex scoring system or the transit time from the hepatic hilum to the duodenum (HDTT) have been promoted as sensitive and specific alternatives.

Aim: To evaluate the scintigraphic scoring system and HDTT in patients with suspected biliary SO dysfunction undergoing SO manometry.

Methods: Cholecystectomised patients undergoing SO manometry for persistent biliary-type pain, as defined by the Rome II criteria, for which all other causes had been excluded, were prospectively studied. Scintigraphy with cholecystokinin octapeptide infusion was performed within a month prior to manometry. Scoring of the scans and measurement of HDTT was performed by independent blinded observers. Manometry of the biliary sphincter was performed per-endoscopically and defined as abnormal if basal pressure was > or = 40 mm Hg.

Results: Thirty two patients were enrolled (30 females, mean age 45.1 years). Three patients were excluded from analysis because manometry from the bile duct was not technically possible. Eight patients had abnormal manometry. Scintigraphic scoring had a sensitivity of 25-38%, a specificity of 86-89%, positive predictive value (PPV) of 40-60%, and a negative predictive value (NPV) of 75-79%. The coefficient of variation for interobserver variation in scores was 0.72. HDTT sensitivity was 13%, specificity 95%, PPV 50%, and NPV 74%.

Conclusions: Our findings indicate that scintigraphy using these methods of analysis correlates poorly with manometry in post cholecystectomy patients with suspected biliary SO dysfunction.

Figure 1

Four composite static images from the early phase of a scan and at its completion. Time since injection of diethyl iminodiacetic acid (DIDA) is indicated in the top left hand corner (in minutes). The time activity curves for liver and common bile duct (CBD) activity are also shown. This is a normal scan with a score of 1. Criteria for scoring are shown in table 1 ▶. In this patient peak hepatic activity was less than 10 minutes (see activity curve), the bile duct can be clearly seen in less than 15 minutes, the biliary tree is not prominent, the duodenum is clearly seen in less than 15 minutes, the CBD empties by more than 50% (see activity curve), and the CBD at 60 minutes, while more evident than the liver at the same time, is less active than the liver at 15 minutes (score 1). This patient had a normal sphincter of Oddi (SO) basal pressure of 23.2 mm Hg at the time of SO manometry. These static images also show early appearance of duodenal activity (hepatic hilum to duodenal transit time four minutes, duodenal appearance time eight minutes).

Figure 2

Static images from the same time points as well as time activity curves for a patient with sphincter of Oddi (SO) stenosis, as in fig 1 ▶. These static images, when compared with those in fig 1 ▶, show delayed appearance of tracer in the bile duct and duodenum, with the tracer at 60 minutes being more prominent in the biliary tree. This scan was scored by both observers as abnormal with a score of 6. The duodenum was not clearly evident at 15 minutes (score 1) although when the scan was analysed to determine hepatic hilum to duodenal transit time (HDTT) and duodenal appearance time (DAT) by the third observer, DAT was found to be 14 minutes from the one minute digital images (HDTT eight minutes). There is increasing common bile duct (CBD) activity seen at 60 minutes from the time activity curve (score 3) and the CBD at 60 minutes is equal in intensity to the liver at 15 minutes (score 2). This patient had an elevated basal pressure of 94.2 mm Hg and subsequently underwent sphincterotomy.

Figure 3

These four scatter graphs reveal the significant overlap between normal and abnormal manometry with respect to defining “cut off” values. SOBP, sphincter of Oddi basal pressure.