An Alternative to Kinevac

TO THE EDITOR:

Our referring physicians have found hepatobiliary scanning with gallbladder stimulation by Kinevac (sincalide for injection; Bracco Diagnostics Inc., Princeton, NJ) to be useful in the management of their patients. With Kinevac no longer available (1), we sought to develop an alternative procedure to provide similar information.

On the basis of our review of fatty-meal gallbladder stimulation studies using ultrasonography (2,3) and cholescintigraphy (4,5), we developed a protocol using a standardized oral fatty meal to serve as the stimulus for gallbladder contraction. At 60 min after the intravenous administration of 185 MBq (5 mCi) of ^99mTc-mebrofenin, and assuming normal visualization of the gallbladder, we give the patient 90 mL (3 oz) of heavy whipping cream sweetened with a teaspoon of sugar. This quantity contains 30 g of fat. Imaging is performed immediately after ingestion of the meal and at 15, 60, and 75 min after ingestion. The ejection fraction is calculated using the peak (baseline or, rarely, 15 min) and trough (75 or, rarely, 60 min) counts. On the basis of our previous experience and for simplicity’s sake, background and decay correction are not performed.

We analyzed the data for the first 82 consecutive patients on whom the protocol could be successfully accomplished. The whipping cream was usually not given to patients with nasogastric tubes, and only 2 other patients could not tolerate the meal. When an ejection fraction of <40% was considered abnormal and 40%–49% was considered borderline, 11 (13%) of 82 patients had an abnormal ejection fraction and 21% had an abnormal or borderline ejection fraction. When the same parameters were used on our last 32 consecutive Kinevac-stimulated scans, 3 (9%) of 32 patients had abnormal ejection fractions and 5 (16%) of 32 had abnormal or borderline ejection fractions. For fatty-meal and Kinevac stimulation, the average ejection fractions of all patients were 70% and 71%, respectively.

We conclude that fatty-meal-stimulated cholescintigraphy is well tolerated and easy to perform and results in ejection fraction values similar to those obtained with Kinevac-stimulated cholescintigraphy. We are in the process of evaluating the clinical significance of the ejection fractions obtained with the fatty meal.