E-Poster Presentation ESA-SRB-ANZBMS 2021

Audit of selective arterial calcium stimulation with right versus bilateral hepatic venous sampling: a single-site experience (#358)

Mawson Wang 1 2 , David R Chipps 1 2
  1. Department of Diabetes and Endocrinology, Westmead Hospital, Westmead, NSW, Australia
  2. Westmead Clinical School, University of Sydney, Westmead, NSW, Australia

Background and Aim

In patients with endogenous hyperinsulinaemic hypoglycaemia, negative oral sulphonylurea screen, negative insulin antibodies, and inconclusive imaging, selective arterial calcium stimulation (SACST) with hepatic venous sampling is the next step in insulinoma localisation1-3. The Harmonisation Protocol advises sampling from the right hepatic vein only, however our local preference has been bilateral venous sampling. This audit assesses the concordance rate between the two hepatic veins in SACST2.

 

Methods

At Westmead Hospital, six patients with seven SACSTs were retrospectively identified between 2002 and 2021, all with bilateral hepatic venous sampling. Protocols differed slightly in terms of collection timepoints, stimulated arteries and the second hepatic vein sampled (left vs. middle). A relative-fold increase in hepatic venous insulin concentration (rHVI) of ≥2 at any timepoint compared to baseline is positive.

 

Results

6/7 SACSTs yielded positive results in ≥1 artery, indicating good selection of subjects. 20 out of 37 stimulated arteries were positive (54.1%). Allowing for minor variations in low concentrations of both basal and stimulated insulin concentrations, 33/37 (89.2%) stimulations produced concordant results between the hepatic veins sampled. The 4 discordant stimulations occurred in 2 patients with discordant results at several different time points.  One patient exhibited vastly different baseline and stimulated insulin levels between the hepatic veins, and the other had widely fluctuating insulin levels and several elevated baseline insulin levels, suggestive of either a sustained response to the previous stimulation or insufficient time between sample collection.

 

Conclusion

This audit demonstrates the need to ensure accurate sample collection and adequate timing between subsequent arterial stimulation. After excluding samples with likely false discordance due to minor variations in insulin concentrations, the concordance rate between the hepatic veins is sufficient to support sampling from the right hepatic vein only during SACST, which may reduce the potential for collection errors.

  1. Cryer, P. E., Axelrod, L., Grossman, A. B., Heller, S. R., Montori, V. M., Seaquist, E. R., Service, F. J., & Endocrine Society (2009). Evaluation and management of adult hypoglycemic disorders: an Endocrine Society Clinical Practice Guideline. The Journal of clinical endocrinology and metabolism, 94(3), 709–728. https://doi.org/10.1210/jc.2008-1410
  2. Thompson, S. M., Vella, A., Thompson, G. B., Rumilla, K. M., Service, F. J., Grant, C. S., & Andrews, J. C. (2015). Selective Arterial Calcium Stimulation With Hepatic Venous Sampling Differentiates Insulinoma From Nesidioblastosis. The Journal of clinical endocrinology and metabolism, 100(11), 4189–4197. https://doi.org/10.1210/jc.2015-2404
  3. Guettier, J. M., Kam, A., Chang, R., Skarulis, M. C., Cochran, C., Alexander, H. R., Libutti, S. K., Pingpank, J. F., & Gorden, P. (2009). Localization of insulinomas to regions of the pancreas by intraarterial calcium stimulation: the NIH experience. The Journal of clinical endocrinology and metabolism, 94(4), 1074–1080. https://doi.org/10.1210/jc.2008-1986