This is an arterial stimulation-venous sampling procedure to help localize an insulinoma. This patient has an insulinoma somewhere in the pancreas, but it is not seen on any imaging likely because it is too small. One way to localize it so it can be surgically removed is to selectively stimulate it by injecting calcium gluconate into different arteries and then measuring insulin levels in the venous outflow (right hepatic vein) at different time points. Depending on which artery caused the insulin levels to increase will determine the location of the insulinoma. #### There are 4 main territories to test: ###### SMA/IPDA (Superior mesenteric artery and inferior pancreaticoduodenal artery) - This will localize the tumor to the inferior pancreatic head and uncinate process ###### GDA/SPDA (Gastroduodenal artery and superior pancreaticoduodenal artery) - This will localize the tumor to the superior pancreatic head and neck ###### Splenic artery - This will localize the tumor to the pancreatic body and tail ###### Hepatic artery - This will localize the tumor to the liver (possible metastatic insulinoma) ![[pancreatic-blood-supply.jpg]] As you can see, this does not localize the tumor in a super precise way, but it can help divide the pancreas into thirds so that the surgeon can surgically remove the correct section. After each injection of **calcium gluconate (0.025 ug/kg)**, venous samples are then taken from the right hepatic vein at 0, 30, 60, and 120 seconds and insulin is measured. So this will result in four stimulations and a total of 16 venous samples tested for insulin. One main concern is tracking of the samples and how we can differentiate them in epic. The samples will need to be plotted on a chart to create a graph of the rising insulin. See pic below. Brad, is there anyway this can be done automatically? How will we keep track of the order in which they were taken when some samples might be taken within the same minute? ![[venous-insulins-after-arterial-stimulation.jpg]]