Excising a diseased pancreas removes not only pancreatic cells that produce digestive enzymes but also Islet of Langerhans cells that produce insulin to control blood sugar. Without natural insulin, a patient becomes diabetic and may require lifelong insulin injections to control blood sugars.

Auto islet cell transplantation takes these islets of Langerhans cells from the pancreas and transplants them to the liver to reduce the diabetic risk. To do this, the removed pancreas is processed to isolate the insulin-producing Islets of Langerhans cells.

The isolated cells are suspended in a solution and are then slowly infused through the splenic vein back into the patient’s liver where it is anticipated that they will implant, grow and produce insulin to metabolize sugar.

Fig. 1: Steps: Auto Islet Cell Transplantation
a) Removal of pancreas (pancreatectomy)
b) Isolation of Islet cells from removed pancreas
c) Islet cells placed in Infusion bag with solution
d) Islet cells infused into splenic vein
e) Islet cells implanted in liver

Typically, 800–1500cc of solution are infused into the portal vein, distal to the splenic vein (Fig. 2) over an extended period of time. The team may elect to infuse a small amount over 5 minutes and allow the patient to recover before resuming the infusion. Blood pressure and flow are monitored continuously and for 10 minutes after the infusion is completed (Fig. 1).

Fig. 2: Enlarged view of islet cell infusion into the splenic/portal
venous system.

Flow Measurement During Islet Infusion

Surgeons measure portal venous flow during islet cell infusion to detect any sudden decrease in flow that may foreshadow a problem. A 10–14mm Perivascular Flowprobe is placed on the portal vein and flow is measured continuously. The Flowprobe is chosen to comfortably encompass–but not constrict–the portal vein.

If needed, saline can be used to provide acoustic contact between the vein and Flowprobe. Readings stabilize within 1–2 minutes. Wide fluctuation of measurements may indicate improper positioning of the Flowprobe with poor alignment or fat within the ultrasonic sensing window. Repositioning can normally correct this problem.

Discussion

Portal venous flow measurements provide a continuous volumetric measure of flow that informs the surgeon about the safety, fluidity, and success of auto islet cell transplantation.

Flowprobe Needs:

COnfidence Flowprobes® provide highly accurate measurements in vessels with fluctuating flows such as the portal vein. The Probes may be left in place for extended measurements and then easily removed via a ring attached to the pliable liner that cushions and protects the vessel.

8–14mm FMV Vascular Handle Flowprobes are recommended for spot-check portal venous flow measurements during islet cell infusion.

F.A.S.T During Auto Inlet Transplantation surgery is based on the following:

• Sutherland DE et al, “Total pancreatectomy and islet autotrans-plantation for chronic pancreatitis,” J Am Coll Surg. 2012; 214(4): 409-24.
• Bramis K et al, “Systematic review of total pancreatectomy and islet autotransplantation for chronic pancreatitis.”Br J Surg. 2012; 99(6): 761-6.
• http://www.hopkinsmedicine.org/transplant/programs/auto_islet/description.html#total_pancreatectomy
• Henderson JM et al, “Hemodynamics During Liver Transplantation: The Interactions Between Cardiac Output and Portal Venous and Hepatic Arterial Flows,” Hepatology 1992; 16(3): 715-718.
• Henderson JM et al, Volumetric and Functional Liver Blood Flow Are Both Increased in the Human Transplanted Liver,” J Hepatology 1993; 17: 204-207.
• Troisi R, de Hemptinne B, “Clinical Relevance of Adapting Portal Vein Flow in Living Donor Liver Transplantation in Adult Patients, Liver Transplantation 2004; 9(9): S36-S41.

F.A.S.T Medical Notes are intended to assist in surgical decision-making and are not diagnostic tools. Surgical interpretation is required.