Physicians rely on a spectrum of treatments to manage the pain caused chronic pancreatitis. Still, many patients become so disabled from the disease that they are unable to work.
Building on its expertise in organ transplantation, UCSF is the only medical center west of the Mississippi offering islet transplantation as an option for managing the diabetes that results from a treatment of last resort—removal of the diseased pancreas. The procedure, in which functioning islet cells are harvested after the pancreas is removed and then are infused into the patient's liver, is performed by Hobart Harris, M.D., chief of General Surgery at UCSF Medical Center, and Andrew Posselt, M.D., Ph.D., a transplant surgeon and codirector of the UCSF Pancreatic Islet Transplant Program.
About 15,000 Americans are diagnosed each year with chronic pancreatitis, with the condition striking twice as many men as women. An estimated 70 to 80 percent of cases are related to alcohol abuse. The remainder arise from conditions such as gallbladder disease, reactions to medications or congenital anatomic abnormalities of the pancreas.
Inflammation associated with recurrent bouts of pancreatitis causes scarring and blockage of the pancreatic ducts. This produces chronic pain that is often difficult to relieve with medications. In addition to pain, patients may also develop malabsorption because the function of digestive enzymes is compromised.
Treatments range from noninvasive approaches such as pain medications and pancreatic enzyme supplementation to endoscopic procedures designed to open blocked pancreatic ducts. More invasive pain control measures may include nerve ablation or surgical procedures that attempt to improve pancreatic drainage or remove diseased portions of the organ. Most cases respond at least for a while to these interventions, but often the improvement does not last, according to Harris.
Removing the entire pancreas provides significant pain relief, but leaves patients severely diabetic because they no longer have pancreatic islets, which produce insulin. After removal of the pancreas, patients are completely dependent on external sources of insulin and their blood sugar can be extremely difficult to control.
UCSF is one of only five U.S. institutions currently offering autologous pancreatic islet transplantation as a way to minimize the severity of diabetes after the pancreas is removed. The technique, pioneered at the University of Minnesota, involves harvesting functioning islets from the patient's diseased pancreas and then infusing them into the portal vein, where they migrate to the liver. This is a modification of a transplant technique used at UCSF to manage severe insulin-dependent (type 1) diabetes. In treating type 1 diabetes, healthy islets are harvested from a deceased donor pancreas and then infused into the patient. In chronic pancreatitis, the patient's own islets are used.
After the pancreas is removed, it is taken to the laboratory, where Posselt and his team use a complex procedure to separate the islets from the pancreatic tissue. When the islets come from the recipient's own pancreas, the isolation procedure is somewhat more rapid than for a cadaver donor. Because there is no risk of rejection, the islets do not need to be as thoroughly purified and the islet yield can be lower, said Posselt, who supervises the isolation procedure while Harris finishes the abdominal surgery. The islets are then infused into the patient's portal vein while he or she is still in the operating room.
UCSF has had excellent success with the small number of patients (five) who have so far received autologous islet transplants for chronic pancreatitis. In keeping with published findings from the few other institutions using the technique, 70 percent to 80 percent of patients have had a substantial decrease in their pain medications and 40 percent to 50 percent have been able to stop pain medications completely. The need for supplemental insulin is a function of the numbers of islets that are harvested. Of the five patients transplanted at UCSF, three need some insulin and two do not. That 40 percent insulin-free rate is comparable to published reports, according to Harris.
The procedure is a good choice for highly motivated patients with a strong social support structure, including a primary care physician who can monitor their withdrawal from pain medications. Ideal patients have not yet developed diabetes from destruction of the pancreas and islets, nor have they had other pancreatic surgeries, which often produce scarring and consequently lower the islet yield. However, patients are evaluated on an individual basis.
For more information, please contact the Islet and Cellular Transplantation Center at (415) 353-8893.
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