2 The procedure

2.1 Indications and current treatments

2.1.1 Some patients with chronic pancreatitis or benign pancreatic endocrine tumours are treated by total or partial pancreatectomy, resulting in a type of insulin-dependent diabetes.

2.1.2 Post-pancreatectomy diabetes requires the daily injection of exogenous insulin and is relatively difficult to control.

2.2 Outline of the procedure

2.2.1 This procedure is performed with pancreatectomy in a single operation, with the patient under general anaesthesia. The pancreatectomy is carried out, and islet cells are isolated and prepared for transplantation. Under continuous portal vein pressure monitoring (to help prevent portal vein thrombosis), the islet cells are infused through a catheter directly into the portal vein or a tributary, and further onto the liver parenchyma, where some will remain viable.

Sections 2.3 and 2.4 describe efficacy and safety outcomes which were available in the published literature and which the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview.

2.3 Efficacy

2.3.1 In four case series of 64, 45, 40 and 13 patients treated by autologous islet cell transplantation following partial or total pancreatectomy, between 24% and 85% of patients were insulin independent at follow-up periods ranging from less than 6 months to 18 months (one study did not state follow-up duration).

2.3.2 In a case series of 48 patients (of whom 39 were evaluated after the procedure), 15 of the 20 patients who were insulin independent at 1 month remained insulin independent at mean follow-up of 5 years, and one patient remained so at 10 years. In the case series of 13 patients, 38% (5/13) were insulin independent after 2 years.

2.3.3 In the case series of 40 patients, all 14 patients who were followed up at 3 years were classed as either having diabetes or impaired glucose tolerance. In a case series of 24 patients, 33% (8/24) required insulin within 8 years of the procedure.

2.3.4 The Specialist Advisers considered key efficacy outcomes to include quality of life, glycaemic control, glucose tolerance, avoidance of severe hypoglycaemia, long-term insulin independence and prevention of long-term diabetic complications.

2.4 Safety

2.4.1 The case series of 48 patients reported that two patients who also had splenectomy at the time of transplantation had 'uncontrollable' splenic hilar bleeding due to increased portal pressure. Asymptomatic portal vein thrombosis was suspected in one patient but the vein was not thrombosed one week after the operation.

2.4.2 A case series of 40 patients reported that complications in the first 24 patients included one case each of portal vein thrombosis, splenic infarction and splenic thrombosis requiring splenectomy. In the last 16 patients, the series reported that complications included pancreatic fistula formation and rupture and subsequent resection of the spleen (raw data not reported; timing and cause of adverse events not adequately described).

2.4.3 A case report described a patient who developed heparin-induced thrombocytopenia following the procedure.

2.4.4 The Specialist Advisers considered theoretical and anecdotal adverse events to include portal vein thrombosis, portal hypertension, hepatic infarction, liver steatosis, liver failure, intra-abdominal haemorrhage, bile leakage, splenic rupture, disseminated intravascular coagulation, infection, intrahepatic sepsis and islet cell pulmonary emboli.

2.5 Other comments

2.5.1 The Committee noted that the National Commissioning Group (NCG), which has a remit to commission highly specialised national services for very rare conditions or treatments for the population of England, has designated centres for pancreatic islet cell isolation. Scottish residents also have access to the service under an agreement between the NCG and the National Services Division, Scotland. Health Commission Wales has a separate agreement with the provider for Welsh residents. The Regional Medical Services Consortium (RMSC) commissions specialist regional services for the population of Northern Ireland. The RMSC will commission outside the region, on an individual basis, in cases for which services are not available in Northern Ireland.