Comparable Long-Term Glycemic Control and Insulin-Independent Rate at Less Cost By Using Intra-Operative vs. Islet Cell Laboratory Isolation for Total Pancreatectomy With Islet Auto-Transplantation

Abstract

Total pancreatectomy with intraportal islet cell autotransplantation (TPIAT) allows for the islets to be isolated and subsequently re-infused to prevent the complications associated with post-pancreatectomy diabetes in patients with chronic or recurrent pancreatitis. TPIAT requires a complex islet isolation process of the explanted pancreas, and historically required a specialized lab to perform islet cell isolation. We report our unique 5-year experience comparing our new technique of intra-operative islet isolation to the prior use of off-site specialized islet lab, thereby making the isolation process simpler, faster, and more accessible. Method: We performed a retrospective, comparative effectiveness analysis of 50 adult patients who underwent TPIAT at our tertiary care center from 2012 to 2020 (excluding patients with partial- or completion pancreatectomy with IAT). From 2012–2015, isolation occurred at a remote location 130 miles away in which the pancreas was explanted at our center, transported to the islet isolation lab, and returned the same day to our center for portal system infusion. From 2015–2020, islet isolation was performed using the novel intra-operative technique at our institution without a specialized islet isolation lab. We measured the islet equivalents per body weight (IEQ/kg), monitored glycemic control, and compared insulin-independent rate for patients in each group yearly up to 5 years. Results: Twenty patients underwent TPIAT with remote isolation while thirty patients underwent intra-operative isolation of islet cells. Baseline characteristics were similar between these groups. Mean islet yields-IEQ/kg (4,294 remote group vs. 3,015 intra-op group, p=0.06) were not different between the groups. Post-operative mean c-peptide levels at 1 and 3 years were stable over time and were not different between the groups (1.51 and 1.65 ng/mL remote group vs. 0.91 and 0.98 ng/mL intra-operative group, p=0.1 and 0.15 respectively). Mean HbA1c levels at 1–5 years were 7.5–8.2% in the remote group vs. 7.1–7.4% intra-op group, p=0.67, which suggests reasonable and durable glycemic control in both groups. Insulin independent rate was also very similar (43% vs 41%, p=0.10) at 3 years after the surgery when both groups reached the same number of patients (n=20) for the comparison. Average cost of hospitalization was less in the intra-operative group ($104,398 remote vs $78,986 intra-op). Conclusion: Intra-operative islet isolation has similar effectiveness in regard to glycemic outcomes and insulin independent rates but at a lower cost when compared with the use of a dedicated islet cell isolation lab. This technique can allow many more centers without a dedicated islet cell lab to offer islet cell auto-transplantation, which in turn will help reduce the burden of difficult diabetes care post-pancreatectomy and improve quality of life for the appropriate patients.