Omental Pouch Technique for Combined Site Islet Autotransplantation Following Total Pancreatectomy

Abstract

Total pancreatectomy and islet autotransplantation (TPIAT) is an effective treatment for selected patients with chronic pancreatitis. The portal circulation is the standard infusion site for islet transplant, but marked elevation of portal pressures may prevent complete islet infusion. Herein we report a novel technique of combined site islet autotransplantation using an omental pouch. This technique may be useful when technical limitations prevent complete intraportal transplantation. In four TPIAT recipients with intraoperative issues precluding the complete intraportal infusion of islets, an omental pouch was created to contain the remaining islet mass. Patients were monitored for complications, and islet graft function was assessed using mixed meal tolerance testing and compared with matched controls who received only intraportally transplanted islets. All patients had decreasing insulin requirements as their recovery progressed. At 3 months follow-up there were no significant differences in glycemic control or graft function for the combined site recipients compared with their matched controls who only received an intraportal islet infusion. The omentum has potentially desirable qualities such as accessibility, capacity, and systemic/portal vascularity comparable to the native pancreas. The omental pouch technique may represent a safe and effective alternate site for islet autotransplantation. Further study is needed to confirm these findings.

Inducible Pluripotent Stem Cells as a Potential Cure for Diabetes

“…Insulin independence necessitates adequate islet engraftment without fibrosis, which is currently only offered with omentum and intraportal ICT. Omental ICT has demonstrated positive early results in animal and human studies [ 125 , 128 , 129 ]. Stice et al (2018) demonstrated successful omental autologous ICT in four patients confirming prior promising animal studies.…”

“…Stice et al (2018) demonstrated successful omental autologous ICT in four patients confirming prior promising animal studies. The omentum releases hormones into portal circulation, supports islet engraftment, and is relatively accessible if resection is needed [ 128 , 129 ]. The omentum also limits IBMIR, since no direct blood contact occurs [ 129 ].…”

“…The omentum also limits IBMIR, since no direct blood contact occurs [ 129 ]. A limitation of this site is that surgical placement is required, which may limit widespread use due to cost and access to operative time, but all clinical trials to date involving omental implantation have used minimally invasive laparoscopic approaches [ 128 , 129 ]. Clinical trials have begun to further evaluate the omentum, but direct comparisons with the intraportal site are needed to guide future endeavors.…”

Unsurpassed Intrahepatic Islet Engraftment – the Quest for New Sites for Beta Cell Replacement

“…The omentum appears to provide more rapid revascularization compared with intrahepatic islets 36 . In humans, patients receiving autologous IT due to chronic pancreatitis have partially been transplanted to the omental pouch, in cases when increased portal pressure prevented complete intraportal transplantation 40 . However, results are so far disappointing, with only a small number of patients that have been rendered insulin independent, while the majority of grafts have failed.…”

Where’s Waldo? Extrahepatic Site Options for Islet Transplantation

“…Baidal et al reported an allotransplant to the omentum in a type 1 diabetic recipient who achieved insulin independence at one year follow up [85]. At the University of Minnesota, islets are occasionally placed into the omentum or peritoneum when prohibitive portal pressures prevent the full volume of islets from being transfused during TPIAT [86]. There is a clinical trial ongoing where a portion of islets are placed in the omentum regardless of portal pressures (NCT03779139).…”