Introduction: Pancreatic islet transplantation (PIT) is an alternative to pancreas transplantation. Isolated PIT is extremely rare in children but could be considered in cases of other organ transplants from deceased donors when post-transplant diabetes is expected. A unique donor is often sufficient to provide an adequate number of islets in pediatric recipients, as 4000-10 000 islet-equivalents per kilogram are needed, offering a distinct advantage, especially in cases of weight mismatch. This study reports a single center pediatric cases of combined liver (LT) and PIT from the same donor.
Methods: From 2017 to date, 3 pediatric patients underwent combined LT and PIT. The first patient was a 9-year-old girl diagnosed with cystic fibrosis that presented with exocrine and endocrine pancreatic insufficiency and liver cirrhosis. At the time of transplantation, she had glucose intolerance and a history of temporary insulin therapy. Left lateral segment LT was performed and PIT one week later. PI engraftment was confirmed at liver biopsy. Insulin therapy was required for the first two postoperative months, then discontinued, and she has been insulin-free at 7 years follow-up.The second one was a seven-month-old boy born with Mitchell-Riley syndrome (neonatal total pancreatic insufficiency, intestinal failure and biliary cirrhosis after few months). Left lateral segment LT was performed and PIT six days later. Initial PI engraftment was confirmed by C peptide levels, which peaked at 0.76 nM after 2 weeks postoperatively. Unfortunately, the patient developed multiple biliary complications requiring liver retransplantation after 10 months and ultimately deceased after. The last one, was a 9-year-old boy with Ehlers-Danlos disease, presented with a spontaneous rupture of the superior mesenteric artery. Surgery was complicated by uncontrolled bleeding, requiring ligation of the celiac trunk, leading to ischemic necrosis of the liver, pancreas, spleen, stomach, and proximal jejunum. He underwent urgent LT and PIT was performed one week subsequently. C peptide levels, which peaked at 3 weeks postoperatively, have now stabilized around 0.5 nM at 6 weeks after PIT.
In all cases, the donor pancreas was retrieved “en bloc,” and islets were isolated, cultured, and injected into the portal venous system, either via the inferior mesenteric vein, via the spleen parenchyma or directly through a trans-hepatic ultrasound-guided puncture for the later. Patients followed an immunosuppressive regimen including thymoglobulin, tacrolimus, mycophenolate mofetil, etanercept, anakinra, and steroid avoidance when possible. An exendin 4 PET CT is expected for the first patient in order to disclose the viability of the islets at such long term.
Conclusion: Combined PIT and LT in children is feasible and safe, with the advantage of utilizing a single donor for both organs. Given the increased risk of allogeneic tissue, tailored immunosuppressive protocols are essential.