Islet autotransplantation offers a valuable addition to surgical resection of the pancreas, as a treatment for chronic pancreatitis; and even in cases in which insulin independence is not achieved, the potential beneficial effects of C-peptide make the procedure worthwhile.
The encapsulation of islets of Langerhans in alginate-poly-l-lysine has been proposed as a method for the immunoprotection of transplanted islets. Although several capsule compositions have been reported, there has been no published study concerning the effect of capsule composition on the severity of the foreign body reaction. Empty capsules were prepared from high mannuronic acid alginate and were coated with: (1) poly-l-lysine alone, (2) poly-l-lysine plus high guluronic acid alginate, or (3) poly-l-lysine plus high mannuronic acid alginate. The capsules were placed in the renal subcapsular space or the peritoneal cavity, and retrieved after three weeks of histological examination. The recipients were WAG/01a, nude (athymic), diabetic BB, and non-diabetes prone BB rats. The severity of reaction to the capsules was determined by measuring the thickness of the pericapsular cell infiltrate or by a scoring system. The severity of the reaction to the capsules was strain-dependent in both the renal and peritoneal sites, with the BB and nude rats displaying the most severe responses. The degree of response was not affected by capsule composition in the renal subcapsular space, but in the peritoneum, the high mannuronic acid alginate capsules provoked the weakest response, and this type of capsule will be used for future transplantation work. The infiltrating cells were characterised by immunohistochemistry and electron microscopy and found to be mostly fibroblasts and macrophages.
ObjectiveTo assess the safety and efficacy of islet autotransplantation (IAT) combined with total pancreatectomy (TP) to prevent diabetes. Summary Background DataThere have been recent concerns regarding the safety of TP and IAT. This is thought to be related to the infusion of large volumes of unpurified pancreatic digest into the portal vein. Minimizing the volume of islet tissue by purifying the pancreatic digest has not been previously evaluated in terms of the postoperative rate of death and complications, pain relief, and insulin independence. MethodDuring a 54-month period, 24 patients underwent pancreas resection with IAT. Islets were isolated using collagenase and a semiautomated method of pancreas digestion. Where possible, islets were purified on a density gradient and COBE processor. Islets were embolized into the portal vein, within the spleen and portal vein, or within the spleen alone. The total median volume of digest was 9.9 mL. ResultsThe median number of islets transplanted was 140,419 international islet equivalents per kilogram. The median increase in portal pressure was 8 mmHg. Early complications included duodenal ischemia, a wedge splenic infarct, partial portal vein thrombosis, and splenic vein thrombosis. Intraabdominal adhesions were the main source of long-term problems. Eight patients developed transient insulin independence. Three patients were insulin-independent as of this writing. Patients had significantly decreased insulin requirements and glycosylated hemoglobin levels compared with patients undergoing TP alone. Of the patients alive and well as of this writing, four had failed to gain relief of their abdominal pain and were still opiate-dependent. ConclusionCombined TP and IAT can be a safe surgical procedure. Unfortunately, almost all patients were still insulin-dependent, but they had decreased daily insulin requirements and glycosylated hemoglobin levels compared with patients undergoing TP alone. A prospective randomized study is therefore needed to assess the long-term benefit of TP and IAT on diabetic complications.Chronic pancreatitis is a progressive inflammatory disease causing irreversible structural damage to the pancreatic parenchyma. It culminates in permanent impairment of pancreatic exocrine function and, in severe cases, diabetes mellitus. The incidence has quadrupled in the past 30 years, and patient management remains a major challenge.1 Patients generally have chronic, intractable abdominal pain that is often relieved only by large quantities of opiates, to which many patients develop tolerance and dependence. There is no agreement as to the best management strategy. Conservative approaches combine medical and supportive modalities (e.g., exocrine enzyme supplements, Octreotide, and antioxidants), nerve blockade (e.g., celiac plexus block, thoracoscopic splanchnic nerve division), or partial resection when the disease is localized. Although these management strategies can be successful, most reports Supported by the Leicester General Hospital NHS Trust.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.