Total pancreatectomy with islet autotransplantation in diabetic and pre-diabetic patients with intractable chronic pancreatitis

Current status of total pancreatectomy with islet autotransplantation for chronic and recurrent acute pancreatitis

Total pancreatectomy with islet autotransplantation (TPIAT) is an established and effective treatment modality for patients diagnosed with intractable chronic pancreatitis (CP) and recurrent acute pancreatitis (RAP). TPIAT primarily aims to manage debilitating pain leading to impaired quality of life among patients with CP or RAP, which can be successfully managed with medical, endoscopic, or surgical interventions. TPIAT is significantly successful in relieving pain associated with CP and improving health-related quality of life outcomes. Furthermore, the complete loss of pancreatic endocrine function attributed to total pancreatectomy (TP) can be compensated by autologous islet transplantation (IAT). Patients receiving IAT can achieve insulin independence or can be less dependent on exogenous insulin compared with those receiving TP alone. Historically, TPIAT has been mainly used in the United States, and its outcomes have been improving due to technological advancements. Despite some challenges, TPIAT can be a promising treatment for patients with CP-related intractable pain. Thus far, TPIAT is not commonly performed in Japan. Nevertheless, it may improve health-related quality of life in Japanese patients with CP, similar to Western patients. This review article aimed to provide an overview of the indications, related procedures, and outcomes of TPIAT and to discuss future prospects in Japan.

Current practices in islet cell autotransplantation

INTRODUCTION

Chronic pancreatitis and recurrent acute pancreatitis comprise a spectrum of disease that results in complications related to exocrine and endocrine insufficiency and chronic pain with narcotic dependence and poor quality of life. The mainstay of therapy has been medical and endoscopic therapy; surgery, especially total pancreatectomy, was historically reserved for few select patients as the obligate exocrine insufficiency and pancreatogenic diabetes (type 3C) are challenging to manage. The addition of islet cell autotransplantation after total pancreatectomy helps to mitigate brittle type 3c diabetes and prevents mortality related to severe hypoglycemic episodes and hypoglycemic unawareness. There have been more recent data demonstrating the safety of surgery and the beneficial long-term outcomes.

AREAS COVERED

The purpose of this review is to describe the current practices in the field of islet cell autotransplantation including the selection and evaluation of patients for surgery, their preoperative work up and management, surgical approach, post-operative management and outcomes.

EXPERT OPINION

Total pancreatectomy and islet cell autotransplantation has the ability to drastically improve quality of life and prevent brittle diabetes for patients suffering with chronic pancreatitis.

The unique pathophysiological features of diabetes mellitus secondary to total pancreatectomy: proposal for a new classification distinct from diabetes of the exocrine pancreas

INTRODUCTION

Diabetes of the exocrine pancreas (DEP; a.k.a. pancreatic diabetes or pancreatogenic diabetes or type 3c diabetes mellitus or T3cDM) refers to different diabetes types resulting from disorders of the exocrine pancreas. DEP is characterized by the structural and functional loss of glucose-normalizing insulin secretion in the context of exocrine pancreatic dysfunction. Among these forms, new-onset diabetes mellitus secondary to total pancreatectomy (TP) has unique pathophysiological and clinical features, for which we propose a new nomenclature such as post-total pancreatectomy diabetes mellitus (PTPDM).

AREAS COVERED

TP results in the complete loss of pancreatic parenchyma, with subsequent absolute insulinopenia and lifelong need for exogenous insulin therapy. Patients with PTPDM also exhibit deficiency of glucagon, amylin and pancreatic polypeptide. These endocrine abnormalities, coupled with increased peripheral insulin sensitivity, deficiency of pancreatic enzymes and TP-related modifications of gastrointestinal anatomy, can lead to marked glucose variability and increased risk of iatrogenic (insulin-induced) severe hypoglycemic episodes ('brittle diabetes').

EXPERT OPINION

We believe that diabetes mellitus secondary to TP should not be included in the DEP spectrum in light of its peculiar pathophysiological and clinical features. Therefore, we propose a new classification for this entity, that would likely provide more accurate prognosis and treatment strategies.

Effectiveness of Intraoperative Versus Dedicated Islet Cell Laboratory Isolation for Total Pancreatectomy With Islet Autotransplant

Background.

Total pancreatectomy with islet autotransplantation (TPIAT) requires a complex islet isolation process of the explanted pancreas. Islet isolation has historically required a specialized laboratory to perform islet isolation. We report our experience with a novel technique of intraoperative islet isolation that does not require a specialized islet laboratory, thereby making the isolation process simpler, more accessible, and less costly.

Methods.

We performed a retrospective, comparative effectiveness analysis of 50 adult patients who underwent TPIAT from 2012 to 2020 (TPIAT with remote isolation [n = 20] versus intraoperative isolation of islet cells [n = 30]). The primary outcome was islet equivalents per body weight (IEQ/kg) for patients in each group.

Results.

Mean IEQ/kg‘s (4294 remote group versus 3015 intraoperative group, P = 0.06) and 1-y postoperative C-peptide levels (1.51 ng/mL remote group versus 0.91 ng/mL intraoperative group, P = 0.10) were not different between groups. Mean 1-y HbA1c levels (7.7% in the remote group versus 7.1% intraoperative group, P = 0.67) and 1-y insulin requirements (P = 0.31) were not statistically different. Lower average cost of hospitalization was seen in the intraoperative group, although this was not statistically significant ($104 398 remote versus $78 986 intraoperative, P = 0.81).

Conclusions.

Intraoperative islet isolation has similar effectiveness in regard to glycemic outcomes compared with the use of a dedicated islet cell isolation laboratory at a lower cost.

Pain resolution and glucose control in pediatric patients with chronic pancreatitis after total pancreatectomy with islet auto-transplantation

BACKGROUND

Chronic pancreatitis (CP) and acute recurrent pancreatitis (ARP) in pediatric patients are strongly associated with genetic mutations and lead to pan-parenchymal disease refractory to medical and endoscopic treatment. Our aim was to assess pain resolution and glucose control in patients with CP and ARP following total pancreatectomy with islet auto-transplantation (TPIAT).

METHODS

We retrospectively analyzed prospectively collected clinical data of 12 children who developed CP and ARP and underwent TPIAT when 21 years old or younger at the University of Chicago between December 2009 and June 2020. Patients with recurrent or persistent abdominal pain attributed to acute or chronic pancreatic inflammation and a history of medical interventions attempted for the relief of pancreatic pain were selected by a multi-disciplinary team for TPIAT. We followed patients post-operatively and reported data for pre-TPIAT, post-operative day 75, and yearly post-TPIAT.

RESULTS

All 12 patients experienced complete resolution of pancreatic pain. The overall insulin-independence rate after 1 year was 66% (8/12) and 50% (3/6) at 4 years. Shorter duration of CP/ARP pre-TPIAT, higher mass of islets infused, and lower BMI, BMI percentile, and BSA were associated with insulin-independence post-TPIAT.

CONCLUSIONS

TPIAT is a viable treatment option for pediatric patients with CP and ARP. Pediatric patients undergoing TPIAT for CP achieved resolution of pancreatic-type pain and reduced opioid requirements. The majority were able to achieve insulin-independence which was associated with lower pre-TPIAT BMI and higher islet mass transplanted (i.e., over 2000 IEQ/kg), the latter of which can be achieved by earlier TPIAT.

LEVEL OF EVIDENCE

Treatment study, Level IV.

Metabolic measures before surgery and long-term diabetes outcomes in recipients of total pancreatectomy and islet autotransplantation

In this single-center, retrospective cohort study, we aimed to elucidate simple metabolic markers or surrogate indices of β-cell function that best predict long-term insulin independence and goal glycemic HbA1c control (HbA1c ≤ 6.5%) after total pancreatectomy with islet autotransplantation (TP-IAT). Patients who underwent TP-IAT (n = 371) were reviewed for metabolic measures before TP-IAT and for insulin independence and glycemic control at 1, 3, and 5 years after TP-IAT. Insulin independence and goal glycemic control were achieved in 33% and 68% at 1 year, respectively. Although the groups who were insulin independent and dependent overlap substantially on baseline measures, an individual who has abnormal glycemia (prediabetes HbA1c or fasting glucose) or estimated IEQs/kg < 2500 has a very high likelihood of remaining insulin dependent after surgery. In multivariate logistic regression modelling, metabolic measures correctly predicted insulin independence in about 70% of patients at 1, 3, and 5 years after TP-IAT. In conclusion, metabolic testing measures before surgery are highly associated with diabetes outcomes after TP-IAT at a population level and correctly predict outcomes in approximately two out of three patients. These findings may aid in prognostic counseling for chronic pancreatitis patients who are likely to eventually need TP-IAT.

Use of Continuous Glucose Monitoring for evaluation of hypoglycemia pre- and post-operatively for patients undergoing Total Pancreatectomy with Autologous Islet Cell Transplant

INTRODUCTION

Total pancreatectomy with autologous islet transplant (TPAIT) is indicated for patients with chronic pancreatitis to improve quality of life while reducing complications from hypoglycemia. Continuous glucose monitoring (CGM) was used to assess overall islet function and the incidence of hypoglycemia pre- and post-operatively.

METHODS

Nineteen patients who underwent TPAIT at a single center from 2018 to 2020 were included. Pre-operatively, patients were defined by diabetic status. HbA1c, stimulated C-peptide, and CGM were used to characterize glycemic function.

RESULTS

Pre-operatively, three patients had diabetes, and 16 patients did not have diabetes. Eight out of 16 non-diabetic patients were insulin independent (50%). Of six non-diabetic patients with > 10% hypoglycemia on pre-operative CGM, 33% were insulin-independent post-operatively (P = .3). Of non-diabetic patients with ≥ 80% time in the euglycemic range, 62% were insulin-independent post-operatively (P = .2). For patients without diabetes, the median percent time in hypoglycemic range was reduced from 8% to 1% (P = .001). Delta C-peptide had a positive correlation with islet yield (P = .03).

DISCUSSION

Conventional evaluation of TPAIT patients assesses primarily beta cell function. As pancreatogenic diabetes is concerning principally for the risk of hypoglycemia, assessment of alpha cell function can improve the quality of care. CGM better captures islet function and increases the identification of hypoglycemia.

What Is New with Total Pancreatectomy and Autologous Islet Cell Transplantation? Review of Current Progress in the Field

Patients with chronic pancreatitis have benefited from total pancreatectomy and autologous islet cell transplantation (TPAIT) since the 1970s. Over the past few decades, improvements have been made in surgical technique and perioperative management that have led to improved success of islet cell function, insulin independence and patient survival. This article focuses on recent updates and advances for the TPAIT procedure that continue to expand and innovate the impact on patients with debilitating disease.