Interventional procedures in whole organ and islet cell pancreas transplantation

Human pancreatic tissue dissociation enzymes for islet isolation: Advances and clinical perspectives

BACKGROUND AND AIMS

Successful clinical human allo or auto-islet transplantation requires the recovery of a sufficient number of functional islets from either brain-dead or chronic pancreatitis pancreases respectively.

METHODS

In the last two decades (2000-2019), significant progress has been made in improving the human islet isolation procedures and in standardizing the use of different tissue dissociation enzyme (TDE; a mixture of collagenase and protease enzymes) blends to recover higher islet yields.

RESULTS AND CONCLUSIONS

This review presents information focusing on properties and role of TDE blends during the islet isolation process, particularly emphasizing on the current developments, associated challenges and future perspectives within the field.

Histopathological characteristics of needle core biopsy and surgical specimens from patients with solitary hepatocellular carcinoma or intrahepatic cholangiocarcinoma

BACKGROUND

Pathological manifestations of hepatic tumours are often associated with prognosis. Although surgical specimens (SS) can provide more information, currently, pre-treatment needle core biopsy (NCB) is increasingly showing important value in understanding the nature of liver tumors and even in diagnosis and treatment decisions. However, the concordance of the clinicopathological characteristics and immunohistochemical (IHC) staining between NCB and SS from patients with hepatic tumours were less concerned.

AIM

To introduce a more accurate method for interpreting the IHC staining results in order to improve the diagnostic value of hepatic malignancy in NCB samples.

METHOD

A total of 208 patients who underwent both preoperative NCB and surgical resection for hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC) between 2008 and 2015 were enrolled in this study. The expression of CK19, GPC3, and HepPar1 were detected by IHC staining. Clinicopathological, NCB, and surgical data were collected and analysed using χ² and kappa statistics.

RESULTS

Morphologically, the presence of compact tumour nests or a cord-like structure in NCB was considered the primary cause of misdiagnosis of HCC from ICC. The kappa statistic showed a moderate agreement in histomorphology (k = 0.504) and histological grade (k = 0.488) between NCB and SS of the tumours. A 4-tier (+++, ++, +, and -) scoring scheme that emphasized the focal neoplastic cell immunoreactivity of tumour cells revealed perfect concordance of CK19, GPC3 and HepPar1 between NCB and SS (k = 0.717; k = 0.768; k = 0.633). Furthermore, with the aid of a binary classification derived from the 4-tier score, a high concordance was achieved in interpreting the IHC staining of the three markers between NCB and final SS (k = 0.931; k = 0.907; k = 0.803), increasing the accuracy of NCB diagnosis C (k = 0.987; area under the curve = 0.997, 95%CI: 0.990-1.000; P < 0.001).

CONCLUSION

These findings imply that reasonable interpretation of IHC results in NCB is vital for improving the accuracy of tumour diagnosis. The simplified binary classification provides an easy and applicable approach.

Multi-Modality Imaging Evaluation of the Whole-Organ Pancreas Transplant

Pancreas transplants are an important treatment options for patients with severe diabetes mellitus and other medical conditions. Multiple-imaging modalities, including computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US) are available to evaluate the pancreas transplants and their vascular supply, with the graft having a characteristic appearance on each modality. Complications of the graft and its vascular supply present interesting challenges to the clinicians and radiologists caring for this patient population. Being able to identify the imaging appearance of normal and abnormal pancreas transplants, it is necessary to ensure these patients are provided optimal care.

Imaging of Pancreas Transplantation and Its Complications

Whole pancreas transplantation is an effective treatment for obtaining euglycemic status in patients with insulin-dependent diabetes mellitus, and is usually performed concurrent with renal transplantation in the affected patient. This article discusses complex surgical anatomical details of pancreas transplantation including surgical options for endocrine and exocrine drainage pathways. It then describes several possible complications related to surgical factors in the immediate post operative period followed by other complications related to systemic issues, vasculature, and the pancreatic parenchyma.

The efficacy of on-site evaluation for identification of transplant pancreas

OBJECTIVE

Pancreatic transplantation has been relatively uncommon until the last 2 decades, but is now an accepted therapeutic intervention for type I diabetes. Core biopsies of pancreas transplants are frequently performed to rule out rejection, which is a leading cause of graft failure. Often, it is difficult to localize the graft for biopsy by imaging. Our objective was to determine whether on-site assessment by cytopathology can assist in procedure protocols for biopsy of pancreas transplants.

STUDY DESIGN

We reviewed cytology and surgical pathology reports from 68 instances of pancreas transplant biopsy at our institution and evaluated the correlation between cytology (fine needle aspiration, touch preparation or both) and the final core biopsy.

RESULTS

Pancreatic tissue was identified by on-site assessment in 56/68 cases and was present on core biopsy in 53/68 cases. There were 3 cases where fine needle aspiration/touch preparation results were not concordant with final core biopsy results. The positive predictive value of a positive on-site assessment was 96.4%. More importantly, the negative predictive value of on-site assessment was 100%.

CONCLUSIONS

On-site evaluation by cytopathology is highly effective for the identification of transplant pancreas. In cases where no pancreatic tissue is identified by on-site assessment, relocalization of the biopsy needle is recommended.

Pancreatic islet cell transplantation: an update for interventional radiologists

Pancreatic islet cell transplantation is a promising cellular-based therapy for type 1 diabetes mellitus. This procedure involves portal venous injection of islet cells and affords 1-year insulin independence in as many as 80% of recipients. Although transplant surgeons represent historical drivers of islet therapy, requirement for image guidance and transcatheter techniques has fostered collaboration with interventional radiologists, who are positioned to play a significant role in clinical performance of islet transplantation and in basic science research in this field. This review article aims to familiarize interventional radiologists with islet cell transplantation patient selection, procedure technique, clinical outcomes, and future clinical and research avenues.

Feasibility, safety, and efficacy of percutaneous transhepatic injection of beta-cell grafts

PURPOSE

To evaluate the safety, feasibility, and clinical efficacy of percutaneous transhepatic injection of beta-cell grafts in patients with type 1 diabetes mellitus.

MATERIALS AND METHODS

Between December 2001 and November 2003, 15 patients with C-peptide-negative type 1 diabetes underwent 31 percutaneous injections for intraportal implantation of beta-cell grafts. Grafts consisted of cultured beta-cell preparations as previously described. In 13 cases, the transplant procedure was done under sedation, whereas in 18 cases, general anesthesia was given. In all procedures, percutaneous access to the right portal vein occurred under ultrasound (US) guidance with use of a microbore puncture needle. The subsequent catheterization of the main portal vein was performed under fluoroscopic and angiographic control with use of a microbore delivery catheter and guide wire. Clinical, biochemical, and radiologic evaluation was performed before and after the procedure.

RESULTS

In all cases, it was possible to access the portal vein (median number of needle passes, 1; range, 1-6). The volume of cultured beta-cell grafts injected for each transplantation averaged 0.58 mL (range, 0.26-1.60 mL) and the mean recorded procedure time (from puncture to catheter withdrawal) was 19 minutes (range, 10-80 min). Three patients presented with transient abdominal pain immediately after the procedure; postprocedural duplex US of the liver revealed a patent portal vein and end branches in all cases and a minor perihepatic fluid collection in another three patients. From the end of week 1 to week 3, a mean 3.8-fold increase in liver aminotransferase levels was measured in all recipients after the first implantation session. A similar increase was seen in only one patient after a second transplantation session. At 6 months after transplantation, 13 of 15 patients (86%) had a functioning graft with plasma C-peptide levels greater than 0.5 ng/mL.

CONCLUSIONS

The combined US, fluoroscopic, and angiographic monitoring of percutaneous transhepatic injection with use of a microbore delivery catheter is a safe and reproducible radiologic procedure for transplantation of beta-cell grafts in diabetic patients. Increased posttransplantation C-peptide levels, which demonstrate acceptable graft function, can be obtained.