EUS-guided in vivo microdialysis of the pancreas: a novel technique with potential diagnostic and therapeutic application
Received 11 February 2009; accepted 29 May 2009. published online 21 October 2009.
Background
Microdialysis has been used in vivo to measure dynamic temporal variations in extracellular or interstitial concentrations of non-protein–bound substances that are unstable in the systemic circulation.
Objective
To evaluate the technical feasibility and possible complications of EUS-guided in vivo microdialysis of the pancreas.
Design and Intervention
Under the guidance of an echoendoscope inserted into the stomach of each dog, the pancreatic parenchyma was punctured by using a 19-gauge needle. A specially developed microdialysis probe threaded through the lumen of the 19-gauge needle was positioned in the pancreas. The probe was constantly perfused with saline solution at a flow rate of 1.0 μL/minute.
Setting
Experiments on 8 beagle dogs.
Main Outcome Measurements
The concentration of 5-fluorouracil (5-FU) in the microdialysate was measured at 10-minute intervals, once before and for 8 times after a single (20 mg/kg) bolus intravenous infusion of 5-FU.
Results
Following the administration of 5-FU, the concentration of 5-FU in all macrodialysate samples exceeded the cut-off value by more than 100-fold. The 5-FU levels in the microdialysate increased rapidly, peaked by 10 minutes (13.9 μg/mL), and gradually declined thereafter. No local bleeding or accumulation of fluid around the pancreas was observed.
Limitation
Sampling was unsuccessful in 2 of the 8 dogs because the probe broke while being inserted into the pancreatic parenchyma.
Conclusion
EUS-guided pancreatic microdialysis is feasible and has multiple potential clinical/therapeutic applications, including monitoring pharmacokinetics focally and detecting novel biomarkers that are unstable or undetectable in the plasma.
Current affiliations: Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kinki University School of Medicine, Osaka-Sayama, Japan
Reprint requests: Masayuki Kitano, MD, PhD, Divison of Gastroenterology and Hepatology, Department of Internal Medicine, Kinki University School of Medicine, 377-2 Ohno-higashi, Osaka-sayama 589-8511, Japan.
DISCLOSURE: All authors disclosed no financial relationships relevant to this publication. The microdialysis probe was made for this study by Eicom Co. Ltd. according to our specifications, but there was no financial relationship. The microdialysis probe and the microinfusion pump are commercially available. This study was supported by grants from the Japan Society for Promotion of Science, the Japan Research Foundation for Clinical Pharmacology, and the Japanese Foundation for Research and Promotion of Endoscopy.
If you would like to chat with an author of this article, you may contact Dr. Kitano at m-kitano@med.kindai.ac.jp.
ABSTRACT