EUS-guided in vivo microdialysis of the pancreas: a novel technique with potential diagnostic and therapeutic application.
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.


METHODS
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 microL/minute.


METHODS
Experiments on 8 beagle dogs.


METHODS
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 microg/mL), and gradually declined thereafter. No local bleeding or accumulation of fluid around the pancreas was observed.


CONCLUSIONS
Sampling was unsuccessful in 2 of the 8 dogs because the probe broke while being inserted into the pancreatic parenchyma.


CONCLUSIONS
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.
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kinki University School of Medicine, Osaka-Sayama, Japan. m-kitano@med.kindai.ac.jp
Masayuki
M
Kitano
Hiroki
H
Sakamoto
Kshaunish
K
Das
Takamitsu
T
Komaki
Masatoshi
M
Kudo
D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000032:analysis*; D004285:Dogs; D019160:Endosonography; D005240:Feasibility Studies; D005472:Fluorouracil / Q000032:analysis*; D008297:Male; D017551:Microdialysis / Q000379:methods*; D010179:Pancreas / Q000737:chemistry*
D000964:Antimetabolites, Antineoplastic; D005472:Fluorouracil