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.
Kitano
Masayuki
M
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Kinki University School of Medicine, Osaka-Sayama, Japan. m-kitano@med.kindai.ac.jp
Sakamoto
Hiroki
H
Das
Kshaunish
K
Komaki
Takamitsu
T
Kudo
Masatoshi
M
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