Comparison of gas clearance and radioactive microspheres for pancreatic blood flow measurement.
Measurement of pancreatic blood flow (PBF) is technically demanding. Although radiolabeled microspheres are considered the "gold standard" for PBF assessment, they have practical limitations. In the current study, H2 and xenon-133 gas clearance techniques were adapted to PBF measurement and compared to radiolabeled microsphere techniques. Simultaneous measurements of PBF were made using either hydrogen or xenon gas washout and radiolabeled microspheres. Measurements were made under basal, vasoconstricted (vasopressin 2U i.v. or nicotine 4 micrograms/kg/h) and stimulated (secretin 125 ng/kg/h or 2 U/kg i.v.) conditions (random order). Mean PBF was 26.9 +/- 5.3, 50.5 +/- 2.3 and 27.6 +/- 5.2 ml/min/100 g basally, 36.9 +/- 8.0, 90.1 +/- 18.9, and 81.7 +/- 14.5 ml/min/100 g in the stimulated state, and 24.2 +/- 7.8, 25.0 +/- 3.5, and 14.9 +/- 7.5 ml/min/100 g in the vasoconstricted state for hydrogen gas clearance, xenon gas clearance, and radiolabeled microspheres, respectively. The H2 clearance technique resulted in tissue trauma, was complicated by frequent electrode displacement, and correlated poorly (r2 = 0.36, p greater than 0.05) with microsphere values. In contrast, xenon clearance measurement had no apparent effect on the pancreas and correlated well (r2 = 0.83, p less than 0.01) with microsphere data. We conclude that xenon clearance offers an attractive, validated alternative to radiolabeled microspheres for measuring pancreatic blood flow.
Department of Surgery, Sepulveda Veterans Administration Medical Center, California.
A R
AR
DeMar
L S
LS
Graham
R
R
Lake
A S
AS
Fink
D000818:Animals; D004285:Dogs; D005740:Gases; D006859:Hydrogen; D008863:Microspheres; D010179:Pancreas / Q000098:blood supply*; D011868:Radioisotopes; D014980:Xenon Radioisotopes
D005740:Gases; D011868:Radioisotopes; D014980:Xenon Radioisotopes; D006859:Hydrogen