Objective: Near-infrared spectroscopy (NIRS) is a noninvasive technique
with the potential to determine the degree of tissue oxygenation. The
aim of the current study was to investigate the use of NIRS as a
reliable method of detecting calf muscle pump dysfunction in groups of
patients with venous disease.
Methods: Patients with superficial venous insufficiency (SW) or history
of deep venous thrombosis (DVT) were classified according to the
comprehensive classification system for chronic venous disorders
(clinical class, etiology, anatomy, and pathophysiology) and compared
with controls (GROUP variable). A 10-stage evaluation of ambulatory
venous function was performed, and corresponding values of calf regional
oxygen saturation (crSaO(2), %) at each phase were recorded (TIME
variable). Thereafter, the percentage changes of crSaO(2) values (A
scores, %) between a given phase and the reference phase were
estimated. Differences among groups and phases were evaluated using
analysis of variance. Subgroup analysis between C0-C2 and C3-C6 patients
was performed. The receiver operating characteristic curve analysis was
used to detect the best predictive capability for SW and DVT.
Results: A total of 30 patients with SW, 31 patients with DVT, and 34
controls were included in the study. A statistically significant effect
of TIME (F = 382.4; P < .001) and TIME x GROUP interaction (F = 6.3; P <
.001) was recorded. Concerning prediction, we found a statistically
significant area under the curve (AUC) for SW (AUC = 0.72; 95%
confidence interval, 0.58-0.83; P = .003) and for DVT (AUC = 0.83; 95%
confidence interval, 0.71-0.92; P < .0001) patients.
Conclusions: The measurement of crSaO(2) using NIBS detected alterations
in calf muscle pump oxygenation during exercise and differences in
tissue oxygenation among SW patients, DVT patients, and controls. NIBS
may represent a reliable noninvasive tool for the study of calf muscle
dysfunction in venous disease and a useful vehicle for generating
testable hypotheses in the laboratory setting
