[Effects of hyperbaric oxygen therapy in the management of chronic wounds and its correlation with CD34(+) endothelial progenitor cells].

Objective: To evaluate the effects of hyperbaric oxygen (HBO) therapy in the management of chronic wound and observe the correlation between wound healing and CD34+ endothelial progenitor cells (EPCs).
Methods: A total of 119 patients with chronic wound in lower extremities lasting > 3 months were recruited for this randomized, single-center, placebo-controlled clinical trial. The changes of CD34+ average count before and after HBO therapy were detected by flow cytometry (FACS). There were 97 patients on long-term HBO therapy and in 22 patients on hyperbaric air therapy as control group. The CD34/Scal-1+ and CD34/CXCR4 dual-positive populations of gated cell were determined respectively by FACs. The outcomes of two groups were compared. Treatment was administered within a single-place hyperbaric chamber for 90-min daily (session duration 120 min) for 5 days a week for 4 weeks (20 treatment sessions).
Results: The wound size decreased at the 4-week end point (62.7% ± 22.3% in the HBO group vs 34.4% ± 20.6% in the control group, P < 0.05). After 10 episodes of HBO therapies for chronic non-healing wound, the peripheral CD34+ EPCs average count rose from 0.24% ± 0.03% at pre-treatment to 1.32% ± 0.05% while the number was 1.75% ± 0.17% after 20 episodes of HBO (P < 0.05). Both were significantly different from that of the patients at pre-treatment. However the overall circulating white cell count was not significantly elevated. The CD34/Scal-1+ and CD34/CXCR4 dual-positive populations of gated cell in HBO group were 5.8 and 5.2 folds than those at pre-treatment respectively. The number of EPCs was positively correlated with wound healing in lower extremities (correlation coefficient 0.84; P < 0.01).
Conclusion: Adjunctive treatment of HBO facilitates the healing of chronic non-healing wound in selected patients through the mobilization of EPCs.