French Oak Wood (Quercus robur) Extract (Robuvit) in Primary Lymphedema: A Supplement, Pilot, Registry Evaluation.

The aim of this pilot supplement study was the evaluation of an oak wood extract (Robuvit, Quercus robur [QR], Horphag Research) in an 8-week registry study on lymphatic signs in primary lymphedema. Subjects with primary lymphedema confined to a single leg without skin changes or ulcerations were followed for at least 8 weeks. Lymphedema was mainly present distally (below the knee). Three groups were formed: one group used only the standard management for lymphedema; one used the same management plus 300 mg Robuvit; and one used the standard management plus 600 mg of Robuvit. The three groups were comparable. After 8 weeks the variation in leg volume was on average -6.2% with standard management, -15% in the QR 300 mg group, and -18.9% in the 600 mg group. The edema score was also significantly lower at 8 weeks in the two QR groups. The variation in proteins in the interstitial fluid in comparison with initial values was -14.8% in controls in comparison with -29.9% in QR 300 mg group and -36.9% in QR 600 mg group. Skin flux significantly improved (increased) in the two QR groups. Ultrasound pretibial skin thickness was decreased on average 6% in controls versus 10.3% in the low-dose QR group and 11.8% in the higher dose group. Perimalleolar thickness was decreased 7% in controls and more in the two QR groups. Ankle circumference was decreased 4.4% in controls and more in the two supplement groups. This pilot registry indicates that Robuvit can be effective in the management of primary lymphedema. More patients and longer evaluation periods are needed.