Prevention of post thrombotic syndrome with Pycnogenol® in a twelve month study

Panminerva Med. 2011 Sep;53(3 Suppl 1):21-7.


Aim: Post-thrombotic syndrome is a common complication following deep vein thrombosis. The aim of this twelve month registry study was to compare the efficacy of compression stockings and per oral administration of Pycnogenol® standardized pine bark extract on the severity and incidence of post thrombotic syndrome signs and symptoms.

Methods: One hundred fifty-six patients with a single, major episode of proximal deep vein thrombosis (DVT) were assigned to one of three groups receiving treatment with either compression stockings (group 1), Pycnogenol® (group 2) or the combination of both (group 3) over an investigational period of one year. The study evaluated treatment on edema using a scoring system, the ankle circumference, and the limb volume as ratio to the healthy contralateral limb.

Results: Two new incidents of DVT occurred in the group of 55 patients wearing compression stockings between the third and sixth months, whereas no DVT cases occurred in the two other groups which took Pycnogenol®. The edema symptom score was gradually decreased in all three groups during the one year treatment period. Pycnogenol® was significantly more effective from six months onwards than compression stockings for relieving edema symptoms (P<0.05). Symptoms were more effectively reduced with the combination of Pycnogenol® and compression stockings than with the individual regimen alone (P<0.05). Limb volume and ankle circumference were likewise more effectively reduced with Pycnogenol® plus stockings than with compression stockings alone after six months. Ambulatory venous pressure progressively decreased in all three groups after twelve months treatment as compared to baseline. Compression stockings and Pycnogenol® were of comparable efficacy, there were no significant differences of ambulatory venous pressure between groups following twelve months treatment. Laser Doppler flowmetry at the dorsum of feet showed improved micro-circulation which was further demonstrated by increased pO2 and decreased pCO2. Importantly, none of the patients developed ulcerations during the observational period.

Conclusion: This study suggests that Pycnogenol® may have significant long-term protective efficacy for individuals following a thrombotic event. Moreover, Pycnogenol® appears to be at least as effective for post-thrombosis management as compression stockings, while the combination of both is superior. An important aspect is the patient compliance which was found to be much better in the Pycnogenol® group with two drop-outs due to non-medical reasons, whereas in the compression stockings group eighteen patients were lost to follow-up because wearing stockings at higher temperatures is bothersome.

Publication types

  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Ankle
  • Combined Modality Therapy
  • Edema / drug therapy
  • Edema / pathology
  • Edema / therapy
  • Female
  • Flavonoids / therapeutic use*
  • Humans
  • Male
  • Middle Aged
  • Phytotherapy
  • Plant Extracts
  • Platelet Aggregation Inhibitors / therapeutic use
  • Postthrombotic Syndrome / prevention & control*
  • Stockings, Compression
  • Venous Thrombosis / drug therapy*
  • Venous Thrombosis / pathology
  • Venous Thrombosis / therapy


  • Flavonoids
  • Plant Extracts
  • Platelet Aggregation Inhibitors
  • pycnogenols