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Bandaging and blood flow in lower leg ulcers.
- Les O. Simpson (5 May 2009)
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Les O. Simpson, retired experimental pathologist Dunedin, New Zealand 9077
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Because there is no mention or discussion of other treatment options for intractable leg ulcers, this report could be construed as an indication that bandaging is the only accepted treatment. However, as pressure bandaging will impair venous return, it has yet to be explained just why pressure bandaging is curative. As ulcers heal with bed rest, when the effects of gravity on venous return are greatly reduced, it would seem that blood flow is an important factor. The authors quote a paper which states, "Compression bandaging is thought to assist ulcer healing by reducing distension in leg veins and accelerating blood flow." Just how blood flow would be accelerated by putting pressure on the vein was not explained, as it would require an increased rate of flow in capillaries and in post- capillary venules. However, the mention of blood flow is relevant as there is good reason to consider that the primary cause of lower leg ulcers is the the effects of increased blood viscosity and poorly deformable red cells in causing a region of stasis. Lower leg ulcers are problems associated with diabetes, increasing age and in obesity, and those conditions share the common feature of increased blood viscosity and poorly deformable red cells. What could be important is that there are agents which can improve the flow properties of the blood, which means that by using such agents it would be possible to treat the cause of the ulcers, in contrast to the focal effects of bandaging. In 1986 (1) we reported the beneficial effects of 4 grams daily of evening primrose oil in the treatment of intractable leg ulcers. Prior to the study we had measured the nail fold temperatures of the big toe of the ulcer-carrying leg and in age-related people without ulcers. The lower temperatures in those with ulcers (the lowest was 13.8 degrees C) was taken as an indication of impaired blood flow. In addition, we had assessed the filtrability of blood samples from the blood donor panel and found that those with ages of 59 years or younger had more filtrable blood that those aged 60 years or older. Those findings were consistent with a 1998 report by Ajmani and Rifkind (2). Our interest in evening primrose oil was that it was a rich source of gammalinolenic acid, a precursor to prostaglandin E1 (PGE1). A daily intake of 4 grams has been shown to produce a significant rise in the blood levels of PGE1. In 1974, Kury et al (3) reported that PGE1 increased the fluidity of the red cell membrane, and in the following year, Rasmussen et al (4) reported that PGE1 increased blood filterability. We reported similar findings, when it was found that evening primrose oil increased the filterability of cigarette smoker's blood. (5) In conjunction with community nurses, we embarked on a study of leg ulcers under the care of nurses, and every second patient was offered 4 grams daily of evening primrose oil, as well as usual care. After 6 weeks there were obvious benefits in those taking the oil and at 20 weeks 50% of the ulcers had healed and in 44.4% the lesions were much smaller. Thirtyfive weeks after the completion of the study, none of the healed ulcers had broken down. In our report we cited other agents which had been helpful. A 1971 study of the treatment of venous insufficiency with hydroxyethylrutosides noted that a varicose ulcer in one of the participants had healed in 3 weeks. The translated abstract of a 1979 German paper reported that pentoxifylline was effective in the treatment of leg ulcers. It is noteworthy that pentoxifylline reduces blood viscosity and improves red cell deformability. So it was not surprising that a Cochrane review of the effects of pentoxifylline in the treatment of venous leg ulcers in 2002 (6) should state, "Combining eight trials that compared pentoxifylline with placebo (with or without compression) demonstrated that pentoxifylline is more effective than placebo in terms of complete ulcer healing or significant improvement." That finding is comparable to the beneficial effects of evening primrose oil. In addition there was a 1990 report of the successful treatment of sickle cell leg ulcers with pentoxifylline. (7) What remains unexplained is why such reports which show clearly the role of impaired blood flow in leg ulcers, have failed to gain recognition in the field of ulcer treatment. While the unexplained mechanisms of pressure bandaging may produce localised healing, the effects of improving the flow properties of the blood are systemic, with the potential to improve the quality of life. References. 1. Simpson LO, Shand BI, Olds RJ. The effects of dietary supplementation with efamol on the healing rate of intractable leg ulcers: a pilot study. NZ Fam Physn 1986;13:66-70. 2. Ajmani RS, Rifkind JM. Hemorheological changes during human aging. Gerontology 1998; 44: 111-20. 3. Kury PG, Ramwell PW, McConnell HM. Th effect of prostaglandin E1 on the human erythrocyte as monitored by spin labels. Biochim Biophys Res Commun 1974; 56: 478-83. 4. Rasmussen H, Lake W, Allen JE. The effect of catecholamines and prostaglandins upon human and rat erythrocytes. Biochim Biophys Acta 1975; 411; 63-73. 5. Simpson LO, Olds RJ, Hunter JA. Changes in rheologic properties of blood in cigarette smokers taking Efamol: a pilot study. Proc Univ Otago Med Sch 1984; 62: 122-3. 6. Jull AB, Waters J, Arroll B. Pentoxifylline for treating leg ulcers. Cochrane Database Syst Rev 2002;(1) CD001733. 7. Frost ML, Treadwell P. Treatment of sickle cell leg ulcers with pentoxifylline. Int J Dermatol 1990; 29:375-6. Competing interests: None declared |
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