The Effect of Vacuum-assisted Closure on the Tissue Oxygenation of Venous Ulcers: A Pilot Study

9/15/2009
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Author(s):

Manar Khashram, MB ChB; Justin A. Roake, MB ChB, DPhil, FRCS, FRACS(Vasc); David R. Lewis, MB ChB, MD, EBSQ(Vasc), FRACS, FRCS

Initial sensor positions were marked with a surgical marker and remarked on day 3 (during dressing change) to ensure that measurements were obtained from the same skin areas.

Due to financial constraints in the public system, a Duplex ultrasound scan of the venous system to identify reflux in the deep or perforator veins was not performed. However, as we measured the response of tissue oxygenation with VAC therapy, the presence of reflux in the deep system would probably not affect the results of this study.

TCOM is used to assess patients being considered for HBOT, to monitor the response to HBOT, and to predict the healing patterns of lower limb amputation levels.^17,22–24 Studies have revealed that in order for wounds to heal successfully, TcPO2 must remain > 40 mmHg.²³ However, a similar study suggests that TCOM does not significantly predict venous ulcer recurrence in patients with healed venous ulcers.²⁵

A study of negative pressure therapy in induced wounds in a rabbit model showed the negative pressure increased blood flow by increasing capillary density and the caliber diameter.⁹ These acquired experimental wounds might differ significantly from chronic venous ulceration in humans and this may partially explain the lack of observed change in TCOM in this study. Christenson²⁶ showed that patients with venous ulcers had elevated subcutaneous and intramuscular pressures and reduced TcPO2. Patients who had subcutaneous fasciotomy following superficial reflux elimination surgery had significantly improved wound healing rates and improved TcPO2 compared to the group who had surgery alone.²⁶ This possibly explains why TcPO2 following negative pressure therapy did not improve during our observed period.

Intermittent compression treatment has been shown to improve skin perfusion and tissue oxygenation of venous ulcers when applied over a 60-minute period.²⁷ Future experiments using quantitative techniques such as capillary microscopy, laser Doppler flowmeter and TCOM in patients with venous ulcers can be used to examine the skin blood flow response while TNP is applied in situ and post therapy. In addition, longer study duration might reveal a more established change in the microcirculation.

Conclusion

Negative pressure therapy applied over a 6-day period did not change oxygen partial pressure of the skin close to chronic venous ulcers. However, the study demonstrated moderate tissue hypoxia despite normal ABPIs.

Acknowledgments

The authors thank Dr. Mike Davis and the nursing staff from the Hyperbaric Medicine Unit at Christchurch Hospital for access to their facility, Intermed-KCI Auckland for providing the VAC equipment, and Dr. John Pearson for his statistical assistance in manuscript preparation.

Disclaimer: All VAC equipment was provided by Intermed-KCI. This did not influence the study design, data analysis, or submission of the manuscript for publication.

References:

1. Browse NL, Burnand KG. The cause of venous ulceration. Lancet. 1982;2(8292):243–245.
2. Coleridge Smith PD, Thomas P, Scurr JH, Dormandy JA. Causes of venous ulceration: a new hypothesis? Br Med J (Clin Red Ed). 1988;296(6638):1726–1727.
3. Hunt TK. The physiology of wound healing. Ann Emerg Med. 1988;17(12):1265–1273.
4. Robson MC. Disturbances of wound healing. Ann Emerg Med. 1988;17(12):1274–1278.
5. Smart D, Bennett M, Mitchell S. Transcutaneous oximetry, problem wounds and hyperbaric oxygen therapy. Diving Hyperb Med. 2006;36(2):72–86.
6. Messmer K, ed. Microcirculation in Chronic Venous Insufficiency; vol 23. Basel, Switzerland: Karger; 1999.
7. Morykwas MJ, Argenta LC, Shelton-Brown EI, McGuirt W. Vacuum-assisted closure: a new method for wound closure and treatment: animal studies and basic foundation. Ann Plast Surg. 1997;38(6):553–562.
8. Fabian TS, Kaufman HJ, Lett ED, et al. The evaluation of subatmospheric pressure and hyperbaric oxygen in ischemic full-thickness wound healing. Am Surg. 2000;66(12):1136–1143.
9. Chen SZ, Li J, Li XY, Xu LS. Effects of vacuum-assisted closure on wound microcirculation: an experimental study. Asian J Surg. 2005;28(3):211–217.
10. Wackenfors A, Sjögren J, Gustafsson R, Algotsson L, Ingemansson R, Malmsjö M. Effects of vacuum-assisted closure therapy on inguinal wound edge microvascular blood flow. Wound Repair Regen. 2004;12(6):600–606.
11. Eklöf B, Rutherford RB, Bergan JJ, et al. Revision of the CEAP classification for chronic venous disorders: consensus statement. J Vasc Surg. 2004;40(6):1248–1252.
12. Blair SD, Wright DD, Backhouse CM, Riddle E, McCollum CN. Sustained compression and healing of chronic venous ulcers. BMJ. 1988;297(6657):1159–1161.
13. Khashram M, Huggan P, Ikram R, Chambers S, Roake JA, Lewis DR. Effect of TNP on the microbiology of venous ulcers: a pilot study. J Wound Care. 2009;18(4):164–167.
14. Lorée S, Dompmartin A, Penven K, Harel D, Leroy D. Is vacuum assisted closure a valid technique for debriding chronic leg ulcers? J Wound Care. 2004;13(6):249–252.
15. Sheffield PJ. Measuring tissue oxygen tension: a review. Undersea Hyperb Med. 1998;25(3):179–188.
16. Jünger M, Steins A, Hahn M, Häfner HM. Microcirculatory dysfunction in chronic venous insufficiency (CVI). Microcirculation. 2000;7(6 Pt 2):S3–S12.
17. Cina C, Katsamouris A, Megerman J, et al. Utility of transcutaneous oxygen tension measurements in peripheral arterial occlusive disease. J Vasc Surg. 1984;1(2):362–371.
18. Byrne P, Naughton PM, O’Higgins NJ. Transcutaneous oxygen tension (PtcO2) in the lower limbs in venous disease. Br J Surg. 1984;71(12):990.
19. Clyne CA, Ramsden WH, Chant AD, Webster JH. Oxygen tension on the skin of the gaiter area of limbs with venous disease. Br J Surg. 1985;72(8):644–647.
20. Moosa HH, Falanga V, Steed DL, et al. Oxygen diffusion in chronic venous ulceration. J Cardiovasc Surg (Torino). 1987;28(4):464–467.
21. Nemeth AJ, Eaglstein WH, Falanga V. Clinical parameters and transcutaneous oxygen measurements for the prognosis of venous ulcers. J Am Acad Dermatol. 1989;20(2 Pt 1):186–190.
22. Dowd GS. Predicting stump healing following amputation for peripheral vascular disease using the transcutaneous oxygen monitor. Ann R Coll Surg Engl. 1987;69(1):31–35.
23. Hopf HW. Development of subcutaneous wound oxygen measurement in humans: contributions of Thomas K. Hunt, MD. Wound Repair Regen. 2003;11(6):424–430.
24. Padberg FT Jr, Back TL, Hart LC, Franco CD. Comparison of heated-probe laser Doppler and transcutaneous oxygen measurements for predicting outcome of ischemic wounds. J Cardiovasc Surg. 1992;33(6):715–722.
25. Stacey MC, Burnand KG, Layer GT, Pattison M. Transcutaneous oxygen tensions in assessing the treatment of healed venous ulcers. Br J Surg. 1990;77(9):1050–1054.
26. Christenson JT. Postthrombotic or non-postthrombotic severe venous insufficiency: impact of removal of superficial venous reflux with or without subcutaneous fasciotomy. J Vasc Surg. 2007;46(2):316–321.
27. Kolari PJ, Pekanmäki K. Effects of intermittent compression treatment on skin perfusion and oxygenation in lower legs with venous ulcers. Vasa. 1987;16(4):312–317.