A Randomised, Blinded Study to Assess the Effect of Betadine in the Groin Wound of Patients Undergoing Primary Varicose Vein Surgery

Introduction. Varicose vein surgery is common. Worldwide, the commonest indication for this type of surgery is cosmesis. However, there are also some medical indications, including venous eczema, lipodermatosclerosis and venous ulceration. The surgery is usually straight forward and can in most instances be done as a day case. Patient and medical practitioner expectations are therefore high. Surgery in the groin is notorious for its risk of wound infection. In primary varicose vein surgery, the groin wound infection can rate can be as high as 20% 1. A more realistic figure might be approximately 10% (Sains PS, Reddy KM, Jones HJS and Derodra JK. Audit of varicose vein surgery: the patients perspective. Phlebology 2005 20(4) 179 - 182.)

A small prospective study has been conducted at the Royal Hobart Hospital to establish the wound infection rate in this hospital. All procedures were performed under the care of a single surgeon who routinely soaks the groin wound in Betadine. Patients were followed up on a weekly basis for six weeks and had wound inspections by an independent nurse consultant. Of the 11 patients (five female, mean age 50.3years, range 31 - 74 years, mean weight 92kg, range 60 - 130kg, mean body mass index 41) who have now completed six weeks of follow up, there were a total of 17 groin wounds. Only one of these (6%) has had an infection. Unfortunately, this study was terminated prematurely as the independent nurse who was performing the wound assessments has been replaced and there was a lag interval of at least 6 weeks before her replacement was due to start.

One of the major problems with varicose vein surgery is the risk of recurrence. Recurrent varicose veins are more difficult to deal with than primary varicose veins and thus every effort must be made at the time of the primary surgery to perform an operation with the lowest recurrence rate. Despite adequate surgery, recurrence can develop via neovascularisation in the groin. This may be part of the normal wound healing process. If neovascularisation can be prevented, this may reduce the recurrence rate. However, this should not be at the detriment of healing of the groin wound.

Previous in vitro studies have looked at the effect of povidone-iodine on some of the components of wound healing. It can be toxic to granulocytes, monocytes and keratinocytes 2, 3 . Dilute Povidone-Iodine solutions are also known to inhibit human skin fibroblast growth in vitro 4, 5. In vivo studies, however, have failed to show any clinically significant delay in wound healing when wounds are irrigated with povidine iodine 4.

Povidine-iodine has bacteriocidal effects 6. Could it be that those groin wounds which develop an infection develop neovascularisation as part of the inflammatory response? Topical antimicrobial agents are commonly used in wound management. This is based on the premise that reduction of bacterial contamination aids wound healing. Sindelar showed that the incidence of superficial infections of surgical wounds irrigated with povidone-iodine solution prior to closure was less than wounds irrigated with saline (2.9% vs. 15.1%) 7 .