Prevention of Vascular Graft Infection With Hypochlorous Acid - A Pilot Study

Background Infection of prosthetic bypass grafts is a major concern in patients who undergo vascular surgical procedures, since they are associated with significant mortality, morbidity and healthcare costs. Vascular prosthetic graft infections (VGI) are known to occur in 0.5% to 5.0% of intracavity grafts and in as many as 6% of extra-cavity grafts which involve surgery in the groin. VGI rates are higher in critical limb ischemia and in emergent procedures.

Infections of aortic grafts have a mortality rate of between 24 and 75%, and lower limb graft infections have amputation rates of up to 70%.

Intraoperative contamination of vascular grafts is considered to be the most common source of graft infection. Hematogenous spread from infections in other areas such as pneumonia, urinary tract, gastrointestinal tract, etc. are much less common than intraoperative contamination and are more likely in the early post-operative period.

Reducing VGI has clear benefits for the patient and also for the healthcare system. A Cochrane review on the prevention of surgical site infection was unable to identify any clear evidence for lavage of the wound, however it did suggest that the use of antibacterial solutions compared to non-antibacterial solutions may reduce surgical site infections. Hypochlorous acid (HOCl) is an antimicrobial solution that occurs naturally in the human body in white cells as a defence against bacteria. HOCl ultimately degrades to saline and water and leaves no residual harmful chemicals.

HOCl has been used in a number of clinical evaluations in patients with different medical conditions to reduce the risk of subsequent infection, including patients with perforated appendicitis, peritonitis from different sources, and coronary artery bypass graft surgery. There have been no concerns with patient safety and the studies do suggest efficacy in these different clinical conditions. Hypochlorous acid is also widely used in the management of patients with chronic wounds and burns in Canada. There has been no evaluation of its use in preventing VGI. A Canadian manufacturer of hypochlorous acid, Sterasure Inc (now Biomiq Inc), has produced a version of hypochlorous acid in sterile packaging, that is ideal for use in the operating room. This sterile product has Health Canada approval for use in wound care and soft tissue irrigation in chronic and acute wounds. It does not have explicit Health Canada approval for the use in the prevention of VGI and health Canada approval is being sought for its use in this clinical trial. There are no published data on the use of HOCl to prevent vascular graft infection. The cost of the sterile preparation of hypochlorous acid is <$50 per 500 ml.