Cath Lab Digest

Background

Hemophilia A is a congenital bleeding disorder where factor VIII, a protein necessary for normal coagulation, is present in decreased amounts or is completely absent in the blood stream. Of patients with this disorder, 21% to 33% will develop an inhibitor or antibody against factor VIII,¹ preventing the use of conventional treatment (replacement of the factor VIII protein). Historically, people with high titer inhibitors are treated with bypassing agents. These infusion products bypass the requirement for factor VIII or IX in the coagulation chain.¹ However, bypassing agents are not as reliable in achieving hemostasis as factor VIII and their effect cannot be adequately monitored with specific laboratory tests,² especially in a surgical setting. Therefore, non-invasive procedures should be considered whenever possible and surgical intervention should be used only as a last resort. Traditional methods of medical treatment may not be possible and alternative treatments must be sought.

One such alternative is maggot debridement therapy (MDT) - the medical use of live maggots (Phaenicia sericata, green blowfly larvae) for cleaning nonhealing wounds. From as early as the 1500s, physicians noted that soldiers with worm-infested wounds tended to heal better than those with non-infested wounds. William Baer, an orthopedic surgeon at Johns Hopkins University, Baltimore, Md., was the first physician in the US to actively promote maggot therapy; his results were published posthumously by his colleagues in 1932. The use of maggots lost favor after WWII with the introduction of antibiotic therapy and the improvement of surgical techniques and was used only occasionally during the 1970s and 1980s when antibiotics, surgery, and other modalities of modern medicine failed.³

Sherman et al⁴ performed prospective controlled studies to examine the utility of MDT in the treatment of soft tissue wounds. They found that medicinal maggots have three actions: They debride wounds by dissolving necrotic tissue, they disinfect the wound by killing bacteria, and they stimulate wound healing with proteolytic enzymes and secretions of such substances as calcium carbonate, allantoin, and urea.⁴ As such, this modality was shown to be a viable treatment option for many patients with necrotic or nonhealing wounds. The controlled studies demonstrated that MDT debrided wounds faster than other nonsurgical modalities, including hydrocolloid pads, topical disinfectants (one-fourth strength Dakin's solution, acetic acid), and bacitracin saline wet-to-dry gauze packs. Subsequent case reports support these findings.

History

Thirty-nine-year-old Mr. J was admitted to the hospital in September 2002 with a necrotic ulcer of his right foot, complicated by a history of severe factor VIII deficit hemophilia with a high titer inhibitor and hepatitis C, contracted several years before as a result of using blood products to control his hemophilia-related bleeding. Because he was involved in a motor vehicle accident when he was 20 that caused a non-union of his left femur, he uses a wheelchair full time for mobility. Mr. J described his current pain at a level 8 to 10. On admission, wound cultures showed no bacterial growth to explain his symptoms. Magnetic resonance imaging ruled out osteomyelitis.