Minimally Invasive VAC Therapy with Instillation for Treating Infected Skin-Implant Interfaces in Percutaneous Osseointegrated Devices
Abstract
Any major limb amputation is a devastating event that results in a dramatic change to one’s personal and professional life. In the U.S. alone, there are currently 1.6 million patients living with one or more amputations. Of these cases, 846,000 limbs (54%) were lost due to poor blood flow as seen in diabetes, 705,000 limbs (45%) were lost due to trauma, and 18,000 limbs (1%) were lost due to cancer. Unfortunately, due to the increasing number of metabolic syndromic diseases in the developed world, these numbers will only be expected to increase over the next several generations. Locally, within the United States, high-energy motor vehicle collisions and all-terrain vehicle accidents are the top contributors to the number of limbs amputated due to trauma. Abroad, advancements in battlefield medicine and technology have saved more combatants than ever before. Unfortunately, modern body armor provides inadequate protection for the extremities; thus, many U.S. warriors are returning from combat with traumatic limb amputations. Many of these patients are receiving treatment within either the Walter Reed National Military Medical Center or Brooke Army Medical Center. The majority of these patients are likely to require follow-up care, extensive rehabilitation, and expensive prosthetic services from the Military and Department of Veterans Affairs healthcare systems. For most amputees, the standard of care currently is the socket-suspension of an exoprosthesis to the residual limb, but this is not suitable for all limb loss patients. The technology fails when applied to short residual limbs that are often caused by severe battlefield injuries involving improvised explosive devices (IEDs). Even patients successfully fitted with suspension-type attachments can be dissatisfied because they frequently experience discomfort and pain. Blast-related heterotopic ossification (HO; i.e., abnormal bone formation within the skeletal muscles) is prevalent within many of these patients, which further exacerbates suspension fit problems. In fact, HO patients loading their suspension-type attachments can compress local soft tissues, which can cause severe skin necrosis. Especially for these individuals, percutaneous osseointegrated (OI) prosthetics are currently a viable alternative. Percutaneous OI prosthetics not only eliminate many problems associated with socket-suspension, but also allow essentially pain-free ambulation and virtually unlimited prosthesis “wear time” each day. The ability to sit after ambulation without the need to remove bilateral sockets, as well as the greater economy of energy and increased endurance, markedly improve patients’ quality of life. Sadly, the weak link of this superior technology is often infection that originates from the implant post exit sites. Currently, infection rates with the percutaneous OI prosthetics are being reported as high as 54%. Our research group has been working since 2006 to bring percutaneous OI prosthetics to the United States for all amputees. Data from our Food and Drug Administration’s (FDA) early feasibility study showed an infection rate of 20% over a year. Generally, when infection occurs, patients are treated with an appropriate antibiotic therapy targeting pathogenic bacteria locally, orally, or systemically. Although somewhat successful, these therapies cannot completely eradicate bioburdens that colonize the implant surface. As a consequence, patients often have reoccurring infections in deeper tissues and at the bone-implant interface and may even develop antibiotic resistance. Thus, there is a need for developing alternative antibiotic therapies. One potential method for treating infected tissue locally, as well as to clean the skin-implant interface, is through the direct application of negative pressure wound therapy with installation (NPWTi) at the implant exit site. Studies report that, with NPWTi, complex wounds take fewer days to heal. This t
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 10, 2021
- Source ID
- W81XWH2010606
Entities
People
- Jayant Agarwal
Organizations
- United States Army
- University of Utah