Identifying Appropriate Interventionists for Lower-Limb Preservation

  Today's Wound Clinic would like to know the referral habits of our readers related to wound care interventionists. The results of this survey will be published in a future issue of the journal. The survey can be found at the following link: https://www.surveygizmo.com/s3/1281109/TWC-Reader-Survey-Working-with-Wound-Care-Interventionists.   To witness wound care centers evolve into “limb preservation centers” over roughly the past quarter century speaks to the demands of the market as well as the meeting of medical, business, and logical (yet sometimes opportunistic) marketing. The term “limb salvage” has become a common buzzword within the wound care community as the magnitude of the problem surrounding diabetic foot ulcer management has become increasingly apparent. However, not one medical specialty can truly claim ownership of limb salvage expertise over the years. Podiatrists, who focus on the lower extremity, would seem to have the most logical reason to capture the limb salvage market, but the concept of limb salvage has gained rapid acceptance among those in vascular medicine, with the advent of endovascular interventional procedures serving as the catalyst for a greater range of specialists to promote themselves as “limb salvage experts.” Interventional cardiologists, radiologists, and vascular surgeons all recognize the impact of limb preservation, and members within each specialty have marketed their practices as “limb salvage centers.”   Can anyone justifiably make these claims? How should wound care providers best determine whom to refer to and when? Definitive answers require practitioners within wound care centers to clearly understand the expertise available to them and to track the clinical success of interventionists they have used or are considering for their patients.

The Roots of Limb Salvage

  Interestingly, limb salvage initially referred to the surgical focus of neoplasm removal that would otherwise be treated by amputation.¹ Traditionally an orthopedic specialty, limb salvage focused on both adequate removal of bone tumors followed by bone and soft tissue reconstruction. The Ilizarov techniques utilized in Charcot foot reconstruction have further brought attention to the concept of limb preservation versus amputation, and certainly the acceptance of the concepts of advanced and evidence-based wound care have taken the concept of limb preservation into the medical mainstream.   As the population ages and the number of people living with diabetes continues to rise, the need for proficient and efficient wound healing and limb preservation specialists is sure to increase concomitantly. A unique opportunity exists for the multidisciplinary wound care team approach to emerge as the standard model for the delivery of care in limb preservation versus the informal, word-of-mouth network that presently exists. Let’s examine some of the basics, obstacles, and reasons for optimism in the emerging specialty of limb preservation.

Emerging From ‘Silos’

  It’s becoming cliché to hear the sentiment in wound care that many people are or are not “working in silos.” Although the comparison being made here refers to silos used on farms for storage (each silo on a farm is designated for one specific type of grain), the term has really come into vogue with the emergence of information technology systems and refers to “information silos,” or management systems that are incapable of reciprocal operation with other related information systems. Likewise, the term “silo effect” refers to a lack of communication and common goals being shared between departments within a given organization. Focusing on the patient’s need, ensuring quality outcomes, and reducing patient morbidity while operating within a viable fiscal management plan helps to create a shared purpose and vision.   While this may sound like an idyllic referral network within one’s practice, it is necessary as the changes resulting from healthcare reform begin to take hold on the practice of medicine. The “silo effect” is a fair assessment of how much of the medical community beyond wound care has long functioned. “Incapable of reciprocal operation with other related specialties” and a “lack of communication and common goals between departments in an organization” could just as easily describe experiences or the dynamic many of us have encountered when trying to engage specialists such as vascular surgeons in our patient care efforts.   Knowing, or not knowing, the scope of practice of each other’s specialties is part of the difficulty that exists when seeking to move beyond “silos” and into the dedicated limb preservation team. Finding the appropriate providers who share equally in the motivation to preserve limbs is another challenge.   Wound care providers must understand that identifying the correct endovascular specialist for individual patients may determine not only whether a patient could undergo a potentially unnecessary amputation, but may also hold a key as to long-term success and viability of a wound/limb salvage center.   Differentiating the differences among endovascular specialists is the first important step in integrating interventionists into the limb preservation team. That said, a brief overview and understanding of peripheral arterial disease (PAD) will enhance the process of wound specialists teaming with interventionists in the fields of radiology, cardiology, and vascular surgery.² Significant PAD (or the more serious life-and-limb-threatening versions), critical limb ischemia, and acute limb ischemia are often associated with multiple areas of occlusion (multisegmental disease) and presents bilaterally, although one extremity will typically be more symptomatic. Not everyone living with PAD requires intervention. However, the disease state results in atherosclerosis throughout the body and the presence of PAD correlates highly with the presence of coronary arterial and carotid disease. Therefore, screening of these patients is recommended on an annual basis by the American College of Cardiology and the American Heart Association, if the individual is 50 years or older and has a history of diabetes or tobacco use, or if he/she is 70 or older and in otherwise good health. The reasoning here is the increased risk of heart attack and stroke in addition to the complications seen in the lower extremity, such as claudication, rest pain upon elevation of the extremity, ulcer formation, and amputation. Vascular surgeons have long been those specialists who have received the referrals from wound care providers when revascularization of an ischemic limb has been needed. The “toe and flow” model championed by Lee Rogers, DPM, and George Andros, MD, et al, has been cited for its call for podiatrists to work closely with vascular surgeons, and vice versa.³    (For more on PAD, see the article “Peripheral Arterial Disease: Giving Appreciation to an Often-Overlooked Cause of Poor Wound Healing” in this issue.) While this relationship between specialties is an important consideration, the exclusion of cardiologists and radiologists from this model is less of an oversight than an illustration of how quickly the emergence of endovascular technology has created a paradigm shift in the way limb preservation is extending beyond the traditional team members.   Interventionists refer to vascular surgeons, cardiologists, and radiologists (as well as neurologists and neurosurgeons) who utilize endovascular techniques to restore perfusion to previously occluded arteries. Such techniques are typically minimally invasive and less traumatic than traditional surgical bypass procedures that have (until within the last 10 years) been standard of care for revascularization. Endovascular procedures are usually categorized as atherectomy (physical removal of plaque from arteries either through a cutting or rotating sanding device), stenting (placing of a metal mesh implant designed to keep artery patent), angioplasty (use of a balloon device to physically open a blocked artery), laser, and thrombolysis (when a blood clot has formed in an area of plaque or narrowing, a small catheter is placed at the site of the clot and a clot-dissolving drug is administered directly to the site. In some cases, thrombolysis is followed by angioplasty and/or stenting to further open the vessel).   Deciding which procedure(s) to employ is the decision of the interventionist. Techniques to be used are determined by the location and severity of the occlusion(s). Even the type of blockage can be a factor in that some plaque tends to be more “rubber-like” in texture, while some is far more calcified — more of the consistency of porcelain or cement. As far as vascular tests are concerned, the acuity of the situation will dictate the timing and tests that the interventionist will employ. It would not be appropriate for the wound specialist to order an angiogram or a magnetic resonance angiogram, for example. These tests are the domain of the interventionist. However, the wound care provider should have some familiarity with vascular testing for the sake of knowing which tests to consider and when to order them in order to expedite patient care. The additional ability to perform some cursory arterial tests may further expedite care in situations in which screening, such as an ankle-brachial index, transcutaneous pressure of oxygen, or skin perfusion pressure could validate a clinical concern. One important role the wound care provider plays that is often greatly appreciated by the interventionist is that of “post-procedure advisor.” Within the team approach to limb preservation, the continuum of care model has the wound care provider making timely referrals to the interventionist. After a successful endovascular procedure, the patient continues to be followed by the wound care specialist, who can utilize the same pre-procedure screening tests in the post-procedure setting. This is critical for several reasons. Remember, the typical PAD patient has multisegmental bilateral disease, and, therefore, is always at risk of developing an occlusion at another vessel or within the same vessel. Also, re-occlusion can occur in the same vessel. Diligent monitoring of these patients to the point of erring on the side of caution in communicating any suspicious changes back to the interventionist is always preferred over waiting for obvious ischemic changes to appear. Diligent monitoring of the patient after the intervention is not just sound wound care practice, but is now essential to avoid a 30-day readmission.

Determing Basis of Expertise

  There are other questions that wound care providers should ask themselves before choosing an interventionist to join in patient care: What special training do interventionists undergo to become proficient in endovascular techniques? Are all interventionists equal in knowledge and scope? How does one determine true aptitude when judging interventionists from a wound care provider’s perspective?   Some frank discussion is in order as the rapid evolution of endovascular medicine has facilitated the preservation of many limbs that would have previously been amputated less than a decade ago. Still, this emergence into the mainstream and arguably the new standard of care has created plenty of debate regarding the validity, fiscal responsibility, and examination of who is performing endovascular procedures. Similarities exist between wound care providers and interventionists in that the majority of training that occurs in each field is not typically part of post-graduate training or residency. Much of the clinical experiences obtained by both classes of providers stems from a personal desire or preference to practice in the respective specialty. Interventionists may receive peer-to-peer mentoring in on-site training programs that may be subsidized by industry. At face value, this may seem to hold the potential to create inherent commercial bias, but in reality the demand to train skilled interventionists has outpaced the number of providers. As the number of skilled interventionists continues to grow, the natural progression will see endovascular training become a part of post-graduate medical residencies.   Just as wound care providers have varying levels of skill and aptitude, the same must be said of interventionists. One barometer to consider when evaluating an endovascular specialist who focuses on limb preservation is the ability to take his/her skill set to the arteries below the knee. The trifurcation below the popliteal artery is where arteries become less robust and, therefore, are more susceptible to occlusion. Placing a stent or performing an angioplasty within the superficial femoral artery is much less technically difficult than performing the same procedure within the anterior tibial, peroneal, or posterior tibial arteries. Truth be told, not every interventionist may have the ability or inclination to perform procedures below the knee. These cases tend to be physically demanding on the interventionist, who must wear a protective lead vest weighing approximately 40 pounds while standing for hours in cases that can often run between 4-6 hours in a cath lab (or often in an angiography suite). Ultimately, the body of work that an interventionist produces over time truly determines whether or not he/she is appropriate for the limb preservation team. The same must be said regarding wound care providers. One thing is certain, however: There is a mutual respect and admiration between members of both groups that comes with repeated success. This is amplified when members work together and communicate with one another as well as with the patient.   Desmond Bell is a board-certified wound specialist (CWS-American Academy of Wound Management, for which he’s a board member) and a fellow of the American College of Certified Wound Specialists. He is founder of the Limb Salvage Institute and Wound Care on Wheels LLC. A frequent lecturer and author on wound care, peripheral arterial disease, and diabetes, Bell was awarded the Frist Humanitarian Award by Specialty Hospital in 2009. He may be reached at drbell@savealegsavealife.org.   Leah Amir, MS, MHA, is a healthcare economist with experience bringing together multidisciplinary teams to focus on cost-effective patient management. She is executive director of the Institute for Quality Resource Management, St. Louis, MO.

References

1. Gitelis S, Malawer M, McDonald D, Derman G. Principles of limb salvage. Chapman’s Orthopaedic Surgery. 126; 3310. Lippincott Williams and Wilkins. 2001. 2. Thrombolysis in the management of lower limb peripheral arterial occlusion — A consensus document. J Vasc Interv Radiol. 2003; 7:S337–S349. 3. Rogers LC, et al. Toe and flow: Essential components and structure of the amputation prevention team. J Vasc Surg. 2010 Sep;52(3 Suppl):23S-27S.