When Do You Refer A Patient For Vascular Intervention?

Despite devastating five-year mortality rates that rival those of several forms of cancer, peripheral arterial disease (PAD) remains somewhat under-recognized, even by healthcare providers. This author emphasizes the importance of appropriate screening of high-risk patients and timely referrals for vascular interventionalists.

When the words “pink ribbon” are juxtaposed, what do you think of? Without hesitation, you make the connection to breast cancer awareness.

   I have often asked this very question when lecturing, whether to colleagues, other professionals or laypeople. The first follow-up question is usually, “Why?” To which the response is usually, “due to the marketing” that has surrounded breast cancer awareness for many years now.

   The next follow-up question I pose is, “When is Peripheral Arterial Disease (PAD) Awareness Month?” While October has become synonymous with breast cancer awareness, it is on the rarest occasion that I have received the correct reply, September, when it comes to the disease that is far more deadly and far less known than breast cancer.

   This general lack of awareness underscores an even greater concern that healthcare providers equally misunderstand PAD. How can we expect providers who are lacking in fundamental appreciation of PAD to know when to refer patients who have any significant degree of the disease to an appropriate vascular specialist or for vascular intervention?

   Let’s get back to basics before we recommend a solution to the problem that grows alongside the ever increasing diabetic population both here and abroad.

What You Should Know About Screening For PAD

A recent poll on Podiatry Today’s Web site asked readers, “Which non-invasive test do you rely on (in your office or hospital) for PAD diagnosis?” (see https://tinyurl.com/8eyn92w ). I will discuss the results of this poll a bit later.

   The wording of the question may be a bit misleading as there is a difference between screening and diagnosing. Screening refers to identifying those who may be at risk for a particular condition or disease state. Diagnostics help confirm a diagnosis.

   The American College of Cardiology/American Heart Association recommends PAD screening for anyone over the age of 50 who has diabetes and/or smokes, and those over 70 years of age.1 Additionally, an expert panel brought together by the American Diabetes Association recommends that people with diabetes over the age of 50 have an ankle-brachial index (ABI) to test for PAD.2 While the ABI has a fairly high reliability for PAD recognition, it is not intended to be the test that confirms the diagnosis.

   The same holds true for methods such as palpation of pulses or the use of a handheld Doppler. These tests provide some information but each has inherent flaws that may result in either misdiagnosed or false negatives if one uses them as the definitive criteria for diagnosing PAD. For example, when a patient has calcified arteries, an ABI may yield falsely elevated values that can place a patient with diabetes and significant PAD into a perceived normal category.

   Palpation of pulses is another screening test with variable results. Not only is the test dependent on the proficiency of the provider, there is also the potential to perceive one’s own finger pulses to be those of the patient’s pedal pulses.

   Portable Doppler examination of pedal pulses can provide audible evidence of turbulence in partially to severely occluded arteries. However, one should correlate this with other exams such as segmental waveforms when screening for PAD. Again, the provider’s ability to determine the quality of audible signals suggestive of mild, moderate or severe PAD is an obvious variable. This variable makes relying on a Doppler exam for the diagnosis of PAD less than optimal despite its important place overall as a tool in the vascular disease assessment toolbox.

   The point here is that in-office screening for PAD should not really be confused with the actual diagnosis of PAD. Yes, screening is very important but when one suspects PAD, it is imperative that referral to a vascular specialist occur.

Stressing The Mortality Rates Associated With PAD

I cannot emphasize enough the importance of PAD recognition and the five-year mortality rates that compare several potentially fatal conditions support this point.3-8

   Simply stated, PAD carries a potential for death that is greater than both prostate and breast cancer combined. Yet providers and the public alike are seemingly unaware of the gravity associated with PAD.

   Imagine the scenario in which a woman who has recently discovered a lump on her breast and what ensues upon presenting to her primary care physician. There would likely be an immediate call to action as the PCP would pursue appropriate diagnostic testing and a referral to a specialist would be the standard of care.

   Yet what happens when a patient presents with either a non-healing diabetic foot ulcer or generalized pain in the legs and feet upon elevation or during ambulation? In the case of the non-healing diabetic foot ulcer, is referral to a wound specialist the standard of care or is the norm the prescribing of an oral antibiotic and orders to keep a dressing in place? How often do we consider PAD in a neuropathic patient due to the overlap of symptoms between the two conditions? In either case, a lack of urgency to refer to either a wound or vascular specialist may be rooted in the lack of understanding that this patient is actually presenting with a life-threatening condition.

A Closer Look At Classifying PAD And CLI

To better understand the course of progression that PAD may take, the Rutherford-Becker categorization can be extremely useful when considering the potential severity of the disease.

   The Rutherford-Becker Classification system to categorize the extent and level of PAD suggests that Category 4 through 6 is indicative of critical limb ischemia (CLI).9

Category 0: Asymptomatic
Category 1: Mild
Category 2: Moderate
Category 3: Severe
Category 4: Ischemic rest pain
Category 5: Minor tissue loss (i.e. non-healing ulcer, focal gangrene)
Category 6: Major tissue loss (i.e. above the transmetatarsal level)

   Critical limb ischemia is persistently recurring rest pain that requires regular analgesia and typically presents with non-healing ulceration or gangrene of the foot or toe and the threat of limb loss or tissue loss.

   Any patient falling into a Rutherford-Becker Category 4 through 6 should get a referral to a vascular interventionalist without hesitation. An interventionalist can be a vascular surgeon, cardiologist or interventional radiologist, who can perform procedures to open occluded arteries. In a number of instances, vascular surgeons perform both traditional bypass surgeries as well as the minimally invasive endovascular procedures, such as angioplasty, atherectomy, stenting and laser procedures, which many skilled cardiologists and interventional radiologists also embrace.

Understanding The Strong Socioeconomic Impact Of PAD

In July, I interviewed Mary Yost, MBA, who is the President of the Sage Group, LLC, for the Save A Leg, Save A Life radio program. The Sage Group is a for-profit research and consulting company specializing in vascular disease of the lower limbs including PAD, intermittent claudication, CLI, acute limb ischemia and diabetic foot ulcers (DFU).

   During this program, I asked Yost about the economic burden of PAD on the U.S. healthcare system. She noted that in 2010, the total cost of PAD (inpatient and outpatient) ranged between $164 and $300 billion. The $164 billion represents annual costs per patient in the U.S. REACH Registry.10 Patient costs in 2010 dollars were multiplied by the 17.6 million people with PAD.

   As Yost noted, the $300 billion estimate is more accurate because it includes all-cause hospitalizations.10 Even so, it understates the real cost because it does not include nursing home care, home healthcare, lost wages and other factors related to long-term care of patients who have had amputations to CLI.10

   Seventy-five percent of those with PAD are asymptomatic. While they do not have leg symptoms, 70 percent most likely have coronary and/or cerebrovascular disease.10

   It is estimated that between 5 and 10 percent of patients requiring below-knee amputations die in the hospital. Approximately 15 to 20 percent of patients who require above-knee amputations die while hospitalized.10 One in-hospital death from PAD or CLI can cost $12,000.10

   Additionally, there is a high rate of revision amputations. The revision amputation rate is 20 percent in patients requiring below-knee amputations and 12 percent in patients who require above-knee amputations.10

   Each of these statistics adds to the total national bill for amputation. This is before you consider the adverse patient outcomes such as the 60 to 80 percent of patients who are unable to walk, those suffering from depression, hospital re-admissions for amputation-related problems, the necessity for long-term care, etc.10

   The cost in dollars varies, depending on a number of factors. That being said, the socioeconomic impact of PAD is extensive.

What Medicolegal Liability Can Podiatrists Face For PAD?

In my travels, I have had the opportunity to visit many communities and colleagues who are seeking better ways to apply the team approach to limb preservation.

   Intuitively, we know that the team approach is preferred, if for no other reason than knowing that the patient population that is at the greatest risk for PAD and CLI has multiple comorbidities that make them among the sickest of the sick. While the team approach makes sense in terms of achieving better outcomes and reducing amputations, there is another important reason that podiatrists should know when to refer to a vascular specialist.

   Several years ago, during a trip to Detroit, I opened up the local phone book to see if any old classmates may be practicing in the area. While this exercise did not yield any information regarding old classmates, it did send a jolt through my system that I have not forgotten since that day.

   There in the yellow pages of the Detroit phone book was an attorney advertising that he specializes in cases surrounding lower extremity amputation.

   Consider an earlier Podiatry Today article from by Janov that highlighted the story in which a Michigan jury awarded $1.23 million for a podiatrist’s failure to refer a patient to a vascular surgeon in a timely manner.11 A patient initially saw the podiatrist for severe vascular insufficiency and ischemic foot ulceration. The patient received antibiotics and instructions to return in two weeks. Upon his return, the patient got a referral to a vascular specialist for consultation 17 days later and one month after the initial podiatric evaluation.

   The patient, however, went to a local emergency room with a necrotic foot before ever seeing the vascular specialist. He subsequently underwent a below-knee amputation a week after finally seeing the vascular surgeon while in the hospital.

   The patient filed a lawsuit against the podiatrist. Ultimately, the jury rejected the podiatrist’s defenses including the following alleged points:

• “The patient had chronic but stable symptoms.”
• “The patient did not need an urgent referral.”
• “Any delay was due to the vascular visits.”

   Was this case an isolated incident? Perhaps in the broadest sense but given the results of the Podiatry Today poll I alluded to at the beginning of this article, there must be a high suspicion that we often do not detect or screen aggressively for PAD and CLI.

   This statement refers to the fact that there are many who are not using what would be considered sophisticated methods in combination with their clinical observations when it comes to identifying patients who are at increased risk for PAD and CLI. In fact, relying solely on any screening method at the exclusion of clinical judgment is foolish to say the least.

   As this article goes to press, 293 people have replied to the poll question “Which non-invasive test do you rely on (in your office or hospital) for PAD diagnosis?” (see “What An Online Poll Revealed About Non-Invasive Tests And PAD” at left).

Where To Turn For Help To Find A Vascular Specialist

Since we are often the frontline providers when it comes to detecting PAD and CLI, the chances are that at some point, you will be the one holding the figurative “hot potato” and find yourself with a patient in need of a vascular specialist referral. Indeed, this will happen sooner than later if you haven’t already encountered these patients in your practice. Knowing the litigious nature of society today, protecting yourself is as important as serving the best interests of your patients. The key here is not to overlook or take the consequences of PAD lightly.

   Screening patients for PAD and CLI may also uncover those who could have possibly faced myocardial infarction or a cerebrovascular accident in addition to preventing a lower extremity amputation.

   Frustration can come from the helpless feeling of realizing a patient is in real need of a vascular specialist referral but not knowing where to turn. Hospital or community politics can sometimes play a role in getting a patient into the hands of the specialist who has the skill set and determination to not make amputation a first-line treatment.

   When seeking out a vascular interventionalist, keep in mind a few last points. Not all interventionalists have the same level of training or skill set. In other words, not every interventionalist is comfortable going beyond the superficial femoral artery and below the knee in an attempt to “target the lesion.” Targeting the lesion involves identifying the location of an ulcer or gangrenous changes, and following the angiosome map of the lower extremity along with information obtained from an arteriogram or a magnetic resonance angiogram (MRA) that reveals the precise location of an occlusion. Interventionalists can subsequently use any of the technology and various devices available in an attempt to open the blocked artery.

   Finding such a partner in the quest for saving legs and lives may take some trial and error. The good news is that the endovascular device industry has become increasingly aware of the value of teaming podiatrists with vascular interventionalists, and have increasingly developed programs and sponsored educational meetings to introduce members from the respective professions.

   Organizations such as the Vascular Disease Foundation (https://vasculardisease.org/ ), the Society for Vascular Surgery (https://www.vascularweb.org/ ), the PAD Coalition (https://vasculardisease.org/padcoalition/ ) and the Save A Leg, Save A Life Foundation (https://savealegsavealife.org/ ) all can potentially assist podiatrists in locating interventionalists in their communities, and can help in facilitating better patient care and outcomes.

   Dr. Bell is a board certified wound specialist of the American Academy of Wound Management and a Fellow of the American College of Certified Wound Specialists. He is the founder of the “Save a Leg, Save a Life” Foundation, a multidisciplinary, non-profit organization dedicated to the reduction of lower extremity amputations and improving wound healing outcomes through evidence-based methodology and community outreach.

References
1. American Diabetes Association Consensus Statement. Peripheral arterial disease in people with diabetes. Diabetes Care. 2003; 26(12):3333-3341.
2. American Diabetes Association Consensus. Diagnosis of PAD is important for people with diabetes. Diabetes Care. November 21, 2003. Available at https://www.diabetes.org/living-with-diabetes/complications/peripheral-a… .
3. Available at https://seer.cancer.gov/statfacts/html/prost.html . Accessed Oct. 24, 2012.
4. Available at https://seer.cancer.gov/statfacts/html/breast.html . Accessed Oct. 24, 2012.
5. Weitz JI, Byrne J, Clagett GP, et al. Diagnosis and treatment of chronic arterial insufficiency of the lower extremities: a critical review. Circulation. 1996; 94(11):3026-49.
6. Young MJ, McCardle JE, Radall LE, Barclay JI. Improved survival of diabetic foot ulcer patients 1995-2008: possible impact of aggressive cardiovascular risk management. Diabetes Care. 2008; 31(11):2143-2147.
7. Ljungman C, Holmberg L, Bergqvist D, et al. Amputation risk and survival after embolectomy for acute arterial ischaemia. Time trends in a defined Swedish population. Eur J Vasc Endovasc Surg. 1996; 11(2):176-182.
8. Creager MA, Bell DP, Nanjundappa A, Stevens SL. Early detection and minimally invasive treatment of PAD: a multidisciplinary discussion. Available at https://www.medscape.org/viewarticle/769576 . Published Aug. 30, 2012. Accessed Oct. 24, 2012.
9. Hirsch AT, Haskal ZJ, Hertzer N, et al. ACC/AHA Guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric and abdominal aortic). J Amer Coll Cardiology. 2006; 47(6):1239-1312.
10. TASC Consensus Paper, Outcome Assessment Methodology in Peripheral Arterial Disease – Impetus for Outcomes Research, Page 39, Table IX; Classifications of PAD. Available at www.tasc-2-pad.org .
11. Yost M. Interview, WOKV radio. Jacksonville, FL: July 8th, 2012. Podcast available at www.WOKV.com .
12. Janov J. Seven keys to preventing malpractice lawsuits. Podiatry Today. 2007; 20(8):96-106.

   For further reading, see the DPM Blog “PAD Awareness Month And The Case For Limb Preservation” at https://tinyurl.com/c9utpfy .