Commentary

Point/Counterpoint: Is limb salvage always best in diabetes?


 

 

Salvage limbs at all costs

Aggressive limb salvage in people with diabetes leads to an overall reduction in cost not only economically, but also from the patient’s perspective. The vast majority of diabetic patients with critical ischemia are actually good candidates for limb salvage. Tragically, many of these patients are never referred for evaluation for limb salvage because of misconceptions about the pathophysiology of the disease.

An argument against limb salvage is that primary amputation prevents or shortens the course of wound care and enables patients to become ambulatory, albeit with a prosthesis, faster. However, in the modern era of vascular surgery, revascularization can be performed successfully with minimal mortality and excellent rates of limb salvage, especially when it’s done within a team-based approach.

Dr. Trissa A. Babrowski
Dr. Trissa A. Babrowski
Limb salvage in people with diabetes is a urgent public health issue. Today 29 million U.S. adults have diabetes, nearly a quarter of whom are undiagnosed. Ninety million U.S. adults are glucose intolerant. Diabetes is by far the most common cause of nontraumatic amputation in the United States; the Centers for Disease Control and Prevention estimated 73,000 nontraumatic adult amputations in 2010 – about 44,000 in diabetics. That means nearly 2 million Americans are living with an amputation today. That will rise to 3.6 million by 2050.

The mortality in primary amputation is shockingly high, anywhere from 5% to 23% higher than revascularization alone, and the major complication rate of amputation associated with diabetes is also unacceptably high – up to 37%. This is in contrast to a 17% rate in major nonamputation vascular surgery and 1%-5% in endovascular procedures (BMC Nephrol. 2005;6:3).

We can’t ignore the economic burden this places on the country. In 2014, primary amputations cost the health care system $11 billion annually, and that is expected to grow to more than $25 billion in the next several years, according to the SAGE Group. It’s important to keep in mind that Medicare covers over 80% of this cost.

A number of studies have shown that conservative management with wound care and amputation is more cost effective than primary amputation in ambulatory, independent adults. Data can be difficult to interpret because of different recording strategies for all the costs associated with amputation, but a single-institution study concluded that revascularization costs almost $5,280 more than expectant management, but $33,900 less than primary amputation alone (Cardiovasc Surg. 1999;7;62-9).

We must also consider the costs of revision after primary amputation; above-the-knee amputation has a 12% in-hospital revision rate, and below-the-knee amputation about 20%. Endovascular interventions, on the other hand, have a 1%-9% in-hospital revision rate, and only 2%-4% of these patients will go on to require an amputation during the same admission (Eur J Vasc Endovasc Surg. 2006;32:484-90; Arch Phys Med Rehabil. 2005;86:480-6).This does not include the costs of those complications as well as other indirect costs of amputation, such as nursing home care and living situation modification (Int J Behav Med. 2016;23:714-21; Pak J Med Sci. 2014; 30:1044-9). They quickly add up to that $25 billion.

The proponents of primary amputation tell us that it leads to quicker recovery time and an earlier time to ambulation. However, only 47% of patients will actually ambulate after amputation, in contrast to 97% who will ambulate after limb salvage as a primary procedure. In a nonambulatory cohort, 21% of those patients go on to regain functional status that was lost prior to surgery (J Vasc Surg. 1997;25;287-95).

Many question if our success with vascular surgery over the past few decades can translate to helping the most difficult subset of patients. An Italian study reported on a cohort of diabetic vs. nondiabetic patients and determined both groups have similar amputation-free rates after infrainguinal arterial reconstruction for critical limb ischemia, with excellent primary and secondary patency rates and a limb salvage rate of 88% at 5 years (J Vasc Surg. 2014;59:708-19). This tells us that we do have the skill set necessary to save these limbs.

A multidisciplinary limb preservation team is paramount to the success of any limb salvage program. A revascularization team should be in place which uses early intervention to achieve the highest limb salvage rates possible. Wound care needs to be an integrated part of it. Advanced podiatric reconstructive surgery also is key because this can provide complex foot reconstructions and help ambulatory patients return home.

Dr. Trissa A. Babrowski is an assistant professor of surgery, specializing in vascular surgery and endovascular therapy, at the University of Chicago Heart and Vascular Center. She had no financial relationships to disclose.

Primary amputation can be OK

I am not an amputationalist. I do practice limb salvage. In fact I’m probably the most aggressive limb salvage surgeon in my hospital. But primary amputation is a completely acceptable option for a selected group of patients with diabetes. We should not try to do limb salvage “at all costs.”

I do not find this to be a contradictory position. In fact, I think it adds credence to my support of limb salvage that I think primary amputation can be OK. In all honesty, there are very few things in life that should be done at all costs.

Dr. Timothy J. Nypaver
Dr. Timothy J. Nypaver
Bypass revascularization efforts to prevent amputation can fail, and many of them do so frequently in the first year. These failures can often be predicted preoperatively. Appropriate application of primary amputation based on data not only improves cost-effectiveness and patients’ quality of life, but improves our outcomes overall for critical limb ischemia (CLI).

A study out of Loma Linda University involving patients with CLI compared primary amputation vs. revascularization; 43% of patients had a primary amputation (Ann Vasc Surg. 2007;21:458-63). A multivariate analysis showed that patients with major tissue loss, end-stage renal disease (ESRD), diabetes and nonambulatory status were more likely to undergo primary amputation rather than revascularization.

While major tissue loss (Rutherford category 6) is certainly an indication for primary amputation, ambulatory status can represent a gray area in determining the best course. ESRD and diabetes are much more nonspecific factors; probably more than 10% of the patients that we see with CLI have ESRD. Also, 50%-70% of these patients with CLI, and in some series even higher percentages, have diabetes. Thus, these factors by themselves do not assist us in determining which patients potentially should be offered primary amputation vs. revascularization.

In general, we know that we can get good results in limb bypass or revascularization in patients with CLI: The PREVENT III multicenter trial, with the use of the vein as the conduit, showed 1-year limb salvage rates of 88% in these high-risk patients (J Vasc Surg. 2006;43:742-51). However, one of the major risk factors that adversely affected outcome was ESRD.

We know that ESRD is a significant predictor of lowering our chances of saving a limb successfully. Knowing the cost of multiple continued episodes of revascularization in these patients prior to proceeding with an amputation, it’s intuitive that these patients would benefit from a more precise process in their treatment from the beginning. A number of papers have concluded that a primary amputation may be the preferred approach in patients with ESRD.

Can we preoperatively predict which patients with CLI will fail operative revascularization? Data from the New England Vascular Quality Initiative identified eight variables associated with failure of revascularization, among them age younger than 59, ESRD, diabetes, CLI, conduit requiring venovenostomy, tarsal target, and nursing home residence (Ann Vasc Surg. 2010;24:57-68). The presence of three or more risk factors has a 27.7% risk of limb loss and/or graft thrombosis within 1 year.

Postponing amputation is a major cost issue. Direct costs of bypass for critical limb ischemia were $3.6 billion in 2004 (J Vasc Surg. 2011;54:1021-31), and we know that a functional outcome can be problematic in this patient group. Factors associated with a poor functional outcome include dementia, dependent-living situation preoperatively and nonambulatory status.

Unfortunately, there are not a lot of data that deal with quality of life outcomes for patients with CLI who have undergone bypass. Using a point system comprised of dialysis (4 points), tissue loss (3 points), age above 75 (2 points), hematocrit less than or equal to 30 (2 points), and coronary artery disease (1 point), a follow-up study of patients in the PREVENT III trial found that a high-risk group (greater than or equal to 8 points) had an amputation-free survival of only 45% (J Vasc Surg. 2009;50:769-75). Again, these results do not justify the effort and costs of limb salvage in this high-risk patient group.

We should consider the following options carefully in selecting a cost-effective patient-focused approach in patients with CLI: wound care, primary amputation, bypass revascularization, or endovascular revascularization. I would argue that the vascular surgeon who is qualified as an expert in all of the above is best positioned to select an appropriate plan of treatment based upon the patient’s risk factors, wound factors, ambulatory ability, pattern of disease, severity of ischemia, and living status.

Thus, upon presentation, a patient with CLI should undergo confirmatory tests and optimize his or her risk factors. The vascular surgeon then has the option, in discussion with the patient and family, to pursue an appropriate treatment plan inclusive of primary amputation – not one of limb salvage “at all costs.”

Primary amputation should be used in situations where there is dementia and nonambulatory status, and in patients who are poor candidates for revascularization because of high risk of failure and limited life expectancy. The recently developed WIfI (wound, ischemia, and foot infection) classification can also be utilized, as stage 4 WIfI classification is associated with high risk of limb loss – 38%-40% at 1 year.

Primary amputation is an option that can result in better care overall, and it is a cost-effective approach for a selected group of patients. We should not try to do limb salvage at all cost. Primary amputation, in selected patients, is OK.

 

Dr. Timothy J. Nypaver is head of vascular surgery at Henry Ford Hospital, Detroit. He had no financial relationships to disclose.

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