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

January 3, 2017|Internal Medicine

Trissa A. Babrowski, MD;Timothy J. Nypaver, MD

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.

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.