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Taking a team approach to diabetic limb salvage

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Hospitals with multidisciplinary diabetic foot care programs have found that adding vascular surgeons to the team makes their amputation prevention efforts more effective, but also adds an extra layer of challenges in terms of coordinat­ion and communication.

By Cary Groner

Clinicians specializing in preventing foot and lower-limb amputations in diabetes patients have long understood the value of collaboration. Diabetologists and endocrinologists help control patients’ glycemic levels, podiatrists and foot surgeons debride and repair wounds and correct underlying deformities, and vascular surgeons improve pedal blood flow, greatly enhancing the body’s healing capabilities.1

Such collaborations date back to the 1920s, when Elliott Joslin, MD, established the first hospital foot clinic at New England Deaconess Hospital in Boston. For decades, the hospital was a world leader in diabetes wound care, developing revascularization approaches in the 1950s, expanding and refining approaches to ischemic foot ulceration (including extreme distal revascularization) in the 1980s, and disseminating knowledge and clinical expertise ever since.

What’s changed recently, in Boston and elsewhere, is not so much the fundamental approach as the speed with which it unfolds. Today, hospitals are launching comprehensive interdisciplinary interventions to prevent amputation that are implemented in hours instead of weeks. A 2010 article in the Journal of Vascular Surgery outlined the basic approach, which includes screening and prevention, wound healing, infection management, and revascularization—and in which the team of diabetic podiatrist and vascular surgeon form the “irreducible minimum.”2

The stakes are high: According to the Centers for Disease Control and Prevention, roughly 25.8 million Americans have diabetes—8.3% of the population.3 The condition is associated with $116 billion in annual direct costs and another $58 billion in indirect costs (e.g., loss of productivity, disability, mortality).

Figure 1: Complex circumferential leg wound with guillotine transmetatarsal amputation following necrotizing infection in patient with contralateral below-knee amputation and leg debridement. The figures that follow will illustrate her multi- disciplinary treatment. (Photo courtesy of David Armstrong, DPM, MD, PhD, and Joseph Mills, MD.)

Peripheral vascular and neuropathic complications represent 31% and 24% of those expenses, respectively. One in five foot ulcers ultimately leads to some level of amputation, and in the US, patients with diabetes represent up to 80,000 lower extremity amputations annually—constituting roughly 60% of annual nontraumatic amputations.4-6 Although amputation rates in patients with diabetes are decreasing,7 the aggregate numbers continue to pose a considerable clinical challenge.

The view from Georgetown

John Steinberg, DPM, an associate professor in the Department of Plastic Surgery at the Georgetown University School of Medicine in Washington, DC, works in an integrated limb-salvage program that includes nurses, hospitalists, prosthetists and pedorthists, physical therapists, endocrinologists, nephrologists, rheumatologists, infec­tious disease specialists, and a bevy of surgeons—vascular, plastic, podiatric, and orthopedic.

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“Two key elements that need to be in place for successful wound healing and limb salvage are vascular surgery and podiatry,” Steinberg said. “Many other parts go into the multidisciplinary team, but you have to have blood flow and someone to deal with biomechanics.”

The goal, Steinberg continued, is to put specialists together in an environment conducive to rapid communication, consultation, and cotreatment. Different specialists may all see an inpatient case together, and outpatients are scheduled to see specialists with as little delay as possible between appointments. Nurse practitioners and case managers follow outpatients closely to be sure tests are done as ordered and results reported in a timely fashion. Inpatients are tracked primarily by residents, but nurse practitioners help manage care as well. Steinberg gathers with surgical residents at the end of each day to review cases and go on rounds.

In outpatient care, physical proximity to other team members is crucial, Steinberg added.

Figure 2. Angiograms before and after endovascular intervention. (Images courtesy of Joseph Mills, MD.)

“The people who evaluate blood flow are a couple of floors up from us, but if we want an evaluation, we can page them and have them come to the clinic right away,” he said. “We can also call the nurse manager and have the patient scheduled for an angiogram the next day.”

One of the biggest advantages is that when a patient presents with a serious diabetic wound, there’s no ambiguity about who to call.

“Our limb salvage team is a defined service within the hospital,” Steinberg explained. “People used to stress over who to call first—vascular surgery, or podiatry, or infectious disease. Now the ER staff knows that when someone comes in with a bad foot or leg, they call limb salvage.”

Interventions and results

Research supports the efficacy of multidisciplinary approaches to limb salvage. In a study at Madigan Army Medical Center in Tacoma, WA, investigators reported that the implementation of the hospital’s Limb Preservation Service resulted in an 82% decrease in lower extremity amputations over five years, from 9.9 to 1.8 per 1000 diabetes patients. (Actual amputation numbers dropped from 33 to 9, reported from 1999 to 2003.) Moreover, this decline took place even as diabetes cases jumped 48%.6

The paper’s lead author, Vickie Driver, DPM, who is now an associate professor of surgery at the Boston University School of Medicine, told LER that the initial challenges were obvious.

“We had not been very successful at saving limbs, and we didn’t have a clear idea of how to develop a pathway,” Driver said.

After the multidisciplinary team was assembled and the hospital staff trained, a fundamental aspect of the subsequent transformation in care was simple speed.

“You want to arrange consults with the appropriate clinicians immediately,” she said. “Initially, it took about 162 hours for an ER patient to get the necessary consults within our service. In the new program it took 162 minutes. Everyone on the front line was plugged into what the process should look like, so patients would immediately start seeing the appropriate people and getting the necessary diagnostics.”

The approach has decreased amputation rates in other settings, as well. A retrospective Swedish study reported a decline of 51% in all amputations, and 78% in major amputations, over 11 years.8 A prospective UK study found a drop of 40% in all amputations, and 62% in major amputations, also over 11 years.9 Italian researchers reported a drop in major amputations from 10.7 to 6.24 per 100,000 inhabitants—a decline of 42%—after five years.10

Other research specifically supports the revascularization part of the equation. For example, at New England Deaconess Hospital, aggressive distal bypass revascularization in diabetes patients with ischemic ulcers correlated precisely with a significant decrease in every category of amputation.11 Another paper by the same team reported a reduction in major amputations, length of stay, and total care costs.12 And investigators in Europe reported that when endovascular revascularization techniques were used, only 10 of 191 patients thus treated—5.2%—later required major amputa­tion.13

Costs

In a 2010 literature review, Driver outlined the costs associated with the diabetic foot.5

For example, one paper reported that the average cost for an ulcer episode was $4595—although Wagner grade 5 ulcers averaged $15,792—and poor vascular status was strongly associated with longer inpatient stays and higher average payments.14 Another found the average cost per ulcer episode was $13,179, with grade 4/5 ulcers averaging $27,721, and confirmed a higher cost per episode in patients with poor vascular status.15

Figure 3: Treatment also included skin grafting (left) and negative pressure wound therapy (center). (Photos courtesy of David Armstrong, DPM, MD, PhD.)

Such cost disparities reflect different care models and patient variables, Driver said.

“There are differences in infection rates, admission rates, types of surgery, revascularization procedures—all those things affect cost,” she explained. “Does the patient have a deep ulcer? Is it infected? Is the bone infected? Do they need to be admitted? Do they need a PICC [peripherally inserted central catheter] line? It’s all variable.”

Research has determined that care cost for diabetes patients with lower extremity ulcers is up to 2.4 times higher than that of diabetes patients without ulcers, for example—and up to 5.4 times higher in the year after the ulcer episode.16

Amputation, not surprisingly, is also associated with significant costs. One 1994 paper reported that healing without amputation cost an average of $6664, versus $44,790 when an amputation was required.17 Researchers have yet to determine, however, the extent to which the savings associated with amputation prevention might offset the costs of surgical revascularization.

Proximity

At the University of Arizona Medical Center in Tucson, the Southern Arizona Limb Salvage Alliance (SALSA) includes a “Toe and Flow” program that functions as much like a family as a confederation of clinicians. The “toe” part of the clan consists largely of podiatrists and podiatry residents, while vascular surgeons and their residents constitute the “flow” tribe.

According to David Armstrong, DPM, MD, PhD, professor of surgery and SALSA’s codirector, inpatients are evaluated by members of both sides, then one or the other takes the lead depending on the patient’s needs. Outpatients, by contrast, initially see either a podiatrist or a vascular specialist, but the first question is the same in either case, namely, “What is the flow like?”

To assess flow, the team starts with noninvasive tests such as a pulse exam or Doppler scan.

“If flow is deemed adequate on the initial screen, they will be treated primarily on the ‘toe’ hallway—medically, surgically, and mechanically—to heal and prevent severe recurrence,” said Armstrong. (The services operate on parallel hallways on the same floor.)

If the blood supply is determined to be inadequate, however, the patient will be treated mainly in the “flow” hallway until those issues are resolved, then sent to the “toe” side.

“During these periods, we are constantly in and out of each other’s rooms with our mutual patients,” Armstrong added. “This kind of collaboration is very hard to do, because you have to do it every day and scheduling can get difficult.”

SALSA’s codirector, vascular surgeon Joseph Mills, MD, agreed.

“It gets harder, when you get bigger, to maintain that unity,” he said.

Mills noted, however, that due to office remodeling, the team members have been temporarily crammed into an old lab space together, along with the fellows and administrative staff. It’s turned out to be surprisingly fruitful.

“We have more research meetings and just talk about things,” he said. “If you get people with overlapping interests together in the same physical space it’s synergistic.”

Armstrong likened the temporary space to a dorm room.

“We’ve enjoyed it so much that the new space they’re building is going to mirror it to some degree in terms of proximity,” he said.

Both physicians agree that it’s a lot like family; but of course, families argue. Asked how much of a problem this is, Armstrong deferred to his colleague, but Mills wouldn’t take the bait.

“I want to hear your perspective,” he said. “Then I’ll decide how nice to be.”

Armstrong laughed. “We argue more than we get along, but we get along by arguing.”

Lingo

The colleagues may sometimes differ over personal style—Armstrong is a notorious technophile, for example, and Mills is not—but they rarely disagree about clinical matters. One major challenge is how to manage patients who require both a podiatrist and a vascular surgeon in roughly equal doses.

“There are people who just have pressure sores from neuropathy, but their blood flow is normal, so they don’t really need me,” Mills said. “Then there are people who are obviously ischemic and don’t have much of a mechanical issue. But the vast majority of patients are somewhere in between.”

In many clinics, he noted, patients with even mildly abnormal blood flow get an angiogram and receive treatment for any vascular lesions detected.

“We don’t think that’s necessarily appropriate, because they may not need it to heal,” he said. “It’s meddlesome and it’s expensive, and I don’t like inappropriate medical procedures.”

Instead, the team follows such patients closely, provides wound care, and only raises the possibility of revascularization if the patient doesn’t respond adequately.

Dealing with complicated cases sometimes means addressing the expectations of other team members, too.

“Over the years, we’ve grown to appreciate the difficulties inherent in each other’s practices,” Armstrong said. “I might look at a patient and say, ‘This is clearly ischemic, just fix the flow,’ as if it’s easy. And he’ll say, ‘This is not a little chip-shot lesion; it’s really complicated and I’ll show you why.’ Conversely, we might have a patient on whom heroic vascular work has been done, but who has a little wound that won’t heal because it’s hard to offload. Joe will say, ‘Look, this is a mechanical problem, why can’t you figure something out?’ And it’s not that easy.”

One goal for the new space is to set up a clinic so patients who have major issues in both realms can be seen jointly, Mills added.

In any case, Armstrong said that by this time he’s seen more vascular surgery than most podiatrists, and that Mills has had significantly more exposure to podiatry than most vascular surgeons.

“We’ve learned each other’s lingo,” Armstrong said. “It’s like we speak in Esperanto.”

Great expectations

Expectations have to be addressed in other ways as well, both men emphasized.

“Once we’ve intervened and improved the flow, podiatrists sometimes assume that it’s going to stay that way forever,” Mills said. “But some of our procedures fail, or the patients get restenosis before the foot is healed.”

He noted that diabetic foot problems resemble cancer in some ways.

“We never talk about curing cancer,” he explained. “We talk about remission. Once you’ve had a diabetic foot, you’re never cured, even if you don’t have ischemia.”

Patients with both toe and flow problems need to have follow-up from both services, Mills emphasized.

“These people get bounced around [among specialists outside the medical center] like balls in a Pachinko machine,” Armstrong added. “The little SALSA bowl at the bottom is where they finally collect.”

Toe and Flow clinics can take lessons from cancer treatment in other ways, it turns out.

“You want to make it easy for the patient to get treated by all the specialists,” Mills said. “The hospital wanted to move us to different floors at one point, but we were adamant about not doing that. Patients are on crutches, in wheelchairs, using walkers. Asking them to travel around the hospital to get their care doesn’t make sense. We want to make it one-stop shopping.”

Armstrong also made it clear that, as in cancer, there are simply times when you can’t help.

“One predictor of mortality is functional activity, how many steps the patient takes,” he said. “Our goal is to facilitate that, but if we can’t, then we try to keep the person comfortable. Five or ten percent of our patients are essentially in foot hospice; our goal isn’t to heal them but to keep them uninfected. We just try to treat them in a humane way, so that the problem they have with their extremity is fifty-first on their list of fifty most important things to do in their life.”

Ambitions

Figure 4: With her wound healed, the patient was able to walk around in the community and dance at her niece's wedding. (Photo courtesy of David Armstrong, DPM, MD, PhD, and Joseph Mills, MD.)

The multidisciplinary SALSA environment appears to be self-propagating partly because it works so well for the residents, Mills noted.

“All the residents here are trained in an array of competencies,” he said. “Lots of practices aren’t like that; even in academic centers there are silos, where everyone just works in their own area and there isn’t a lot of cross-linkage. Here they learn to rely on each other, call each other for curbside consults. The focus is: How do we take care of these patients better?”

The quantity of research multiplies in such a fertile environment as well. The team has produced roughly 150 papers in the past three years—about one a week—a prodigious output given that the people writing those papers also deal with 13,000 annual clinic visits.

“For translational research that you can apply in clinical practice, the best questions come because you’re struggling with a problem, wondering if you could be doing something better,” Mills said. “When you get people who look at things from different perspectives working together, those ideas get refined.”

Armstrong said that there’s no reason any academic medical center couldn’t have the same model—and in fact, both of the unit’s fellows are interviewing to start their own Toe and Flow units at other major university medical centers.

“Our goal is to make this less unique,” said Armstrong, who drew an analogy to President Kennedy’s 1961 speech about sending a man to the moon.18

“Sometimes you do things because they are hard,” Armstrong said. “This kind of thing is especially hard, but it is inherently good. We always say the team trumps technology.”

Cary Groner is a writer based in the San Francisco Bay Area.

REFERENCES

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13. Faglia E, Mantero M, Caminiti M, et al. Extensive use of peripheral angioplasty, particularly infrapopliteal, in the treatment of ischemic diabetic foot ulcers: clinical results of a multicentric study of 221 consecutive diabetic subjects. J Intern Med 2002;252(3):225-232.

14. Holzer SE, Camerota A, Martens L, et al. Costs and duration of care for lower extremity ulcers in patients with diabetes. Clin Ther 1998;20(1):169-181.

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17. Apelqvist J, Ragnarson-Tennvall G, Persson U, Larsson J. Diabetic foot ulcers in a multidisciplinary setting: An economic analysis of primary healing and healing with amputation. J Intern Med 1994;235(5):463-471.

18. National Aeronoautics and Space Administration. The decision to go to the moon: President John F. Kennedy’s May 25, 1961 speech before a joint session of Congress. Available at: http://history.nasa.gov/moondec.html. Accessed March 1, 2012.

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