How to build a limb salvage program

Abstract

Patients with chronic limb-threatening ischemia (CLTI) are medically complex and continue to experience high rates of amputation, despite improved diagnosis and treatment. Limb salvage programs and multidisciplinary teams provide comprehensive patient care and have been associated with reduced amputation rates. Recent societal guidelines suggest the adoption of limb salvage programs to improve care of patients with CLTI. In this article, we describe the critical components of a limb salvage program and outline the following steps to aid in their construction: community and institution assessment, formation of a multidisciplinary team, provision of patient care, and monitoring outcomes and processes refinement.

1. Introduction

Chronic limb-threatening ischemia (CLTI) is a clinical syndrome defined by the presence of peripheral artery disease (PAD) in combination with rest pain, gangrene, or lower limb ulceration longer than 2 weeks in duration. CLTI is the end stage of systemic atherosclerosis and is associated with high rates of smoking, diabetes, hypertension, and hypercholesterolemia [1,2]. Successful treatment of CLTI remains challenging, due in part to medical complexity. All-cause mortality rates of 22% have been observed when CLTI is left untreated [3].

Over the past decade, the diagnosis and treatment of CLTI has improved significantly with the advent of the Wound, Ischemia, and foot Infection (WIfI) classification and the Global Anatomic Staging System (GLASS) framework [4,5], as well as a growing armamentarium of tools and techniques. Nationwide outcomes have responded with improved in-hospital mortality and major amputation rates [6]. However, patients with CLTI frequently require major lower extremity amputations, with rates up to 25% observed at 1 year [7]. Multiple studies have shown the benefits of revascularization versus amputation with improved survival, lower risk of subsequent major amputation and lower health care costs; nonetheless, limb salvage remains a challenge in many situations [6,8].

Revascularization is integral to limb salvage, however, in isolation it is inadequate. It is imperative to address all modifiable risk factors in these patients, as wound healing and amputation prevention remain complex issues with multiple determinants spanning various medical specialties. The implementation of a multidisciplinary team model has been associated with significantly lower rates of major lower extremity amputations compared with the rates pre-implementation [9–11]. With acknowledgment of the benefits of a multidisciplinary limb salvage team, the GLASS guidelines have outlined the characteristics of centers of excellence for amputation prevention. The GLASS guidelines separate limb salvage teams into the following tiers: basic, intermediate, and centers of excellence. Each corresponding tier is dependent on setting, role, and potential clinicians involved (Table 1). The following are criteria for a center of excellence designation: multidisciplinary team of specialists, protocol-driven care, outcomes monitoring and reporting, methods of improvement, and educational resource [5]. Although the components of limb salvage programs are well described, many approaches exist for the successful creation of the program. The purpose of this article was to describe how to create a limb salvage program, particularly a center of excellence.

Table 1 –

Characteristics of the three tiers of limb salvage programs.

Tier	Role	Setting	Potential clinicians
Basic	Prevention and basic curative care Close collaboration with referral centers	General practitioner’s office, health center, small community hospital	General practitioner Internist Podiatrist Diabetic nurse Physical therapist
Intermediate	Active collaboration with other departments in the hospital and extramural facilities Advanced assessment and diagnosis	Regional hospital or multidisciplinary clinic	Endocrinologist Vascular surgeon Interventionalist Orthopedic surgeon Podiatric surgeon Diabetic nurse Wound nurse Physical therapist Diabetes educator Nutritionist
Center of excellence	Capable of specialized care for complex cases Collects and reports outcomes Facilitates regional education	Large teaching hospital, tertiary referral center	Endocrinologist Vascular surgeon Interventionalist Orthopedic surgeon Infectious disease Orthotist Physical therapist Diabetes educator Nutritionist Wound nurse Physical therapist

From Rogers LC, Andros G, Caporusso J, et al. Toe and flow: essential components and structure of the amputation prevention team. J Vasc Surg 2010;52(3 suppl):23S–27S [14], adapted with permission.

2. Limb salvage program: Critical components

In the early 1930s, [12] pioneered the multidisciplinary team approach to the diabetic foot in response to observed high rates of amputation and mortality. In the intervening years, diagnosis and treatment of CLTI underwent radical changes; however, the multidisciplinary limb salvage concept was cemented as standard of care [12].

A limb salvage program is defined as a team of multidisciplinary specialists with established clinical practice pathways who work to prevent limb loss. In order to create a successful limb salvage program, researchers have proposed seven essential functions, which were expanded to nine in the GLASS guidelines (Table 2) [5,13]. The formation of the team should include specialties and individuals with the training and expertise to accomplish one or several of the essential skills of a limb salvage program (Table 3).

Table 2 –

The nine essential skills of a limb salvage program.

Essential skills
1. The ability to perform hemodynamic and anatomic vascular assessment
2. The ability to perform a peripheral neurologic workup
3. The ability to perform site-appropriate culture technique
4. The ability to perform wound assessment and staging or grading of infection and ischemia
5. The ability to perform site-specific bedside and intraoperative incision and drainage or debridement
6. The ability to initiate and to modify culture-specific and patient-appropriate antibiotic therapy
7. The ability to perform revascularization
8. The ability to perform soft-tissue or osseous reconstruction of deformities and defects
9. The ability to perform appropriate postoperative monitoring to reduce risks of recurrent ulceration and infection

From Conte MS, Bradbury AW, Kolh P, et al. Global vascular guidelines on the management of chronic limb-threatening ischemia. J Vasc Surg 2019;69(6S):3S–125S.e40 [5], adapted with permission.

Table 3 –

Potential specialties for inclusion in nascent limb salvage programs.

Specialty
Vascular specialist
Podiatry
Wound care
Endocrinology
Infectious disease
Nephrology
Plastic surgery
Orthopedic surgery
Physical medicine and rehabilitation
Palliative care
Nutrition
Social work
Prosthetics/orthotics specialist

A primary advocate or program director is a key component to starting and running a successful limb salvage program. At program inception, this person may need to play multiple roles within the program in order to ensure success. Before the initiation of a limb salvage program, program directors should consider the facilities necessary to treat the continuum of CLTI. These include vascular imaging capability, cross-sectional imaging (computed tomography and magnetic resonance), block time for both operative procedures (such as toe amputation, debridement, or bypass), as well as a hybrid/interventional suite for revascularization procedures. Lastly, a wound care center providing weekly standardized care is a useful addition and allows for patient retention, aggressive wound monitoring, and treatment. In order to adequately care for these patients, a hybrid inpatient/outpatient limb salvage program may be best for the provision of comprehensive care. Indeed, centers of excellence are most likely to be affiliated with a large teaching or university hospital or tertiary referral center, as opposed to a basic or intermediate model of care [14].

As an example of the organizational structure of a limb salvage program, our institution developed the Stanford Extremity Preservation Program, a multidisciplinary board functioning to coordinate and expedite care for patients with complex limb threat. This outpatient “tumor board–like” service is coupled closely with the Stanford Advanced Wound Care Center, a multidisciplinary outpatient wound care center, creating a hybrid limb salvage program. The Stanford Extremity Preservation Program at its core is an in-person discussion between key specialties to coordinate care of the most complex patients. Specialties involved typically include vascular surgery, podiatry, infectious disease, and endocrinology. An internal analysis of the program revealed all participants also had improved health-related quality of life, regardless of whether the participants attained limb salvage or amputation. Patients were given a RAND-36 questionnaire, a validated survey for assessing health-related quality of life before and after participation in the limb salvage program. Health-related quality of life consists of physical function, role limitations caused by physical and emotional health problems, social functioning, emotional well-being, energy, pain, and general health perceptions. This underscores an additional benefit of limb salvage programs when coupled with psychosocial assessment, which may increase a patient’s quality of life [15]. Although quality of life is not routinely assessed in all patients at our institution using a RAND-36 questionnaire, it or other similar health-related quality of life tools can be used during comprehensive program assessments or as a quality improvement metric to provide insight into treatment success from the patient’s point of view.

From this experience, six core elements for advanced wound care centers were developed, with significant overlap with the GLASS criteria for centers of excellence (Table 4). Reductions in lower extremity amputations and an increase in lower extremity interventions were observed when compared with outcomes before the Stanford Advanced Wound Care Center [10]. Although patients were treated on the inpatient vascular service initially and referred to the Stanford Advanced Wound Care Center postoperatively, improved outcomes and volume were seen. A potential theory is that these results were due to a larger community presence with increased referrals and a stronger institutional wound care network. However, limb salvage programs must be tailored to a community and institution—there is not a one size fits all approach. Thus, we believe a four-step planning approach can aide in the development of a limb salvage program.

Table 4 –

Core elements of advanced wound care centers.

Multidisciplinary team that offers weekly wound care

Comprehensive patient assessment including full-service noninvasive vascular laboratory

Wound care-specific electronic medical record for high-resolution tracking of individual wound outcomes and healing rates

Hyperbaric oxygen therapy capabilities, specialized orthotics and dressings, and advanced wound therapies

Weekly team discussion for high-risk patients (similar to a tumor board)

Coordinated case management scheduling of specialty care and transfer for patients requiring hospitalization or revascularization

From Flores AM, Mell MW, Dalman RL, et al. Benefit of multidisciplinary wound care center on the volume and outcomes of a vascular surgery practice. J Vasc Surg 2019;70:1612–9 [10], adapted with permission.

2.1. Step 1: Community and institution assessment

A thorough examination of the immediate and surrounding community, available resources, and institutional support can maximize a program’s impact and effectiveness. Regional Medicare data have shown that regions with a high major amputation rate are associated with a lower intensity of vascular care compared with regions with low major amputation rates [16]. The regions were predominately located in the southern United States and included Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia, highlighting the need for limb salvage programs in these areas. In addition, patients who are non-White, poor, and Medicaid recipients have been observed to have higher rates of amputation compared with relatively more affluent and White patients [17]. A suggested explanation for the disparity observed in this patient subset is a lack of access to health care and poor education of the general population and primary care providers of CLTI.

The community setting and resources available should be considered when choosing which model of care to pursue. Areas with low intensity of resources and vascular care may consider a “basic” tier limb salvage program focused on patient education, risk factor modification, and expedited referral to higher level care when necessary [14].This model limb salvage program, however, although dependent on a referral platform, can still make a significant difference in patient outcomes.

If aiming to create an intermediate care model or a center of excellence, institutional collaboration and support are vital, as the upfront costs of establishing a limb salvage program can be substantial. Galmer et al [18] asserted the following three key principles to consider when evaluating the cost-effectiveness of limb salvage: amputations are the sixth costliest surgery; amputees are readmitted frequently, with high associated resource utilization; and limb salvage saves lives, with associated reductions in amputation and mortality rates [18]. In addition, multidisciplinary wound care centers have been found to increase revascularization referrals significantly, with an increase of 64% seen in lower extremity interventions during a 3-year period after program establishment [10]. Even when considering rising procedural costs, treatment of peripheral arterial occlusive disease and resultant lower extremity interventions have been found to have the highest margin and are the greatest source of revenue for vascular surgery practices [19].

Limb salvage programs may be financially advantageous when considering amputation prevention and generation of downstream interventional revenue, which can be used to garner institutional collaboration and support.

2.2. Step 2: Form a multidisciplinary team

Due to mounting evidence of the benefit of a multidisciplinary approach to limb salvage, societal guidelines have recommended implementation; however, no suggestions for specific composition were stated [5]. Limb salvage is an effort that requires the expertise of multiple specialties and no one specialty is equipped to provide the whole continuum of care. A team of physicians, nurses, and allied health professionals with a focus on one aspect of care can create a sum greater than its parts. A leader of the team or “captain” who is passionate and has the authority to guide a multidisciplinary team is paramount. The facilitation of open communication is highly encouraged, particularly for the most challenging patients, as this can reduce fragmentation of care and improved efficiency. Chung et al [20] reported that their multidisciplinary care was associated with improved amputation-free survival compared with standard wound care from a single specialty.

Although there is a described “irreducible minimum” or a team consisting of a vascular interventionalist and surgeon with wound debridement capabilities, most teams include more specialties [14]. A recent review article examined 33 studies of multidisciplinary teams to reduce major amputations and found team composition to be highly variable. The average team consisted of five distinct disciplines. Medical specialties most commonly included endocrinology (82%) and infectious diseases (37%). Surgical specialties most commonly included vascular surgery (74%), orthopedic surgery (67%), and podiatry (52%) [11]. Nephrologists are commonly included as well, due to the elevated prevalence of chronic kidney disease in patients with CLTI.

Although the ultimate goal of a limb salvage program is limb loss prevention, not all limbs are salvageable and both nonoperative and operative patients must be considered when forming a multidisciplinary team. A recent analysis of a 15-year single-center experience with a palliative limb care pathway for CLTI found that patients within the care pathway had an observed mortality rate of 88.2% [21]. Given the high mortality rate in these patients, palliative care specialists and discussion can avoid unnecessary procedures and surgery at the end of life.

Similarly, once a limb is deemed nonsalvageable in an operative candidate, early physical and occupational therapy, Physical medicine and rehabilitation (PMNR), and prosthetists involvement is paramount to maximizing long-term functionality and independence [22]. Amputation and the subsequent prosthetic fitting is a complex medical and psychosocial process requiring expertise and longitudinal care until rehabilitation has been completed.

The team should aim to accomplish all nine essential skills identified by the GLASS guidelines. Ancillary staff that should be considered include wound care nursing, prosthetist, occupational care, case managers, and a program coordinator.

2.3. Step 3: Patient care

The overarching patient flow through limb salvage programs should be guided by established care referrals and algorithms [23]. The establishment of a limb salvage program and care pathways has been found to reduce time to vascular assessment [9]. Successful multidisciplinary teams and limb salvage programs have consistently addressed the following four tasks: vascular disease, glycemic control, local wound management, and infection control [11]. After initial enrollment, rapid patient assessment using the WIfI classification can expedite and tier care. A higher risk of limb amputation has been correlated with higher WIfI score, allowing identification of patients who require expeditious care [24]. Comprehensive patient assessment should also be conducted with a goal of risk factor modification. This includes glycemic control, smoking cessation, and hypertension and hypercholesterolemia management with the aid of endocrinologists and cardiologists.

The cornerstone of initial patient management is contingent on a noninvasive vascular laboratory for peripheral artery disease diagnosis and treatment. The vascular laboratory should be able to perform standard of care diagnostics, such as ankle-brachial index or toe-brachial index, toe pressures, and duplex ultrasounds. Patients requiring revascularization may also require cross-sectional imaging for surgical planning. Revascularization is a critical component in the management of patients with CLTI, as insufficient arterial flow results in rapid tissue death and impediment of wound healing [25]. Although the debate of open surgical versus endovascular revascularization continues, revascularization is trending toward an endovascular approach. Goodney et al [26] reported that, in a 10-year period, endovascular revascularizations outnumbered open revascularizations three to one. As such, the endovascular operator should be adept in advanced techniques, including tibial angioplasty and pedal arch revascularization, which have been found to reduce rates of major amputation and promote wound healing [27].

In our experience, local wound management is best accomplished with an inpatient service and outpatient wound care center. The tenets of wound care can be followed using established frameworks, such as the DIME (devitalized tissue, infection/inflammation, moisture balance, and edge preparation) guidelines [28]. Broadly, the goal of wound care is to salvage as much healthy tissue as possible via removal of nonviable tissue. The result should be production of healthy granulation tissue and thus healing. Although extensive wound debridement and minor amputations should be conducted in an operating room, the benefit of an outpatient wound care center is clear. Outpatient wound care centers allow for high-frequency weekly debridement and aggressive management of infection. Adjunctive therapies, such as vacuum-assisted closure devices, hyperbaric oxygen therapy, biologic tissue replacements, and skin flaps should be considered with the aid of medical and ancillary staff. Plastic surgeons are especially valuable in this respect due to their soft-tissue expertise.

All patients with CLTI with pedal wounds should undergo mechanical offloading as a primary component of treatment to aide in wound healing and prevent recurrence. Total contact casting is considered the reference standard for mechanical offloading, however, other methods may be used as well, depending on supply and staff [5,29]. Physical therapists are similarly important for patient education and mobility training with mechanical offloading. Adequate mobility training helps the patient maintain independence and perform activities of daily living.

Within the determinants of wound healing, the presence of infection has the potential to severely impede wound healing, and approximately 20% of moderate or severe diabetic foot infections lead to an amputation [30]. Multidisciplinary teams incorporating infectious diseases specialists are invaluable in the appropriate treatment of wound infections, as these infections are frequently complex and polymicrobial [31]. Accurate culture data and treatment often require a surgeon to obtain the bone or deep tissue culture with the appropriate antibiotic course determined by the infectious diseases specialist. As mentioned previously, these concepts are essential skills for a limb salvage team.

2.4. Step 4: Monitor outcomes and refine processes

The final step in the construction of a limb salvage program requires refinement of patient care and pathways, as well as monitoring outcomes, in order to inform areas for improvement. Patients with CLTI require continual follow-up, as the risk of re-ulceration increases after an initial ulceration [32]. Patients should be followed aggressively, at least until their wounds are healed. However, surveillance becomes complex when patients have been revascularized, as there are no consensus guidelines for optimal surveillance after percutaneous intervention.

The optimization of patient care pathways hinges on monitoring outcomes, which has been outlined in the GLASS guidelines (Table 5). Our program monitors all outcomes suggested by the GLASS guidelines, including limb salvage rates, amputation rates, and wound healing percentages. In our institution, outcomes were assessed before and after the implementation of a multidisciplinary wound care center and limb salvage program, allowing the establishment of institutional benchmarks for the outcomes. Our center also monitors in patient length of stay for revascularization and CLTI care, as well as readmission rates. After the implementation of the limb salvage program, these were found to be significantly improved compared with previous years and with other academic hospitals in California, based on Vizient data. A potential explanation for this trend may be attributable to the defragmentation of CLTI care, with programs providing increased communication between specialists, decreased referral times, and consistent ambulatory follow-up.

Table 5 –

Major outcome measures for chronic limbthreatening ischemia.

Outcome measure
Quality assurance measure
Limb salvage rate
Major to minor amputation ratio
Healing percentage, all wounds
Healing percentage, DFUs
Median days to heal, DFUs
Noninvasive vascular study, DFUs
Revascularization success, open bypass
Revascularization success, endovascular

From Conte MS, Bradbury AW, Kolh P, et al. Global vascular guidelines on the management of chronic limb-threatening ischemia. J Vasc Surg 2019;69(6S):3S–125S.e40 [5], adapted with permission.

Abbreviation: DFU, diabetic foot ulcer

The GLASS guidelines do not address specific benchmarks of requisite outcomes for centers of excellence. Monitoring these outcomes is imperative to establish benchmarks, as there are no widely agreed upon values. Institutions with limb salvage programs can contribute to benchmark establishment by joining the Society for Vascular Surgery Vascular Quality Initiative to provide data on procedures and quality measures.

In our experience, this requires dedicated personnel to monitor the outcomes and identify areas for improvement, as they are not easily tracked in conventional electronic medical records. A limb salvage program coordinator maintains our database and develops quality improvement projects. Frequently, centers of excellence have multiple committees to accomplish this task, such as ongoing clinical review, science and technology, and quality committees [18]. With monitoring of the appropriate outcomes and constant improvement, this step ensures continued program effectiveness and can also ensure team member engagement and cost-effective care.

3. Conclusions

An effective limb salvage program is formed by a motivated, diverse, and highly specialized medical and ancillary staff. Limb salvage programs are rapidly becoming standard of care due to the complexity of patients with CLTI and a body of literature showing improved limb preservation. An effective limb salvage program can be created by following these four steps: community and institution assessment, formation of a multidisciplinary team, provision of patient care and management, and lastly, monitoring outcomes and refining processes. Continual refinement of patient care pathways ensures program effectiveness and success.