A conservative approach to select patients with ischemic wounds is safe and effective in the setting of deferred revascularization

Peripheral Vascular Disease

Peripheral artery disease is most often caused by atherosclerosis. Arterial insufficiency from atherosclerotic blockages in the limbs can impair walking distance and put patients with severe disease at risk of limb loss. Management of the disease centers around early diagnosis, supervised exercise therapy and lifestyle modification, optimizing medical care (with the goal of reducing fatal cardiac and cerebrovascular events), and revascularization.

Therapeutic Alternatives in Diabetic Foot Patients without an Option for Revascularization: A Narrative Review

Background: The healing of foot wounds in patients with diabetes mellitus is frequently complicated by critical limb threatening ischemia (neuro-ischemic diabetic foot syndrome, DFS). In this situation, imminent arterial revascularization is imperative in order to avoid amputation. However, in many patients this is no longer possible (“too late”, “too sick”, “no technical option”). Besides conservative treatment or major amputation, many alternative methods supposed to decrease pain, promote wound healing, and avoid amputations are employed. We performed a narrative review in order to stress their efficiency and evidence. Methods: The literature research for the 2014 revision of the German evidenced-based S3-PAD-guidelines was extended to 2020. Results: If revascularization is impossible, there is not enough evidence for gene- and stem-cell therapy, hyperbaric oxygen, sympathectomy, spinal cord stimulation, prostanoids etc. to be able to recommend them. Risk factor management is recommended for all CLTI patients. With appropriate wound care and strict offloading, conservative treatment may be an effective alternative. Timely amputation can accelerate mobilization and improve the quality of life. Conclusions: Alternative treatments said to decrease the amputation rate by improving arterial perfusion and wound healing in case revascularization is impossible and lack both efficiency and evidence. Conservative therapy can yield acceptable results, but early amputation may be a beneficial alternative. Patients unfit for revascularization or major amputation should receive palliative wound care and pain therapy. New treatment strategies for no-option CLTI are urgently needed.

Conservative Management of Non-Infected Diabetic Foot Ulcers Achieves Reliable Wound Healing and Limb Salvage in the Setting of Mild-Moderate Ischemia

OBJECTIVE

The Society for Vascular Surgery (SVS) Wound, Ischemia, and foot Infection (WIfI) classification system has been validated to predict wound healing among patients with critical limb threatening ischemia (CLTI). Our goal was to analyze the use of a previously reported conservative wound care approach to non-infected (foot infection score of zero), diabetic foot ulcers (DFU) with mild-moderate peripheral arterial disease (PAD) enrolled in a conservative tier of a multidisciplinary limb preservation program.

METHODS

Veterans with CLTI and tissue loss were prospectively enrolled into our Prevention of Amputation in Veterans Everywhere (PAVE) program. All patients with wounds were stratified to a conservative approach based on perfusion evaluation and a validated pathway of care. Retrospective analysis of a prospectively maintained database was performed to evaluate all conservatively managed patients presenting without foot infection for the primary outcome of wound healing as well as secondary outcomes of time to wound healing, delayed revascularization, wound recurrence, and limb loss.

RESULTS

Between January 2006 and December 2019, 1113 patients were prospectively enrolled into the PAVE program. A total of 241 limbs with 281 wounds (217 patients) were stratified to the conservative approach. Of these, 122 limbs (89 patients) met criteria of having diabetic foot wounds without infection at the time of enrollment and are analyzed in this report. Of the 122 limbs, 97 (79.5%) healed their index wound with a mean time to healing of 4.6 months (0.5-20 months). Wound recurrence ensued in 44 (45.4%) limbs, 93.2% of which healed again after recurrence. There were three (3.1%) limbs requiring major amputation in this group (one due to uncontrolled infection and two due to ischemic tissue loss). Of the 25 (20.5%) limbs that did not heal initially, four (16%) required amputation due to progressive symptoms of CLTI.

CONCLUSIONS

In patients` with diabetes and lower extremity wounds without infection in the setting of mild to moderate PAD, there appears to be an acceptable rate of index wound healing, and appropriate rate of recurrent wound healing with a low risk of limb loss. While wound recurrence is frequent, this can be successfully treated without the need for revascularization.

A single center's 15-year experience with palliative limb care for chronic limb threatening ischemia in frail patients

OBJECTIVE

Our institution's multidisciplinary Prevention of Amputation in Veterans Everywhere (PAVE) program allocates veterans with critical limb threatening ischemia (CLTI) to immediate revascularization, conservative, primary amputation or palliative limb care based on previously published criteria. These four groups align with the approaches outlined by the Global Guidelines for management of CLTI. The current study delineates the natural history of the palliative limb care group of patients and quantifies procedural risks and outcomes.

METHODS

Veterans prospectively enrolled into the palliative limb cohort of our PAVE program between January 2005 and January 2020 were analyzed. The primary outcome was mortality. Secondary outcomes included overall and limb-related readmissions, limb loss and wound healing. Clinical Frailty Score (CFS) was calculated and 5-year expected mortalities were estimated using the Veterans Administration Quality Enhancement Research Initiative (VA QUERI) tool. Regression analysis was performed to establish associations among the following variables: mortality, WIfI score, Clinical Frailty Score, overall admissions and limb-related admissions.

RESULTS

The PAVE program enrolled 1158 limbs over 15 years. 157 (13.5%) limbs in 145 patients were allocated to the palliative limb care group. The overall mortality of the group was 88.2% (median 3.5 months; range 0-91 months). Of the patients that expired, 50% (n=64) died within 3 months of enrollment. The predicted 5-year mortality for the group was 66%. The average frailty score of the group was 6.2, denoting someone who is moderately to severely frail. Based on CFS, 106 patients were considered frail while 39 were considered not frail. There was no difference in mortality between frail and non- frail patients, however there was a statistically significant difference in early mortality (<3 months), 56.2% vs 37.5% (p = 0.032), respectively. The 30-day limb-related readmission rate was 4.7%. Eventual major amputation was necessary in 18 (11.5%) limbs. Wound healing occurred in 30 patients (20.6%). Regression analysis demonstrated no association between frailty score and mortality (r = 0.55, p = 0.159) or between WIfI score and mortality (r = 0.0165, p = 0.98). There was a significant association between WIfI score and limb-related admissions (r = 0.97, p <0.001).

CONCLUSION

Frail, chronic limb threatening ischemia patients have a high early mortality and a low risk of limb-related complications. They also have a low incidence of deferred primary amputation or limb-related readmissions. In our cohort, the vast majority of patients died within a few months of enrollment without needing an amputation. A comprehensive approach to the management of CLTI patients should include a palliative limb care option as a significant proportion of these patients have limited survival and can potentially avoid unnecessary surgery or major amputation.

The Society for Vascular Surgery Objective Performance Goals for Critical Limb Ischemia are attainable in select patients with ischemic wounds managed with wound care alone

BACKGROUND

To set therapeutic benchmarks, in 2009 the Society for Vascular Surgery defined objective performance goals (OPG) for treatment of patients with chronic limb threatening ischemia (CLTI) with either open surgical bypass or endovascular intervention. The goal of these OPGs are to set standards of care from a revascularization standpoint and to provide performance benchmarks for 1 year patency rates for new endovascular therapies. While OPGs are useful in this regard, a critical decision point in the treatment of patients with CLTI is determining when revascularization is necessary. There is little guidance in the comprehensive treatment of this patient population, especially in the nonoperative cohort. Guidelines are needed for the CLTI patient population as a whole and not just those revascularized, and our aim was to assess whether CLTI OPGs could be attained with nonoperative management alone.

METHODS

Our cohort included patients with an incident diagnosis of CLTI (by hemodynamic and symptomatic criteria) at our institution from 2013-2017. The primary outcome measured was mortality. Secondary outcomes were limb loss and failure of amputation-free survival. Descriptive statistics were used to define the 2 groups - patients undergoing primary revascularization and patients undergoing primary wound management. The risk difference in outcomes between the 2 groups was estimated using collaborative-targeted maximum likelihood estimation.

RESULTS

Our cohort included 349 incident CLTI patients; 60% male, 51% white, mean age 63 +/- 13 years, 20% Rutherford 4, and 80% Rutherford 5. Most patients (277, 79%) underwent primary revascularization, and 72 (21%) were treated with wound care alone. Demographics and presenting characteristics were similar between groups. Although the revascularized patients were more likely to have femoropopliteal disease (72% vs. 36%), both groups had a high rate of infrapopliteal disease (62% vs. 57%). Not surprisingly, the patients in the revascularization group were less likely to have congestive heart failure (34% vs. 42%), complicated diabetes (52% vs. 79%), obesity (19% vs. 33%), and end stage renal disease (14% vs. 28%). In the wound care group, 2-year outcomes were 65% survival, 51% amputation free survival, 19% major limb amputation, and 17% major adverse cardiac event. The wound care cohort had a 13% greater risk of death at 2 years; however, the risk of limb loss at 2 years was 12% less in the wound care cohort.

CONCLUSIONS

A comprehensive set treatment goals and expected amputation free survival outcomes can guide revascularization, but also assure that appropriate outcomes are achieved for patients treated without revascularization. The 2-year outcomes achieved in this cohort provide an estimate of outcomes for nonrevascularized CLTI patients. Although multi-center or prospective studies are needed, we demonstrate that equal, even improved, limb salvage rates are possible.

Precision Medicine Enables More TNM-Like Staging in Patients With Chronic Limb Threatening Ischemia

Introduction: In cancer, there are survival-based staging systems and tailored, stage-based treatments. There is little personalized treatment in vascular disease. The 2019 Global Vascular Guidelines on the Management of CLTI proposed successful treatment hinges upon Patient risk, Limb severity, and ANatomic complexity (PLAN). We sought to confirm a three axis approach and define how increasing severity affects mortality, not just limb loss.

Methods: Patients revascularized for incident CLTI at our institution from 2013 to 2017 were included. Outcomes were mortality, limb loss, the composite endpoint of amputation-free survival. Using Bayesian machine learning, specifically supervised topic modeling, clusters of patient features associated with mortality were formed after controlling for revascularization type. Patients were assigned to the cluster they belonged to with highest probability; clusters were characterized by analyzing the characteristics of patients within them. Patient outcomes were used to order the clusters into stages with increasing mortality.

Results: We defined three distinct clusters as the basis for patient- and limb-centered stages. Across stages, rates of 1-year mortality were 7.6, 13.8, 18.9% and rates of amputation-free survival were 84.8, 79.3, and 63.2%. Stage one had patients with rest pain and previous revascularization who were less likely to have wounds, diabetes, and renal disease. Stage two had doubled mortality, likely related to diabetes prevalence. Stage three is characterized by high rates of complicated comorbidities, particularly end stage renal disease, and significantly higher rate of limb loss (22.6 vs. 8% in stages one and two).

Conclusion: Using precision medicine, we have demonstrated clustering of CLTI patients that can be used toward a robust staging system. We provide empiric evidence for PLAN and detail about how changes in each variable affect survival and amputation-free survival.