SLR - February 2017 - Adam J. Badaczewski

Not All Patients with Critical Limb Ischaemia Require Revascularization

Reference: Santema TB, Stoekenbroek RM, van Loon J, Koelemay MJ, Ubbink DT. Not All Patients with Critical Limb Ischaemia Require Revascularization. Eur J Vasc Endovasc Surg. 2016 Dec 2. pii: S1078-5884(16)30554–8.

Reviewed By: Adam J. Badaczewski, DPM
Residency Program: Suburban Community Hospital

Podiatric Relevance: Chronic critical limb ischemia (CLI) increases a patient’s risk for lower-extremity amputation, diminished quality of life and mortality. As foot and ankle surgeons, we see a large number of patients who have compromised blood flow to the lower extremity. Revascularization procedures are attempted for pain relief, amputation prevention and wound healing in the realm of limb salvage. Much research has been performed to date on the success of invasive surgical techniques to treat CLI, but not much research has been performed on the success of conservative treatments for CLI. Some patients, due to comorbidities or other factors, are not good candidates for revascularization procedures. The aim of this study is to examine if the amputation-free survival (AFS) rates and overall survival (OS) rates are similar among patients with CLI treated with surgical and conservative means. The paper also goes one step further and looks at other clinical characteristics outside of CLI, which correlate with increasing or decreasing rates in each measure of AFS and OS.

Methods: This was a retrospective cohort study performed at a Dutch University Hospital. All consecutive patients were selected with CLI presenting between January 2010 and January 2014. Clinical criteria for selection were ischaemic rest pain or tissue loss and systolic ankle pressure < 50mmHg or systolic toe pressure < 30mmHg. Both criteria needed to be met for patient selection into study. Exclusion criteria included acute limb ischaemia, Buerger’s disease or vasculitis. Patients who received an amputation at initial presentation were also excluded. Patient characteristics were collected, including age, gender, smoking history, body mass index, diabetes, cerebrovascular disease, end-stage renal disease, chronic obstructive pulmonary disease, heart disease, hypertension, presence of ischaemic rest pain (Fontaine stage III), presence of ulceration or gangrene (Fontaine stage IV) and prior revascularization procedures. Follow-up data included information about revascularization procedures, limb salvage and survival. Patients were divided into one of three groups: 1) invasive (if revascularization took place within six weeks of CLI diagnosis), 2) deferred invasive (if revascularization took place after six weeks of CLI diagnosis) and 3) permanently conservative (if no revascularization took place since initial CLI diagnosis and death or last follow-up). The primary outcome measure of the study was AFS rate, which is determined by if the patient remained alive without major amputation (proximal to the ankle joint) of affected limb after the diagnosis of CLI. OS was also assessed in the study, which measures patient mortality rate after the diagnosis of CLI is made.

Results: One hundred forty-four patients were included in the study with a mean age of 71.2 years and 50.7 percent (N=73) where female. The mean follow-up for patients was 99 weeks. The invasive group (< six weeks for revascularization) included 96 patients (66.7 percent), which, of this group, 70.8 percent (N=68) underwent endovascular revascularization. The deferred invasive group (> six weeks for revascularization) included 26 patients (18.1 percent). Of this group, 69.2 percent (N=18) underwent endovascular revascularization, 26.9 percent (N=8) underwent bypass revascularization, and one patient had a hybrid procedure performed. In this deferred group, the mean time to having a revascularization procedure was 17 weeks. The permanent conservative group included 22 patients (15.3 percent). The reasons not to perform revascularization procedures included comorbidities (N=9), good healing tendencies or denying symptoms (N=7), no options for revascularization (N=3) and unknown reasons (N=3). An analysis of the AFS rates at one year was 67.3 percent in the invasive group, 83.6 percent in the deferred invasive group and 72.7 percent in the permanent conservative group. At two years, AFS rates were 56.0 percent, 74.8 percent and 54.2 percent, respectively. It was noted that there was no statistical difference between the three groups. Major amputation was noted only in the invasively treated patient group (49 events total with 18 of those events being noted after the four years of the study). After one year, the OS in the invasive group was 77.3 percent, 87.8 percent in the deferred invasive group and 72.2 percent in the permanent conservative group. After two years, the OS rates were 64.6 percent, 83.4 percent and 54.2 percent, respectively. As with the AFS rates, there was no statistical significance noted in OS rates between the three groups. It was noted that the type of treatment plan (invasive, deferred invasive or conservative) was not a significant predictor in either the OS rates or the AFS rates. Statistically significant predictors of shorter AFS (greater likelihood of amputation in shorter time period) were higher at age of diagnosis of CLI, COPD and heart disease. Statistically significant predictors for shorter OS (greater likelihood of death in a shorter time period) were higher at age of diagnosis of CLI, hypertension and COPD.

Conclusions: Limitations of this study were selection bias because the study is observational and not a randomized control study. Also, immediate revascularization patients could have had more extensive and severe CLI. It is noted that among the three groups in this study, the AFS and OS rates are very similar regardless of treatments with no statically significant differences. The study also showed that the prognosis for patients with CLI can be driven by their comorbidities. It was shown in this study that the presence of advanced age, COPD and heart disease were independent predictors of poor AFS, and advanced age, hypertension and COPD were independent predictors of poor OS. This study shows that all patients do not need a revascularization procedure performed and that there can be optimism in treating CLI patients with conservative care. Further studies need to be performed to design a criterion for patients with CLI that would benefit from conservative treatment due to the high risks of a revascularization-type procedure. 

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