Risk factors analysis of thromboembolectomy for acute thromboembolic lower extremity ischemia in native arteries.

BACKGROUND: Aim of this study is to report the results of thromboembolectomy (ThEmb) for acute thromboembolic lower limb ischemia (ATLI) in native arteries and to create a predictive score for amputation-free survival (AFS) at 30 days.

METHODS: It is a single center, retrospective analysis of a four years period. All patients had ThEmb: adjunctive procedures included femoral and/or popliteal endarterectomy in 30 (18.3%) cases, PTA-stent in 24 (14.6%), and femoral endarterectomy plus PTA-stent in 12 (7.3%). Fasciotomies were performed in 6 (3.6%) patients. Predictors of AFS identified on univariate screen (inclusion threshold, P<.20) were included in a multivariable model. The resulting significant predictors were assigned an integer score to stratify patients into risk groups.

RESULTS: Authors analyzed 164 limbs in 164 patients. Mean age was 80±10 years (range, 40-99). In-hospital mortality was 9.8% (N.=16); AFS at 30 days was 84.7% (N.=139). The anatomic level (iliac vs. femoropopliteal vs. infrapopliteal) of the occlusion did not affect AFS (P=.326). Multivariable analysis identified six significant predictors of AFS at 30 days: age >85 (P=0.050), chronic obstructive pulmonary disease (P=0.008), chronic renal insufficiency (P=0.019), late (>6 hours) onset (P=0.004), the presence of major neurologic deficit (P=0.023), and an increased (>800IU/L) level of creatine phosphokinase (P=0.001). An integer score generated two risk groups (low-risk 0-2 [70.1% of cohort], and high-risk ≥3 [29.9% of cohort]): stratification of the patients according to risk category yielded significantly different AFS at 30 days (low-risk 5.2% vs. high-risk 38.8%, P<0.0001).

CONCLUSIONS: Among patients selected to undergo ThEmb for ATLI in native arteries, this risk score identified a group of patients with a 40% chance of death or major amputation at 30 days. The score can help to optimize the operative strategy, but further prospective validation is needed.