Purpose
The performance of atherectomy devices has been variable. The purpose of this study was to evaluate our experience using the SilverHawk atherectomy (Fox Hollow Technologies, Redwood City, Calif) device for lower extremity procedures to determine predictors of midterm success.
Methods
Records of all patients who underwent lower extremity atherectomy with the SilverHawk atherectomy catheter were reviewed. Patient demographics, vessel treated, number of vessels treated, lesion characteristics, and postoperative courses were analyzed. Cumulative patency rates, limb salvage, mortality, and factors associated with outcomes were determined using the Kaplan-Meier Method with Cox Proportional Hazards modeling.
Results
Between January 2004 and January 2006, 167 vessels were atherectomized with the SilverHawk in 73 patients. There were 42 men and 31 women treated, and the mean age was 68.8 ± 13.8. Five patients had both legs treated for a total of 78 legs treated. Of the 78 legs intervened on, 25.6% (20/78) had 1 vessel treated, 51.3% (40/78) had 2 vessels treated, 11.5% (9/78) had 3 vessels treated, 9% (7/78) had 4 vessels treated, and 2.6% (2/78) had 5 vessels treated. A total of 78% (61/78) of patients had intermittent claudication, 71% (56/78) had rest pain, and 58% (45/78) had tissue loss. Adjunctive procedures were performed in 63 vessels in 33 patients (61 percutaneous transluminal angioplasty [PTA] and 2 PTA + stent). Eighty-four vessels treated were totally occluded and 83 stenotic. Cumulative 1-year primary, primary assisted, secondary patency, limb salvage, and survival rates with confidence intervals, respectively, are: 43% (30,57), 49% (36,63), 57% (43,71), 75% (57,92), and 90% (80,100). Multivariable analysis demonstrated tobacco use, renal disease, diabetes, and tissue loss are all predictors of patency loss, while only diabetes and tissue loss were associated with greater limb loss. There was no difference in patency rates irrespective of location of Trans Atlantic Inter-Societal Consensus (TASC) classification, vessel treated (femoral vs tibial), or degree of stenosis (occluded vs stenotic). Also, multiple vessels treated in the same patients had no affect on patency. The mean ankle brachial index (ABI) pre-op was 0.57 ± 0.19, and this increased to 0.81 ± 0.21 (P < .001) at 30 days post-op.
Conclusion
Lower extremity atherectomy procedures with the SilverHawk device are safe and effective means in improving symptoms. However, there is decreased durability and significant patency and limb loss over time. Diabetes, renal disease, tobacco use, and tissue loss are all associated with inferior outcomes.
