Prospective comparison of infrainguinal bypass grafting in patients with and without antiphospholipid antibodies.

PURPOSE

The antiphospholipid antibodies (APL)-anticardiolipin antibodies (ACL) and lupus anticoagulant (LA)-are widely believed to be associated with decreased lower extremity bypass graft patency rates. To date, no prospective cohort study has confirmed this assumption. A prospective comparison of the result of infrainguinal revascularization procedures performed since 1990 in patients with and without APL forms the basis of this report.

METHODS

Patients who underwent elective infrainguinal bypass procedures from 1990 to 1994 were evaluated for hypercoagulable states (ACL, LA, protein C, protein S, and antithrombin III). Patient data were prospectively entered in a computerized vascular registry, and postoperative follow-up was maintained for life. Graft patency, limb salvage, and patient survival rates were calculated by life-table methods.

RESULTS

Three hundred twenty-seven lower extremity bypass grafting procedures were performed in 262 patients. APLs were present in 83 patients (32%); 70 patients (84%) had ACLs only, 11 patients (13%) had LA only, and two patients (3%) had both ACLs and LA. There was no significant difference between APL-positive and APL-negative patients with respect to demographics, associated medical conditions, indication for operations, and type of procedures performed. More patients who had APLs had warfarin treatment after surgery (43% vs 24%, p = 0.002). Life table 4-year primary patency rates showed minimal difference (APL-positive, 43%; APL-negative, 59%; p = 0.087), and no significant difference was noted in assisted primary patency rates (APL positive, 72%; APL negative, 73%; p = NS), limb salvage rates (APL positive, 79%; APL negative, 88%; p = NS), and patient survival rates (APL positive, 67%; APL negative, 66%; p = NS).

CONCLUSIONS

APLs were found in a surprising one third of the patients who underwent leg bypass grafting procedures. The majority of APLs identified were ACLs (87%). There was minimal difference in graft primary patency rates, and no difference in assisted primary patency, limb salvage, and survival rates between patients with and without APLs who underwent leg bypass grafting procedures. The extreme morbidity rate associated with APLs in previous reports is not confirmed by this prospective study. APLs should not be regarded as a contraindication to indicated leg bypass grafting procedures.