Extracorporeal shockwave lithotripsy in patients treated with antithrombotic agents

Patients and Methods: Between January 1996 and December 1999, 749 patients underwent electromagnetic SWL. Among them, 23 patients, 19 with renal and 4 with ureteral stones, were receiving antithrombotic drugs (aspirin, ticlopidine, dipyridamole). According to the cardiologist and hematologist, we divided these patients into two groups: Group 1 had a low thromboembolic risk (previous myocardial infarction), and Group 2 had a high thromboembolic risk (aortocoronary bypass, atrial fibrillation, cerebrovascular disease, peripheral occlusive arterial disease). Group 1 patients discontinued their antiplatelet therapy 8 days prior to SWL to permit a sufficient number of functioning platelets to remain. Group 2 patients suspended antiplatelet therapy, and unfractioned heparin 5000 IU tid (8 a.m., 4 p.m., and 12 p.m.) was administered for the 8 days prior to SWL. On the ninth day of withdrawal, SWL was performed in all patients. Close follow-up was performed during the postoperative period (hemoglobin, hematocrit, kidney ultrasonography, plain abdominal film). The antithrombotic therapy was restored in all patients within 10 to 14 days of withdrawal. Results: Hematomas and thromboembolic events were not observed. At 3 months' follow-up, 14 patients (61%) were stone free, 3 (13%) had <4-mm fragments, and 6 (26%) had >4-mm residual fragments. Conclusion: Our schedules for the suspension or substitution of antithrombotic therapy, although tested in a small number of patients, allowed us to perform SWL without hemorrhagic or thromboembolic complications.