Blood pressure surges during office-based transurethral microwave therapy for the prostate

OBJECTIVE: To investigate the occurrence of adverse blood pressure (BP) events during transurethral microwave therapy (TUMT) for benign prostatic hyperplasia. PATIENTS AND METHODS: We conducted a retrospective study of the vital signs of 185 consecutive patients who received TUMT (via 6 devices) at 4 institutions from March 1, 2003, to September 18, 2005. Maximum change, percent change in systolic BP, diastolic BP, mean arterial pressures, heart rate, and oxygen saturation were evaluated. RESULTS: Of the 185 patients, 77 patients (42%; 95% confidence interval [CI], 35%-49%) experienced an increase in systolic BP of more than 30 mm Hg during TUMT; 30 patients (16%; 95% CI, 12%-22%), an increase of more than 50 mm Hg; and 10 patients (5%; 95% CI, 3%-10%), an increase of more than 70 mm Hg. A greater than 20% change in systolic BP from baseline was observed in 95 patients (51%; 95% CI, 44%-58%). Many men experienced multiple events, with an average time of onset of 15.9 minutes into treatment. Significant differences were noted among the devices. CONCLUSION: This retrospective study demonstrates a significant number of BP surges during TUMT for benign prostatic hyperplasia. These BP changes represent a potential risk of cardiovascular events in patients with known or occult cardiovascular disease. Our study is the first to recognize the incidence of this BP response. Until further studies identify the mechanisms responsible for these surges in BP, the results of this study suggest that BP should be monitored, treatment adjusted, and antihypertensive medications continued during all TUMT.