Results of high-energy transurethral microwave thermotherapy in patients categorized according to the American Society of Anesthesiologists operative risk classification

Objectives. To evaluate the relation between the American Society of Anesthesiologists (ASA) classification and response to transurethral microwave thermotherapy (TUMT) in patients with lower urinary tract symptoms and benign prostatic hyperplasia (BPH). Methods. Two hundred forty-seven patients with symptomatic BPH treated with high-energy TUMT were scored retrospectively for ASA status. Student's t test was used to determine differences in improvement at each point of follow-up between patients classified as ASA 1 or 2 and patients classified as ASA 3 or 4. Logistic regression analysis was performed to assess the predictive value of ASA status for response using the World Health Organization response evaluation criteria for International Prostate Symptom Score, maximal flow rate, and urodynamic obstruction. Results. There was a significant improvement in objective and subjective parameters at 12, 26, and 52 weeks of follow-up in both ASA 1 and 2 patients and ASA 3 and 4 patients. There was no difference in objective and subjective improvement between both groups at each point of follow-up. Objective and subjective improvement in ASA 3 and 4 patients with cardiovascular disease and ASA 3 and 4 patients with noncardiovascular disease was the same, although patients with cardiovascular disease received less energy during TUMT. Using logistic regression analysis, ASA classification was not predictive of response after high-energy TUMT. Conclusions. There is no relation between ASA classification and outcome after high-energy TUMT. Because these patients are considered at high risk of perioperative complications and postoperative morbidity, TUMT could contribute considerably to the treatment of BPH in this specific group of patients. (C) 1999, Elsevier Science Inc. All rights reserved.