TRUS versus transabdominal ultrasound as a predictor of enucleated adenoma weight in patients with BPH: a tool for standard preoperative work-up?

Background: Despite being formally included in the assessment of patients presenting with lower urinary tract symptoms (LUTS), transrectal ultrasonography (TRUS) is not routinely offered to these patients. This tactic however might not be optimum since data exist on the superiority of TRUS over transabdominal ultrasound in accurately predicting prostate volumes. We aimed to evaluate TRUS as a standard tool in the evaluation of patients with benign prostate hyperplasia (BPH) with a special focus on the potential impact it might have on the decision of open versus transurethral surgery.
Patients and Methods: Seventy-one patients presenting with LUTS due to BPH and eventually managed with open surgery based on their preference and prostate volume were included in the protocol. TRUS was performed in all patients preoperatively and calculations of the transition zone were made. These were compared with respective transabdominal calculations of the prostate volume as well as the enucleated specimen weight (W).
Results: TRUS slightly underestimated W by 4.4% (95% CI 10.5, 1.7) while transabdominal ultrasound overestimated it by 55.7% (95% CI 31.8, 79.6). Regression analysis indicated TRUS as a better predictor of W (R (2) = 0.817, P < 0.0005) followed by transabdominal ultrasound (R (2) = 0.669, P < 0.0005). Strictly based on European Association of Urology (EAU) criteria, transabdominal measurements miscategorized 25 cases by falsely assigning them to the open surgery (>80 cc) group while TRUS did so for four cases.
Conclusion: TRUS is more accurate than transabdominal ultrasound in predicting adenoma volume in patients with BPH and its standard use might lead to fewer open approaches, with consequent less morbidity and hospitalization.