The value of contrast-enhanced ultrasonography in detection of prostatic infarction after prostatic artery embolization for the treatment of symptomatic benign prostatic hyperplasia.

Abstract

We aimed to assess the clinical and predictive role of contrast-enhanced ultrasonography (CEUS) as the primary method for imaging evaluation of prostatic artery embolization (PAE) for the treatment of symptomatic benign prostatic hyperplasia (BPH). Thirty-one patients with symptomatic BPH, treated with PAE from October 2016 until February 2018, were enrolled in this prospective, single-center study. Microspheres (100-700 µm) were utilized for PAE. International prostate symptom score (IPSS), quality of life (QoL), maximum urinary flow (Qmax), prostatic volume (PV) and post void residual volume (PVR) were measured at baseline and at 1, 3, and 6 months post PAE. Unenhanced transabdominal US was utilized for PV and PVR measurements; prostatic enhancement was studied with transabdominal CEUS at baseline, during the procedure, 1 day and 1, 3, and 6 months post PAE. Technical success was defined as embolization of the PA of at least one pelvic side. Clinical success was based on the improvement of IPSS and QoL, with no need for any additional treatment. Follow-up time ranged from 6 to 18 months (mean, 9.7±4.3 months). Clinical success rates were calculated and changes in prostatic enhancement were correlated with the outcome parameters. Technical success rate was 90.3%. Clinical success rates at 3, 6, and 12 months post PAE were 85.7%, 85.7%, and 79.1% respectively. Improvement of outcome parameters (baseline vs. 6-month values) was statistically significant, with 12.4 points mean reduction of IPSS (50.4%, P = 0.003), 2.0 points mean reduction of QoL (45.4%, P < 0.001), 30.3 mL mean reduction of PV (30.2%, P < 0.001), 72.6 mL mean reduction of PVR (51.8%, P = 0.005) and 8.6 mL/s mean increase in Qmax (103%, P = 0.002). The most significant complications were bladder ischemia (n=1), and ischemic rectal ulcer (n=1), both attributable to nontarget embolization, with complete recovery. CEUS 1 day post PAE demonstrated prostatic infarcts in 26/28 (92.8%) patients. The percentage of prostatic infarction (pPI, defined as prostatic infarcted volume 1 day post PAE divided by baseline PV) was 1%-71%. There was a very strong positive correlation between pPI and prostate shrinkage (r=0.81, P < 0.001), but a weak correlation between pPI and the improvement of the other outcome parameters (r= 0.01-0.36; P = 0.093-0.965). However, in the subgroup of patients with indwelling bladder catheter (9/28 patients), successful removal of the catheter was achieved only in patients with pPI>10%. CEUS appears to be a practical method for the study of the local ischemic effect of PAE, with potential predictive value.