The histology of prostate tissue following prostatic artery embolization for the treatment of benign prostatic hyperplasia

Objective: Prostatic artery embolization (PAE) for the treatment of patients with symptomatic benign prostatic hyperplasia (BPH) is believed to be a safe procedure with a low risk of adverse side effects. Artery embolization is a viable treatment option in patients who are refractory to the classic noninvasive treatments. Knowledge of the histological characteristics of prostate tissue following the procedure is still limited. In this study, we describe the microscopic aspects of the prostate following PAE for BPH. Materials and Methods: Two patients underwent transurethral resections of the prostate (TURP) after PAE. Embolizations were performed under local anesthesia with an initial pelvic angiography to evaluate the iliac vessels and the prostate arteries using a 2.8 French microcatheter. The prostate was embolized with 300-500 mu m Microspheres (Embosphere (R)), using complete blood stasis as the end point. The prostate tissues were analyzed histologically to characterize the effects of the embolization. Results: The embolic material within the prostate tissue was easily identified as homogeneous, bright eosin-red spheroids filling the vessel lumens. Ischemic necrosis surrounded or not by chronic inflammatory reactions containing macrophages were considered as a result of the artery embolization. Also, some aspects related to the healing process were observed being fibrotic nodules surrounded by glands with squamous metaplasia of the epithelial lining the most important. In the remaining sections, due to the precocious surgical intervention, the classic findings of BPH were still present with the glandular and stromal hyperplasia associated with nonspecific chronic prostatitis. Conclusions: This is the first description of prostate histology in BPH patients treated by PAE, a new procedure that is being used increasingly as a therapeutic intervention. The recognition of the changes caused by this new modality of treatment has become a very important differential in a chronic granulomatous reaction of the prostate tissue.