Prostatic artery embolization with polyethylene glycol microspheres: evaluation in a canine spontaneous benign prostatic hyperplasia model

Abstract

Background: Prostatic artery embolization (PAE) is a minimally invasive technique for the management of symptomatic benign prostatic hyperplasia (BPH) relieving the lower urinary tract symptoms in patients. Various embolic agents have been tested in animal models and subsequently used in human patients. The purpose of this study was to evaluate the technical feasibility, effectiveness, and safety of PAE with polyethylene glycol microspheres in a canine spontaneous BPH model. Results: Five adult male Beagle dogs (4.78 ± 1.11 years) were diagnosed by tranrectal ultrasonography of spontaneous BPH (prostate volume > 18 ml) and underwent PAE with polyethylene glycol microspheres (400 ± 75 μm). PAE procedures were performed successfully in all dogs. After PAE, all dogs were inspected for potential procedure-related complications during 1 month of follow-up. No major complications were observed any animal. Follow-up angiography was performed in each animal at 1 month of follow-up. Recanalization was demonstrated in all the embolized prostatic arteries or main branches at the end of the study. Magnetic Resonance Imaging (MRI) evaluations were performed immediately before PAE as baseline data, and 1 week, 2 weeks and 1 month after PAE. MRI study showed that the prostate shrank substantially with ischemic necrosis in each dog. There was a significant reduction in the mean prostate volume at 2 weeks and 1 month compared with the baseline data, from 19.95 ± 1.89 mL to 13.14 ± 2.33 and 9.35 ± 2.69 mL (p < 0.001), respectively. Histopathological study was conducted after 1-month follow-up angiography and confirmed the therapeutic responses with diffuse glandular atrophy and interstitial fibrosis. Conclusions: The findings of the present study support that PAE with the use of polyethylene glycol microspheres is a safe and feasible procedure that may induce a significant shrinkage of prostate due to the local ischemia and secondary glandular atrophy. Early recanalization of target arteries remains to be further addressed in both laboratory investigation and clinical practice.

Prostatic artery occlusion: initial findings on pathophysiological response in a canine prostate model

“…However, it is worth noting that the mean PV at one week after PAO significantly increased (+70.71%) compared with the baseline data due to hemorrhagic infarct along with severe inflammation induced by PAO which caused tissue swelling at this stage. Of note, previous studies on PAE in dogs by Lucas-Cava et al ( 16 , 24 ) demonstrated that there was a slight decrease in the mean PV at 1 week after PAE, from −2.4% to −9.07%. The inconsistency suggested that PAO induced a global ischemia of the prostate with severe secondary inflammatory reaction and massive edema increasing the PV in the acute phase; whereas PAE led to local ischemia with less inflammatory reaction.…”

Establishment of hormone-induced canine benign prostatic hyperplasia model: A prospective, controlled study

“…In our study, the bilateral prostates were supplied by independent vascularization in all the 16 dogs (100%), that branched out to communicate with the rectal artery (37.5%), ductus deferential artery (25%), and the urethral branch (12.5%). Familiarity with the anatomy of the prostatic artery in beagle dogs can reduce the operation time of PAE and can predict if there will be complications after embolization, such as ischemic necrosis of the urinary bladder or rectal mucosa or fistula between prostate and urethra [ 13 ].…”

Canine Prostate Cancer: Current Treatments and the Role of Interventional Oncology

“…In a similar study evaluating the delivery of polyethylene glycol microspheres sized 400 +/− 75 µm in a spontaneous BPH model in intact beagles, a significant reduction in prostate volume was noted at 2-and 4-weeks post-embolization. A histopathological exam revealed diffuse glandular atrophy and interstitial fibrosis, although the partial or complete recanalization of all prostate arteries was demonstrated 1 mo following initial embolization [38].…”