70- to 150-mm Radiopaque Spherical Embolics for PAE

Use of 70- to 150-mm Radiopaque Spherical Embolics for Prostatic Artery Embolization

Clinical question
To describe the use of radiopaque spherical embolics for PAE in treating lower urinary tract symptoms secondary to BPH

Take away point
PAE with 70- 150-mm radiopaque spherical embolics are safe and effective for treating lower urinary tract symptoms secondary to BPH

Reference
Maron, S. Z., et al. (2020). "Use of 70- to 150- mm Radiopaque Spherical Embolics for Prostatic Artery Embolization." Journal of Vascular and Interventional Radiology 31(7): 1084-1089.

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Study design
Retrospective

Funding Source
None

Setting
Academic hospital, Department of Radiology, Icahn School of Medicine at Mount Sinai, Mount Sinai Hospital, New York





Figure 4. Axial and coronal cone-beam CT of left-sided distribution of microspheres. (a) Axial cone-beam CT performed immediately after bilateral PAE (the left side was treated first) demonstrates predominantly left-sided distribution of 70- to 150-μm radiopaque mi- crospheres in the prostate gland (arrow). (b) Coronal cone-beam CT performed immediately after bilateral PAE (left side was treated first) demonstrates predominantly left-sided distribution of 70- to 150-μm radiopaque microspheres in the prostate gland (arrow).

Summary

Prostatic artery embolization (PAE) is effective for treating lower urinary tract symptoms (LUTS) of benign prostatic hyperplasia (BPH), however previous studies have described clinical failure rates up to 25%. The authors investigated the effectiveness of 70- 150-mm radiopaque microspheres for PAE. The 70- 150-mm spheres have intrinsic radiopacity allows visualization of the embolic distribution and a more targeted embolization. Additionally, the 70- 150-mm may provide additional clinical benefit due to a deeper embolization.

The authors reviewed 21 patients who underwent bilateral PAE with 70- 150-mm radiopaque spherical embolics over the course of one year. Of the 21 patients, 6 had indwelling urinary catheters and 2 required intermittent self-catheterization. The primary outcome was evaluated using the International Prostate Symptom Score (IPSS), quality of life score (QOL), and International Index of erectile function 5 questionnaire (IIEF-5). The prostate size was assessed with MRI at 6 months.

Technical success, defined by stasis in both prostatic arteries and direct visualization of the treated area on cone-beam CT, was 81% (17/21). 4 cases could not be embolized bilaterally due to tortuosity and atherosclerotic disease. 19/21 patients had transradial access and 2/21 received transfemoral access. The mean total embolic used was 6.5 mL. Non-target embolization was identified in 2 cases. 4 of 6 patients with indwelling catheters were able to remove their catheters at an average of 42 days post procedure. Neither patient requiring intermittent catheterization was able to progress to spontaneous voiding. Reported adverse events included dysuria, pelvic pain, hematospermia, and hematuria. One major complication was because of E coli urosepsis, however, was thought to be unrelated to PAE. Of the 2 cases of non-target embolization, 1 experienced hematospermia and 1 was asymptomatic.

The clinical response was positive at 1 and 2 months follow up, with improvement observed in QOL (-2 ± 1.2), IPSS (10.6 ± 7.6), and IIEF (9.3 ± 4.1) scores. The rate of successful urinary catheter removal was 67%. The prostate volume decreased by a mean of 28 ± 16.2 g at 6 months.

Commentary

The authors retrospectively reviewed 21 patients who received bilateral PAE with 70- 150-mm radiopaque spheres. The radiopaque spheres provide direct visualization of the embolized area on cone beam CT and allow for assessment of non-target embolization. Improvements in QOL, IPSS, and IIEF scores are promising, and the clinical results from this study are comparable to results from previous PAE meta-analyses. The theory that smaller embolics may produce further clinical benefit is intriguing. However, further evaluation with a larger sample size and additional analysis of Qmax, post-void residual volume, and PSA would be helpful to better characterize the potential advantages. Although the published complication rate from non-target embolization is low, the risk exists and the inherent radiopacity may better evaluate and highlight this. The authors, however, described difficulty differentiating the radiopaque embolic from retained contrast. This review presents an interesting peek into possible improvements for PAE, however more extensive investigation is needed to further characterize the benefits of 70- 150-mm radiopaque spherical embolics.

Post Author
Maxwell Cretcher, D.O.
Integrated Interventional Radiology Resident, PGY-3
Department of Interventional Radiology
Dotter Interventional Institute, Oregon Health and Science University
@MCretcher