Adjunctive Coil Embolization of the Prostatic Arteries After Particle Embolization for Prostatic Artery Embolization

Machine Learning to Predict Prostate Artery Embolization Outcomes

PURPOSE

This study leverages pre-procedural data and machine learning (ML) techniques to predict outcomes at one year following prostate artery embolization (PAE).

MATERIALS AND METHODS

This retrospective analysis combines data from the UK-ROPE registry and patients that underwent PAE at our institution between 2012 and 2023. Traditional ML approaches, including linear regression, lasso regression, ridge regression, decision trees and random forests, were used with leave-one-out cross-validation to predict international prostate symptom score (IPSS) at baseline and change at 1 year. Predictors included age, prostate volume, Qmax (maximum urinary flow rate), post-void residual volume, Abrams-Griffiths number (urodynamics score) and baseline IPSS (for change at 1 year). We also independently confirmed our findings using a separate dataset. An interactive digital user interface was developed to facilitate real-time outcome prediction.

RESULTS

Complete data were available in 128 patients (66.7 ± 6.9 years). All models predicting IPSS demonstrated reasonable performance, with mean absolute error ranging between 4.9-7.3 for baseline IPSS and 5.2-8.2 for change in IPSS. These numbers represent the differences between the patient-reported and model-predicted IPSS scores. Interestingly, the model error in predicting baseline IPSS (based on objective measures alone) significantly correlated with the change in IPSS at 1-year post-PAE (R2 = 0.2, p < 0.001), forming the basis for our digital user interface.

CONCLUSION

This study uses ML methods to predict IPSS improvement at 1 year, integrated into a user-friendly interface for real-time prediction. This tool could be used to counsel patients prior to treatment.

Early Outcomes of Prostatic Artery Embolization using n-Butyl Cyanoacrylate Liquid Embolic Agent: A Safety and Feasibility Study

This retrospective study evaluated the feasibility, safety, and short-term effectiveness of prostatic artery embolization (PAE) using n-butyl cyanoacrylate (nBCA) glue embolization in 244 patients from June 2022 through May 2024. Technical success, defined as bilateral glue embolization, was achieved in 95% of cases. The median fluoroscopy time was 22.2 minutes (interquartile range [IQR], 17.1-30.0 minutes), and the median air kerma was 753 mGy (IQR, 417-1,559 mGy). Compared with baseline, statistically significant improvements were observed at 7.1 weeks for the International Prostate Symptom Score (9.5 [SD ± 6.0] vs 20.5 [SD ± 6.7]; P < .01), quality of life (1.8 [SD ± 1.5] vs 4.0 [SD ± 1.1]; P < .01), Qmax (10.4 mL/s [SD ± 6.3] vs 6.1 mL/s [SD ± 2.5]; P < .01), and prostate grand volume at 6 months (113.3 mL [SD ± 69.3] vs 156.6 mL [SD ± 104.6]; P < .01). These results demonstrate the use of nBCA for PAE as a technically feasible and safe option with excellent short-term outcomes.

Prostate Artery Embolization with 4D-CT

Prostate artery embolization (PAE) is a technically challenging angiographic therapy that has been shown to have excellent clinical outcomes for men with benign prostatic hyperplasia and lower urinary tract symptoms. Although clinical outcomes have been well documented, several questions remain regarding various technical details of the procedure. This article is a brief review of indications and technical parameters of PAE as well as commonly debated topics throughout the literature. Finally, the article serves to report tips and tricks from a high-volume center.

Repeat Prostatic Artery Embolization with the Addition of a Liquid Embolic Agent: Short-term Results

RATIONALE AND OBJECTIVES

The long-term effectiveness of prostatic artery embolization (PAE) can be hampered by the recanalization of the previously embolized prostatic arteries (PA). The use of a liquid embolic agent (LEA) could limit this risk. The purpose of this study was to assess the safety and efficacy of repeat PAE (rePAE) using a LEA (Squid Peri) coupled with microspheres in patients experiencing recurring symptoms after initial embolization.

MATERIALS AND METHODS

This retrospective single-center study included all consecutive patients who underwent rePAE using Squid Peri coupled with microspheres. Angiographic patterns of prostatic revascularization were identified. Outcomes were assessed at the 3-month follow-up using the International Prostate Symptom Score (IPSS) and the Quality of Life (QoL) score. The primary endpoint was clinical success defined as an IPSS < 18 with > 25% decrease and a QoL score ≤ 3 with ≥ 1 point decrease. Safety was assessed by using the modified Clavien-Dindo classification.

RESULTS

30 consecutive men (mean age: 67.1 ± 9.5 years) were included. Recanalization of the previously embolized PA was found in 83.3% of patients. Technical success was 93.3%. Median follow-up was 4.9 months [IQR: 3.9 - 9.8]. Clinical success rate was 76.7%, with a mean decrease in IPSS of -9.3 ± 7.3 (p < 0.001) and a median decrease in QoL of -2 [IQR: - 4 - - 1] (p < 0.001). One patient presented with an acute urinary retention requiring readmission (grade IIIa complication).

CONCLUSION

Repeat PAE using Squid Peri coupled with microspheres is safe and effective for patients with recurring symptoms after initial embolization.

Benefits of Repeat Prostatic Artery Embolization on Persistent or Recurrent Lower Urinary Tract Symptoms in Patients with Benign Prostatic Hyperplasia

OBJECTIVES

To evaluate the benefits of repeat prostatic artery embolization (rePAE) for patients with persistent or recurrent symptoms after initial prostatic artery embolization (PAE).

MATERIALS AND METHODS

This is a single-center retrospective study of all patients who underwent a rePAE between December 2014 and November 2020 for persistent or recurrent lower urinary tract symptoms. Symptoms were assessed before and after PAE and rePAE, using the International Prostate Symptom Score and quality of life (QoL) questionnaires. Patient characteristics, anatomical presentations, technical success rates, and complications of both procedures were collected. Clinical failure was defined as one of the following: less than 2 points' decrease in QoL, a QoL score higher than 3, acute urinary retention, and secondary surgery.

RESULTS

A total of 21 consecutive patients (mean age: 63.8 ± 8.1; [40-75] years) who underwent rePAE were included. The median follow-up after PAE was 27.7 [18.1-36.9]) months and 8.9 [3.4-10.8] months after rePAE. rePAE was performed at a mean of 19 ± 11.1 [6.9-49.6] months following PAE, and the overall clinical success rate was 33% (7/21). In patients undergoing rePAE because of persistent symptoms, the clinical success rate (18%) was non-significantly lower than that for patients treated for recurrent symptoms (50%) [OR 4.5 (95% CI 0.63-32 P = 0.13)]. The main anatomical revascularization pattern was recanalization of the native prostatic artery (29/45, 66%).

CONCLUSION

Patients who experience recurrent symptoms after PAE may benefit more from rePAE than those with persistent symptoms after PAE. Clinical success rates seem to be relatively low in both clinical scenarios.

Controversies in Prostate Artery Embolization: Future Best Practice

Prevalence of lower urinary tract symptoms secondary to benign prostatic hyperplasia is correlated with age. Men seeking treatment options with a low side effect profile often turn to prostate artery embolization (PAE). PAE continues to be refined with advanced tools and optimized techniques. Nonetheless, there exist controversies in terms of best practices for the management of lower urinary track symptoms (LUTS) with PAE. These controversies are essential for medical progress. Herein we suggest best practices moving forward based on currently available data. Given extensive safety data, we recommend PAE be considered alongside medical management and as a precursor to surgery. Given demonstrated efficacy across gland sizes, PAE can be performed in a single session, ideally in a hybrid angio-CT suite, without preoperative cross-sectional imaging. PAE should be initially performed with 300- to 500-μm size particles, and instead consider exploring other particles and sizes for repeat PAE. Finally, PAE can also be considered as first-line option for recurrent disease given the efficacy and excellent safety profile. This article is not meant to purport a dogma, but rather to serve as a guide to the experienced practitioner in challenging his or her own biases when performing PAE.

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

Background

Prostatic artery embolization (PAE) is an alternative treatment for symptomatic benign prostatic hyperplasia (BPH) in men. A technical modification of conventional PAE has been developed in a canine prostate model consisting of prostatic artery occlusion (PAO) using Onyx^® whose therapeutic effect is prostate shrinkage. However, the underlying mechanisms are not well clarified. The purpose was to evaluate the biological mechanisms responsible for therapeutic effects of PAO in the canine prostate.

Methods

Ten adult male beagles (5.0±0.82 years) underwent PAO with Onyx-18 (n=7) and prostatic artery angiography as control (n=3). Blood samples were taken at different time points of follow-up (baseline, 1 week, 2 weeks, 1 month, 3 months and 6 months) to measure the serum canine prostate specific esterase (CPSE). MRI examinations were also performed to document the prostate volume (PV) before and after interventions at different time points of follow-up. Prostates were harvested at 2 weeks (n=2) in the PAO-group, and the remaining ones (n=8) at 6 months for the determinations of intraprostatic testosterone and dihydrotestosterone (DHT) by ELISA, apoptosis by TUNEL assay and histopathological study.

Results

The mean serum CPSE concentration started to decrease significantly from 2 weeks to 6 months after PAO along with PV compared with baseline data. In addition, a moderate but significant correlation was observed between CPSE and PV (r=0.655, P=0.000). Regarding intraprostatic androgens, testosterone was significantly higher after PAO than control (19.70 vs. 4.87 ng/mL, P=0.002), whereas DHT was lower but no significant (112.52 vs. 138.35 pg/mL, P=0.144). In histological study, PAO induced a severe hemorrhagic necrosis in the whole prostates along with inflammatory cell infiltration at early 2 weeks, and then diffuse interstitial fibrosis with atrophy of the glandular epithelium and intraprostatic cavity formation at 6 months. Apoptosis was detected in all specimens with higher apoptotic index after PAO at 2 weeks (7.35%) and at 6 months (4.38%) compared with control (2.64%), without statistically significant difference between groups.

Conclusions

PAO induces hemorrhagic ischemia predominantly resulting in necrosis rather than apoptosis with prostate shrinkage. CPSE is a potential biomarker to assess the response to PAO in the canine prostate.

Prostate Artery Embolization in Patients above Eighty Years Old: Clinical Efficacy and Safety

Purpose Prostate artery embolization (PAE) has been established as an effective treatment option for benign prostate hyperplasia or hematuria of prostatic origin. We aim to confirm the effectiveness and safety of PAE in elderly patients aged ≥ 80 years old.

Materials and Methods Between January 2014 and August 2020, PAE was attempted on 54 elderly patients with lower urinary tract symptoms (LUTS) or prostatic hematuria who were unfit for surgical treatment or opted for PAE. Outcome parameters (International Prostate Symptom Score [IPSS], quality of life [QoL] score, International Index of Erectile Function score (IIEF), maximal urinary flow rate, postvoid residual, and prostate volume) were collected and analyzed at baseline, 6 months, 1, 2, and 3 years.

Results The mean patient age was 85.29 years (range: 80–98). Technical success was achieved in 50 patients (92.6%). Mean IPSS improved from 18 at baseline to 7.7, 8.5, 8.6, and 9.1 at 6 months, 1, 2, and 3 years. Mean QoL improved from 4.9 at baseline to 2.8, 1.7, and 1.5 at 6 months, 1, and 2 years. Mean prostate volume reduced from a baseline of 152.7 to 123.5 mL within 6 months and 120.5 mL after 7 months of PAE. Urinary catheter removal was successful in 13 out of 19 patients with urinary retention. PAE succeeded in stopping bleeding in 16 out of 17 patients with prostate-induced hematuria.

Conclusion PAE is a feasible low-risk treatment for LUTS with or without urinary retention or prostatic hematuria in elderly patients.