Prostatic Artery Embolization to Treat Lower Urinary Tract Symptoms Related to Benign Prostatic Hyperplasia and Bleeding in Patients with Prostate Cancer: Proceedings from a Multidisciplinary Research Consensus Panel

Prostate Artery Embolization as Minimally Invasive Treatment for Benign Prostatic Hyperplasia: An Updated Systematic Review

Background/Objectives: Benign prostatic hyperplasia (BPH) has a significant impact on the quality of life of symptomatic patients. In patients manifesting lower urinary tract symptoms (LUTS), prostatic arterial embolization (PAE) has become a topic of interest in recent years. The purpose of this systematic review is to analyze and review techniques and clinical outcomes of patients who underwent endovascular treatment of BPH, with a special focus on the comparison of surgical and endovascular procedures. Methods: Through the major scientific databases, 1225 articles were selected from the initial research utilizing specific keywords and medical subject headings. Based on the inclusion and exclusion criteria established for selecting relevant studies for our purposes, the systematic analysis of the literature was conducted on a total of seven articles. Results: We collected data on 718 male patients (408 patients underwent PAE and 310 received TURP). The technical success rate varied from 86% to 100% for TAE and was 100% for TURP. During a 12-month follow-up period, both PAE and TURP were comparable on the reduction in IPSS and QoL questionnaire, while TURP showed significant improvements in Qmax and in the reduction in prostate volume. Length and cost of hospitalization were lower for PAE. Complication and adverse events rates were higher in the TURP group rather than in the PAE group (60.6% vs. 35.5%). Conclusions: Prostatic artery embolization represents an emerging minimally invasive procedure for BPH. According to previously released clinical studies, quality-of-life and urological symptom scores of the PAE group were comparable to those of the TURP group. Our research strengthens the evidence supporting the effectiveness and safety of PAE as a therapy for LUTS related to BPH.

Safety and efficacy of transcatheter arterial embolization for management of refractory hematuria of prostatic origin

Objective

To estimate the safety and efficacy of transcatheter arterial embolization (TAE) in the treatment of refractory hematuria of prostatic origin (RHPO).

Methods

This retrospective study included 23 patients who underwent TAE for RHPO between May 2013 and August 2021. Technical and clinical success rates were calculated, and arteriogram findings and complications were detected.

Results

Embolization was performed 24 times in 23 patients. Technical success was achieved in 24/24 (100%) embolization procedures. Contrast agent extravasation was detected during 2 of the 24 angiographic procedures. Bilateral embolization was performed in 23 (95.8%) of the 24 procedures. The clinical success rate was 21/23 (91.3%), and hematuria stopped 1–4 days after TAE. No serious complications were observed.

Conclusion

TAE is a safe and effective minimally invasive technique for treating patients with RHPO.

Interventional therapy in malignant conditions of the prostate

Interventional therapies are emerging modalities for the treatment of localized prostate cancer. Their aim is to reduce the morbidity associated with radical therapies (rT) by minimizing damage to non-cancerous tissue, with priority given to sparing key structures such as the neurovascular bundles, external sphincter, bladder neck, and rectum, while maintaining local cancer control. Interventional ablative technologies deliver energy in different ways to destroy cancer cells. The most widely investigated techniques are brachytherapy, external beam radiotherapy, cryotherapy, and high-intensity focused ultrasound. Although functional outcomes of focal therapies have been encouraging, with generally low rates of urinary incontinence and erectile dysfunction, robust medium- and long-term oncological outcomes are not available for all techniques. To date, major controversies in focal therapy concern appropriate patient selection, efficacy of focal therapies, as well as treatment paradigms based on the dominant index lesion hypothesis. This review articles discusses the current status of interventional therapies and the oncological and functional outcomes.

Outcomes of prostate artery embolisation for benign prostatic hyperplasia in 10 cases at Steve Biko Academic Hospital

Background

Benign prostate hyperplasia (BPH) remains a common cause of lower urinary tract symptoms (LUTS) in ageing men in South Africa and can impact significantly on the quality of life (QOL) of these patients. The Urology Department at Steve Biko Academic Hospital (SBAH) can generally only offer men with LUTS the following treatment options: watchful waiting, medical treatment and surgical management. In men with symptomatic BPH, who are refractory to medical treatment, where anaesthesia is contra-indicated because of co-morbidities or transurethral resection of the prostate (TURP) is contra-indicated because of the prostate size, the Urology and Radiology departments at SBAH recently introduced prostate artery embolisation (PAE).

Aim

To assess the outcome of PAE in 10 men with LUTS, secondary to BPH, by comparing their urinary symptoms, QOL and prostate volume before and 3 months after they underwent PAE in the Radiology Department at SBAH.

Method

The review included the first 10 men who had undergone therapeutic PAE for symptomatic BPH from May 2016 to September 2016. The subjective symptomatic feedback was assessed according to the International Prostate Symptom Score (IPSS) and the Global Quality of Life questionnaire, created by the American Urological Association (AUA). The reduction in the size of the prostate was measured on magnetic resonance imaging (MRI).

Results

Embolisation was technically achieved in all 10 patients. Bilateral embolisation was performed on nine patients. One patient received unilateral embolisation secondary to unilateral tortuous and atherosclerotic changes of the iliac arteries. Within the 3-month follow-up, the mean IPSS score improved by 15.7 points (p < 0.0039), the mean QOL improved by 4.1 points (p < 0.0039) and the mean prostate volume reduction was 21.8 mL (p < 0.0039). Despite improvements observed, there was one clinical failure. No major complications were reported that increased hospital stay, required hospital readmission or required surgery.

Conclusion

The study on the first 10 PAE performed in SBAH concludes that PAE is a safe and effective procedure with favourable short-term follow-up results. This indicates that PAE can safely be offered to patients, who are refractory to medical treatment and not suitable candidates for surgery, in urology departments such as in SBAH.

Precision and accuracy of magnetic resonance imaging for lobar classification of benign prostatic hyperplasia

PURPOSE

To validate the application of a magnetic resonance imaging (MRI)-based lobar classification of benign prostatic hyperplasia (BPH) for use in research and clinical management.

METHODS

Two radiologists with 5 and 11 years post-fellowship experience were trained in the lobar classification of BPH using an internally developed atlas of prostate anatomy with example MRI images edited by a third senior radiologist designated as the "administrator" of the study. A study population of 140 patients referred to a tertiary academic medical center with known or suspected prostate cancer was selected by the administrator to test the interrater reliability (IRR; precision) of the classification as well as accuracy of the two readers compared to the administrator as the "gold" standard. The intrarater reliability of repeat readings of the administrator was also examined. Percentage of agreement, proportion of agreement, and Cohen's κ were applied. This was a retrospective IRB-approved study.

RESULTS

IRR (precision) between the two interpreting radiologists was 64% agreement, corresponding to unweighted κ of 0.52. Composite proportion of agreement across all BPH types (categories) for interpreting radiologists was 0.67. Observer accuracy was 62% agreement, unweighted κ 0.49, for observer 1 and 67%, unweighted κ 0.58, for observer 2. Intrarater reliability for the administrator was 87% agreement, unweighted κ 0.81 with composite proportion of agreement across all categories of 0.87.

CONCLUSIONS

MRI lobar classification of BPH is a reproducible and reliable tool for research and clinical applications.

Prostatic Artery Embolization versus Standard Surgical Treatment for Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia: A Systematic Review and Meta-analysis

CONTEXT

Prostatic artery embolization (PAE) has been introduced into clinical practice for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH-LUTS) despite a lack of high-level evidence.

OBJECTIVE

To perform a systematic review and meta-analysis of clinical trials comparing efficacy and safety of PAE versus established surgical therapies.

EVIDENCE ACQUISITION

Medline, Embase, and York CRD were searched up to June 23, 2018. Only comparative studies were included. The risk of bias was assessed by the Cochrane Collaboration tool. Meta-analyses were performed using RevMan 5.3.

EVIDENCE SYNTHESIS

Five studies including 708 patients met the selection criteria. Risk of bias was rated high for most of the studies. Mean reduction in the International Prostate Symptom Score was lower after PAE compared with standard surgical therapies (mean difference 3.80 points [95% confidence interval: 2.77-4.83]; p<0.001). PAE was less efficient regarding improvements in all functional parameters assessed including maximum urinary flow, post void residual, and reduction of prostate volume. In contrast, patient-reported erectile function (International Index of Erectile Function 5) was better after PAE and significantly fewer adverse events occurred after PAE.

CONCLUSIONS

Moderately strong evidence confirms efficacy and safety of PAE in the treatment of BPH-LUTS in the short term. Significant advantages regarding safety and sexual function, but clear disadvantages regarding all other patient-reported and functional outcomes were found for PAE. Large-scale randomized controlled trials including longer follow-up periods are mandatory before PAE can be considered as a standard therapy and to define the ideal indication for PAE in the management of BPH-LUTS.

PATIENT SUMMARY

We reviewed the role of prostatic artery embolization (PAE) in the treatment of symptoms associated with benign overgrowth of the prostate. The results suggest that PAE is not as effective as established surgical therapies but has fewer side effects. Further research is required to determine whether PAE is the best treatment for certain types of patients. PAE should, therefore, not yet be considered a standard treatment.

State of the art of prostatic arterial embolization for benign prostatic hyperplasia

Prostatectomy via open surgery or transurethral resection of the prostate (TURP) is the standard treatment for benign prostatic hyperplasia (BPH). Several patients present contraindication for standard approach, individuals older than 60 years with urinary tract infection, strictures, post-operative pain, incontinence or urinary retention, sexual dysfunction, and blood loss are not good candidates for surgery. Prostatic artery embolization (PAE) is emerging as a viable method for patients unsuitable for surgery. In this article, we report results about technical and clinical success and safety of the procedure to define the current status.

Case-Control Study of Intra-arterial Verapamil for Intraprostatic Anastomoses to Extraprostatic Arteries in Prostatic Artery Embolization for Benign Prostatic Hypertrophy

PURPOSE

It is hypothesized that intra-arterial administration of verapamil is a safe and effective way to reverse the flow in intraprostatic anastomoses to extraprostatic arteries without compromising treatment outcomes in prostatic artery embolization (PAE) for benign prostatic hypertrophy (BPH).

MATERIALS AND METHODS

A prospective study of 62 prostate sides in 31 consecutive patients (median age, 66 y; range, 60-71 y) with symptomatic BPH was undertaken. Median prostate volume was 72.4 mL (range, 48.8-85.8 mL), median International Prostate Symptom Score was 21 (range, 15-23), and median urine peak flow rate was 4 mL/s (range, 2-6 mL/s). The arterial anastomoses were classified as types I-III according to vascular morphology. Treatment safety was assessed in terms of adverse events and complications, and treatment effectiveness was assessed in terms of success rate of angiographic flow reversal.

RESULTS

The PAE procedure was successfully completed in all 31 patients (100%). Adverse events in both groups were transient and mild and did not necessitate prolonged hospitalization. There was no clinical evidence of any significant nontarget ischemic complication in either group. Intraprostatic anastomosis was diagnosed in 19 of 31 patients (61.3%) and 22 of 62 prostate sides (35.5%). Success rates of verapamil treatment were 88.9% overall (20 of 22) and 100% (19 of 19) in type II and III anastomoses. There was no difference between the treatment group and the control group in clinical, urologic, and imaging outcomes of PAE.

CONCLUSIONS

Intra-arterial verapamil treatment was probably safe and effective in causing flow reversal in type II and III intraprostatic anastomoses and in preventing ischemic complications in PAE for BPH without compromising PAE outcomes.

Prostate Artery Embolization for Complete Urinary Outflow Obstruction Due to Benign Prostatic Hypertrophy

BACKGROUND

We aimed to evaluate the effectiveness of PAE in weaning of catheter and relieving obstructive urinary symptoms in patients with acute urinary retention (AUR) due to benign prostatic hypertrophy (BPH) and failed trial without catheter (TWOC).

MATERIALS AND METHODS

In this prospective study approved by the institutional review board, a signed informed consent was obtained. Eighteen consecutive patients with AUR due to BPH and failed TWOC were recruited. Nineteen consecutive patients with BPH but without AUR were recruited as a control. Patients with CTA evidence of arterial occlusion or significant stenosis along the prostate artery access path were excluded. PAE was performed using microspheres (100-300 μm diameter). Outcome assessment included successful weaning of catheter in 2 weeks, procedure-related complications, change of symptomatology and urodynamic findings at 1 month as compared to baseline, percent non-perfused prostate volume, and prostate volume reduction on MRI at 2 weeks.

RESULTS

Two patients in the study group and four in the control group were excluded due to arterial pathology. Embolization of bilateral prostate arteries was achieved in all patients in both the groups (100%). There was no complication. The catheter was successfully weaned in 87.5% (14/16) of patients within 14 days in the treatment group. There was no significant difference in patient demographics, prostate characteristics, and all outcome assessment parameters between both the groups.

CONCLUSIONS

PAE was probably safe and effective in weaning of catheter and relieving obstructive urinary symptoms in patients due to BPH, with treatment outcomes comparable to those without AUR.

MRI assessment of prostatic ischaemia: best predictor of clinical success after prostatic artery embolisation for benign prostatic hyperplasia

AIM

To identify predictive factors of clinical success after prostatic artery embolisation (PAE) for patients with acute urinary retention (AUR) secondary to benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

Twenty-four patients with long-term indwelling urinary catheters (duration: 8±3 months) underwent PAE. Factors such as patient age, duration of urinary retention, prostate volume decrease, volume of ischaemic prostate tissue (assessed using magnetic resonance imaging [MRI]), and embolisation technique were studied as potential predictors of clinical success of PAE, defined as the ability to remove the urinary catheter (allowing spontaneous voiding) within 60 days of PAE.

RESULTS

Bilateral embolisation was performed in 21 patients, and unilateral embolisation was performed in three, due to technical challenges. Length of follow-up was 17 months (range: 3-29). No major complications were encountered. Clinical success was achieved in 15 patients (63%) with prostate volume decreasing 24% versus 16% (p=0.03) in the unsuccessful cases. Thirteen of the 15 successful cases (87%) showed ischaemic areas in the prostate on MRI obtained 30 days after embolisation, but only one unsuccessful case (11%) showed a very small area of ischaemia.

CONCLUSION

Prostatic ischaemia observed on early post-embolisation MRI appears to be the best predictor of clinical success after PAE in patients with AUR secondary to BPH.

Prostatic artery embolization: radiation exposure to patients and staff

The aim of this study was to evaluate the radiation doses to patients and staff received from the first cases of prostatic artery embolization (PAE) conducted in a public hospital in Recife, Brazil. Five PAE procedures for 5 men diagnosed with benign prostatic hyperplasia were investigated. In order to characterize patient exposure, dosimetric quantities, such as the air kerma-area product (P KA), the cumulative air kerma at the interventional reference point (Ka,r), the number of images, etc, were registered. To evaluate the possibility for deterministic effects, the peak skin dose (PSD) was measured using radiochromic films. For evaluation of personal dose equivalent and effective dose to the medical staff, thermoluminescent dosemeters (TLD-100) were used. The effective dose was estimated using the double dosimetry alghoritm of von Boetticher. The results showed that the mean patient's PSD per procedure was 2674.2 mGy. With regard to the medical staff, the mean, minimum and maximum effective doses estimated per procedure were: 18 μSv, 12 μSv and 21 μSv respectively. High personal equivalent doses were found for the feet, hands and lens of the eye, due to the use of multiple left anterior oblique projections and the improper use of the suspended lead screen and the lead curtain during procedures.

Automatic three-dimensional detection of prostatic arteries using cone-beam CT during prostatic arterial embolization

The purpose of this study was to evaluate the automatic three-dimensional detection of prostatic arteries (PAs) with the use of dual-phase cone-beam computed tomography (CT) imaging and vessel-tracking software during prostatic artery (PA) embolization (PAE). In six patients, six right PAs and five left PAs were detected by using the software (sensitivity, 92%). The false-positive arteries (right side, 14%; left side, 25%) were deleted after cone-beam CT review. Automatic software detection of PAs from cone-beam CT may permit identification of the PA during PAE.

Prostatic Arterial Embolization with Small Sized Particles for the Treatment of Lower Urinary Tract Symptoms Due to Large Benign Prostatic Hyperplasia: Preliminary Results

Background:

The clinical failure after prostatic artery embolization (PAE) with conventional particles was relatively high, in treatment for lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). We reported the results of PAE with combined polyvinyl alcohol particles 50 μm and 100 μm in size as a primary treatment in 24 patients with severe LUTS secondary to large BPH.

Methods:

From July 2012 to June 2014, we performed PAE in 24 patients (65–85 years, mean 74.5 years) with severe LUTS due to large BPH (≥80 cm³) and refractory to medical therapy. Embolization was performed using combination of 50 μm and 100 μm in particles size. Clinical follow-up was performed using the International Prostate Symptom Score (IPSS), quality of life (QoL), peak urinary flow (Q_max), postvoid residual (PVR) volume, the International Index of Erectile Function (IIEF), prostatic specific antigen (PSA), and prostatic volume measured by magnetic resonance imaging at 1, 3, 6, and every 6-month thereafter. Technical success was defined when PAE was completed in at least one pelvic side. Clinical success was defined as the improvement of both symptoms and QoL. A Student's t-test for paired samples was used.

Results:

PAE was technically successful in 22 patients (92%). Bilateral PAE was performed in 19 (86%) patients and unilateral in 3 (14%) patients. Follow-up data were available for 22 patients observed for mean of 14 months. The clinical improvement at 1, 3, 6, and 12-month was 91%, 91%, 88%, and 83%, respectively. At 6-month follow-up, the mean IPSS, QoL, PVR, and Q_max were from 27 to 8 (P = 0.001), from 4.5 to 2.0 (P = 0.002), from 140.0 ml to 55.0 ml (P = 0.002), and from 6.0 ml/s to 13.0 ml/s (P = 0.001), respectively. The mean prostate volume decreased from 110 cm³ to 67.0 cm³ (mean reduction of 39.1%; P = 0.001). The PSA and IIEF improvements after PAE did not differ from pre-PAE significantly. No major adverse events were noted.

Conclusions:

The combination of 50 μm and 100 μm particles for PAE is a safe and effective treatment method for patients with severe LUTS due to large BPH, which further improves the clinical results of PAE.

Can prostatic arterial embolisation (PAE) reduce the volume of the peripheral zone? MRI evaluation of zonal anatomy and infarction after PAE

OBJECTIVES

To assess the impact of prostatic arterial embolisation (PAE) on various prostate gland anatomical zones.

METHODS

We retrospectively reviewed paired MRI scans obtained before and after PAE for 25 patients and evaluated changes in volumes of the median lobe (ML), central gland (CG), peripheral zone (PZ) and whole prostate gland (WPV) following PAE. We used manual segmentation to calculate volume on axial view T2-weighted images for ML, CG and WPV. We calculated PZ volume by subtracting CG volume from WPV. Enhanced phase on dynamic contrasted-enhanced MRI was used to evaluate the infarction areas after PAE. Clinical results of International Prostate Symptom Score and International Index of Erectile Function questionnaires and the urodynamic study were evaluated before and after PAE.

RESULTS

Significant reductions in volume were observed after PAE for ML (26.2 % decrease), CG (18.8 %), PZ (16.4 %) and WPV (19.1 %; p < 0.001 for all these volumes). Patients with clinical failure had smaller volume reductions for WPV, ML and CG (all p < 0.05). Patients with significant CG infarction after PAE displayed larger WPV, ML and CG volume reductions (all p < 0.01).

CONCLUSIONS

PAE can significantly decrease WPV, ML, CG and PZ volumes, and poor clinical outcomes are associated with smaller volume reductions.

KEY POINTS

• The MRI segmentation method provides detailed comparisons of prostate volume change. • Prostatic arterial embolisation (PAE) decreased central gland and peripheral zone volumes. • Prostates with infarction after PAE showed larger decreases in volume. • A larger decrease in prostate volume is associated with clinical success.

Prostatic Artery Embolization (PAE) for Symptomatic Benign Prostatic Hyperplasia (BPH): Part 1, Pathological Background and Clinical Implications

Pathological features of benign prostatic hyperplasia (BPH) dictate various responses to prostatic artery embolization (PAE). Typically, BPH originates in the transition zone and periurethral region, where should be considered the primary target area in PAE procedures. Given that histological heterogeneity of components in hyperplasia nodules, epithelial or stromal, identifying the more responsive nodules to PAE will have clinical implications. Since some lower urinary tract symptoms (LUTS) in patients with BPH are usually related to bladder outlet obstruction-induced changes in bladder function rather than to outflow obstruction directly, proper selection of candidate patients prior to PAE is of great clinical importance. BPH is a typical chronic progressive condition, suggesting PAE could aim not only to relieve LUTS but also to delay or prevent the clinical progression. Awareness of the pathological background of BPH is essential for interventional radiologists to improve clinical outcomes and develop new treatment strategies in clinical practice of PAE.

Use of MRI for Lobar Classification of Benign Prostatic Hyperplasia: Potential Phenotypic Biomarkers for Research on Treatment Strategies

OBJECTIVE

We present an MRI classification of benign prostatic hyperplasia (BPH) for use as a phenotype biomarker in the study of proposed therapeutic interventions.

CONCLUSION

Six patterns of BPH distribution were identified. Illustrations are provided for each classification type.

Minimally invasive devices for treating lower urinary tract symptoms in benign prostate hyperplasia: technology update

Benign prostatic hyperplasia (BPH) represents a spectrum of related lower urinary tract symptoms (LUTS). The cost of currently recommended medications and the discontinuation rate due to side effects are significant drawbacks limiting their long-term use in clinical practice. Interventional procedures, considered as the definitive treatment for BPH, carry a significant risk of treatment-related complications in frail patients. These issues have contributed to the emergence of new approaches as alternative options to standard therapies. This paper reviews the recent literature regarding the experimental treatments under investigation and presents the currently available experimental devices and techniques used under local anesthesia for the treatment of LUTS/BPH in the vast majority of cases. Devices for delivery of thermal treatment (microwaves, radiofrequency, high-intensity focused ultrasound, and the Rezum system), mechanical devices (prostatic stent and urethral lift), fractionation of prostatic tissue (histotripsy and aquablation), prostate artery embolization, and intraprostatic drugs are discussed. Evidence for the safety, tolerability, and efficacy of these "minimally invasive procedures" is analyzed.

Early results and complications of prostatic arterial embolization for benign prostatic hyperplasia

PURPOSE

To review current knowledge on clinical outcomes and peri-operative complications of prostatic arterial embolization (PAE) in patients treated for lower urinary tract symptoms (LUTS) related to benign prostatic obstruction (BPO).

METHODS

A systematic review of the literature published from January 2008 to January 2015 was performed on PubMed/MEDLINE.

RESULTS

Fifty-seven articles were identified, and four were selected for inclusion in this review. Only one randomized clinical trial compared transurethral resection of the prostate (TURP) to PAE. At 3 months after the procedure, mean IPSS reduction from baseline ranged from 7.2 to 15.6 points. Mean urine peak-flow improvement ranged from +3.21 ml/s to +9.5 ml/s. When compared to TURP, PAE was associated with a significantly lower IPSS reduction 1 and 3 months after the procedure. A trend toward similar symptoms improvement was however reported without statistical significance from 6 to 24 months. Major complications were rare with one bladder partial necrosis due to non-selective embolization. Mild adverse events occurred in 10 % of the patients and included transient hyperthermia, hematuria, rectal bleeding, painful urination or acute urinary retention. Further comparative studies are mandatory to assess post-operative rates of complications, especially acute urinary retention, after PAE and standard procedures.

CONCLUSION

Early reports suggest that PAE may be a promising procedure for the treatment of patients with LUTS due to BPO. However, the low level of evidence and short follow-up of published reports preclude any firm conclusion on its mid-term efficiency. Further clinical trials are warranted before any use in clinical practice.