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

Prostatic Arterial Embolization for Treatment of Lower Urinary Tract Symptoms Associated with Benign Prostatic Enlargement

PURPOSE OF REVIEW

Prostatic artery embolization (PAE) is an emerging minimally invasive technique for lower urinary tract symptom reduction from benign prostatic hypertrophy (BPH). While the technique is becoming increasingly popular with patients and interventional radiologists, most urologists remain skeptical of the PAE's long-term efficacy and comparative success to the gold standard transurethral resection of the prostate.

RECENT FINDINGS

PAE has been found in multiple meta-analyses to perform similarly to the gold standard transurethral resection of the prostate (TURP) with regard to patient-driven measures like IPSS and IPSS-QoL, while also performing favorably in objective measurements including Qmax and PVR out to at least 12 months post intervention. Furthermore, PAE has a demonstrated shorter hospital length of stay and fewer adverse events when compared to TURP. PAE provides patients with an alternative to transurethral options for the management of LUTS in the setting of bladder outlet obstruction. While long-term evidence demonstrating the durability of PAE is still forthcoming, the procedure has been demonstrated to be safe according to multiple meta-analyses. Patients deserve to be counseled on PAE as an alternative to surgery and made aware that while the overall treatment effect may not be as robust or durable, the procedure carries a favorable adverse event profile that is attractive to patients wishing to avoid a trans-urethral approach.

Clinical Study on the Treatment of Benign Prostatic Hyperplasia by Embolization of Prostate Artery Based on Embosphere Microspheres and Gelatin Sponge Granules

Prostatic hyperplasia can cause dysuria, such as frequent urination, urgency of urination, increased nocturia, poor urination, and other symptoms, which seriously affect the quality of life of old men. We aim to compare and analyze the safety and clinical effect of embolization of the target blood vessels of ruptured prostatic hyperplasia with gelatin sponge particles and embosphere microspheres. Methods. The transcatheter MRI was performed in 422 patients. Among them, 198 patients were treated with gelfoam particles and 224 patients were treated with embosphere microspheres. The clinical effect and adverse reactions were observed and analyzed by biochemical and imaging examination. Four hundred and twenty two cases were hemostasis. In the gelatin sponge group, 34 patients had recurrent bleeding 24–36 hours after embolization, 122 patients had different degrees of elevation of prostatic hyperplasia transaminase (31 cases increased to more than 1000 U/L), 198 patients had different degrees of elevation of bilirubin; in the microsphere group, there was no significant difference in prostatic hyperplasia function indexes between the two groups. Conclusion. Compared with the gelfoam embolic agent, the embosphere embolic microsphere has a good efficacy and safety in the treatment of prostatic hyperplasia rupture and hemorrhage, with a light adverse reaction, a low probability of recanalization, and little damage to the postoperative prostatic hyperplasia function, which is conducive to the benign recovery of perioperative patients and is worthy of clinical application.

Role of Ultrasound Elastography in Patient Selection for Prostatic Artery Embolization

PURPOSE

To determine the effects of prostatic artery embolization (PAE) on prostate elasticity as assessed using ultrasound elastography (US-E) and to describe baseline US-E's potential role in patient selection.

MATERIALS AND METHODS

This was a prospective investigation that included 20 patients undergoing PAE to treat lower urinary tract symptoms attributed to benign prostatic hyperplasia (BPH). US-E with measurement of the prostatic elastic modulus (EM) and shear wave velocity (SWV) was performed before PAE and at 1-month follow-up. Baseline, 3-month, and 1-year follow-up evaluations included prostate-specific antigen, uroflowmetry, pelvic magnetic resonance imaging, and clinical assessment using the International Prostate Symptom Score (IPSS) and quality of life (QoL) metrics.

RESULTS

Seventeen patients entered statistical analysis. US-E showed a significant reduction in mean prostatic EM (34.4 kPa vs 46.3 kPa, -24.7%, P < .0001) and SWV (3.55 m/s vs 4.46 m/s, -20.0%, P < .0001) after PAE. There were moderate positive correlations between baseline EM and 1-year IPSS (R = 0.62, P = .007) and between baseline SWV and 1-year IPSS (R = 0.68, P = .002). Baseline SWV ≥ 5.59 m/s and baseline EM ≥ 50.14 kPa were associated with suboptimal IPSS and QoL outcomes after PAE with high degrees of sensitivity (100%) and specificity (69-100%).

CONCLUSIONS

PAE led to a positive effect on the BPH dynamic component related to prostatic elasticity. There was a moderate positive correlation between baseline prostatic elastographic parameters and 12-month IPSS. Measurement of baseline elastographic characteristics may become useful for the evaluation and selection of patients for PAE.

Safety and efficacy of holmium laser enucleation of prostate as salvage procedure for persistent or recurrent lower urinary tract symptoms secondary to bladder outlet obstruction after prior prostate artery embolization: a match analysis

PURPOSE

To evaluate safety and efficacy of Holmium laser enucleation of Prostate (HoLEP) for management of persistent or recurrent lower urinary tract symptoms after prior prostate artery embolization (PAE). We also evaluated histopathological changes in prostate after PAE.

METHODS

Ten patients who underwent HoLEP after prior PAE were matched according to age, weight of resected prostate tissue, and anticoagulation status in 1:2 ratio with patients who underwent HoLEP without prior PAE by a researcher who was blinded to patient's outcome at the time of matching. Histopathological examination of prostate tissue was performed to look for changes related to prior PAE. Patient's demographics, perioperative parameters, and follow-up data were retrospectively compared.

RESULTS

The median interval between PAE and HoLEP was 25 months [IQR 14.5-37.5]. Patients demographic were comparable in both groups. Intra-operatively plane of enucleation were well-maintained in spite of prior PAE. The differences in duration of surgery, enucleation efficiency, hemoglobin drop, duration of catheterization and hospital stay, and complications were statistically insignificant. Incidental prostate cancer was identified in 10% specimens from both groups. Post-PAE prostate specimens demonstrated evidence of remote-healed infarction represented by dense hyalinized paucicellur connective tissue with surrounding squamous metaplasia. There were no statistically significant differences in AUA symptom scores, maximum urine flow rate, post-void residual urine volume, and PSA at 3- and 6-month follow-up between both groups.

CONCLUSIONS

Plane of enucleation is well-maintained after prior PAE. Salvage HoLEP is safe and effective after previous PAE and provide outcome comparable with HoLEP as a primary procedure.

A state-of-art review on the preservation of sexual function among various minimally invasive surgical treatments for benign prostatic hyperplasia: Impact on erectile and ejaculatory domains

There is a strong association between benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS) and sexual dysfunction. While transurethral resection of the prostate (TURP) is considered the standard BPH treatment, it is however associated with a high rate of erectile and ejaculatory dysfunctions. Over the past decade, new and novel minimally invasive BPH therapies have been shown to improve various parameters of voiding domains while minimizing adverse sexual effects. These minimally invasive BPH therapies can be largely be divided into those with cavitating technology (Rezum, Histotripsy, Aquablation), intra-prostatic injections (Botulinum neurotoxin Type A, Fexapotide Triflutate, prostate specific antigen-activated protoxin PRX-302), and mechanical devices which include intraprostatic stents (Urospinal 2™, Memotherm™, Memokath™, and Allium triangular prostatic stent™) and intraprostatic devices (iTIND™, Urolift™), as well as prostatic artery embolization. Published literature on these technologies showed reasonable preservation of erectile function with limited data reported on ejaculatory domain. Further validation of the performance of these novel minimally invasive treatment options for LUTS due to BPH in well-designed and multi-centre studies are desired, to evaluate their role (or lack of such a role) in clinical practice and whether these BPH therapies can provide equivalent standard or better than TURP.

Prostate Artery Embolization: State of the Evidence and Societal Guidelines

Medically refractory benign prostatic hyperplasia induced lower urinary tract symptoms is an extremely prevalent issue in older men. The current gold standard therapy transurethral resection of the prostate does produce urologic improvements but is also associated with higher than desired morbidity. This has led to the need to develop new minimally invasive means to treat this disease; prostate artery embolization (PAE) has emerged as one minimally invasive treatment option for these patients. The body of evidence which supports the use of PAE has grown quickly and substantially over the last decade. The goal of this review is to introduce and summarize the published urologic outcomes for PAE when utilized to treat benign prostatic hyperplasia induced lower urinary tract symptoms as well as document the established complication profile. Finally, the paper reviews current societal recommendations as they relate to PAE.

Initial Canadian Experience of Prostate Artery Embolization for Symptomatic Benign Prostatic Hyperplasia: Midterm Outcomes

INTRODUCTION

This study aimed to assess the midterm outcomes and safety of prostate artery embolization (PAE) for the treatment of benign prostatic hyperplasia (BPH).

METHODS

A single-center, retrospective review of PAE performed for BPH was performed. Validated International Prostate Symptom Score (IPSS), quality of life (QoL) index, and International Index for Erectile Function (IIEF-5) questionnaires were completed at baseline and at least 12 months post-procedure. Prostate imaging was performed preprocedure as well as 3 months and 12 months post-procedure to assess prostate volume (PV). Uroflowmetry was also performed at baseline and 12 months post-procedure to assess urine flow rate (Q_max) and post-void residual (PVR) volume. Adverse events were graded according to Society of Interventional Radiology (SIR) guidelines.

RESULTS

Eighty male patients underwent the PAE procedure (mean age 69 years). Prostate volume decreased significantly from a mean volume 156 to 107 mL after 12 months post-procedure, commensurate with a mean reduction of 27.5% (P < .05). Significant improvements were seen in IPSS (21.8 vs 10.5) and QoL (4.5 vs 2.0) from baseline to 12 months post-procedure (P < .05). There was no significant change in IIEF-5 score. There was a significant reduction in PVR (202 vs 105 mL) and improvement in Q_max (5.9 vs 10.0 mL/s) between baseline and 12 months post-procedure (P < .05). No major complications occurred; 4 minor complications occurred (SIR grade A or B).

CONCLUSION

Prostate artery embolization achieved a clinically and statistically significant prostate volume reduction, symptom and QoL improvement, and enhanced uroflowmetry parameters in patients with BPH.

REDUCTION OF STAFF RADIATION DOSE IN PROSTATIC ARTERY EMBOLISATION

Prostatic artery embolisation (PAE) is used to treat patients with benign prostatic hyperplasia and with lower urinary obstructive tract symptoms. It is an interventional procedure which uses fluoroscopy equipment and can result in exposure to high doses of radiation in patients and staff. We aimed to demonstrate the reduction of radiation doses received by staff during PAE by implementing an optimised protocol called Radiation Exposure Curtailment for Embolisation (RECiFE). This protocol was implemented in cooperation with the medical team and technical team using Siemens Combined Applications to Reduce Exposure (CARE) protocol. The results showed approximately 83% reduction in the radiation doses received by the main physician during PAE. Thus, by adjusting the acquisition parameters of the angiographic equipment and implementing the RECiFE protocol, it is possible to optimise the PAE procedure and reduce the staff radiation dose.

Transurethral resection of the prostate versus prostatic artery embolization in the treatment of benign prostatic hyperplasia: a meta-analysis

Background

To compare the clinical efficiency and safety of transurethral resection of the prostate (TURP) and prostatic artery embolization (PAE) for the treatment of Benign prostatic hyperplasia (BPH).

Methods

We searched PUBMED, EMBASE and the Cochrane Central Register for studies from May 1998 to May 2018 for studies comparing the efficiency and safety of TURP with PAE. Four studies met the inclusion criteria for our meta-analysis. After data extraction and quality assessment, we used RevMan 5.2 to pool the data.

Results

A total of four studies involving 506 patients were included in our meta-analysis. The pooled data showed that the Qmax was higher in TURP group than PAE with a significant difference (WMD:4.66, 95%CI 2.54 to 6.79, P < 0.05). The postoperative QOL was lower in the TURP than PAE group (WMD: -0.53, 95%CI -0.88 to − 0.18, P < 0.05). The postoperative prostate volume was significantly smaller in the TURP than PAE group (WMD: -8.26, 95%CI -12.64 to − 3.88, P < 0.05). The operative time was significantly shorter in the TURP than PAE group (WMD: -10.55, 95%CI -16.92 to − 4.18, P < 0.05). No significant difference was found in the postoperative IPSS and complications between TURP and PAE (P > 0.05, WMD:1.56, 95%CI -0.67 to 3.78, p = 0,05, OR:1.54, 95%CI 1.00 to2.38, respectively).

Conclusions

TURP could achieve improved Qmax and QoL compared to PAE. Therefore, for patients with BPH and lower urinary tract symptoms (LUTS), TURP was superior to PAE.

Prostate volume measured by magnetic resonance imaging is not a predictor of lower urinary tract symptoms

Purpose:

Prostate volume is frequently utilized to counsel patients presenting to family medicine physicians with voiding complaints. We evaluated the relation between International Prostate Symptom Score (IPSS) and prostate volume measured by phased-array surface coil magnetic resonance imaging (MRI).

Methods:

We performed an institutional review board (IRB)–approved retrospective study of all patients who received a prostate MRI between 2015 and 2017. Correlation between the overall IPSS, IPSS components, prostate volume stratified by prostate specific antigen (PSA) (<1.4 vs. ≥1.4 g/dL), and race (black vs. white) was examined.

Results:

In all, 592 patients had prostate MRIs performed between 2015 and 2017. Two hundred and twenty-nine of these patients had IPSS and prostate volume information available in their medical records. The mean age of the cohort was 64.67 (SD = ±7.82) and mean PSA was 7.75 (SD = ±8.3). The mean IPSS was 9.77 (SD ± 7.2), and mean prostate volume was 55.88 cubic cm (SD = ±38.9). The correlation coefficient between prostate volume and IPSS was 0.12789 (P = 0.05). The correlation between prostate volume and IPSS was also not significant in 128 men with prostate volume above 40 cubic cm. Stratifying analysis by race and PSA showed no significant correlation between volume and IPSS. Analysis of the correlation between the different dimension of prostate volume and IPSS revealed significant but weak associations.

Conclusions:

Even with more precise estimation with MRI, prostate volume does not predict obstruction complaints. This finding is of importance when treating males presenting with voiding dysfunction to primary care.

Prostatic Artery Embolization with 250-μm Spherical Polyzene-Coated Hydrogel Microspheres for Lower Urinary Tract Symptoms with Follow-up MR Imaging

PURPOSE

To evaluate clinical outcomes and possible MR imaging predictors of clinical success after prostatic artery embolization (PAE) with 250-μm hydrogel particles.

MATERIALS AND METHODS

During a span of 1.5 years, 30 patients with moderate to severe lower urinary tract symptoms were included in a prospective, nonrandomized study. Embolization of at least one prostatic artery was considered as technical success. International Prostate Symptom Score (IPSS), quality of life (QOL), peak urinary flow rate (Q_max), residual urine volume, prostate volume, prostate-specific antigen level, and International Index of Erectile Function (IIEF) were recorded at baseline and at 1, 3, and 6 months after PAE. Multiparametric MR imaging was performed before PAE (n = 25) and 1 day (n = 25), 1 month (n = 7), 3 months (n = 7), and 6 months (n = 22) after intervention. A Wilcoxon-Mann-Whitney test was used to assess changes over time, and Spearman rank-correlation coefficient was used for outcome prediction.

RESULTS

PAE was technically successful in 90% of patients (n = 27). Clinical success (IPSS < 18 with decrease > 25% and QOL score < 4 with decrease ≥ 1 or Q_max ≥ 15 mL/s and increase of ≥ 3.0 mL/s) rates were 59% (16 of 27), 63% (17 of 27), and 74% (20 of 27) after 1, 3, and 6 mo, respectively. IIEF scores did not differ significantly during follow-up. The following adverse events occurred after PAE: urethral burning (5 of 27), fever (2 of 27), and urethral bleeding, rectal bleeding, cystitis, and penile burning sensation (1 of 27 each). No statistical correlations between initial multiparametric MR imaging changes and clinical parameters after 6 months were found (P values from .14 to .98).

CONCLUSIONS

PAE with 250-μm hydrogel microspheres led to good clinical success after 6 months with a low complication rate. Significant MR imaging predictors of clinical success were not identified.

MRI features after prostatic artery embolization for the treatment of medium- and large-volume benign hyperplasia

PURPOSE

To assess magnetic resonance imaging (MRI) features after prostatic artery embolization (PAE) for the treatment of medium- and large-volume benign prostatic hyperplasia and to correlate prostate volume with clinical indexes.

METHODS

We retrospectively evaluated 28 patients who underwent PAE. MRI examinations of the prostate were performed to evaluate signal intensity changes and the characteristics of infarcted areas. Prostate volume and the apparent diffusion coefficient (ADC) were measured at an average of 10 days post-PAE and at 1, 3, 6, and 12 months post-PAE. Some clinical indexes were evaluated before and 12 months after PAE. The paired t test, ANOVA, and multiple linear correlation analyses were performed by using the statistical software, SPSS.

RESULTS

All patients experienced prostatic infarction. The prostate volume decreased continuously (p < 0.05). The ADC values before and after 1, 3, 6, or 12 months of embolization (b = 1000 and 2000 s/mm²) were statistically significantly different. The ADC values (b = 3000 s/mm²) were also statistically significantly different before and at each interval time after embolization (p < 0.05). Prostate volume changes correlated significantly with patient age and post-void residual urine volume (p < 0.05).

CONCLUSIONS

MRI can be used for assessing changes in signal intensity and ADC values of infarction as well as the volume of the prostate after PAE. After PAE, ultrahigh b value diffusion-weighted imaging (DWI) can show early infarction better than lower b value DWI.

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.

Benign prostatic hyperplasia after prostatic arterial embolization in a canine model: A 3T multiparametric MRI and whole-mount step-section pathology correlated longitudinal study

PURPOSE

To explore the morphological and functional characteristics of prostatic arterial embolization (PAE) in a canine model of benign prostatic hyperplasia (BPH) with 3T multiparametric magnetic resonance imaging (mp-MRI) and whole-mount step-section pathology correlation.

MATERIALS AND METHODS

Eight adult male beagle dogs with hormone-induced BPH underwent 3T mp-MRI before and 1, 3, and 6 months after PAE, with subsequent whole-mount step-section pathologic assessment. Images were acquired using T₁ -weighted images (T₁ WI), T₂ WI, 3D-SPACE, diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), T₂ -mapping, and dynamic contrast-enhanced (DCE) sequences. Variance analysis was performed to assess statistical differences in prostatic volume (PV), apparent diffusion coefficient (ADC), and T₂ values. Pearson correlation analysis was performed to correlate ADC, T₂ , and PV.

RESULTS

The PV decreased from baseline to 1, 3, and 6 months after PAE from (25.88 ± 7.09) cm³ to (6.48 ± 2.08) cm³ , (6.48 ± 3.39) cm³ , (6.20 ± 2.88) cm³ . The ADC values sequentially decreased from baseline to 1, 3, and 6 months after PAE from (1497.06 ± 222.72) × 10^-6 mm² /s to (1056.00 ± 189.46) × 10^-6 mm² /s, (950.48 ± 77.85) × 10^-6 mm² /s, (980.98 ± 107.78) × 10^-6 mm² /s. The T₂ values decreased from baseline to 1, 3, and 6 months after PAE were (83.74 ± 5.29) msec, (68.72 ± 5.66) msec, (53.96 ± 15.04) msec, (49.81 ± 13.34) msec, respectively. ADC and T₂ values were positively correlated with PV (r = 0.823 and 0.744, respectively). Microhemorrhages and hemosiderin were found on SWI after PAE.

CONCLUSION

3T mp-MRI may facilitate noninvasive assessment of morphological and functional changes of BPH after PAE.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1220-1229.

A Systematic Review of Prostatic Artery Embolization in the Treatment of Symptomatic Benign Prostatic Hyperplasia

PURPOSE

To summarize current evidence on outcomes and complications of prostatic artery embolization as a treatment for patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia.

METHODS AND MATERIALS

A database search of MEDLINE, Embase, Web of Science, and Cochrane Library was performed for published literature up to August 2015 concerning PAE in the treatment of BPH. Inclusion and exclusion criteria were applied by two independent reviewers, and disagreements were resolved by consensus. Peer-reviewed studies concerning PAE with BPH with a sample size >10 and at least one measured parameter were included.

RESULTS

The search yielded 193 articles, of which ten studies representing 788 patients, with a mean age of 66.97 years, were included. Patients had LUTS ranging from moderate to severe. At 6 months following procedure, PV, PVR, Qmax, IPSS, and QoL were significantly improved (P < 0.05), while for PSA there was no significant change. At 12 and 24 months, PV, PSA, PVR, Qmax, IPSS, and QoL were significantly improved (P < 0.05). IIEF was unchanged at 6 and 12 months but was significantly reduced at 24 months.

CONCLUSION

This suggests that PAE is effective in treating LUTS in the short and intermediate term.

Prostate Artery Embolization for Benign Prostatic Hyperplasia: Current Status

Prostate artery embolization has garnered much attention as a promising treatment for lower urinary tract symptoms secondary to benign prostatic hyperplasia. We aim to provide an up-to-date review of this minimally invasive technique, including discussion of potential benefits and technical challenges. Current evidence suggests it is a safe and effective option for patients with medication-refractory urinary obstructive symptoms who are poor surgical candidates or refuse surgical therapy. Larger, randomized studies with long-term follow-up data are needed for this technique to be formally established in the treatment paradigm for benign prostatic hyperplasia.

Benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH), which causes lower urinary tract symptoms (LUTS), is a common diagnosis among the ageing male population with increasing prevalence. Many risks factors, both modifiable and non-modifiable, can increase the risk of development and progression of BPH and LUTS. The symptoms can be obstructive (resulting in urinary hesitancy, weak stream, straining or prolonged voiding) or irritative (resulting in increased urinary frequency and urgency, nocturia, urge incontinence and reduced voiding volumes), or can affect the patient after micturition (for example, postvoid dribble or incomplete emptying). BPH occurs when both stromal and epithelial cells of the prostate in the transitional zone proliferate by processes that are thought to be influenced by inflammation and sex hormones, causing prostate enlargement. Patients with LUTS undergo several key diagnostic investigations before being diagnosed with BPH. Treatment options for men with BPH start at watchful waiting and progress through medical to surgical interventions. For the majority of patients, the starting point on the treatment pathway will be dictated by their symptoms and degree of bother.

Prostatic Artery Embolization (PAE) for Symptomatic Benign Prostatic Hyperplasia (BPH): Part 2, Insights into the Technical Rationale

Rationale of prostatic artery embolization (PAE) in the treatment of symptomatic benign prostatic hyperplasia is conventionally believed to include two parts: shrinkage of the enlarged prostate gland as a result of PAE-induced ischemic infarction and potential effects to relax the increased prostatic smooth muscle tone by reducing the number and density of α1-adrenergic receptor in the prostate stroma. This review describes new insights into the likely mechanisms behind PAE, such as ischemia-induced apoptosis, apoptosis enhanced by blockage of androgens circulation to the embolized prostate, secondary denervation following PAE, and potential effect of nitric oxide pathway immediately after embolization. Studies on therapeutic mechanisms in PAE may shed light on potentially new treatment strategies and development of novel techniques.

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.

MRI findings after prostatic artery embolization for treatment of benign hyperplasia

OBJECTIVE

The purpose of this article is to assess and describe the MRI findings after prostatic artery embolization for treatment of benign prostatic hyperplasia.

MATERIALS AND METHODS

We retrospectively evaluated 17 patients who underwent prostatic artery embolization as part of different prospective studies to evaluate this alternative treatment of benign prostatic hyperplasia. Clinical results were evaluated by assessment of urinary catheterization and International Prostate Symptom Score (IPSS). Serial MRI examinations were performed, and the prostatic central gland and peripheral zone were evaluated for signal intensity changes and the presence and characteristics of infarcted areas. Statistical analysis was performed with ANOVA for repeated measures and Student t test.

RESULTS

All patients had clinical success, as defined by the removal of indwelling urinary catheter or decreased IPSS after embolization. Infarcts were seen in 70.6% of the subjects, exclusively in the central gland, were almost always characterized by hyperintensity on T1-weighted images and predominant hypointensity on T2-weighted images, and became smaller (mean reduction, p < 0.001) and isointense to the remaining of the central gland over time. Volume reduction of the prostate after embolization was significant (averaging 32.0% after 12-18 months; p < 0.001) only in patients with infarcts. No statistically significant association was seen between the development of infarcts and IPSS.

CONCLUSION

MRI can be used for assessing the development of infarcts and volume reduction in the prostate after embolization. Further studies are needed to correlate these findings to clinical outcome.

The "PErFecTED technique": proximal embolization first, then embolize distal for benign prostatic hyperplasia

Prostatic artery embolization requires a refined technique to achieve good imaging and clinical success. The PErFecTED (Proximal Embolization First, Then Embolize Distal) technique has produced greater prostate ischemia and infarction than previously described methods with clinical improvement of lower urinary symptoms and lower recurrence rates. The microcatheter should cross any collateral branch to the bladder, rectum, corpus cavernosum, gonad, or penis and be placed distally into the prostatic artery before its branching to the central gland and peripheral zone. This technique allows better distribution of embolic material in the intraprostatic arteries and reduces risk of spasm or thrombus. Because benign prostatic hyperplasia develops primarily in the periurethral region of the prostate, the urethral group of arteries should be embolized first. Subsequent distal investigation and embolization completes occlusion and stasis of blood flow to the prostatic parenchyma. Since we added the second step to the PErFecTED technique, we have observed infarcts in all patients submitted to prostatic artery embolization.