The Effect of Transarterial Prostate Embolization in Hormone-induced Benign Prostatic Hyperplasia in Dogs: A Pilot Study

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.

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

Prostate carcinoma is one of the most common cancers worldwide in men, with over 3 million men currently living with prostate carcinoma. In men, routine screening and successful treatment schemes, including radiation, prostatectomy, or hormone therapy, have allowed for high survivability. Dogs are recognized as one of the only mammals to spontaneously develop prostate neoplasia and are an important translational model. Within veterinary medicine, treatment options have historically been limited in efficacy or paired with high morbidity. Recently, less invasive treatment modalities have been investigated in dogs and people and demonstrated promise. Below, current treatment options available in dogs and people are reviewed, as well as a discussion of current and future trends within interventional treatment for canine PC.

Long-Term PAE Results: What Do We Know

Prostatic artery embolization (PAE) is a minimally invasive technique with proven safety and efficacy to treat lower urinary tract symptoms (LUTS) due to benign prostatic obstruction (BPO) or benign prostatic hyperplasia (BPH). In this review, we discuss the required level of evidence to implement and adopt treatment options for patients with LUTS due to BPO/BPH. Focus is given on the long-term (>3 years) data after PAE with reported outcomes including cohort sizes, follow-up times, reintervention rates (repeat PAE and prostatectomy), need for LUTS/BPO medical therapy, and improvements in International Prostate Symptom Score/quality of life score, peak flow rate (Qmax), postvoid residual, prostate volume, and prostate-specific antigen. The durability of treatment effects after PAE and need for prostatic reinterventions need to be taken into consideration when discussing treatment options with patients and referring colleagues from other medical specialties. Developments in medical devices used for PAE have allowed for a continuous drop in unilateral PAE rates over the last 12 years and will probably play a role in optimizing technical and thus clinical outcomes for patients with LUTS due to BPH/BPO.

Prostate artery chemoembolization in prostate cancer: A proof of concept study in spontaneous prostate cancer in a canine model

PURPOSE

The purpose of this study was to assess the feasibility and efficacy of docetaxel-loaded bead chemoembolization in spontaneous prostate cancer in a canine model.

MATERIALS AND METHODS

Five pet dogs with histopathologically proven prostate cancer were referred for prostate artery chemoembolization (PACE). After PACE, all animals were followed, including pharmacokinetic study and clinical and biological evolution, until death. Pelvic contrast-enhanced computed tomography examination was performed at one and two months. Animals were subjected to pathological examination after death.

RESULTS

Both prostate arteries were successfully chemoembolized in all dogs. A median dose of 18 mg (Q1, Q3; 11.8, 20 mg) docetaxel loaded in 3 mL of 50-100 µm super absorbent polymer beads was injected into each dog. At one month, four of the five dogs were still alive and the median prostate volume was 51% lower (prePACE median prostate volume, 18.4 mL [Q1, Q3; 12, 32.1 mL] vs. postPACE median prostate volume, 6.2 mL [Q1, Q3; 6.2, 11 mL]). At two months, three dogs died because of disease progression. The two remaining dogs showed a 70% median decrease in prostate volume. Prostate pathological examination showed 73% of necrosis. No worsening of urinary symptoms was observed. Pharmacokinetic analysis showed limited systemic passage of docetaxel. All dogs died of metastatic spread at nine months.

CONCLUSION

This study suggests that PACE is feasible and safe for the treatment of spontaneous prostate cancer in a canine model and may provide a new approach to treat selected patients with prostate cancer.

Preparation and evaluation of ion-exchange porous polyvinyl alcohol microspheres as a potential drug delivery embolization system

The present study aimed to develop a new drug delivery system with efficient drug loading and sustained drug release for potential application in transarterial chemoembolization (TACE). The porous polyvinyl alcohol microspheres (PPVA MS) were prepared by a combination of inverse emulsification and thermal-induced phase separation (TIPS) method, this was followed by the grafting polymerization of sodium 4-styrene sulfonate (SSS) onto the PPVA MS to obtain the grafted PPVA-g-PSSS MS. The prepared PPVA MS showed a well-defined spherical shape with 'honeycomb-like' porous structure, which could be readily tailored by adjusting the quenching temperature. In vitro biocompatibility analysis indicated the non-cytotoxic and hemocompatible nature of PPVA MS. The porous structure and presence of ionically charged groups in the PPVA-g-PSSS MS favoured the loading of cationic doxorubicin (DOX) onto the MS through ionic-interactions and demonstrated a sustained drug release pattern. Moreover, the cytotoxicity of DOX-loaded PPVA-g-PSSS (DOX@PPVA-g-PSSS) MS against HepG2 cells and the intracellular uptake of DOX demonstrated the potent in vitro antitumor activity. Furthermore, the central auricular artery embolization in rabbits showed that both the PPVA-g-PSSS and DOX@PPVA-g-PSSS MS could occlude the auricular arteries and induced superior embolization effects, such as progressive ear appearance changes, irreversible parenchymal damage and fibrosis, and ultrastructural alternations in endothelial cells. Besides, the DOX fluorescence was distributed around the embolized arteries, without decreasing its intensity when prolonged embolization up to 15 days. These findings suggest that the newly developed DOX@PPVA-g-PSSS MS could be employed as a promising drug-loaded embolic agent for the treatment of hepatocellular carcinoma.

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

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 Embolization for Benign Prostatic Hyperplasia: Bleomycin-Eluting versus Bland Microspheres in a Canine Model

PURPOSE

To prospectively assess safety and efficacy of prostatic artery embolization (PAE) with bleomycin-eluting microspheres for benign prostatic hyperplasia (BPH) in a canine model.

MATERIALS AND METHODS

Twelve adult male beagles (mean age, 1.6 y ± 0.2; range, 1.2-2.0 y) were randomly assigned to group A (n = 6; PAE with bleomycin-eluting 30-60-μm HepaSphere microspheres) and group B (n = 6; PAE with bland 30-60-μm HepaSphere microspheres) between April 2017 and November 2018. Plasma bleomycin concentration in group A was measured within 7 days. Prostate volume (PV) and ischemic volume after PAE were measured by magnetic resonance imaging. Prostates and adjacent organs were harvested after the last magnetic resonance study and histopathologically examined.

RESULTS

Plasma bleomycin concentration peaked at 10 minutes at 2,055.0 ng/mL ± 606.1 and lasted for 1,440 min at low levels after PAE. PV reduction percentage was greater in group A than in group B at 1 month (74.1% ± 4.3 vs 63.7% ± 3.5; P = .006) and 3 months (61.5% ± 6.7 vs 46.1% ± 3.8; P = .001) after PAE. Proportion of prostate ischemic volume was greater in group A than in group B (75.3% ± 3.0 vs 62.0% ± 7.1; P = .006) at 1 month after PAE. Proportion of prostate ischemic volume at 1 month positively correlated with PV percentage reduction at 3 months in group A (r = 0.840, P = .036) and group B (r = 0.844, P = .035). There were no complications or nontarget embolization to surrounding organs after the procedures.

CONCLUSIONS

In a canine model, PAE with bleomycin-eluting microspheres was feasible and well tolerated and caused ischemic necrosis and reduction in PV.

Sexual and functional outcomes of prostate artery embolisation: A prospective long-term follow-up, large cohort study

AIM OF THE STUDY

Among minimally invasive procedures for treating benign prostate hyperplasia (BPH) prostate artery embolisation (PAE) is described as safe and effective. Aim of this study is to report our results, focusing on sexual outcomes (erectile and ejaculatory functions sparing) of PAE in patients suffering from bladder outlet obstruction (BOO) secondary to BPH.

METHODS

We prospectively enrolled and submitted to PAE subjects suffering from BOO secondary to BPH. All patients were not suitable for surgery or declined invasive approaches. All subjects were preoperatively and postoperatively (3, 6, 12 and 18 months after) evaluated by urinary flowmetry, post voiding residual volume, prostate volume, serum PSA levels, International Index of Erectile Function, International Prostate Symptom Score and QoL scores.

RESULTS

PAE was performed in 147 patients (mean age 72.5 y.o.). PAE was technically successful in all patients. The procedure lasted a mean time of 94.3 minutes, with a mean fluoroscopic time of 42.5 minutes. Twelve months follow-up data were available for all patients, while 126 patients (85%) completed the 18 months follow up. At 12 months follow up, the mean IPSS and QoL scores significantly decreased, and all the objective parameters (mean Qmax, PVR and prostate volume) reported a significant improvement. A total of 130 patients (88.5%) at 12 months reported the antegrade ejaculation preserved, and a slight not significant improvement of IIEF scores. The 18 months after PAE outcomes confirmed the significant improvement of all the variables evaluated (even for PSA values and IIEF scores). No major complications occurred.

CONCLUSIONS

Our results evidence prostate artery embolisation as highly feasible and safe procedure with interesting outcomes. In particular, in our study PAE reported promising results in preserving antegrade ejaculation and erectile function. Our data are in line with the literature, confirming how PAE reduces obstructive symptoms in BPH patients not suitable or refusing standard surgical approaches.

Development of finasteride/PHBV@polyvinyl alcohol/chitosan reservoir-type microspheres as a potential embolic agent: from in vitro evaluation to animal study

Benign prostatic hyperplasia (BPH) is a prevalent urological disease affecting elders. Currently, the prostatic artery embolization (PAE) is considered as a minimally invasive and safe technique to treat BPH. However, various drug-loaded embolic agents have not been thoroughly investigated in BPH therapy. In this study, finasteride/poly(3-hydroxybutyrate-3-hydroxyvalerate)@polyvinyl alcohol/chitosan (FNS/PHBV@PVA/CS) reservoir-type microspheres were prepared via the solid-in-water-in-oil (S/W/O) emulsion crosslinking method with the aim to reduce the burst effect and control localized drug delivery. The structure and properties of the drug and resultant microspheres were characterized via field emission scanning electron microscopy (FESEM), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that the drug-loaded hybrid microspheres were well-dispersed and spherical with a mean diameter of 238.1 ± 27.3 μm. All samples exhibited excellent thermal stability. The FNS/PHBV microspheres were successfully encapsulated inside the PVA/CS polymeric matrix, which effectively suppressed the burst effect and prolonged the drug release up to 51 days. In vitro biocompatibility assessment indicated that the microspheres possessed excellent cytocompatibility and hemocompatibility. Furthermore, in vivo studies performed in the rabbit ear embolization model showed the formation of progressive ischemic necrosis after treatment for various periods. Histopathological studies revealed that the microspheres completely occluded the blood vessels with minimal foreign body response and formed the fibrotic area at the periphery of embolized arteries. Furthermore, the auricular vascular endothelial cells showed acute ultrastructural changes, associated with the ischemic necrosis induced by the embolization procedures. All these findings suggest that the FNS/PHBV@PVA/CS hybrid microspheres could be used as a promising drug delivery system for potential applications in BPH therapy.

Embolisation of prostate arteries in benign prostatic hyperplasia in non-surgical patients

OBJECTIVE

To present the results of a multidisciplinary study of two tertiary hospitals, together with urology services, on 102 consecutive patients not candidates for surgery treated for more than 6 years, in whom prostatic arteries were embolised for the treatment of benign hyperplasia.

MATERIAL AND METHODS

From December 2012 to February 2019, 102 patients with symptoms of benign prostatic hyperplasia (BPH) not candidates for surgery or who explicitly rejected surgery, with an average age of 73.9 years (range 47.5-94.5), underwent prostatic artery embolisation. The patients were followed up by questionnaires on urinary symptoms, sexual function and impact on quality of life, as well as measurement of prostate volume, uroflowmetry and prostate specific antigen (PSA) at one, 3 and 6 months and one year following the procedure.

RESULTS

The technique was successful in 96% of patients (76.2% bilateral and 19.8% unilateral). The mean duration of the procedure was 92minutes and of the radioscopy 35.2minutes. Statistically significant changes were demonstrated (p <.05) in PSA, peak urinary flow, QoL (quality of life) questionnaire and the International Index of Erectile Function (IPSS). PSA had reduced by 58% from baseline at 3 months. Similarly, the Qmax had increased significantly by 63% in the third month following embolisation. A significant improvement in the QoL and IPSS tests was achieved, with a reduction of 3.7 points and a mean 13.5 points, respectively, at one year's follow-up. Prostate volume showed a non-statistically significant decrease at follow-up of one year following treatment. A series of minor complications was collected, no case of which required hospital admission.

CONCLUSIONS

Prostatic embolisation for the treatment of BPH proved an effective and safe technique in patients who were not candidates for surgery.

Comparison of Nonspherical Polyvinyl Alcohol Particles and Microspheres for Prostatic Arterial Embolization in Patients with Benign Prostatic Hyperplasia

Purpose

To report early results following prostatic artery embolization (PAE) and compare outcomes between nonspherical polyvinyl alcohol (PVA) particles and microspheres to treat lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH).

Methods

PAE was performed in nine patients (mean age: 78.1 years) with symptomatic BPH. Embolization was performed using nonspherical PVA particles (250–355 μm) in four patients and microspheres (300–500 μm) in five patients.

Results

PAE was technically successful in all nine patients (100%). During a mean follow-up of 10.1 months, improvements in mean International Prostate Symptom Score (IPSS), Quality of Life (QoL), prostatic volume (total volume and transition zone), and peak urinary flow (Q_max) were 9.8 points, 2.3 points, 28.1 mL, 17.8 mL, and 4.5 mL/s, respectively. Clinical success was obtained in seven of nine patients (78%). Patients in the microsphere group showed greater improvement in IPSS, QoL, prostatic volume, and Q_max compared to patients in the nonspherical PVA particle group. However, significant difference was noted only in the prostatic volume.

Conclusion

PAE is a feasible, effective, and safe treatment option for BPH with LUTS. Use of microspheres showed greater prostatic volume reduction compared to nonspherical PVA particles.

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.

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.

Prostatic Artery Embolization: A Promising Technique in the Treatment of High-Risk Patients with Benign Prostatic Hyperplasia

INTRODUCTION

Prostatic artery embolization (PAE) has recently started to be viewed as a promising technology that could be an alternative to different treatment options of benign prostatic hyperplasia (BPH), especially in high-risk patients. The aim of our study was to evaluate the efficacy and safety of PAE in BPH patients who are at high risk for surgery and/or anesthesia.

MATERIALS AND METHODS

Between June 2013 and February 2015, BPH patients >50 years with lower urinary tract symptoms (LUTS) refractory to BPH-related medical therapy or had an indwelling urethral catheter due to refractory urine retention were prospectively enrolled in the study. All patients were at high risk for surgery and/or anesthesia. The PAE was performed and the embolising material used was biosphere 300-500 µm particles. Pre- and 1, 3, 9 months post-intervention, all patients were assessed by detailed medical history, physical examination, serum prostate-specific antigen (PSA), uroflowmetry, and abdominal and transrectal ultrasonography.

RESULTS

Twenty-two consecutive patients with a mean age of 72.50 years and a mean prostate volume of 77.30 ± 14.89 cm3 were included. The PAE procedure was successful in all patients. Throughout the period of follow-up, there was a significant improvement in the LUTS and urinary flow rate, and reduction in prostate volume and serum PSA (for all p < 0.001). No major complications were reported.

CONCLUSION

Our results show that BPH patients with failed medical treatment who are at high risk for surgery and/or anesthesia could be treated safely and effectively through PAE.

Medium- and Long-Term Outcome of Prostate Artery Embolization for Patients with Benign Prostatic Hyperplasia: Results in 630 Patients

PURPOSE

To confirm that prostatic artery embolization (PAE) has a positive medium- and long-term effect in symptomatic benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

Between March 2009 and October 2014, 630 consecutive patients with BPH and moderate-to-severe lower urinary tract symptoms refractory to medical therapy for at least 6 months or who refused any medical therapy underwent PAE. Outcome parameters were evaluated at baseline; 1, 3, and 6 months; every 6 months between 1 and 3 years; and yearly thereafter up to 6.5 years.

RESULTS

Mean patient age was 65.1 years ± 8.0 (range, 40-89 y). There were 12 (1.9%) technical failures. Bilateral PAE was performed in 572 (92.6%) patients and unilateral PAE was performed in 46 (7.4%) patients. The cumulative clinical success rates at medium- and long-term follow-up were 81.9% (95% confidence interval [CI], 78.3%-84.9%) and 76.3% (95% CI, 68.6%-82.4%). There was a statistically significant (P < .0001) change from baseline to last observed value in all clinical parameters: International Prostate Symptom Score (IPSS), quality-of-life (QOL), prostate volume, prostate-specific antigen, urinary maximal flow rate, postvoid residual, and International Index of Erectile Function. There were 2 major complications without sequelae.

CONCLUSIONS

PAE had a positive effect on IPSS, QOL, and all objective outcomes in symptomatic BPH. The medium- (1-3 y) and long-term (> 3-6.5 y) clinical success rates were 81.9% and 76.3%, with no urinary incontinence or sexual dysfunction reported.

Prostatic artery embolization versus conventional TUR-P in the treatment of benign prostatic hyperplasia: protocol for a prospective randomized non-inferiority trial

BACKGROUND

Benign prostatic hyperplasia (BPH) is a prevalent entity in elderly men and transurethral resection of the prostate (TURP) still represents the gold standard of surgical treatment despite its considerable perioperative morbidity. Recently, prostatic artery embolization (PAE) was described as a novel effective and less invasive treatment alternative. Despite promising first results, PAE still has to be considered experimental due to a lack of good quality studies. Prospective randomized controlled trials comparing PAE with TUR-P are highly warranted.

METHODS/DESIGN

This is a single-centre, prospective, randomized, non-inferiority trial comparing treatment effects and adverse events of PAE and TURP in a tertiary referral centre. One hundred patients who are electable for both treatment options are randomized to either PAE or TURP. Changes of the International Prostate Symptom Score (IPSS) after 3 months are defined as primary endpoint. Changes in bladder diaries, laboratory analyses, urodynamic investigations and standardised questionnaires are assessed as secondary outcome measures. In addition contrast-enhanced magnetic resonance imaging of the pelvis before and after the interventions will provide crucial information regarding morphological changes and vascularisation of the prostate. Adverse events will be assessed on every follow-up visit in both treatment arms according to the National Cancer Institute Common Terminology Criteria for Adverse events and the Clavien classification.

DISCUSSION

The aim of this study is to assess whether PAE represents a valid treatment alternative to TURP in patients suffering from BPH in terms of efficacy and safety.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02054013.

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.

Prostatic artery embolization in benign prostatic hyperplasia: preliminary results in 13 patients

AIM

The aim of the paper is to report the clinical outcome after prostatic artery embolisation (PAE) in 13 consecutive patients with benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS).

MATERIALS AND METHODS

From May 2012 to October 2013, we performed PAE in 13 consecutive patients (mean age 75.9 years) with BPH and LUTS and refractory to medical therapy; seven patients had an indwelling bladder catheter. Clinical follow-up (mean follow-up time 244 days) was performed using the international prostate symptoms score (IPSS), quality of life (QoL), the international index of erectile function (IIEF), blood prostatic specific antigen (PSA) testing and transrectal prostatic ultrasound (US) scan with volume and weight calculation at 3, 6 and 12 months. Pre-procedural CT angiography (CTA) was done for vascular mapping. Embolisation was performed using Embosphere (300-500 micron). Technical success was defined when selective prostatic arterial embolisation was completed in at least one pelvic side. Clinical success was defined when symptoms and quality of life were improved.

RESULTS

PAE was technically successful in 12/13 patients (92%). In one patient, PAE was not performed because of tortuosity and atherosclerosis of iliac arteries. PAE was completed bilaterally in 9/13 (75%) patients and unilaterally in three (27%). All patients removed the bladder catheter from 4 days to 4 weeks after PAE. We obtained a reduction in IPSS (mean, 17.1 points), an increase in IIEF (mean, 2.6 points), an improvement in Qol (mean, 2.6 points) and a volume reduction (mean, 28%) at 12 months.

CONCLUSIONS

Consistent with the literature, our experience showed the feasibility, safety and efficacy of PAE in the management of patients with LUTS related to BPH. PAE may play an important role in patients in whom medical therapy has failed, who are not candidates for surgery or transurethral prostatic resection (TURP) or refuse any surgical treatment. Larger case series and comparative studies with standard TURP can confirm the validity of the technique.

How to perform prostatic arterial embolization

Prostatic arterial embolization (PAE) is an experimental alternative treatment for benign prostatic hyperplasia, with promising preliminary results. In comparison with surgery, its main advantages are the minimally invasive nature, outpatient setting, rapid recovery, and low morbidity. To avoid complications and to achieve technical success it is important to know the procedural technique in detail. In addition, for good clinical results, it is important to perform a bilateral and complete prostatic embolization. In this article, the different technical steps, including the initial site of puncture and the catheters and guidewires to be used, are described. Identification of the prostatic arteries is crucial. Correlation between computed tomography angiography and digital subtraction angiography helps to solve the difficulty of such identification. The skills for superselective catheterization of the prostatic arteries, the amounts of contrast injected, the preparation and size of the used particles and the end point of the procedure are also described.

Prostatic arterial embolization: post-procedural follow-up

Prostatic arterial embolization (PAE) gained special attention in the past years as a potential minimally invasive technique for benign prostatic hyperplasia. Treatment decisions are based on morbidity and quality-of-life issues and the patient has a central role in decision-making. Medical therapy is a first-line treatment option and surgery is usually performed to improve symptoms and decrease the progression of disease in patients who develop complications or who have inadequately controlled symptoms on medical treatment. The use of validated questionnaires to assess disease severity and sexual function, uroflowmetry studies, prostate-specific antigen and prostate volume measurements are essential when evaluating patients before PAE and to evaluate response to treatment. PAE may be performed safely with minimal morbidity and without associated mortality. The minimally invasive nature of the technique inducing a significant improvement in symptom severity associated with prostate volume reduction and a slight improvement in the sexual function are major advantages. However, as with other surgical therapies for benign prostatic hyperplasia, up to 15% of patients fail to show improvement significantly after PAE, and there is a modest improvement of the peak urinary flow.

Clinical, laboratorial, and urodynamic findings of prostatic artery embolization for the treatment of urinary retention related to benign prostatic hyperplasia. A prospective single-center pilot study

PURPOSE

This study was designed to describe the clinical, laboratorial, and urodynamic findings of prostatic artery embolization (PAE) in patients with urinary retention due to benign prostatic hyperplasia (BPH).

METHODS

A prospective study of 11 patients with urinary retention due to BPH was conducted. Patients underwent physical examination, prostate specific antigen (PSA) measurement, transrectal ultrasound, and magnetic resonance imaging. International prostate symptom score (IPSS), quality of life (QoL), and urodynamic testing were used to assess the outcome before and after 1 year.

RESULTS

Clinical success was 91% (10/11 patients) with a mean follow-up of 22.3 months (range, 12-41 months). At the first year follow-up, the mean IPSS score was 2.8 points (p = 0.04), mean QoL was 0.4 points (p = 0.001), mean PSA decreased from 10.1 to 4.3 ng/mL (p = 0.003), maximum urinary flow (Qmax) improved from 4.2 to 10.8 mL/sec (p = 0.009), and detrusor pressure (Pdet) decreased from 85.7 to 51.5 cm H2O (p = 0.007). Before PAE, Bladder Outlet Obstruction Index (BOOI) showed values >40 in 100% of patients. After PAE, 30% of patients were >40 (obstructed), 40% were between 20 and 40 (undetermined), and 30% were <20 (unobstructed). Patients with a BOOI <20 had higher PSA values at 1-day after PAE.

CONCLUSIONS

Clinical and urodynamic parameters improved significantly after PAE in patients with acute urinary retention due to BPH. Total PSA at day 1 after PAE was higher in patients with unobstructed values in pressure flow studies.

Embolisation of prostatic arteries as treatment of moderate to severe lower urinary symptoms (LUTS) secondary to benign hyperplasia: results of short- and mid-term follow-up

OBJECTIVES

To evaluate the short- and medium-term results of prostatic arterial embolisation (PAE) for benign prostatic hyperplasia (BPH).

METHODS

This was a prospective non-randomised study including 255 patients diagnosed with BPH and moderate to severe lower urinary tract symptoms after failure of medical treatment for at least 6 months. The patients underwent PAE between March 2009 and April 2012. Technical success is when selective prostatic arterial embolisation is completed in at least one pelvic side. Clinical success was defined as improving symptoms and quality of life. Evaluation was performed before PAE and at 1, 3, 6 and every 6 months thereafter with the International Prostate Symptom Score (IPSS), quality of life (QoL), International Index of Erectile Function (IIEF), uroflowmetry, prostatic specific antigen (PSA) and volume. Non-spherical polyvinyl alcohol particles were used.

RESULTS

PAE was technically successful in 250 patients (97.9 %). Mean follow-up, in 238 patients, was 10 months (range 1-36). Cumulative rates of clinical success were 81.9 %, 80.7 %, 77.9 %, 75.2 %, 72.0 %, 72.0 %, 72.0 % and 72.0 % at 1, 3, 6, 12, 18, 24, 30 and 36 months, respectively. There was one major complication.

CONCLUSIONS

PAE is a procedure with good results for BPH patients with moderate to severe LUTS after failure of medical therapy.

KEY POINTS

• Prostatic artery embolisation offers minimally invasive therapy for benign prostatic hyperplasia. • Prostatic artery embolisation is a challenging procedure because of vascular anatomical variations. • PAE is a promising new technique that has shown good results.

Embolization therapy for benign prostatic hyperplasia: influence of embolization particle size on gland perfusion

PURPOSE

To assess the influence of embolic size on the therapy response of prostatic arterial embolization (PAE) based on perfusional changes seen on dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Twelve beagles underwent PAE, four dogs with each particle size: A: 100-300 μm; B: 300-500 μm; and C: 500-700 μm. Prior to and 1 month after the embolization all dogs underwent prostate DCE MRI.

RESULTS

After embolization, time to maximal perfusion intensity for prostate parenchyma increased in B (188 vs. 135 sec, P = 0.023) and C (200 vs. 120 sec, P = 0.001), while it did not change for A (139 vs. 124 sec, P = 0.39). The maximal relative intensity increased after embolization in C (3.84 vs. 2.38, P < 0.001), while it did not change for A (2.50 vs. 2.44, P = 0.36) and B (3.23 vs. 2.9, P = 0.21). The extent of visualized intraprostatic urethral wall increased after embolization in B compared with A and C, 239.5 ± 138.1% vs. 56.1 ± 34.3, P = 0.04. Enhancement changes correlated with prostate volume changes: prostate volumes in A decreased less as compared with B and C (77 ± 34% vs. 56 ± 14%), P = 0.02.

CONCLUSION

The enhancement and morphological data are useful to monitor response to therapy after embolization. Embolization with 300-500 and 500-700 μm particle may provide better results than with 100-300 μm particles in a canine model.

Fractal dimension and Shannon's entropy analyses of the architectural complexity caused by the inflammatory reactions induced by highly crystalline poly(vinyl alcohol) microspheres implanted in subcutaneous tissues of the Wistar rats

The results of the histopathological analyses after the implantation of highly crystalline PVA microspheres in subcutaneous tissues of Wistar rats are here in reported. Three different groups of PVA microparticles were systematically studied: highly crystalline, amorphous, and commercial ones. In addition to these experiments, complementary analyses of architectural complexity were performed using fractal dimension (FD), and Shannon's entropy (SE) concepts. The highly crystalline microspheres induced inflammatory reactions similar to the ones observed for the commercial ones, while the inflammatory reactions caused by the amorphous ones were less intense. Statistical analyses of the subcutaneous tissues of Wistar rats implanted with the highly crystalline microspheres resulted in FD and SE values significantly higher than the statistical parameters observed for the amorphous ones. The FD and SE parameters obtained for the subcutaneous tissues of Wistar rats implanted with crystalline and commercial microparticles were statistically similar. Briefly, the results indicated that the new highly crystalline microspheres had biocompatible behavior comparable to the commercial ones. In addition, statistical tools such as FD and SE analyses when combined with histopathological analyses can be useful tools to investigate the architectural complexity tissues caused by complex inflammatory reactions.

Animal models for benign prostatic hyperplasia

Although the etiology of benign prostatic hyperplasia (BPH) is unknown, various animal models have been used for several decades to identify potential therapeutic approaches. These models can be divided into those measuring smooth muscle tone and those measuring cellular proliferation. Animal models have played an important role in the development of the two drug classes currently approved for the treatment of BPH: the α-adrenoceptor antagonists and the steroid 5-α-reductase inhibitors. However, models measuring prostatic tone have not been particularly useful in the identification of new α-adrenoceptor antagonists having advantages over currently available drugs, and it is not certain that reduction of prostatic smooth muscle tone is responsible for the relief of BPH symptoms. A further limitation with BPH models is that prostatic hyperplasia similar to the human condition does not occur spontaneously or cannot be induced in any suitable animal species. The identification of a more useful BPH model is focused on cellular mechanisms of prostatic growth, looking similarities between humans and experimental animals.