Effect of Median Lobe Enlargement on Early Prostatic Artery Embolization Outcomes

A correlation study between prostate necrosis rate calculated by 3D Slicer software and clinical efficacy of prostatic artery embolization, along with an analysis of predictors of clinical success after prostatic artery embolization

PURPOSE

To analyze the correlation between the prostate necrosis rate at 1-month after prostatic artery embolization (PAE) and the clinical efficacy at 1-year after PAE, and to explore potential predictors of clinical success after PAE for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH).

METHODS

The prostate magnetic resonance imaging data at 1-month after PAE were imported into 3D Slicer software for calculating the prostate necrosis rate and thus analyzing the relationship between the prostate necrosis rate at 1-month after PAE and the efficacy score ratio at 1-year after PAE. The 151 patients with PAE technical success were divided into a clinical success group (n = 126) and a clinical failure group (n = 25). Independent predictors of clinical success after PAE were analyzed by multifactorial logistic regression, and the predictive performance of each factor was evaluated by applying the receiver operating characteristic curve and the area under the curve (AUC).

RESULTS

There was a linear negative correlation between the prostate necrosis rate at 1-month after PAE and the efficacy score ratio at 1-year after surgery (P < 0.001). In the clinical success group, both the initial prostate volume (PV) and the prostate necrosis rate at 1-month after PAE were significantly higher than in the clinical failure group (P < 0.001), and acute urinary retention (AUR) and adenomatous-dominant BPH were also associated with clinical success (P < 0.05). Multifactorial logistic regression analysis revealed that larger initial PV, a higher prostate necrosis rate at 1-month after surgery, and AUR were independent predictors of clinical success after PAE. The AUC values for these three indicators and their combination were 0.720, 0.928, 0.599, and 0.951, respectively, in which the prostate necrosis rate at 1-month after PAE demonstrating a high predictive value.

CONCLUSION

The higher the prostate necrosis rate at 1-month after PAE, the better the clinical efficacy at 1-year after PAE is likely to be, and the prostate necrosis rate at 1-month after PAE is expected to become a predictor of clinical success after PAE.

The prostatic middle lobe: clinical significance, presentation and management

The role of the prostatic middle lobe in the presentation and management of benign prostatic hyperplasia (BPH) is under-appreciated. Middle lobe enlargement is associated with intravesical prostatic protrusion (IPP), which causes a unique type of bladder outlet obstruction (BOO) via a 'ball-valve' mechanism. IPP is a reliable predictor of BOO and the strongest independent factor for failure of medical therapy necessitating conversion to surgical intervention. Men with middle lobe enlargement tend to exhibit mixed symptoms of both the storage and the voiding types, but symptomatology will vary depending on the degree of IPP present. Initial assessments such as uroflowmetry and post-void residual volumes are inadequate to detect IPP and could confound the clinical picture. Radiological evaluation of prostate morphology is key to assessment as it provides important prognostic information and can help with operative planning. Treatment strategies employed for BPH should consider the shape and morphology of prostate adenomata, specifically the presence of middle lobe enlargement and the degree of associated IPP.

Influence of benign prostatic hyperplasia patterns detected with MRI on the clinical outcome after prostatic artery embolization

BACKGROUND

To investigate the influence of benign prostatic hyperplasia (BPH) patterns detected with MRI on clinical outcomes after prostatic artery embolization (PAE).

MATERIALS & METHODS

This retrospective study included 71 consecutive patients with lower urinary tract symptoms (LUTS), who underwent magnetic resonance imaging (MRI) of the prostate followed by PAE at a single centre. MRI scans were evaluated and BPH patterns were determined according to Wasserman type and a modified BPH classification. Additionally, scans were evaluated regarding the presence of adenomatous-dominant benign prostatic hyperplasia (AdBPH). LUTS were assessed using the International Prostate Symptom Score (IPSS) and urinary flow rate (Qmax). Follow-up examination included MRI and clinical outcome.

RESULTS

For clinical outcome at follow-up, IPSS showed median reduction of 54% (IQR 41-75%) and Qmax improved by 4.1 ml/s. We noted significant reduction in volume, intraprostatic protrusion, and prostatic urethral angle in our collective (p < 0.01). Median volume reduction was 25% (IQR 15%-34%). Bilateral embolization was a significant predictor for volume reduction at follow-up. Multiple linear regression analysis showed significant effect of high initial volume on reduction in IPSS after treatment (p < 0.01). Presence of AdBPH was significantly associated with both, volume loss and clinical improvement in terms of IPSS reduction (p < 0.01). Neither BPH pattern based on the Wassermann type nor modified BPH classification were significantly related with postinterventional IPSS and volume loss.

CONCLUSIONS

Men benefit from PAE regardless the macroscopic BPH MRI pattern. Preinterventional prostate volume and presence of AdBPH on MRI should be considered for outcome prognosis after PAE.

Updates on Preprocedural Evaluation and Patient Selection for Prostatic Artery Embolization

Prostatic artery embolization (PAE) is a safe and effective treatment for benign prostatic hyperplasia. Patient evaluation is a critical and important part of this growing practice. History taking should include symptoms score evaluations for lower urinary tract symptoms, erectile function, and prostatitis symptoms score. The objective evaluations commonly include measurement of prostate specific antigen, postvoid residual volume, and uroflowmetry as well as urodynamic studies in selective patients. Imaging evaluation may include computed tomography angiography or magnetic resonance angiography, elucidating prostate volume, prostate gland morphology, vasculature, and prostate cancer. With evolving knowledge on PAE, we aim to discuss patient evaluation and selection based on updated evidence and discuss specific scenarios.

Prostatic Artery Embolization: Indications, Preparation, Techniques, Imaging Evaluation, Reporting, and Complications

Benign prostatic hyperplasia (BPH) is a noncancerous growth of the transitional zone of the prostate, which surrounds the prostatic urethra. Consequently, it can cause lower urinary tract symptoms (LUTS) and bladder outlet obstruction symptoms that may substantially reduce a patient's quality of life. Several treatments are available for BPH, including medications such as α-blockers and 5α-reductase inhibitors and surgical options including transurethral resection of the prostate and prostatectomy. Recently, prostatic artery embolization (PAE) has emerged as a minimally invasive treatment option for selected men with BPH and moderate to severe LUTS. Adequate pre- and postprocedural evaluations with clinical examinations and questionnaires, laboratory tests, and urodynamic and imaging examinations (particularly US, MRI, and CT) are of key importance to achieve successful treatment. Considering that the use of PAE has been increasing in tertiary hospital facilities, radiologists and interventional radiologists should be aware of the main technical concepts of PAE and the key features to address in imaging reports in pre- and postprocedural settings. An invited commentary by Lopera is available online. Online supplemental material is available for this article. ^©RSNA, 2021.

Prostate Artery Embolization Using N-Butyl Cyanoacrylate Glue for Urinary Tract Symptoms Due to Benign Prostatic Hyperplasia: A Valid Alternative to Microparticles?

Our goal was to evaluate the feasibility, safety, and short-term outcomes of prostate artery embolization (PAE) with N-butyl cyanoacrylate (NBCA) glue as the only embolic agent in patients with benign prostatic hyperplasia (BPH)-related lower urinary tract symptoms (LUTSs). A two-center retrospective study of 50 patients (mean age, 67.6 ± 7.4 years; range, 54-85 years) treated with NBCA between 2017 and 2020 was conducted. PAE was performed using a mixture of Glubran 2 glue and Lipiodol in a 1:8 ratio, under local anesthesia, on an outpatient basis, after cone-beam computed tomography vascular mapping. Mean total injected NBCA/Lipiodol volume was 0.9 ± 0.3 mL, total injection time was 21.9 ± 7.8 s, and total radiation dose was 18,458 ± 16,397 mGy·cm. Statistically significant improvements over time occurred for the International Prostate Symptoms Score (9.9 ± 6.8 versus 20.5 ± 6.7, p = 0.0001), quality-of-life score (2.2 ± 1.5 versus 4.9 ± 1.0, p = 0.0001), prostate-specific antigen level (4.6 ± 3.0 versus 6.4 ± 3.7, p = 0.0001), and prostate volume (77.3 ± 30.5 versus 98.3 ± 40.2, p = 0.0001) at a median of 3 months versus baseline. Minor adverse events developed in 11/50 (22%) patients, but no major complications occurred. The International Index of Erectile Function did not change significantly. PAE with NBCA is feasible, safe, fast, and effective for patients with BPH-related LUTSs. Prospective comparative studies with longer follow-ups are warranted.

Association between intravesical prostatic protrusion and clinical outcomes in prostatic artery embolization

PURPOSE

To evaluate the influence of intravesical prostatic protrusion (IPP) on clinical outcomes after prostatic artery embolization (PAE) in patients with lower urinary tract symptoms due to benign prostatic hyperplasia.

MATERIALS AND METHODS

All consecutive patients who underwent PAE for lower urinary tract symptoms between January 2017 and January 2019 were retrospectively included. IPP was evaluated on pre-treatment magnetic resonance imaging examination and symptoms were assessed at follow-up consultations using the international prostate symptom score (IPSS) and quality of life (QOL) questionnaire. IPPs were classified as grade 1 (<5mm), grade 2 (5-10mm), or grade 3 (>10mm).

RESULTS

A total of 160 consecutive men (mean age 65±7.8 [SD] years; range: 45-89 years), underwent PAE. The mean IPSS was 21±7.3 (SD) (range: 5-35) and prostate volume 87±38 (SD) mL (range: 30-200mL). The IPP grade was 1 for 28 (28/160; 18%), 2 for 52 (52/160; 33%), and 3 for 80 (80/160; 50%) patients. There were no significant differences in IPSS at baseline between the three IPP grades. Patients with severe (grade 3) IPP had a significantly higher reduction in IPSS than those with non-severe IPP (grade 1 or 2), with estimated mean reductions of 12±2.5 (SD) (range: -4-28) and 8.3±1.9 (SD) (range: -8-21) (P=0.02), respectively. The mean reduction in the QOL score was 3.0 for grade 3 and 2.0 for grade 1 or 2 IPP (P=0.02).

CONCLUSIONS

The degree of IPP does not limit the efficacy of PAE in patients with lower urinary tract symptoms due to benign prostatic hyperplasia.

Intravesical Prostatic Protrusion Does Not Influence the Efficacy of Prostatic Artery Embolization

PURPOSE

To compare the outcomes of prostatic artery embolization (PAE) in patients with different intravesical prostatic protrusion (IPP) grades.

MATERIALS AND METHODS

This retrospective single-center study included 128 patients (aged 50-86 years) who underwent PAE from 2013 to 2017. IPP grades were classified as follows: grade I (<10 mm), grade II (10-19 mm), and grade III (≥20 mm). Nineteen patients (14.8%) had grade I [mean IPP 7.8 mm, prostatic volume (PV) 64.1 cm³], 77 (60.2%) had grade II (mean IPP 14.9 mm, PV 87.0 cm³), and 32 (25%) had grade III (mean IPP 26.2 mm, PV 132.6 cm³), P < .01. The outcomes, including PV, international prostate symptom score (IPSS), and quality of life (QoL), were compared between the IPP grades at the 12-month follow-up. Clinical failure was defined as IPSS >7 or QoL >2.

RESULTS

IPP decreased (I: -8.2%, II: -27.3%, and III: -38.7%, P = .01), and all other endpoints improved (P < .01). Adjusted covariance analysis, considering baseline PV as a confounding factor, showed no correlation between the 12-month outcomes and baseline IPP. Clinical failure was observed in 17/128 patients (13.3%) and was similar in prevalence among the IPP groups (P = .20). Minor complications occurred in 43 patients (33.6%) and major in 3 (2.3%). There were statistical differences in the complications between IPP grades II and III (P < .01).

CONCLUSIONS

PAE was similarly effective in all the IPP grades at the 12-month follow-up, and there was no difference in the clinical failure between the groups. Complications in IPP grade III were more frequent than those in IPP grade II.

[Sophisticated surgical management of distinctive patients with benign prostatic hyperplasia (BPH)]

Herein we describe four clinical scenarios. For the standard patient (prostate volume 30-80 ml, life expectancy >10 years) transurethral resection of the prostate (TURP) remains the standard of care, while endoscopic enucleation is a valuable alternative. Patients with a relevant middle lobe profit most from TURP, endourological enucleation procedures, or laser vaporization. In the case of the absence or a moderate-sized middle lobe and the absence of severe bladder outlet obstruction (BOO), minimally invasive procedures such as Rezūm®, UroLift® or prostate artery embolization (PAE) can be offered. Patients have to be informed that long-term data on this specific indication are lacking. Particularly younger men requiring BPH surgery are interested in preserving ejaculatory function. In the presence of severe BOO, ejaculatory-protective TURP or endoscopic enucleation by preserving the pericollicular region or aquablation are the methods of choice providing an antegrade ejaculation in 60-90% of cases. Rezūm®, AquaBeam®, and UroLift® enable preservation of ejaculation in almost 100%; data on PAE with this respect are more controversial. For patients with a small prostate and significant post void residual, a thorough preoperative work-up, including urodynamics and bladder/detrusor wall thickness measurement, is of great importance. Desobstructive surgery provides satisfactory short- and midterm outcome, yet the long-term outcome is disappointing and remains to be determined in greater detail. The broad spectrum of therapeutic options enables today an individualized minimally invasive or surgical management of BPH considering patient wishes, anatomical factors or urodynamic factors. The time of a "one therapy fits all" strategy is definitely history.