Embolization Therapy: Principles and Clinical Applications, 1 Ed.

Benign Prostatic Hyperplasia

Francisco Cesar Carnevale • Airton Mota Moreira

BACKGROUND

Benign Prostatic Hyperplasia

Symptomatic benign prostatic hyperplasia (BPH) typically occurs at the beginning of the sixth decade, with more than 40% of men aged 60 years and older presenting with clinical manifestations. As the world’s population ages, the prevalence of BPH is expected to increase, calling for a therapy that minimizes the risk for adverse outcomes.13

The standard management of BPH is based on the overall health of the patient, on the severity of the lower urinary tract symptoms (LUTS), and on quality-of-life considerations. Voiding difficulties attributable to BPH can be quantified with the American Urological Association Symptom Index (AUA-SI) score or International Prostate Symptom Score (IPSS). Various medications can decrease the severity of voiding symptoms secondary to BPH. Impotence, decreased libido, and ejaculatory disorders are known side effects of these medications. Watchful waiting is a management strategy in which the patient is monitored by his physician but receives no active intervention for BPH; this is the preferred management strategy for patients with mild symptoms.4

The American Urological Association (AUA) guidelines indicate that patients with mild LUTS secondary to BPH (AUA-SI score <8) and patients with moderate or severe symptoms (AUA-SI score ≥8) who are not bothered by their LUTS should be managed using a strategy of watchful waiting. If the patient elects interventional therapy and there is sufficient evidence of obstruction, the patient and urologist should discuss the benefits and risks of the various available interventions.4

Many advances have been made in the medications and minimally invasive procedures used to treat BPH since the 1990s. Despite these advances, transurethral resection of the prostate (TURP), which was developed in the 1920s, remains the treatment of choice when medical management fails. TURP is still the gold standard of interventional treatment for small prostate glands (smaller than 80 to 100 g) and is performed under direct endoscopic visualization with an electrocautery tool to remove prostatic tissue. Although considered a safe technique with a mortality rate below 0.25%, it is not without adverse events. The most frequent complications are ejaculatory disorders (up to 50%), early urinary incontinence (30% to 40%), acute urinary retention caused by blood clots (2% to 5%), sexual impotence (up to 5%), and the need for blood transfusions (0.4% to 7%). Patients who have undergone TURP require surgical retreatment for LUTS symptoms in 3% to 14.5% of cases.46

Open prostatectomy involves the surgical removal (enucleation) of the inner portion of the prostate gland via a suprapubic or retropubic incision in the lower abdomen. Open prostatectomy is typically performed on patients with prostate volumes greater than 80 to 100 mL with a higher risk of blood loss and transfusion and a longer hospital stay than TURP. Open prostatectomies may only be needed for men with very enlarged prostate glands (it may be more effective than TURP in relieving the blockage of urine flow) and for men with bladder diverticula (pockets) or stones.7,8

The high prevalence rate of BPH has a tremendous impact on the health and quality of life of men. Increasingly, BPH therapy trends are moving away from the standard operations toward less invasive pharmacologic options and minimally invasive procedures provided in an outpatient setting. Minimally invasive techniques have been developed as alternative treatments for LUTS, such as transurethral microwave thermotherapy and laser ablations, but they involve introducing energy into the gland and all require access through the urethra. Nevertheless, complications from these procedures are similar to TURP.911 Prostatic artery embolization (PAE) has emerged as a new minimally invasive alternative of treatment for symptomatic patients with enlarged prostates due to BPH.1214

Prostatic Artery Embolization

The first animal study to evaluate the feasibility and safety of PAE was conducted in a canine model and demonstrated the promising potential of PAE to decrease prostate volume and urethral stenosis due to BPH. The success rate for identification and selective catheterization of the prostatic arteries was 100%. Initial computed tomography (CT) showed good distribution of particles in the embolized prostate with no evidence of nontarget embolization. CT after 1 month showed decreased perfusion, cavitary necrosis, and 40% prostate volume reduction. There was excellent radiologic–pathologic correlation.15Subsequently, the technical feasibility and safety of prostate embolization was evaluated in pigs16 and dogs17 with prostate volume reduction and without sexual or erectile complications.

Embolization of the prostatic arteries has been used for many years to control serious bleeding after biopsy or prostatectomy.1820 The first published case in which it was recognized that PAE could have a therapeutic effect on BPH was in 2000 by DeMeritt and colleagues.12 The first intentional treatment of BPH with PAE in humans was done by Carnevale et al.13 in June 2008 and was published in 2010. In this report, PAE was performed in two patients with acute urinary retention due to BPH who were refractory to treatment with selective α-blockers, were being managed with long-term indwelling catheters, and were waiting for surgery. The same investigators published midterm follow-up data for these two patients in 2011, confirming the efficacy of the procedure.14

TECHNICAL DETAILS

Preprocedure Imaging Evaluation

Ultrasound (US) is the most common method to evaluate the prostate and bladder. The prostate volume is measured by standard transabdominal view or transrectal US if prostate biopsy is necessary. Prostate vascularization can be visualized using Doppler, and transabdominal US can measure the postvoid residual urine volume. Bladder evaluation comprises measurement of wall thickness and an assessment of characteristics such as the presence of diverticula, trabeculations, and other possible findings such as polyps, calculus, or other lesions. Protrusion of the median lobe is measured using the prostate protrusion index and prostate volume is measured using three incidences.

Magnetic resonance imaging (MRI) of the prostate is very useful, giving more details than US mainly related to the central gland and peripheral zone. Prostate measurements (cephalocaudal, transverse, and anteroposterior) are obtained and volume is calculated by the ellipse formula. It is the best method to evaluate patients before and after PAE. CT with contrast can be useful to identify the characteristics of the main artery supplying the prostate and any arterial atherosclerotic lesion or obstruction that could contraindicate or make the intervention more difficult.21

Embolization Technique

BPH treatment with PAE requires a well-trained interventional radiologist because of the complex prostatic vascular anatomy and the potential for complications in elderly patients with atherosclerosis, very small prostatic arteries, and comorbidities. Intervention can be performed under local anesthesia on an outpatient basis. A 400 mg intravenous dose of ciprofloxacin is given before the procedure followed by 500 mg orally twice a day for 7 days after PAE. Patients also receive nonopioid analgesics and nonsteroidal anti-inflammatory medications after embolization. Intervention can be performed via a unilateral common femoral arterial approach. Femoral pulses should be examined before choosing which side will be used for access. To provide good orientation to the prostate site and related structures in the pelvis, we recommend that a Foley catheter be placed into the bladder and that the balloon be filled with a mixture of 30% iodinated contrast medium and 70% normal saline (Fig. 51.1). This is used during the procedure to give both a better image and understanding of the prostate, the internal iliac artery branches, and related structures (Fig. 51.2) to help avoid nontarget embolization complications. It is an excellent landmark during the procedure and we have not observed any severe complications due to its use. It can also be a reference if using cone-beam CT and can help eliminate the patient’s need to strain to void after the procedure.

Knowing the vascular anatomy of the prostate is essential for the successful performance of this procedure. Due to many arterial anastomoses and branches to related pelvic structures, various nomenclatures have been used for the arteries supplying the prostate. Names such as the inferior vesical artery (IVA), prostatovesical artery, vesicoprostatic artery, and prostatic artery have been used.21,22 According to the urologists’ nomenclature, the IVA has traditionally been considered the main prostatic artery. It usually arises as the second or third branch of the anterior trunk of the internal iliac artery. Generally, one main prostatic artery is found on each side in that position, but the main prostatic artery or additional prostatic branches arising from the superior vesical, internal pudendal, obturator, and middle rectal arteries can also be found in some patients.23

Initial pelvic angiography is performed (20 mL; 10 mL per second) to evaluate the iliac vessels and the prostate arteries during arterial and late phases (Fig. 51.3). After crossing the aortic bifurcation, selective digital subtraction arteriogram of the internal iliac artery is performed with a 5-Fr vertebral or Cobra 2 (Merit Medical System, Inc., South Jordan, UT) catheter (12 mL; 4 mL per second) to better assess the blood supply to the prostate. The 5-Fr diagnostic catheter should be placed at the common internal iliac trunk to avoid missing any branch arising from the anterior and posterior division. It is not uncommon to find an IVA arising as a common pedicle with the superior vesical artery (also called umbilical artery) as the first branch of the anterior division. The 5-Fr Roberts Uterine Catheter (RUC; Cook Medical, Inc., Bloomington, Indiana) can be used but, due to its long curve, we have observed less torquability and pushability with the microwire when using the coaxial system. For the ipsilateral internal iliac artery catheterization, a Simmons 1 or 2 catheter (Merit Medical System, Inc., South Jordan, UT) can be used, but we prefer to work with the same vertebral catheter making a Waltman loop because, if necessary, it can be used as a regular vertebral catheter to get more torquability and pushability.

The best projection in which to identify the IVA and all possible accessory branches to the prostate is the 25- to 55-degree ipsilateral oblique view. A caudal view (10 to 20 degrees) can help to identify some bladder branches. This perspective, with the help of the Foley balloon filled with dilute contrast, gives a better understanding of all five anterior branches and gives orientation to the prostatic arteries. After performing the internal iliac arteriogram, attention should be given to the arteries feeding the area immediately below the balloon. In this view, the branches of the anterior division will be straightened and the prostate branches and the rectal branches stay in the anterior and posterior position, respectively. The PROVISO acronym (internal Pudendal, middle Rectal, Obturator, Vesical Inferior, and Superior under Oblique view) is a very useful trick to remember the names of the arteries during arteriography (Fig. 51.4).

Catheterization of the IVA is performed using the same ipsilateral oblique perspective under the road map technique. With the microcatheter placed into the IVA, arteriography is performed by manually injecting 2 to 3 mL of contrast medium. The ipsilateral oblique view is useful for identifying any collateral branches, the small group of arteries feeding the urethra, the central gland, and the capsular arteries (Fig. 51.5). The posteroanterior view is more anatomical and helps to identify some contralateral prostate lobe branches and the parenchymal phase (Fig. 51.6). After checking both views, the microcatheter should be advanced well into the IVA at the ostium of the prostatic arteries and embolization is performed under direct fluoroscopic visualization. Care must be taken with the position of the tip of the microcatheter to avoid spasm or dissection of the tiny intraprostatic branches. Concerning the position of the microcatheter for embolization, we define it as distal embolization when the microcatheter tip is placed at the origin of the intraprostatic branches (Fig. 51.7), compared to proximal embolization when the microcatheter tip is at the origin or very proximal portion of the IVA. In this proximal position, there is a higher risk of nontarget embolization, especially to the rectum or bladder. Diagnostic arteriography performed in this position is very important to identify the prostatic branches, to avoid nontarget embolization, and to occlude any collaterals and shunts, if necessary. Cone-beam CT can be very useful to understand the pelvic anatomy and identify the bladder and rectal branches, thus avoiding complications.24

Atherosclerotic disease; thin, tortuous vessels; and lack of knowledge regarding the possible prostatic arterial vessels and sources for nontarget embolization can contribute to increased procedure time. The use of small-diameter hydrophilic microcatheters is mandatory and can facilitate the catheterization of the prostatic arteries, decreasing the procedure and fluoroscopy times. We have used microcatheters smaller than 2.4-Fr in combination with 0.014- or 0.016-in shapable hydrophilic microwires without continuous flushing. Road mapping is used for the catheterization of prostatic arteries. When vasospasm occurs, nitroglycerin can be used but has limited usefulness due to severe atherosclerosis in these arteries. Sometimes, proceeding to the contralateral side may be a good strategy while waiting for the relief of vasospasm.

Varying particulate embolic agents can be used. We have experienced 300- to 500-µm and 100- to 300-µm Embosphere Microspheres (BioSphere Medical, Inc., Roissy-en-France, France) with excellent technical and clinical results after more than 5 years of follow-up in the initial patients. At the end of the embolization, a venous phase blush can be observed, and we consider total stasis as the end point (Fig. 51.8). In general, one 2-mL syringe of microspheres has been enough for bilateral PAE. If any accessory prostatic branch is not embolized, poor long-term clinical results may occur, including reduced prostate shrinkage and return of LUTS. Embolization is performed on the contralateral side using the same technique. Bilateral inferior vesical arteries and any other prostatic branches should be embolized to achieve optimal prostate ischemia, resulting in volume reduction for better long-term results.

Postprocedure Management

After the procedure, patients remain supine for 4 to 6 hours without moving the punctured leg to avoid bleeding complications from disrupting the vascular site. If a vascular closure device is used, bed rest can be reduced. During this resting time after PAE, the use of the Foley balloon is very important because patients can void normally without straining, which reduces the risk of puncture site complications. The Foley catheter is removed after 2 to 4 hours in patients without acute urinary retention and the patient can be discharged home. Patients with acute urinary retention are instructed to return 1 week later for removal of the Foley catheter to attempt spontaneous voiding. If the Foley catheter cannot be removed, another attempt is tried every week. We consider it a clinical failure if the patient cannot urinate spontaneously after 1 month.

PAE is not a painful procedure, and patients typically receive oral hydration, nonopioid pain relievers, antibiotics, and nonsteroidal anti-inflammatory drugs, if needed. Proton pump inhibitors for gastric and duodenal protection are indicated as well. Dysuria and frequent urination are the most common symptoms seen immediately after PAE and usually last for 3 to 5 days. Patients receiving oral medication to control LUTS continue this medication for 1 week after PAE. Telephone follow-up is recommended during the first week after the procedure. Patients return for office follow-up 1 month after the procedure.

Postprocedure Imaging

Both US and MRI are useful methods of measurements before and after PAE. Patients have demonstrated an average of greater than 30% to 40% reduction in the prostate volume after PAE as measured by US and MRI during follow-up. However, we have observed greater variations in the US results and prefer MRI for evaluating and following patients before and after this procedure. Volume decrease is most evident during the first 3 months after embolization and is sustained over time. We have seen a higher volume reduction rate (40%) in patients with large prostate glands (>90 g) compared to small prostate glands (30%). Progressive volume reduction of the prostate occurs after embolization and infarcts have been seen in 70% to 80% of the patients, exclusively in the prostatic central zone. On MRI, this is characterized by hyperintensity on T1 weighted images and predominant hypointensity on T2 weighted images; these areas demonstrate a progressive size reduction over time (Fig. 51.9). Prostate volume reduction has been observed in patients with and without infarcts, but the presence of infarcts is associated with a greater degree of volume reduction after embolization. No significant changes have been found in the prostatic peripheral zone.23

After the PAE procedure, we suggest urodynamic studies every year; IPSS, International Index of Erectile Function questionnaires, quality-of-life questionnaires, prostate-specific antigen test, US, and MRI should be performed to assess effectiveness at 3 and 12 months and every year thereafter. Urodynamic findings after PAE have demonstrated that maximum bladder capacity and maximum flow rates improved significantly. Bladder tone also improves and patients obtained better maximum flow rate (Qmax) with reduction of the detrusor pressure (Pdet) and of the postvoid residual (PVR) urine volume. This means that patients void better without straining and with less residual urine in the bladder after voiding.25,26

OUTCOMES

The aim of PAE is to produce as much gland ischemia as possible because we have observed that better long-term clinical and urodynamic results are correlated with prostate ischemia.23 Technical success is defined as the successful catheterization and embolization of the right and left main prostatic arteries. Clinical success is defined by multiple criteria including removal of the Foley catheter in patients with acute urinary retention, improvement in LUTS and quality of life, and no sexual disorders or serious adverse events from the procedure.

Since the initial case reports on PAE were published, there have been several other case series that have confirmed the technical and clinical success of this procedure. Pisco et al.27 reported on 15 patients undergoing PAE for symptomatic BPH. In this series, the technical success rate for bilateral PAE was 86.7%, and it was 93.3% for unilateral or bilateral PAE with failures due to tortuosity and atherosclerotic change of the iliac arteries. After a mean follow-up of 7.9 months, improvements were noted in LUTS, quality of life, erectile function, and peak urinary flow. The clinical failure rate was 28.6%. On MRI, there was a mean prostate volume decrease of 28.9 mL. Bladder ischemia requiring surgical repair was the only complication reported in this series. Pisco et al.28 followed this study with another report on 89 consecutive patients. In this study, 79/89 underwent a bilateral PAE (88.8%) and 7/89 patients underwent a unilateral PAE (7.9%), for a 96.7% technical success rate for unilateral or bilateral PAE. Ninety-one percent of the patients treated were discharged from the hospital 6 to 8 hours after the procedure, whereas the remaining patients were discharged the following morning. At 3 months, the clinical failure rate was 18.3%. The remaining patients reported improvements in LUTS and quality of life. Minor complications included urinary tract infections (19%), transient hematuria (10%), and transient hemospermia (7%). No other major complications were reported.

Bagla et al.29 has reported early results from a U.S. trial. In this study, the technical success rate was 90%, with 18/20 undergoing bilateral PAE; 1 patient underwent a unilateral PAE. These patients demonstrated improvements in LUTS (AUA score improvement at 1, 3, and 6 months of 10.8, 12.1, and 9.8 points, respectively), quality of life, and sexual function. There was a mean prostate volume decrease of 18%. No minor or major complications were reported in this series.

Our group followed up our original case reports by publishing our experience with PAE in 11 patients with acute urinary retention caused by BPH.25,26 Bilateral PAE was performed in 75% of procedures, with unilateral PAE performed in the remaining patients. Factors precluding performance of bilateral PAE included an IVA dissection, microcatheter tracking failure, and nonvisualization of the prostatic arteries. Ten of 11 patients were able to void spontaneously without catheterization after PAE. Improvements were also noted in quality of life and erectile function. The mean prostate volume reduction was 31.7% on MRI.

We continue to observe significant improvements in quality of life based on patient questionnaires; objective urodynamic data corroborate these self-reported assessments. This improvement appears to be sustained over time. With over 5 years of follow-up in some patients, we have observed initial clinical failure in only 3% and recurrence of LUTS in 8% after PAE in 100 treated patients. It is important to note that good clinical outcomes and improvements in urodynamic data, even in patients who underwent unilateral PAE, suggest that factors from PAE other than prostate reduction, such as prostate tissue change, can contribute to improving symptoms and better voiding. This suggests that some patients can benefit even when only unilateral embolization is possible.2430

POTENTIAL COMPLICATIONS

The major complication rate after PAE is very low. As described earlier, Pisco et al.27 reported one patient who required surgery for limited bladder ischemia. We have not experienced major complications in our series of patients. However, we have noted that there are expected symptoms that should constitute a postembolization syndrome (or post-PAE syndrome). These include nausea, vomiting, fever in the absence of infection, urethral burning, periprostatic or pelvic pain, and very small amounts of blood in urine and/or mixed in the stool with mucus for 2 to 3 days. Because this post-PAE syndrome is mild and the embolization is performed under local anesthesia, patients can be discharged on the same day of the procedure. In our experience, the presence of a small amount of blood in the urine or mixed in the stool (<10%) is likely to be the result of arterial communications between the prostate, bladder, and rectum. Further evaluation of one patient experiencing blood mixed in the stool demonstrated ischemic rectitis with rectal ulcers identified at day 4 by colonoscopy, which disappeared by day 16 without treatment.31Although no patient with these symptoms have required treatment, this does highlight the risk of nontarget embolization in association with this procedure.

TIPS AND TRICKS

• A multidisciplinary approach with urologists, diagnostic radiologists, and interventional radiologists is essential. Interventional radiologists should follow all patients after the procedure to document symptomatic improvement after PAE.

• Gain a complete understanding of BPH and typical presenting symptoms before engaging in PAE.

• Preembolization evaluation with MRI and urodynamic studies should be used for patient selection.

• Use the Foley balloon technique as a landmark during PAE and for patient comfort.

• Use a microcatheter in every case for distal intraprostatic artery positioning and prostate embolization.

• Embolize as much prostatic tissue as possible during PAE procedures.

• Try to perform bilateral PAE for better long-term clinical results.

• Remove the Foley balloon before patient discharge.

• Perform the intervention in an outpatient basis.

• Follow patients very closely during the first week after PAE; patients may often feel worse during this time but will then notice improvement in their symptoms.

• Stop BPH medication 1 week after PAE.

• Use MRI for follow-up.

CONCLUSION

BPH can be treated safely by PAE with low rates of side effects and can reduce prostate volume by an average of more than 30%. Overall clinical improvement in LUTS assessed by IPSS, quality of life, and urodynamic data is achieved without urinary incontinence, ejaculatory disorders, or erectile dysfunction. Nevertheless, a multidisciplinary approach with urologists, diagnostic radiologists, and interventional radiologists is essential.

REFERENCES

 1. Wei JT, Calhoun E, Jacobsen SJ. Urologic disease in America project: benign prostatic hyperplasia. J Urol. 2005;173:1256–1261.

 2. Emberton M, Andriole GL, de la Rosette J, et al. Benign prostatic hyperplasia. A progressive disease of aging men. Urology. 2003;61:267–273.

 3. Ziada A, Rosenblum M, Crawford ED. Benign prostatic hyperplasia: an overview. Urology. 1999;53:1–6.

 4. AUA Practice Guidelines Committee. AUA guideline on management of benign prostatic hyperplasia (2003). Chapter 1: diagnosis and treatment recommendations. J Urol. 2003;170:530–547.

 5. Wasson J, Reda D, Bruskewitz R, et al. A comparison of transurethral surgery with watchful waiting for moderate symptoms of benign prostatic hyperplasia. The Veterans Affairs Cooperative Study Group on Transurethral Resection of the Prostate. N Engl J Med. 1995;332:75.

 6. Rassweiler J, Teber D, Kuntz R, et al. Complications of transurethral resection of the prostate (TURP)—incidence, management, and prevention. Eur Urol. 2006;50:969–979.

 7. Dall’Oglio M, Srougi M, Antunes A, et al. An improved technique for controlling bleeding during simple retropubic prostatectomy: a randomized controlled study. BJU Int. 2006;98:384.

 8. Gacci M, Bartoletti R, Figlioli S, et al. Urinary symptoms, quality of life and sexual function in patients with benign prostatic hypertrophy before and after prostatectomy: a prospective study. BJU Int. 2003;91:196–200.

 9. Rubenstein J, McVary KT. Transurethral microwave thermotherapy of the prostate (TUMT). http://www.usrf.org/news/TUMT/TUMThistory.htm. Accessed September 7, 2014.

10. Muruve NA, Steinbecker K. Transurethral needle ablation of the prostate (TUNA). http://emedicine.medscape.com/article/449477-overview. Accessed September 7, 2014.

11. Wheelahan J, Scott NA, Cartmill R, et al. Minimally invasive laser techniques for prostatectomy: a systematic review. BJU Int. 2000;86:805–815

12. DeMeritt JS, Elmasri FF, Esposito MP, et al. Relief of benign prostatic hyperplasia-related bladder outlet obstruction after transarterial polyvinyl alcohol prostate embolization. J Vasc Interv Radiol. 2000;11:767–700.

13. Carnevale FC, Antunes AA, da Motta Leal Filho JM, et al. Prostatic artery embolization as a primary treatment for benign prostatic hyperplasia: preliminary results in two patients. Cardiovasc Intervent Radiol. 2010;33:355–361.

14. Carnevale FC, da Motta-Leal-Filho JM, Antunes AA, et al. Midterm follow-up after prostate embolization in two patients with benign prostatic hyperplasia. Cardiovasc Intervent Radiol. 2011;34:1330–1333.

15. Faintuch S, Mostafa EM, Carnevale FC, et al. Prostatic artery embolization as a primary treatment for benign prostatic hyperplasia in a canine model. J Vasc Interv Radiol. 2008;19:S7.

16. Sun F, Sánchez FM, Crisostomo V, et al. Benign prostatic hyperplasia: transcatheter arterial embolization as potential treatment—preliminary study in pigs. Radiology. 2008;246:783–789.

17. Jeon GS, Won JH, Lee BM, et al. The effect of transarterial prostate embolization in hormone-induced benign prostatic hyperplasia in dogs: a pilot study. J Vasc Interv Radiol. 2009;20:384–390.

18. Appleton DS, Sibley GN, Doyle PT. Internal iliac artery embolisation for the control of severe bladder and prostate haemorrhage. Br J Urol. 1988;61:45–47.

19. Michel F, Dubruille T, Cercueil JP. Arterial embolization for massive hematuria following transurethral prostatectomy. J Urol. 2002;168:2550–2551.

20. Rastinehad AR, Caplin DM, Ost MC, et al. Selective arterial prostatic embolization (SAPE) for refractory hematuria of prostatic origin. Urology. 2008;71:181–118.

21. Bilhim T, Pisco JM, Furtado A, et al. Prostatic arterial supply: demonstration by multirow detector angio CT and catheter angiography. Eur Radiol. 2011;21:1119–1126.

22. Clegg EJ. The arterial supply of the human prostate and seminal vesicles. J Anat. 1955;89:209–216.

23. Carnevale FC, Antunes AA. Prostatic artery embolization for enlarged prostates due to benign prostate hyperplasia: how I do it. Cardiovasc Intervent Radiol. 2013;36:1452–1463.

24. Bagla S, Rholl KS, Sterling KM, et al. Utility of cone-beam CT imaging in prostatic artery embolization. J Vasc Interv Radiol. 2013;24:1603–1607.

25. Carnevale FC, da Motta-Leal-Filho JM, Antunes AA, et al. Quality of life and clinical symptoms improvement support prostatic artery embolization for patients with acute urinary retention due to benign prostatic hyperplasia. J Vasc Interv Radiol. 2013;24:535–542.

26. Antunes AA, Carnevale FC, da Motta-Leal-Filho JM, et al. 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. Cardiovasc Intervent Radiol. 2013;36:978–986.

27. Pisco JM, Pinheiro LC, Bilhim T, et al. Prostatic arterial embolization to treat benign prostatic hyperplasia. J Vasc Interv Radiol. 2011;22:11–19.

28. Pisco J, Pinheiro LC, Bilhim T, et al. Prostatic arterial embolization for benign prostatic hyperplasia: short- and intermediate-term results. Radiology. 2013;266:668–677.

29. Bagla S, Martin CP, van Breda A, et al. Early results from a United States trial of prostatic artery embolization in the treatment of benign prostatic hyperplasia. J Vasc Interv Radiol. 2014;25(1):47–52.

30. Bilhim T, Pisco J, Tinto HR, et al. Unilateral versus bilateral prostatic arterial embolization for lower urinary tract symptoms in patients with prostatic enlargement. Cardiovasc Intervent Radiol. 2013;36:403–411.

31. Moreira AM, Marques CFS, Antunes AA, et al. Transient ischemic rectitis as a potential complication after prostatic artery embolization: case report and review of the literature. Cardiovasc Intervent Radiol. 2013;36:1690–1694.

Dr. Francisco Carnevale holds the copyright to this chapter.