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.

Improving Cone-Beam CT Angiography for Prostatic Artery Embolization: Is a Low-Dose Protocol Equivalent to the Standard?

PURPOSE: To compare the utility of low-dose versus standard cone-beam computed tomography (CT) angiography protocols in identifying nontarget embolization (NTE) during prostatic artery embolization (PAE). MATERIALS AND METHODS: A prospective, single-center, Phase-1 study (NCT02592473) was conducted for lower urinary tract symptoms in benign prostatic hyperplasia. Prostate volume, international prostate symptom score (IPSS), quality of life score (QoL), International Index of Erectile Function (IIEF), peak flow rate, UCLA Prostate Cancer Index (UCLA-PCI), and postvoid residual were recorded at baseline and 1, 3, 6, 12, and 24-months after PAE. Six-second (standard protocol, n = 29) or 5-second (low-dose protocol n = 45) rotations were made. Images were selected and matched in pairs by areas of NTE and compared by readers using a binomial generalized estimating equation model. Procedural outcomes were analyzed using a linear mixed model. RESULTS: Seventy-four cone-beam CT angiographies were performed in 21 patients. IPSS and QoL scores significantly improved (P <.05). There was no change in UCLA-PCI or IIEF scores. Dose area product of the low- and standard-dose protocol were 37,340.82 mGy·cm2 ± 104.66 and 62,645.66 mGy·cm2 ± 12,711.48, respectively, representing a dose reduction of 40.4%. A total of 120 comparisons showed no preference between the 2 protocols (P =.24). Observers identified 76 and 69 instances of NTE in the standard- and low-dose protocols, respectively (P =.125). CONCLUSIONS: Low-dose cone-beam CT angiography achieved equivalent clinical utility in identifying NTE during PAE, with the advantage of a lower radiation dose.

Meta-Analysis of Prostatic Artery Embolization for Benign Prostatic Hyperplasia.

PURPOSE: To perform meta-analysis of available data on prostatic artery embolization (PAE). MATERIALS AND METHODS: Meta-analysis was conducted on articles published between November 2009 and December 2015. Peer-reviewed studies with > 5 patients and standard deviations and/or individual-level data on one or more of the following outcomes were included: prostate volume (PV), peak flow rate (Qmax), postvoid residual (PVR), International Prostate Symptom Score (IPSS), quality of life (QOL) score, International Index of Erectile Function (IIEF) score, and prostate-specific antigen (PSA) level. A random-effects meta-analysis was performed on the outcomes at 1, 3, 6, and 12 months after PAE compared with baseline values, with a P < .05 decision rule as the null hypothesis rejection criterion. RESULTS: Nineteen of 268 studies were included in data collection, with 6 included in the meta-analysis. At 12 months, PV decreased by 31.31 cm3 (P < .001), PSA remained unchanged (P = .248), PVR decreased by 85.54 mL (P < .001), Qmax increased by 5.39 mL/s (P < .001), IPSS improved by 20.39 points (P < .001), QOL score improved by -2.49 points (P < .001), and IIEF was unchanged (P = 1.0). There were a total of 218 adverse events (AEs) among 662 patients (32.93%), with 216 being Society of Interventional Radiology class A/B (99%). The most common complications were rectalgia/dysuria (n = 60; 9.0%) and acute urinary retention (n = 52; 7.8%). No class D/E complications were reported. CONCLUSIONS: PAE provided improvement in Qmax, PVR, IPSS, and QOL endpoints at 12 months, with a low incidence of serious AEs (0.3%), although minor AEs were common (32.93%). There was no adverse effect on erectile function.

The rise and fall of arterial interventions: presentations at the Society of Interventional Radiology annual scientific meeting.

PURPOSE: To address hypotheses concerning a decline in presentations pertaining to vascular interventions by interventional radiologists and the loss of ground in other areas, such as oncology, of presentations in vascular interventions at the Society of Interventional Radiology (SIR) Annual Scientific Meeting. MATERIALS AND METHODS: All abstracts for scientific presentations and scientific exhibits from the program book of the SIR annual meeting were reviewed from the period 1996-2006. The abstracts were grouped in different classes, such as (a) type of methodology, (b) reports on arterial interventions, (c) reports on oncologic interventions, and (d) geographic origin. RESULTS: Scientific abstracts presented at the SIR annual meeting totaled 3,162. Presentations ranged from 177-407 (1996-2003) plus 250 in 2006 with a mean of 288 presentations per year. The overall number of abstracts reporting arterial interventions had a peak of 89 presentations in 2000 and declined to 34 presentations in 2006. Reports of arterial interventions from the United States had a peak of 48 presentations in 2003 and declined to 12 in 2006. Reports of arterial interventions from Europe had a peak of 37 presentations in 2000 and declined to 11 in 2006. Reports of arterial interventions from Asia had a peak of 10 presentations in 1999 and declined to 6 in 2006. The trends are similar for the three components of arterial interventions when analyzed individually. In 1997, 26.6% of all the presentations were arterial interventions; in 2000, 25.1%; and in 2006, only 13.6%. There was a trend in the increase of oncology presentations starting in 2004. In 2003, it was 10%, and it was 22.4% in 2006. CONCLUSIONS: There has been a decline in the overall number of abstracts presented at the SIR annual meeting after a peak in 2003. There has been a decline in the number of arterial intervention reports. The decline in presentations of arterial interventions that originated in the United States was also observed in presentations that originated from Europe and Asia. There has been an increasing trend in interventional oncology reports starting in 2004.

Inhibition of prostaglandin E(2) signaling through the EP(1) receptor does not affect prostacyclin production in human endothelial cells.

Accumulating evidence suggests that cyclooxygenase-2 (COX-2) and prostaglandin E(2) (PGE(2)) may play an important role in colon carcinogenesis. Thus, blockage of this pathway may be a suitable strategy for colon cancer chemoprevention. Recent clinical studies suggest that COX-2 inhibitors cause adverse cardiovascular effects due to prostacyclin (PGI(2)) inhibition. To test our hypothesis that inhibition of PGE(2) signaling through E-prostanoid (EP) receptors may offer a safer cardiovascular profile than COX-2 inhibition, we analyzed expression of 6-keto PGF(1alpha), a hydrated form of PGI(2) and PGI(2) synthase, which was stimulated with cytokines in human umbilical vein endothelial cells (HUVECs) treated with the EP(1) receptor antagonist ONO-8711 or the COX-2 inhibitor celecoxib. ONO-8711 did not inhibit both 6-keto PGF(1alpha) production and PGIS expression, whereas celecoxib did in HUVECs. ONO-8711 also inhibited cytokine-induced tissue factor expression in HUVECs. These results suggest that ONO-8711 may be a safer chemopreventive agent with respect to cardiovascular events.

Role for sphingosine kinase 1 in colon carcinogenesis.

Sphingosine kinase 1 (SphK1) phosphorylates sphingosine to form sphingosine-1-phosphate (S1P) and is a critical regulator of sphingolipid-mediated functions. Cell-based studies suggest a tumor-promoting function for the SphK1/S1P pathway. Also, our previous studies implicated the SphK1/S1P pathway in the induction of the arachidonic acid cascade, a major inflammatory pathway involved in colon carcinogenesis. Therefore, we investigated whether the SphK1/S1P pathway is necessary for mediating carcinogenesis in vivo. Here, we report that 89% (42/47) of human colon cancer samples stained positively for SphK1, whereas normal colon mucosa had negative or weak staining. Adenomas had higher expression of SphK1 vs. normal mucosa, and colon cancers with metastasis had higher expression of SphK1 than those without metastasis. In the azoxymethane (AOM) murine model of colon cancer, SphK1 and S1P were significantly elevated in colon cancer tissues compared to normal mucosa. Moreover, blood levels of S1P were higher in mice with colon cancers than in those without cancers. Notably, SphK1(-/-) mice subjected to AOM had significantly less aberrant crypt foci (ACF) formation and significantly reduced colon cancer development. These results are the first in vivo evidence that the SphK1/S1P pathway contributes to colon carcinogenesis and that inhibition of this pathway is a potential target for chemoprevention.