Meta-analysis of Prostate Artery Embolization
There is increasing data on outcomes of prostate artery embolization (PAE) for benign prostatic hyperplasia (BPH), but there remains a need for more robust evaluation of this new intervention. Uflacker et al performed a meta-analysis of available PAE studies, including studies which reported standardized urologic and clinical outcomes, and excluding studies which included redundant cases. Six of 268 studies met these criteria, and were analyzed for primary outcomes of International Prostate Symptom Score (IPSS) and Quality of Life (QoL) score. At 1, 3, 6, and 12-months post PAE, there were significant decreases in both scores from baseline values (p < 0.001); the IPSS scores decreased 12.93, 14.98, 15.00 and 20.39 points and the QoL scores decreased 2.17, 2.18, 2.15, and 2.49 points at the respective times points. Secondary outcomes included changes in prostate volume (PV), post void residual (PVR) and International Index of Erectile Function (IIEF) score. Prostate volumes demonstrated significant progressive decreases from baseline, including 62.0 mL at 1-month (p < 0.004) and 85.5 mL at 12-months (p < 0.001) post PAE. Qmax also demonstrated durable improvement, of 4.7 mL/s at 1-month, and 5.4 mL/s at 12-months post PAE (p < 0.001). There was no significant change in the IIEF score at the various time points, up to 12=months post PAE. Complications were also analyzed from nine studies, which revealed a 32.9% complication rate, nearly all of which were minor complications (216/218). The two major complications were severe urinary tract infection and bladder ischemia.
As the authors highlighted in their introduction, there have been numerous challenges to interpreting previous meta-analyses on PAE literature, due to the inclusion of studies with redundant cases. The efforts in this study design to avoid those confounding factors and attain patient-level data, when possible, afforded a cleaner, potentially more valid, evaluation of existing PAE data. The improvements in the primary endpoints of IPSS and QoL as well as secondary endpoints including Qmax seen at up to 12-months after PAE, across the analyzed studies supported the efficacy and durability of PAE, while the exceedingly low rate of major complications also suggested a favorable safety profile. There are numerous limitations to the meta-analysis results, which the authors described in the discussion, including heterogeneity in patient populations and technical approaches between studies, as well as drop-offs in data for the longer post-PAE time points (i.e. 12-month versus 1-month). These factors precluded reliable elucidation of controversial issues including optimal embolic size/agent and unilateral versus bilateral embolization. Outcome comparisons with existing urologic interventions for BPH including transurethral resection of the prostate (TURP) and transurethral holmium laser enucleation (HoLEP) were also not addressed by this meta-analysis. Ongoing and future randomized controlled trials and registries will be essential to provide definitive answers to these questions and delineate the optimal role of PAE in BPH management. Nonetheless, this meta-analysis provides an improved evaluation of currently available evidence on this promising intervention for BPH.
Jeffrey Forris Beecham Chick, MD, MPH, DABR
Assistant Professor of Vascular and Interventional Radiology
Vice Quality Assurance and Safety Officer
University of Michigan Health Systems
Resident in Radiology
Hospital of the University of Pennsylvania