The Role of Accessory Obturator Arteries in Prostatic Arterial Embolization

Abstract

In 9 of 491 patients (1.8%) who underwent prostatic arterial embolization (PAE) for benign prostatic hyperplasia from March 2009-November 2013, prostatic arteries arose from the external iliac artery via an accessory obturator artery (AOA). Computed tomography angiography performed before the procedure identified the variant and allowed planning before the procedure. The nine AOAs were catheterized from a contralateral femoral approach. Bilateral PAE was technically successful in the nine patients. There was a mean decrease in international prostate symptom score of 6.5 points and a mean prostate volume reduction of 15.1% (mean follow-up, 4.8 mo) in the nine patients. ABBREVIATIONSAOA = accessory obturator artery, DSA = digital subtraction angiography, IPSS = International Prostate Symptom Score, PAE = prostatic arterial embolization, PVA = polyvinyl alcohol, QoL = quality of life Prostatic arterial embolization (PAE) to relieve lower urinary tract symptoms in patients with benign prostatic hyperplasia is a challenging procedure partly because of the highly variable origin and complex anatomy of the prostatic arteries (1). Computed tomography (CT) angiography performed before PAE has been used to help identify the prostatic arteries and to guide the procedure (2). The prostatic arteries may arise from the different branches of the internal iliac artery, including from the obturator artery, in 13% of pelvic sides (1,2). However, the obturator artery may arise from the inferior epigastric artery or directly from the external iliac artery and be named an accessory or aberrant obturator artery (AOA). An AOA is a common variation that may be present in 30% of pelvic sides (3). Prostatic arteries arising from AOAs are a possible variant of particular relevance when performing PAE. The purpose of this report is to clarify this anatomic variation and report successful catheterization and embolization in nine patients with lower urinary tract symptoms related to benign prostatic hyperplasia. MATERIALS AND METHODSThe institutional review board waived the need to obtain permission to perform this retrospective analysis. From March 2009-November 2013, PAE was performed in 491 patients to relieve lower urinary tract symptoms secondary to benign prostatic hyperplasia. Nine patients with prostatic arteries arising from AOAs were included. AOAs were classified as (i) obturators arising from the inferior epigastric artery, (ii) obturators arising directly from the external iliac artery, or (iii) codominant obturators originating from both the external and the internal iliac artery systems (3).Among the nine patients evaluated, mean patient age was 62.9 years (range, 51-74 y). Mean International Prostate Symptom Score (IPSS) was 18.9 points (range, 14-21 points), mean quality of life (QoL) score was 4.0 points (range, 3-6 points). Mean peak flow rate was 11.2 mL/s (range, 5.9-13.5 mL/s), mean postvoid residual & SIR, 2014

Anatomical Characteristics and Variants of Prostatic Artery in Patients of Benign Hyperplasia Prostate by Digital Subtraction Angiography

“…There were 2 cases in which PA was originated from the accessory obturator artery-a branch of the external iliac artery (1.7%). According to T. Bilhim et al, the ratio of PA originated from the external iliac artery was 1.8% [13]. Thus, in the case of absence of PA on internal iliac artery angiogram, catheterisation of the external iliac artery is necessary to find PA from the accessory obturator artery.…”

Prostatic Artery Embolization for Benign Prostatic Hyperplasia: Patient Evaluation, Anatomy, and Technique for Successful Treatment

“…The obturator artery travels along the lateral wall of the pelvis and typically exits through the obturator foramen and terminates into anterior and posterior muscular branches with a 90° configuration to supply the hip musculature (31). An accessory or aberrant obturator artery may arise from the inferior epigastric artery (corona mortis) or external iliac artery in up to 30% of cases (29,32).…”

“…Accessory obturator arteries are often identified arising from the inferior epigastric artery or the external iliac artery (29,32). The prevalence of PAs arising from an accessory obturator artery is estimated to be less than 2% (32). This variant can result in an unnecessarily prolonged or unsuccessful procedure if it is not considered when the PA is absent during initial IIA angiography (Fig 7).…”

Society of Interventional Radiology Research Reporting Standards for Prostatic Artery Embolization

“…Investigators should include the use of cone-beam CT, 3-dimensional road mapping, coil embolization, and any other strategies for reducing risks of nontarget embolization if used (including type, number, and size of embolization coils, as well as exact anatomic position of deployment) (82). Anastomotic pathways such as the accessory pudendal artery, the middle rectal artery, and accessory obturator arteries may bear mention (74,76,83,84). Recommended intraprocedural data collection is provided in Table 3.…”