Occlusion of the Internal Iliac Artery is Associated with Smaller Prostate and Decreased Urinary Tract Symptoms

Embolization of the prostatic arteries is emerging as a viable minimally invasive treatment option for patients with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). This study aimed to examine the relationship between proximal occlusion or iatrogenic embolization of the internal iliac artery (IIA) with the presence of LUTS and prostate size. The study consisted of two parts, with part one including 99 men in whom 39 had occlusion of the IIA (17 unilateral and 22 bilateral), and 60 with no IIA occlusion. Of the 61 occlusions, 33 were due to atherosclerosis, with the remaining occlusions secondary to coil embolization, stenting, or bypass grafting. Part 2 consisted of a cohort of 18 men who underwent endovascular aneurysm repair (EVAR) in whom coil embolization of the IIA was performed unilaterally. Presence of LUTS, BPH, and treatment with alpha blockers, impotence, and buttock claudication were recorded. Patients with LUTS due to other causes were excluded. Part 1 results showed smaller prostate sizes in men with IIA occlusion (20.7cc versus 27.3cc, p=0.001), with no difference in size between unilateral versus bilateral occlusion. Men without IIA occlusion were more likely to have LUTS (p=0.04, OR = 3.7). The 18 men in part 2 had average prostate volume of 30.4cc with a decrease to 21.5cc after EVAR (p=0.00001). In 9 of these patients, LUTS were present before EVAR, with 5 having LUTS after EVAR, as well as an improvement in LUTS in 4 of the 5. BMI and age were not independent predictors of LUTS due to BPH.

Comment:

The study had a sizable patient cohort and the statistical analysis was rigorously assessed, with a separate assessment of a cohort within the studied population. While the study demonstrated a positive relationship between prostate size and presence of LUTS in a population of men with IIA occlusions, several caveats should be observed. First, the study did not assess objective measure of clinical outcomes in the population studied, including urodynamic studies, the International Prostate Symptom Score (IPSS), and the International Index of Erectile Function (IIEF). These parameters are useful in evaluating any study that evaluates therapies for LUTS due to BPH. Furthermore, the mean prostate size in the population was small, with an average volume of 27.3cc. The generally accepted size criteria for prostatic enlargement is 30cc. Also, only a single medical therapy for LUTS due to BPH was assessed, and multiple other medical therapies are available, which were not captured in the study.


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Three representative case examples. (Top) In the first patient, pelvic arteriography (a) and CT angiography (b) demonstrate patent IIAs. The prostate is enlarged (c). (Middle) In the second patient, only one IIA is patent on arteriography (d); there is unilateral IIA occlusion secondary to calcified plaque (e) seen on CT angiography. The prostate is smaller on CT (f). (Bottom) The final patient has bilateral IIA occlusions on arteriography (g) and CT angiography (h). The prostate is small on CT (i). Black arrows (a, d) and white arrows (b, e, h) demonstrate the internal iliac arteries. White arrows (c, f, i) show the prostate.


Although a positive relationship was demonstrated, the authors do not mean to imply that proximal embolization of the IIA is a viable alternative for prostatic artery embolization. The study serves to demonstrate that prostate size and symptoms due to BPH have a relationship with pelvic blood flow, and helps lay the groundwork on which further trials of prostatic artery embolization will be based.


Citation: Deipolyi, A. R., Al-Ansari, S., Khademhosseini, A. & Oklu, R. Occlusion of the Internal Iliac Artery Is Associated with Smaller Prostate and Decreased Urinary Tract Symptoms. Journal of Vascular and Interventional Radiology (2015). doi:10.1016/j.jvir.2015.04.019


Post author: Andre Uflacker MD, Fellow in Vascular and Interventional Radiology, University of Virginia