Stent-Graft placement after angioplasty demonstrates improved patency rates compared to angioplasty alone in cephalic arch stenosis

Cephalic arch stenosis is a common cause of fistula dysfunction that has poor patency rates with traditional angioplasty. Stenting has been suggested to improve patency rates; however, to date this is the first prospective study examining the outcomes of stent graft placement for cephalic arch stenosis. This was a randomized, prospective, single blinded study of 14 patients over a four year period, five of whom had PTA alone, and 9 of whom had PTA with placement of a Viabahn stent. The lesions studied showed greater than 50% stenosis, were treated with angioplasty to achieve less than 30% stenosis, and then if randomized to the stent arm, a Viabahn stent was placed and post dilated. Anatomic success (residual stenosis of less than 30%) and clinical success (at least one normal dialysis session post treatment) were achieved in all patients. The mean patency of angioplasty alone was 100 days (range 56-154 days) versus 300 days (range 201-504) in the angioplasty plus stent group. Circuit patency rates (time from intervention to next access thrombosis or intervention) were 0% at 6 months for PTA alone versus 67% at 6 months with PTA and stent (p<0.01).

Comment:

As compared to angioplasty alone, angioplasty plus stent shows improved patency rates in the setting of cephalic arch stenosis greater than 50%. While this study was limited by a small sample size, with enrollment failing to meet the calculated sample size, the results are compelling. Repeat studies are warranted to confirm the authors’ findings.


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(a) Initial fistulogram demonstrates focal stenosis 4 50% near the junction of the cephalic vein with the axillary vein in a 65- year-old woman with right brachiocephalic fistula who presented with decreased access blood flow. (b) After placement of an 8-mm 60-mm stent graft in this patient, a fistulogram demonstrates preservation of flow in the axillary vein. Arrows mark the end point of the stent graft. (c) In another patient, fistulography 8 months after stent-graft placement demonstrates focal stenosis adjacent to the edge (arrow) of the stent graft.


Citation: Rajan, D. K. & Falk, A. A Randomized Prospective Study Comparing Outcomes of Angioplasty versus VIABAHN Stent-Graft Placement for Cephalic Arch Stenosis in Dysfunctional Hemodialysis Accesses. Journal of Vascular and Interventional Radiology (2015). doi:10.1016/j.jvir.2015.05.001


Post Author: Tim Huber, MD. VIR Pathway Resident at University of Virginia

MRI May Predict Midterm Symptom Recurrence after Uterine Artery Embolization for Adenomyosis

Uterine artery embolization (UAE) for adenomyosis has been shown to result in short term symptom relief but may recur after longer follow-up periods. The purpose of this study was to evaluate the relationship between the post-UAE percentage of necrosis and symptom recurrence at midterm follow-up.

This retrospective study analyzed the percentage of necrosis of uterine adenomyosis on contrast-enhanced MR imaging in 50 women who underwent the procedure for symptomatic adenomyosis. Three dimensional reconstruction software was used to measure the volumes of adenomyosis on the baseline scan and the necrotic volume at the 3 month follow up scan, as defined by non-enhancement on T1-weighted post contrast images. Adenomyosis-related symptoms were assessed using an oral questionnaire at baseline and up to 48 months post-procedure.

During the follow up period, symptom recurrence occurred in 24% (12 of 50) of women. Women with < 34.3% necrosis after UAE had a sevenfold higher risk of symptom recurrence compared with patients with > 34.3% necrosis. Initial uterine volume and the type of adenomyosis (focal or diffuse) did not show significant relationships with recurrence. The study was limited by a small number of patients at a single institution. The distribution of the percentage of necrosis found in the patients was heavily skewed in that 38 out of 50 women had > 34% necrosis.

Comment:

The findings suggest that midterm symptom prognosis after UAE for adenomyosis can be predicted by MR imaging at 3 months post-procedure based on percentage of necrosis. This may have implications for early patient management, aggressive imaging, and appropriate counseling. However, the number of limitations in the study warrant further investigation with larger patient populations and additional MRI analysis of necrotic volumes at later intermediate follow up periods.


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A 40-year-old woman who underwent UAE for symptomatic adenomyosis. (a) Sagittal T2-weighted MR image obtained before UAE shows focal junctional zone thickening of the uterus. (b) Sagittal T2-weighted MR image obtained 3 months after UAE shows decreased size of adenomyosis and the uterus. The volume of adenomyosis was calculated semiautomatically to be 142.580 cm3. (c) Sagittal contrast-enhanced T1-weighted MR image obtained 3 months after UAE shows partial necrotic area without enhancement. The volume of necrosis was calculated semiautomatically to be 65.477 cm3. The percentage of necrosis was 45.9%


Citation: Bae, S. H. et al. Uterine Artery Embolization for Adenomyosis: Percentage of Necrosis Predicts Midterm Clinical Recurrence. Journal of Vascular and Interventional Radiology (2015). doi:10.1016/j.jvir.2015.04.026


Author: Laura Traube, MD, MPH, Fellow in Interventional Radiology, UCLA Medical Center

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