New study evaluates factors predicting restenosis in arteriovenous fistulas undergoing intervention

Maintaining long-term hemodialysis access continues to be a challenge in patients with end stage renal disease. Stenosis of native AVFs secondary to neointimal hyperplasia is the most common cause of poorly functioning AVFs and angioplasty is the preferred treatment. This retrospective study aimed to determine predictors of primary and secondary patency after balloon angioplasty of native AVFs. Patient demographics, vasoactive medications, AVF/lesion characteristics, and biochemical data from 207 patients undergoing their first angioplasty of a native AVF were analyzed to determine predictors of AVF patency. An average of 2.2 interventions was performed per patient. Upper arm AVFs, AVFs less than 6 months old, multiple stenoses, and degree of pre procedural stenosis were significantly associated with a shorter time to fistula restenosis or thrombosis. A history of a previously abandoned fistula was the only identified risk factor for post intervention secondary patency loss. Systemic factors such as patient comorbidities, metabolic and inflammatory markers, and vasoactive medication usage did not affect primary patency.

Comments:

This is one of the largest studies to date looking at factors predicting shorter interval restenosis of AVFs postangioplasty. Multiple stenoses was identified as a risk factor for the first time. Unlike prior, smaller studies, pre procedural degree of stenosis was associated with an increased risk of post intervention primary latency loss (HR 1.3 per 10% increase). With these findings, one may consider incorporating more intensive monitoring of fistula function into their treatment algorithm when encountering a lesion with a high degree of stenosis.


Click here to see to the full abstract


Citation:  Neuen, Brendon L., et al. Factors Associated with Patency Following Angioplasty of Hemodialysis Fistulae. J Vasc Interv Radiol 2014: 25:1419-1426.


Post Author: Menaka Nadar, MD

Endovascular therapy to reduce gastric “hunger hormone”

Collaborative researchers from Johns Hopkins and Duke University Medical Centers performed a new therapy known as “bariatric embolization” on 6 swine in a recent study published in the January edition of JVIR. The authors cited the growing obesity epidemic in the United States and relatively high morbidity associated with bariatric weight loss surgery as the stimulus for their investigation.

Their study found a 30% reduction in the ghrelin-immunoreactive cell density in the gastric fundus of pigs that underwent bariatric embolization via the gastric artery with 4-6 mL of diluted 40-µm calibrated microspheres compared to 6 control swine treated with normal saline. A trend toward increased stomach fibrosis (P = .07) was also found in the treated swine, as well as stomach ulcers in half the treatment subset.

This study sheds light upon the impact of bariatric embolization on stomach hormone production and supports the scientific basis for bariatric embolization as a minimally invasive weight loss therapy. The authors are currently planning to begin the first US clinical trial of bariatric embolization on humans this summer at Johns Hopkins Hospital.


Click here to see the full abstract

Immunohistochemical staining of the gastric fundi (×100) and duodena confirms a significant reduction in the ghrelin-immunoreactive cell density in the gastric fundus after embolization. There is no compensatory upregulation of ghrelin-expressing cells in the duodena of treated animals.


Citation:  Paxton, B. E. et al. Histopathologic and Immunohistochemical Sequelae of Bariatric Embolization in a Porcine Model. Journal of Vascular and Interventional Radiology 25, 455–461 (2014).


Post author: Austin Bourgeois, MD