Vascular Access Stenosis Caused by Membranous Structure in Patients on Hemodialysis.

Purpose: A membranous structure (MS) may be seen on ultrasound at a site of vascular access (VA) stenosis in patients on hemodialysis. It can also be encountered during percutaneous transluminal angioplasty (PTA) and be impassable from one side but easily passed from the other. This study aimed to examine the characteristics of MS cases and how to treat them.

Material and method: Percutaneous transluminal angioplasty performed at our hospital for arteriovenous fistula-vascular access stenosis between July 2021 and June 2022 were identified. They were divided into two groups: membranous structure and nonmembranous structure. Data of patients such as age, history of dialysis and vascular access use, number of percutaneous transluminal angioplastys performed for vascular access, and diabetes status were collected. Membranous structure cases were examined in terms of puncture direction.

Result: A total of 72 percutaneous transluminal angioplasty were performed in 37 patients. Membranous structure was identified in nine percutaneous transluminal angioplastys. Patients with membranous structure were older than those without membranous structure (mean age 75.3 ± 7.54 vs. 70.0 ± 10.8 years, P = 0.21) and tended to have a history of vascular access use (57.6 ± 106 vs. 48.4 ± 59.8 months, P = 0.28), a history of dialysis (152 ± 95.6 vs. 91.2 ± 116 months, P = 0.02), fewer percutaneous transluminal angioplasty procedures (1.44 ± 0.726 vs. 3.24 ± 2.69, P = 0.02), and lower incidence of diabetes (1 vs. 38 cases). In the nonmembranous structure group, all percutaneous transluminal angioplastys performed were successful. In the membranous structure group, six percutaneous transluminal angioplastys were successful, two were impassable, and one was acutely occluded. The successful cases and the acute obstruction case were passed by centrally directed puncture. Impassable cases involved peripheral directional puncture.

Conclusions: Vascular access stenosis can be caused by membranous structure and successfully treated by bidirectional puncture.