Customizable modification of banding with external stenting for arteriovenous fistula flow reduction

Abstract

We performed a single-center retrospective study of prospectively collected data for all patients who had flow reduction surgery with FRAME FR between November 2020 and January 2021. Ten patients had arteriovenous fistula flow reduction surgery with this technique. One patient had a distal fistula, whereas nine were within the cubital fossa. In nine patients the device was applied over the postanastomotic arteriovenous fistula outflow vein and in one in the preanastomotic radial artery. Technical success was achieved in all patients with a median flow reduction from 2150 to 825 mL/min. There were no wound or device-specific complications.

Keywords: AVF; Banding; FRAME; Flow reduction; High flow.

Fig 1

(a) Photos of the same device measurements with and without compression. (b-d) Length-diameter relationship of 5 cm length type B (blue), C (orange), and D (gray) FRAME FR devices. According to Poiseuille’s law, “R= 8nL/πr⁴,” resistance to flow is directly correlated with length and inversely related to the fourth power of the radius. Therefore, elongation of the device in situ will lead to reduced lumen diameter and a significant increase in flow resistance, whereas shortening the device will lead to an increase in diameter and lower resistance.

Fig 1

(a) Photos of the same device measurements with and without compression. (b-d) Length-diameter relationship of 5 cm length type B (blue), C (orange), and D (gray) FRAME FR devices. According to Poiseuille’s law, “R= 8nL/πr⁴,” resistance to flow is directly correlated with length and inversely related to the fourth power of the radius. Therefore, elongation of the device in situ will lead to reduced lumen diameter and a significant increase in flow resistance, whereas shortening the device will lead to an increase in diameter and lower resistance.

Fig 2

Illustration of the effect of the device on the resistance induced in the circuit. The same device in nominal length of 5 cm (corresponding diameter of 6 mm) inducing a resistance nearly 8 times more important than the same device compressed for a length of 2 cm (diameter of 8 mm). R = Resistance to blood flow.

Fig 3

Perioperative images: (a) device applied and fixed in a compressed position, (b) patient with previous failed banding that came back with high venous pressure, (c) the same patient with the Frame applied, (d) application of the device on high takeoff radial artery before the anastomosis.

Fig 4

Patient of Fig 3, a, postoperatively: note the length of the device, the regular flow within the device, and the external (6.7 mm) and internal (4.2 mm) diameter measurements.