Effect of twist on flow and patency of vein grafts

Abstract

This article examines the effect of twist on flow through reversed vein segments in vitro and its effect on graft patency in vivo. Excised canine superficial femoral veins were perfused in vitro with normal saline solution or canine blood. Perfusion was carried out at five pressures and against three outflow resistances. Increasing increments of twist were applied to the outflow end of the vein. Flow was measured at each level of twist. With both saline solution and blood, flow was unaltered until twist reached 140 to 180 degrees. Flow then decreased sharply, stopping completely at 175 to 200 degrees of twist. In vivo experiments were then performed in 13 dogs. Reversed superficial femoral veins were used as end-to-end grafts to bypass the iliac arteries. Each graft was deliberately twisted 0, 45, 90, 135, or 200 degrees. All grafts were harvested 6 months after surgery. Eighteen of 20 grafts twisted 135 degrees or less remained patent. However, all five grafts twisted 200 degrees were thrombosed within 4 hours of surgery (p less than 0.05). These data suggest that in patients a slight amount of graft twist probably does not reduce flow; however, more than 135 degrees of twist will greatly reduce flow, leading to early graft thrombosis.

Artery Remodeling Under Axial Twist in Three Days Organ Culture

“…Twist alters both the wall stress distribution and blood flow, thus sustained twist affects reendothelialization and stimulates thrombosis and intimal hyperplasia. 2, 9, 34, 41 Severe twist can cause buckling and kinking in these vessels 8, 41 and can affect the patency of microvascular anastomoses. 24, 39 In addition, twist in tissue engineered vascular grafts can alter their wall stress and thus the wall remodeling and mechanical properties.…”

Twist buckling of veins under torsional loading

“…For example, head turning can cause the internal jugular vein (IJV) to rotate and even cause buckling in some patients, characterized by the formation of a focal kink (Gooding and Stimac 1984; Zivadinov et al 2011). Inadvertent twisting of veins also occurs in surgical operations such as reconstructive surgery and vascular bypassing (Endean et al 1989; Salgarello et al 2001; Wong et al 2007). The most commonly used vein grafts are the human great saphenous veins (GSVs) for bypassing diseased coronary arteries and peripheral arteries (Klinkert et al 2004; Athanasiou et al 2013).…”

“…These changes can lead to increased risks for thrombosis and organ dysfunction (Endean et al 1989; Bilgin et al 2003; Selvaggi et al 2004; Chesnutt and Han 2011; Wang et al 2015). Twist buckling of the IJV has been associated with disease and developmental anomalies (Zivadinov et al 2011).…”

Arterial wall remodeling under sustained axial twisting in rats

“…Severe twisting of arteries and veins can affect their patency, impair endothelium function and delay wound healing in the anastomosis area, and lead to distal ischemia (Barton and Margolis 1975; Endean et al 1989; Izquierdo et al 1998; Topalan et al 2003; Selvaggi et al 2004; Garcia et al 2017). These changes can cause increased risks for thrombosis and organ dysfunction (Endean et al 1989; Bilgin et al 2003; Selvaggi et al 2004; Chesnutt and Han 2011).…”

“…These changes can cause increased risks for thrombosis and organ dysfunction (Endean et al 1989; Bilgin et al 2003; Selvaggi et al 2004; Chesnutt and Han 2011). It has been reported that cervical artery is extremely vulnerable to torsion injury that can lead to dissection and stroke (Norris et al 2000).…”