Hypertensive extracorporeal limb perfusion (HELP): A new technique for managing critical lower limb ischemia

Abstract

Blood flow through collaterals can be very significantly augmented by connection to an extracorporeal pump with isolation from the systemic circulation. The pancycle hyperperfusion can be safely repeated by implantation of an arterial access device. In the longer term, there is evidence of collateral development. When amputation is the only alternative, hypertensive extracorporeal limb perfusion should be considered.

Hypertensive extracorporeal limb perfusion for critical limb ischemia

“…induced by exercise. 2 After pump disconnection, there is recovery of smooth muscle tone. At the vascular endothelial level while on the pump, there is an enormous increase in blood flow velocity.…”

“…The concept of regional hyperperfusion can be used for other ischemic organs and has already been shown in the carotid circulation. 2 Furthermore, the continuous perfusion dramatically increases the total flow through a vessel without the peak perfusion pressure having to be increased, largely due to increased diastolic flow. Theoretically, this may minimize the risk of intracerebral hemorrhage while increasing collateral flow for occlusive cerebral disease.…”

“…The initial approach was to apply a single arterial access system using an endoluminal occlusion and saphenous system. 2 The preferred approach is shown in Fig 1, with inflow and outflow tubes with an extravascular inflatable cuff (Fig 2) between the two access systems. This setup facilitated for high pressure and large volume flows >500 mL/min, particularly where the superficial femoral artery was occluded.…”

“…1 Collateral circulation can be augmented and regulated by connection to an extracorporeal pump at suprasystolic pressures with isolation of the ischemic segment from the systemic circulation by the use of occlusive balloons. 2 This has been achieved by the design of a specific arterial access system to withstand the suprasystolic pressures and high flows similar to those obtained in physiologic peak exercise. In the longer-term, high levels of fluid shear stress (FSS) have been shown to be the moulding force in arteriogenesis.…”

Review: Hemodynamic Studies for Lower Limb Amputation and Rehabilitation

“…The results showed that this gene therapy failed to reduce the amputation rate at 100 days significantly, but meaningful hemodynamic improvement (increase in ankle-brachial index and toe-brachial index) was found. In 2008, Lane et al 20 introduced a new technique named hypertensive extracorporeal limb perfusion for improving critical ischemia and experimented it in the lower limbs of sheep and patients. The theoretical basis of this therapy is that the high arterial pressure would result in high fluid shear stresses on the endothelial surface that will stimulate growth and remodeling of collateral vessels.…”