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A, Arteriovenous coupler and introducer. The ROX coupler is a self-expanding nitinol stent-like device inserted in the catheterization laboratory in a procedure lasting 40 minutes. Reproduced with permission of ROX Medical Inc. B, Fluoroscopically guided arteriovenous (AV) coupler placement. This results in creation of a fixed caliber central anastomosis between external iliac artery and vein.
Source publication
Background:
An entirely novel antihypertensive strategy incorporates a segment of vein into the arterial circuit using an anastomotic coupler device to restore the Windkessel function that results in an immediate and significant fall in blood pressure (BP). This report presents the first detailed physiological characterization of the effects of the...
Contexts in source publication
Context 1
... exhib- ited features of raised arterial stiffness with increased pulse pressure and pulse wave velocity, and it was felt that sym- pathomodulation would not be beneficial for BP control. An arteriovenous anastomosis was created using the ROX cou- pler, inserted in a standard catheterization laboratory setting under fluoroscopic guidance via an endovascular approach through the femoral vessels ( Figure 1). 2 In situ, the coupler creates a fixed-caliber 4 mm conduit between the external iliac artery and vein, transferring 0.8 L/min of blood from the arte- rial to the venous compartment. ...
Context 2
... arteriovenous anastomosis was created using the ROX cou- pler, inserted in a standard catheterization laboratory setting under fluoroscopic guidance via an endovascular approach through the femoral vessels ( Figure 1). 2 In situ, the coupler creates a fixed-caliber 4 mm conduit between the external iliac artery and vein, transferring 0.8 L/min of blood from the arte- rial to the venous compartment. The hemodynamic changes in relation to coupler placement were evaluated with left and right heart catheterization, pulse wave velocity, office BP, and ambulatory BP measurement (Tables 1-3). The opening of the arteriovenous coupler immediately leads to a large reduction in mean arterial pressure of 13% because of a profound reduc- tion in systemic vascular resistance (SVR) by 38% on the table (Figure 2). ...
Citations
... Systemic Vascular Resistance, Cardiac Output, and blood volume are variables known to reflect mechanical and physiological aspects of arterial BP in which arteriovenous fistula (AVF) creation directly targets [65]. AVF creation is the only device-based therapy that targets the hemodynamic aspects of the BP circulation without a mediator with a direct and immediate impact on the pathophysiology of RH, which sets it apart from other therapies that modulate the sympathetic nervous system. ...
Hypertension is the major risk factor for cardiovascular morbidity and mortality. Matter of fact, untreated hypertension can worsen the overall health, whereas pharmacotherapy can play an important role in lowering the risk of high blood pressure in hypertensive patients. However, persistent uncontrolled hypertension remains an unsolved condition characterized by non-adherence to medication and increased sympathetic activity. This paper will review the non-pharmacological treatments for resistant hypertension (RH) that have emerged in recent years. In addition, the technologies developed in device-based RH therapy, as well as the clinical trials that support their use, will be discussed. Indeed, the novel device-based approaches that target RH present a promising therapy which has been supported by several studies and clinical trials, whereas drug non-adherence and high sympathetic activity are known to be the main causes of RH. Nevertheless, some additional aspects of these RH systems need to be tested in the near future, with a particular focus on the device’s design and availability of randomized controlled trials.
... (p < 0,0001). Данные M. Saxena и соавторов (2016) подтвердили значимое снижение периферического сопротивления сосудов легких (-36 %), снижение резистентности пульмональных артерий (-53 %) и увеличение сердечного выброса на 38 % на столе и на 46 % через 6 месяцев [7]. Заключение экспертов 2018 ESC/ESH Guidelines гласит: метод значимо снижает АД, есть клинические исследования о коррекции правосердечной недостаточности с хорошим эффектом после имплантации в краткосрочной перспективе. ...
Arterial hypertension (HTN) needs new treatment methods, including invasive ones, because HTN has severe consequences and involves all regulating systems (neuro-cardio-renal/cerebral continuum). It is often associated with comorbid pathology (obesity, atherosclerosis, sleep disorder, diabetes mellitus, etc.). The paper presents a summary of the position of the European experts on some invasive methods of HTN treatment — “DEVICE-BASED TREATMENT” (DBT) in the section of new recommendations of the European Societies of Cardiology/Hypertension (2018 ESC/ESH Guidelines for the management of arterial hypertension), including carotid baroreceptor stimulation, renal denervation, arteriovenous fistula formation and other. The experts do not recommend to use DBT in routine practice, confirm high requirement and demand of clinical and basic investigations to prove their safety and efficiency.
... In one case report, it was shown that ROX coupler implementation resulted in an immediate as well as long-term (6-month follow-up) reduction of systemic vascular resistance and increment of cardiac output indicating coupler-induced venous filling and hemodynamic unloading of the left ventricle. 38 Moreover, extensive experience in patients with endstage renal disease and similarly sized shunts for dialysis access suggest that the risk of cardiovascular decompensation is low. In patients with end-stage renal disease, highoutput cardiac failure may occur, but volumes exceeding 30% of cardiac output 39 and flow rates of at least 2.0 L/min are necessary. ...
Background
Options for interventional therapy to lower blood pressure (BP) in patients with treatment‐resistant hypertension include renal denervation and the creation of an arteriovenous anastomosis using the ROX coupler. It has been shown that BP response after renal denervation is greater in patients with combined hypertension (CH) than in patients with isolated systolic hypertension (ISH). We analyzed the effect of ROX coupler implantation in patients with CH as compared with ISH.
Methods and Results
The randomized, controlled, prospective ROX Control Hypertension Study included patients with true treatment‐resistant hypertension (office systolic BP ≥140 mm Hg, average daytime ambulatory BP ≥135/85 mm Hg, and treatment with ≥3 antihypertensive drugs including a diuretic). In a post hoc analysis, we stratified patients with CH (n=31) and ISH (n=11). Baseline office systolic BP (177±18 mm Hg versus 169±17 mm Hg, P=0.163) and 24‐hour ambulatory systolic BP (159±16 mm Hg versus 154±11 mm Hg, P=0.463) did not differ between patients with CH and those with ISH. ROX coupler implementation resulted in a significant reduction in office systolic BP (CH: −29±21 mm Hg versus ISH: −22±31 mm Hg, P=0.445) and 24‐hour ambulatory systolic BP (CH: −14±20 mm Hg versus ISH: −13±15 mm Hg, P=0.672), without significant differences between the two groups. The responder rate (office systolic BP reduction ≥10 mm Hg) after 6 months was not different (CH: 81% versus ISH: 82%, P=0.932).
Conclusions
Our data suggest that creation of an arteriovenous anastomosis using the ROX coupler system leads to a similar reduction of office and 24‐hour ambulatory systolic BP in patients with combined and isolated systolic hypertension.
Clinical Trial Registration
URL: http://www.clinicaltrials.gov. Unique identifier: NCT01642498.
In the past decade, efforts to improve blood pressure control have looked beyond conventional approaches of lifestyle modification and drug therapy to embrace interventional therapies. Based upon animal and human studies clearly demonstrating a key role for the sympathetic nervous system in the etiology of hypertension, the newer technologies that have emerged are predominantly aimed at neuromodulation of peripheral nervous system targets. These include renal denervation, baroreflex activation therapy, endovascular baroreflex amplification therapy, carotid body ablation, and pacemaker-mediated programmable hypertension control. Of these, renal denervation is the most mature, and with a recent series of proof-of-concept trials demonstrating the safety and efficacy of radiofrequency and more recently ultrasound-based renal denervation, this technology is poised to become available as a viable treatment option for hypertension in the foreseeable future. With regard to baroreflex activation therapy, endovascular baroreflex amplification, carotid body ablation, and programmable hypertension control, these are developing technologies for which more human data are required. Importantly, central nervous system control of the circulation remains a poorly understood yet vital component of the hypertension pathway and mandates further investigation. Technology to improve blood pressure control through deep brain stimulation of key cardiovascular control territories is, therefore, of interest. Furthermore, alternative nonsympathomodulatory intervention targeting the hemodynamics of the circulation may also be worth exploring for patients in whom sympathetic drive is less relevant to hypertension perpetuation. Herein, we review the aforementioned technologies with an emphasis on the preclinical data that underpin their rationale and the human evidence that supports their use.
Objective:
In patients with resistant hypertension, percutaneous placement of an iliac arteriovenous coupler device leads to a reduction of blood pressure (BP) via decreased total vascular resistance and improved arterial compliance. However, long-term efficacy and safety need to be further explored. We report on the first case of 3.5-year follow-up in a patient who underwent implantation of an iliac arteriovenous coupler device.
Results:
A patient with resistant hypertension was admitted to hospital. Despite treatment with six anti-hypertensive drugs, his BP was poorly controlled. Previously, he had undergone renal denervation, which did not cause a significant BP decrease. Therefore, an arteriovenous coupler device was implanted, leading to an immediate and significant BP decrease. The patient was discharged with an office BP of 122/71 mmHg. After 3 months, there was a sustained BP decrease (-14/9 mmHg), whereas later, it was fluctuant (office BP: 147-173/85-95 mmHg, ABPM: 153-166/81-94 mmHg) probably due to medication non-adherence confirmed by a urinary toxicological screening test. Follow-up right heart catheterization showed changes in hemodynamic parameters related to volume congestion, which were accompanied by progressive dyspnea and weight gain. This was controlled by an optimized diuretic therapy. Additionally, an invasive closure maneuver was performed, leading to an immediate BP increase after closure and a similar decrease after re-opening of the anastomosis, verifying its proper long-term function.
Conclusion:
The implantation of an iliac arteriovenous coupler device appears to be a promising and effective method to decrease BP and therefore reduce cardiovascular risk in patients with severe, treatment-resistant hypertension.
Purpose of review:
Provision of a summary on the physiologic effects of arteriovenous fistula creation and description of previously published human data on the efficacy of a percutaneously implanted device creating an arteriovenous fistula. Though antihypertensive therapy is effective, some patient's blood pressure remains poorly controlled despite adherence to optimal medical therapy. Moreover, some patients are not compliant with recommended medical therapy due to side effects or personal decision. This has prompted exploration of alternative, device-based antihypertensive therapies including, among others, the percutaneous creation of an arteriovenous fistula. An arteriovenous fistula is accompanied by a number of favorable physiologic changes that may lower blood pressure. These physiologic changes, conduction of the procedure, and previously published human experience are summarized in this review article.
Recent findings:
The results of a recently published trial comparing arteriovenous fistula creation and standard antihypertensive therapy versus standard antihypertensive therapy alone are summarized. Creation of an arteriovenous fistula is accompanied by a significant blood pressure reduction likely related to a reduction in total arterial resistance, perhaps blood volume reduction, inhibition of the baroreceptor reflex, and release of natriuretic peptides. These findings foster further interest in studying the impact of an arteriovenous fistula and arterial blood pressure. The design of a large randomized trial comparing arteriovenous fistula creation to sham control is outlined.
Purpose of review:
Novel, interventional treatments have emerged in the last decade for the treatment of resistant hypertension. This review focuses on a unique device that creates a fixed calibre, central iliac arteriovenous anastomosis that is significantly different in haemodynamic and safety profile from traditional haemodialysis fistulae. The background, physiology, and clinical data to date will be presented.
Recent findings:
The single, randomized, controlled clinical trial using the ROX coupler in patients with resistant hypertension demonstrated substantial reductions in both office and ambulatory blood pressure to 12-month postimplantation. There was a common, but manageable, adverse effect of upstream iliac venous stenosis causing ipsilateral lower limb oedema. There were no renal safety concerns. The mechanism of action is proposed to be mechanical by provision of a low-pressure parallel circuit attached to the high-pressure arterial system though detailed physiological evaluation is currently lacking.
Summary:
Preliminary data using the ROX coupler to form a central arteriovenous anastomosis are very encouraging. Concerns regarding the lack of sham control are to some extent mitigated by immediate on table blood pressure reduction with opening of the coupler and will be further addressed in the ongoing pivotal, sham-controlled ROX CONTROL Hypertension2 study which should provide further robust information regarding efficacy and safety.
We report a case of the successful use of a central arteriovenous (cAV) coupler device to treat severe drug-resistant primary hypertension in a 46-year-old female. The device is inserted via a femoral approach to create an ateriovenous fistula between the external iliac artery and vein and has shown promise in the treatment of severe hypertension. The patient's 24-hr ambulatory blood pressure (ABP) pre device insertion on eleven anti-hypertensive medications revealed a mean 24-hr ABP of 165/98 mm Hg. The insertion of the cAV coupler resulted in a sustained anti-hypertensive effect nine months post-procedure, with mean 24-hr ABP of 154/91 mm Hg on only two anti-hypertensives. Her significant anti-hypertensive response may be explained by the presence of an inelastic aortic graft that had been inserted due to prior aortic dissection as it allowed the restoration of elasticity in a previously inelastic arterial system. We believe that the ROX cAV coupler device warrants further investigation. © 2017 Wiley Periodicals, Inc.
Purpose:
Resistant hypertension (RH) is a major and growing public health problem. While noncompliance to antihypertensive medication is a major concern in RH patients, it is estimated that even with adequate multi-drug regimens, approximately 10% of patients diagnosed with hypertension fulfill the criteria of true RH. Patients with sustained blood pressure (BP) elevation display high risk for development of target organ damage and associated cardiovascular morbidity and mortality. While optimized pharmacologic therapy, including the use of mineralocorticoid receptor antagonists to guideline-based antihypertensive drug therapy, is effective for improving BP control in this patient cohort, a sizable proportion of RH patients' BP remains uncontrolled, and alternative therapeutic strategies are warranted.
Methods:
In the past few years, device-based approaches have been studied extensively. Among these, robust clinical experience in patients with RH exists for renal denervation, baroreflex activation therapy, central arteriovenous anastomosis, and, to a lesser extent, deep brain stimulation. Carotid body modulation is the most recent approach under clinical investigation. The common aim of these approaches is direct targeting of relevant pathophysiologic mechanisms involved in BP control, most commonly activation of the sympathetic nervous system.
Findings:
This review article briefly summarizes relevant clinical and experimental evidence and highlights the potential utility, as well as limitations, of each approach.
Implications:
Several device-based approaches show promise in the treatment of RH and have been associated with improved BP control, while generally finding an acceptable side effect profile. Ongoing research is addressing relevant issues relating to patient selection and technical and procedural aspects, and will help to define the future role of device-based approaches for RH in the next few years.
