Carotid Body Removal for the Treatment of Resistant Hypertension

Study Overview
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Brief Summary
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This is a pilot study to assess the effectiveness, safety and feasibility of carotid body removal in patients with high blood pressure (hypertension) resistant to medical treatment. Patients with high blood pressure are at significant risk of medical complications including stroke and heart disease. The principle research question is whether removal of the carotid body will lead to an improvement in the blood pressure of this patient group.

Official Title
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Carotid Body Removal for the Treatment of Chronic Diseases Characterized by Excessive Central Sympathetic Activity Including Resistant Hypertension: a Pilot Study.

Conditions
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Hypertension

Intervention / Treatment
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* Procedure: Carotid body excision


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age of participants will be 18-75 years Resistant HTN criteria: Daytime mean ambulatory systolic blood pressure ≥135mmHg and office systolic blood pressure ≥150mmHg Patients on at least three anti-hypertensive medications, including a diuretic, at maximum tolerated dose No evidence of causes for secondary HTN following thorough clinical assessment Patient medication concordance will be monitored via medication/blood pressure diary Exclusion Criteria: Calculated GFR <45ml/min/1.73m2 Carotid body located outside the defined carotid septum Obstructive carotid atherosclerotic disease with >50% stenosis Oxygen desaturation at rest below 92% Known structural lung disease Requirement for oxygen therapy to maintain oxygen saturation Patients wish to participate in mountain climbing, skin diving or free diving Pregnancy or anticipation of pregnancy Palliative care/chemotherapy Acute coronary syndrome or unstable angina Stroke or transient ischaemic attack (TIA) < 6 months prior to procedure Expected life expectancy less than 12 months due to other disease Intravenous drug use Alcohol intake >28 units/week Febrile illness within two weeks of participation Unable to attend for follow up appointments in Bristol at 1, 3, 6, 12 and 24 months post-operatively. MR imaging related exclusion criteria (all participants): Pace-maker, implantable cardiac defibrillator, cerebral metallic clips or other implanted metal devices/structures Unable to tolerate scanner or history of panic attacks/claustrophobia Learning disability, significant hearing or visual impairment (participant would need to able to communicate from within the MRI scanner)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Carotid body excision<br>Patients undergoing the carotid body excision to test the hypothesis that carotid body excision is sufficient to attain target blood pressure. | Procedure: Carotid body excision<br>* This surgery does not involve any study drug or investigational device. The carotid body will be removed by the so called 'lateral approach' or a combined 'lateral and medial approach'. In all cases the target area was defined as the tissue in between the ECA and ICA, up to 5-6mm above the bifurcation point of the common carotid artery into the ECA and ICA. In a lateral approach the carotid bifurcation is not turned. A combined approach includes usually dissection of the superior thyroid vessel and turning of the carotid bifurcation.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of Blood Pressure | Change from Baseline Blood Pressure at 3 months | Baseline and 3 months |