Carotid Body Removal for the Treatment of Resistant Hypertension

Inclusion Criteria: * Age of participants will be 18-75 years * Resistant HTN criteria: 1. Daytime mean ambulatory systolic blood pressure ≥135mmHg and office systolic blood pressure ≥150mmHg 2. Patients on at least three anti-hypertensive medications, including a diuretic, at maximum tolerated dose 3. No evidence of causes for secondary HTN following thorough clinical assessment 4. 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)