The aim of the study is to assess the safety and effectiveness of a novel device for renal denervation to lower blood pressure in people with uncontrolled hypertension. Prior studies demonstrate the potential benefit of renal denervation in hypertension, though these studies primarily denervate the kidneys by passing catheters through the arteries in the groin into the renal arteries. The TUSK study utilizes the Phoenix system to perform denervation by advancing the device (a thin electrode) through the urinary tract into the kidneys where radiofrequency energy is briefly applied to denervate the kidneys.

Up to 20 patients with uncontrolled hypertension will be treated with the PhoenixTM renal pelvic denervation system, whether or not receiving background medical therapy.

Qualification will be based on documented uncontrolled hypertension by 24-hour ambulatory blood pressure monitoring. Those qualifying will be expected to maintain their medical therapy without changes until after the primary effectiveness assessment two months later.

Following baseline testing, patients will undergo renal pelvic denervation under anesthesia and remain in the hospital overnight. The denervation device is inserted through the urethra into each kidney and all devices are removed at the completion of the procedure. Radiofrequency energy is administered for a single 2-minute treatment period in each kidney.

Follow up visits will extend to one year. Patients will complete medication logs along with repeat assessment of blood pressure in office and via 24-hour ambulatory blood pressure monitor. Follow up testing will also include imaging studies of the kidneys.

Key Inclusion Criteria:

• Off-med group: (1) Ambulatory mean daytime SBP ≥140 mmHg in patients never treated for hypertension or after being taken off anti-hypertension medications for 4 weeks before ambulatory blood pressure assessment. (2) Ambulatory daytime SBP and DBP less than 170/105 mmHg. (3) Subjects will not be on ANY anti-hypertension medications or will be willing to discontinue current anti-hypertension medications.
• On-med group: (1) Subjects who are currently taking 1, 2, or 3 anti-hypertensive medications. (2) Ambulatory mean daytime SBP ≥135 mmHg. (3) Ambulatory daytime SBP and DBP less than 170/105 mmHg.

Exclusion Criteria:

• Females who are either pregnant or breastfeeding.
• Office SBP or DBP ≥180/110 mmHg.
• Untreated urinary tract infection.
• Renal collecting system is compromised, and subject cannot undergo routine cystoscopy and retrograde pyelogram.
• Dialysis patients.
• Renal transplant patients.
• Subjects on the following medications, clonidine, guanfacine and methyldopa.
• Known secondary causes of hypertension such as adrenal disease, renal artery stenosis, renovascular hypertension.
• Subjects with glomerulonephritis or interstitial nephritis or eGFR < 45 ml/min/1.73m2.
• Type I diabetes mellitus.
• Stenotic valvular heart disease for which reduction of blood pressure would be hazardous.
• Subjects with orthostatic hypotension.
• Myocardial infarction, unstable angina, or stroke in the prior 6 months.
• Any medical condition (including psychiatric disease) that would interfere with conducting the study or would not be in the best interest of the subject.
• Inability of the subject to provide informed consent.
• Subjects with sleep apnea.
• Patients taking any drugs that affect blood pressure through off target effects
• Patients with any clinical condition that can affect blood pressure or require the use of drugs that can affect blood pressure. e.g. NSAIDs, steroids, cold remedies.
• Patients who may require any procedure that can affect blood pressure.
• Patients who work a night shift.