Laparoscopic Adventitial Renal Denervation (RDN) for Refractory Hypertension

Rationale: Hypertension is a leading risk factor for cardiovascular disease. A significant portion of patients have refractory hypertension, where blood pressure remains elevated despite the use of multiple antihypertensive medications. The renal sympathetic nervous system plays a crucial role in blood pressure regulation, and its overactivity is a key factor in hypertension. Renal Denervation (RDN) is a device-based therapy designed to lower blood pressure by ablating these nerves. While most existing RDN systems use an endovascular (inside the artery) approach, this method carries potential risks such as endothelial damage, thrombosis, or renal artery stenosis.

Study Objective and Design: This is a prospective, single-center, single-arm, first-in-man (FIM) clinical study designed to provide a preliminary evaluation of the safety and efficacy of a novel laparoscopic adventitial RDN system for treating refractory or drug-intolerant hypertension. A total of 10 subjects will be enrolled. The study aims to gather initial feasibility and safety data to support the design of future, larger clinical trials.

Intervention: The investigational procedure is a laparoscopic renal artery adventitial RDN. This technique involves placing a Renal Artery Radiofrequency Ablation Clamp around the external surface (adventitia) of the main renal arteries. A compatible radiofrequency generator delivers energy to the clamp's electrodes, creating targeted lesions to ablate the sympathetic nerves while preserving the integrity of the arterial wall.

Methodology: Potential subjects will be screened for eligibility. Qualified candidates will enter a 28-day run-in period where they will be treated with a standardized, fixed-dose combination of at least three antihypertensive drugs, including a diuretic. This period is to confirm refractory status and assess medication adherence, which is confirmed via urine analysis. Subjects who still meet the blood pressure criteria after the run-in period will undergo the laparoscopic RDN procedure. Post-procedure, subjects will be followed at discharge (or Day 7), Day 30, Day 90, and Day 180. Antihypertensive medications may be adjusted after 90 days according to a predefined protocol based on blood pressure response. Efficacy will be assessed by changes in office and 24-hour ambulatory blood pressure, as well as changes in medication burden. Safety will be monitored by tracking the incidence of Major Adverse Events (MAE), procedure-related complications, and changes in renal function throughout the 180-day follow-up period.

Inclusion criteria

Age ≥18 years and ≤65 years, any sex.

Diagnosed with primary hypertension.

History of hypertension for at least 6 months.

Blood pressure meets the following two conditions:

Office systolic blood pressure ≥140mmHg and ≤180mmHg, and office diastolic blood pressure ≥90mmHg. If not taking a beta-blocker, resting heart rate must be ≥70bpm.

24-hour ambulatory blood pressure measurement shows an average systolic pressure ≥130mmHg or a daytime average systolic pressure ≥135mmHg.

Has a history of antihypertensive medication use within the last 6 months with uncontrolled blood pressure. Before enrollment, must undergo at least 28 days of a standardized medication regimen (including a diuretic and at least three drugs in total) with ≥80% compliance, while office SBP remains ≥140mmHg and ≤180mmHg, and office DBP remains ≥90mmHg.

Patient is willing and able to comply with follow-up requirements and has signed the informed consent form.

Exclusion criteria

Secondary hypertension.

Target renal artery anatomy is unsuitable, including:

Renal artery diameter >9mm or <4mm.

Multiple renal arteries.

Severe calcification, stenosis >50%, malformation, fibromuscular dysplasia, or aneurysm in either renal artery.

History of renal artery intervention (e.g., balloon angioplasty or stenting).

Unsuitable for laparoscopic surgery via the retroperitoneal approach, including prior retroperitoneal surgery, retroperitoneal fibrosis, or severe obesity (BMI > 40 kg/m²).

History of kidney transplant or severe renal impairment (eGFR < 45 mL/min/1.73m²).

Hospitalization for a hypertensive crisis within the past year.

Severe liver dysfunction (ALT or AST > 3 times the upper limit of normal).

Type 1 diabetes.

History of a cardiovascular event (e.g., myocardial infarction, unstable angina) or cerebrovascular event (e.g., stroke, TIA) within the last 6 months.

Pregnancy or planning to become pregnant during the trial.

Participation in any other investigational drug or device trial within 3 months prior to screening.