Novel Methods and Systems for Renal Denervation using Microwave Ablation

Abstract

Renal Denervation (RDN) is a medical procedure aimed at treating resistant hypertension by ablating the renal nerves located around the renal artery and thus abolishing sympathetic nerve activity to the kidney. These nerves are vital in haemodynamic regulation by sending signals to the kidneys, influencing their blood pressure control function. By disrupting these activities, RDN aims to reduce the excessive sympathetic nervous system activity which can lead to lower blood pressure levels over time.

Microwave Renal Denervation (MW RDN) is a promising new ablation modality that can create deep, circumferential lesions in the renal arteries while preserving the subendothelial zone, thereby minimising significant arterial injury. However, it's important to note that deeper lesions beyond a certain threshold may not necessarily lead to improved RDN out-comes and could potentially damage surrounding organs. Conversely, shallow lesions may not effectively denervate the targeted renal nerves. Therefore, there's a critical need for the development of a new and efficient monitoring system.

A prototype MW catheter and ablation console has been developed and underwent testing in a large animal model experiment. During the ablation process, biophysical measurements were recorded; these measurements were analysed retrospectively to correlate the arterial vessel calibre and lesion volume. After four weeks, the animals were euthanised, and their renal vasculature and tissue were harvested for histological staining to compare the data.

The study demonstrated that biophysical measurements could serve as valuable indicators for assessing vessel calibre and lesion formation in a large animal model, albeit with certain limitations inherent to the measurements and procedural techniques used. Further develop-ment of the MW RDN system will need to be undertaken for a more robust and consistent measurement system, ensuring the reliable and accurate assessment of these crucial factors.