We developed a novel laparoscope-based electrosurgical RDN method for hypertension treatment. The feasibility of our system was confirmed through a simulation study as well as in vitro experiments. Our proposed method could be an effective treatment for resistant hypertension as well as central nervous system diseases.

In a pivotal clinical trial, the percutaneous catheter-based renal denervation system developed to treat resistant hypertension did not show effectiveness in reducing blood pressure because of its fundamental limitation to ablate deeper nerves present around the renal artery. Methods: We propose a new renal denervation strategy called laparoscopic denervation system (LDS) based-on laparoscopy procedure to ablate the renal nerves completely but inhibit the thermal arterial damage. The system has flexible electrodes to bend around the arterial wall to ablate nerves The simulation study using validated in-silico models evaluated the heat distribution on the outer arterial wall, and an acute animal study (swine model) was conducted to demonstrate the feasibility of LDS in vivo. Results: The simulation study confirmed that LDS could localize the heat distribution between the electrode and the outer arterial wall. In the animal study, we could maximize nerve denervation by the localizing ablation energy within the renal nerves and achieve nerve denaturation and decrease in neural density by 20.78 % (P<0.001), while maintaining a constant tip temperature of 65 ℃ for the duration of 70 s treatment. The study confirmed intact lumen artery through histological analysis and acute reduction in systolic blood pressure by 9.55 mmHg (p<0.001) Conclusion: The LDS presented here has potential to effectively and safely ablate the renal nerves, independent of anatomical variation and nerve distribution, to control hypertension in real clinical conditions. Significance: LDS approach is innovative, inventive, and presents a novel technique to treat hypertension.

Catheter-based renal denervation (RDN) was introduced to treat resistant hypertension. However, the reduction in blood pressure after the RDN was modest. Catheter-based RDN was performed only at main renal arteries, except for accessory and branch arteries due to the diameter being too small for the catheter to approach. Here, we retrospectively analyzed the anatomy of diverse renal arteries via 64-channel multi-detector computed tomography angiograms of 314 consecutive donors who underwent living donor nephrectomy from January 2012 to July 2017. Occurrence rates of one or more accessory renal arteries in donors were 25.3% and 19.4% on the left and right sides, respectively. Early branching rates before 25 mm from the aorta to the right and left renal arteries were 13.7% and 10.5%, respectively. Overall, 63.1% and 78.3% of donors had no accessory artery bilaterally and no branched renal artery, respectively. As a result, 47.1% had only main renal arteries without an accessory artery and early-branching artery. Approximately half of the donors had multiple small renal arteries bilaterally, for which catheter-based denervation may not be suitable. Thus, preoperative computed tomography angiography requires careful attention to patient selection, and there is a need for improved methods for denervation at various renal arteries.

The catheter-based renal denervation (RDN) showed promising results for patients in lowering BP, but there were also many non-responders. One of the possible reasons was the incomplete neural ablation due to the ablation of renal nerves at random sites resulting in asymmetric innervation patterns along the renal artery. Methods: We developed a laparoscopic ablation system that is optimized for complete RDN regardless of renal arterial innervation and size. To demonstrate its effectiveness, we evaluated the system using computational simulation and 28-day survival model using pigs. Results: The ablations were focused around the tunica externa, and the ablation patterns could be predicted numerically during RDN treatment. In the animal study, the mean reduction of systolic BP and diastolic BP in the bilateral main renal arteries was 22.8 mmHg and 14.4 mmHg (P<0.001), respectively. The respond to immunostaining targeting tyrosine hydroxylase was significantly reduced at treatment site (108.2 ± 7.5 (control) vs. 63.4 ± 8.7 (treatment), P<0.001), and an increased degree of sympathetic signals interruption to kidneys was associated with the efficacy of RDN. Conclusion: The laparoscopic ablation system achieved complete circumferential RDN at the treatment site and could numerically predict the ablation patterns. Significance: These findings clearly suggest that the proposed system can significantly improve the RDN effectiveness by reducing the variation to the percentage of injured nerves and open up a new opportunity to treat uncontrolled hypertension.

We present a back-to-back (BTB) structured, dual-mode ultrasonic device that incorporates a single-element 5.3 MHz transducer for high-intensity focused ultrasound (HIFU) treatment and a single-element 20.0 MHz transducer for high-resolution ultrasound imaging. Ultrasound image-guided surgical systems have been developed for lesion monitoring to ensure that ultrasonic treatment is correctly administered at the right locations. In this study, we developed a dual-element transducer composed of two elements that share the same housing but work independently with a BTB structure, enabling a mode change between therapy and imaging via 180-degree mechanical rotation. The optic fibers were embedded in the HIFU focal region of ex vivo chicken breasts and the temperature change was measured. Images were obtained in vivo mice before and after treatment and compared to identify the treated region. We successfully acquired B-mode and C-scan images that display the hyperechoic region indicating coagulation necrosis in the HIFU-treated volume up to a depth of 10 mm. The compact BTB dual-mode ultrasonic transducer may be used for subcutaneous thermal ablation and monitoring, minimally invasive surgery, and other clinical applications, all with ultrasound only.