Validation of a Novel Renal Denervation System With Cryoablation: A Preclinical Study and Case Series.
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SUBMITTER: Ji M
PROVIDER: S-EPMC8897167 | biostudies-literature | 2022 Feb
REPOSITORIES: biostudies-literature
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Validation of a Novel Renal Denervation System With Cryoablation: A Preclinical Study and Case Series.
Ji Meng M Chen Han H Shen Li L Zhang Yi Y Yao Zhifeng Z Wu Yizhe Y Xu Yawei Y Ge Junbo J
JACC. Basic to translational science 20220202 2
Recently, we designed a renal denervation with cryoablation (Cryo-RDN) system using liquid nitrogen and proved its short-term safety and effectiveness. In this study, we first conducted a 6-month follow-up in a swine model. Renal sympathetic nerve activity remained at a significantly lower level than that of the control group after 6 months. In patients with resistant hypertension, Cryo-RDN demonstrated preliminary safety. Renal function fluctuations and vascular-related complications were not d ...[more]
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Project description:PurposeCryoablation, which induces cellular death without extensive tissue damage, has been extensively used to denervate the myocardium. However, periadventitial external circumferential application of cryotherapy to denervate the renal artery sympathetic nerves has, to our knowledge, never been tested in humans. The main aim of this study was to examine the safety and potential effects of cryotherapy on ambulatory blood pressure levels and other outcomes that are indirectly related to sympathetic tone, including pulse-wave velocity, central pulse pressure, and glucose levels.Materials and methodsFive patients who underwent the denervation of the renal arteries during open surgery of the abdominal aortic aneurysm and four controls who did not undergo denervation during the surgery were enrolled. An argonpowered cryotherapy catheter (Cardioblate; Medtronic Inc., USA) was applied periadventitially to each renal artery in the five patients and then activated by infusion with liquid nitrogen for 1 minute.ResultsNo cryoablation-related complications occurred in the five consecutive patients. Their ambulatory blood pressures 3 to 5 months after surgery did not demonstrate any general blood pressure-reducing effects, but two patients responded favorably with the reduction of antihypertensive medication and decreased 24-hour blood pressure. The patients' mean HbA1C levels decreased from 5.9±0.78% to 5.6±0.71% (P=0.042).ConclusionThis pilot study suggests that periadventitial cryoablation during open surgery can be used in the study of renal denervation in humans, as it had no complications in five patients in this study. The effectiveness of cryoablation for treating hypertension should be proven in a phase II clinical trial.
| S-EPMC7531304 | biostudies-literature
Project description:BACKGROUND Hypertension is a common complication of renal dialysis and is inadequately controlled in approximately one-third of patients. Intravascular renal denervation is an option to control sympathetic overdrive and decrease blood pressure. Four renal dialysis patients are presented with uncontrolled hypertension who were treated with intravascular renal denervation. CASE REPORT In a renal dialysis unit, patients were screened for therapy-resistant hypertension, which was defined as an outpatient blood pressure >160/100 mmHg and a blood pressure by interdialytic ambulatory blood pressure monitoring (ABPM) >130/80 mmHg. Four patients were identified with a mean ABPM of 175/95 mmHg. The four patients included a 24-year-old man with neurogenic bladder undergoing hemodialysis; a 55-year-old woman with a history of type 1 diabetes mellitus undergoing peritoneal dialysis; a 56-year-old woman with a history of autosomal dominant polycystic kidney disease (ADPKD) undergoing peritoneal dialysis; and a 72-year-old man with a history of ADPKD undergoing hemodialysis Following intravascular renal denervation, one patient had antihypertensive medicines withdrawn at 12 months, and he remained normotensive up to renal transplantation at 24 months. In two patients, ABPM did not decrease until renal transplantation was performed. The fourth patient was not a candidate for renal transplantation, and he was also a non-responder for intravascular renal denervation. None of the patients experienced hypotension or other adverse events following intravascular renal denervation. CONCLUSIONS A case series of four patients showed that, for some patients who have unresponsive hypertension while on renal dialysis, intravascular renal denervation is a safe procedure.
| S-EPMC6111771 | biostudies-literature
Project description:BACKGROUND:Clinical data show that due to the limited effects of lifestyle regulation and unsatisfactory drug adherence, only half of the hypertensive population have their blood pressure (BP) under control. In recent years, catheter-based renal denervation (RDN) has been used as a novel approach for treating uncontrolled hypertension. The safety and efficacy of catheter-based RDN have been confirmed by a number of studies and trials in which the participants were all non-Chinese and RDN was conducted via radiofrequency or ultrasound. METHODS/DESIGN:This study is a prospective multicenter randomized sham-controlled trial that aims to investigate the safety and efficacy of cryoablation RDN (cryo-RDN) using a novel dedicated cryoablation balloon catheter (Cryofocus, China). A total of 200 Chinese patients who have uncontrolled hypertension despite standard medical treatment will be enrolled. With drug standardization, eligible participants will be randomized in a 1:1 ratio to undergo cryo-RDN treatment or renal angiography alone as a sham treatment. The primary endpoint is defined as the change in 24-h ambulatory systolic blood pressure from baseline to 6 months. Office BP and other 24-h ambulatory BP are included as secondary endpoints. Safety endpoints primarily include any adverse effects. DISCUSSION:This study was designed to verify the safety and efficacy of cryo-RDN with Cryofocus balloon catheters in uncontrolled hypertensive patients on polypharmacy. The aim is to provide a new way to improve the control of hypertension in China as a complement to drug therapy. TRIAL REGISTRATION:ChiCTR, ChiCTR1800017707. Registered on 10 August 2018.
| S-EPMC6883652 | biostudies-literature
Project description:PurposeAlthough percutaneous catheter-based ablation of renal sympathetic nerve fibers has been used in the treatment of patients with resistant hypertension, a recent phase III study did not confirm its efficacy. In this study, we developed a novel laparoscopic renal denervation system and evaluated its safety and initial feasibility using an animal model.Materials and methodsA novel surgical instrument that uses a smart algorithm with temperature-monitoring feedback was developed. We used 4 male pigs (6 weeks old, weighing approximately 45 kg each) to evaluate the safety and efficacy of the laparoscopic renal denervation system. We performed immunohistochemical staining analysis after renal denervation using various tip temperatures and over various durations through an open approach.ResultsWhen the temperature of the outer wall of the renal artery was maintained at 90℃ for 180 seconds, the artery was completely denervated without damaging its inner layer, as evaluated using Masson's trichrome staining. When the temperature ranged from 70℃ to 90℃ and the duration ranged from 90 to 420 seconds, partial or complete denervation without significant vessel injury was confirmed with anti- growth-associated protein 43 and anti-S100 staining.ConclusionsThis animal study confirmed the safety and feasibility of the novel laparoscopic renal denervation system. A safe and effective protocol was developed with ablation at a constant tissue temperature of 70℃ to 90℃ within 180 seconds. However, further developments are necessary before its clinical use.
| S-EPMC6946818 | biostudies-literature
Project description:In light of evidence linking radical nephrectomy and consequent suboptimal renal function to adverse cardiovascular events and increased mortality, research into nephron-sparing techniques for renal masses widely expanded in the past two decades. The American Urological Association (AUA) guidelines now explicitly list partial nephrectomy as the standard of care for the management of T1a renal tumors. Because of the increasing utilization of cross-sectional imaging, up to 70% of newly detected renal masses are stage T1a, making them more amenable to minimally invasive nephron-sparing therapies including laparoscopic and robotic partial nephrectomy and ablative therapies. Cryosurgery has emerged as a leading option for renal ablation, and compared with surgical techniques it offers benefits in preserving renal function with fewer complications, shorter hospitalization times, and allows for quicker convalescence. A mature dataset exists at this time, with intermediate and long-term follow-up data available. Cryosurgical recommendations as a first-line therapy are made at this time in limited populations, including elderly patients, patients with multiple comorbidities, and those with a solitary kidney. As more data emerge on oncologic efficacy, and technical experience and the technology continue to improve, the application of this modality will likely be extended in future treatment guidelines.
| S-EPMC3930655 | biostudies-other
Project description:Catheter-based approaches may have inherent limitations in achieving effective renal denervation (RDN) and treatment of atrial fibrillation (AF). This study aimed to investigate the acute effects of novel laparoscopic RDN on modulating AF inducibility using a swine model. Four and five swine were randomly allocated to the sham and RDN groups, respectively. Each swine underwent measurement of the atrial effective refractory period (AERP) and AF induction tests using burst atrial pacing before and immediately after sham or RDN procedures with and without vagal nerve stimulation (VNS). A laparoscopic RDN procedure circumferentially ablated the renal nerves round the renal arteries using radiofrequency energy. There was no significant difference in the baseline AERP between the two groups (p > 0.05). Under VNS, AERP was significantly increased by 20 ms after laparoscopic RDN (95% CI = 0-30, p = 0.004). Compared to the sham group, the RDN group showed significantly reduced AF inducibility [OR (95% CI) = 0.32 (0.13-0.76) and 0.24 (0.11-0.57) with and without VNS, respectively]. After laparoscopic RDN, the duration of inducible AF episodes was significantly shortened from 28 (10-77) s to 7 (3-11) s (p < 0.001). The novel laparoscopic RDN can immediately reduce AF inducibility in a swine model.
| S-EPMC10640613 | biostudies-literature
Project description:BackgroundPreclinical models have provided key insights into the response of local tissues to radiofrequency (RF) renal denervation (RDN) that is unobtainable from human studies. However, the anatomic translatability of these models to the procedure in humans is incompletely understood. Aims: We aimed to compare the renal arterial anatomy in normotensive pigs treated with RF-RDN to that of human cadavers to evaluate the suitability of normotensive pigs for determining the safety of RF-RDN.MethodsHistopathologic analyses were performed on RF-treated renal arteries in a porcine model and untreated control renal arteries. Similar analyses were performed on untreated renal arteries from human cadavers. Results: In both human and porcine renal arteries, the median number of nerves was lower in the more distal sections (the numbers in the proximal, middle, distal, 1st bifurcation, and 2nd bifurcation sections were 65, 58, 47, 22.5, and 14.7 in humans, respectively, and 39, 26, 29, 16.5, and 9.3 in the porcine models, respectively). Renal nerves were common in the regions between arteries and adjacent veins, but only 3% and 13% of the renal nerves in humans and pigs, respectively, were located behind the renal vein. The semiquantitative score of RF-induced renal arterial nerve necrosis was significantly greater at 7 days than 28 days (0.98 vs 0.75; p=0.01), and injury to surrounding organs was rarely observed.ConclusionsThe distribution of nerve tissue and the relative distribution of extravascular anatomic structures along the renal artery was similar between humans and pigs, which validates the translational value of the normotensive porcine model for RDN.
| S-EPMC9909452 | biostudies-literature
Project description:Advances in imaging techniques (CT and MRI) and widespread use of imaging especially ultrasound scanning have resulted in a dramatic increase in the detection of small renal masses. While open partial nephrectomy is still the reference standard for the management of these small renal masses, its associated morbidity has encouraged clinicians to exploit the advancements in minimally invasive ablative techniques. The last decade has seen the rapid development of laparoscopic partial nephrectomy and novel ablative techniques such as, radiofrequency ablation (RFA), high-intensity focused ultrasound (HIFU), and cryoablation (CA). In particular, CA for small renal masses has gained popularity as it combines nephron-sparing surgery with a minimally invasive approach. Studies with up to 5-year followup have shown an overall and cancer-specific 5-year survival of 82% and 100%, respectively. This manuscript will focus on the principles and clinical applications of cryoablation of small renal masses, with detailed review of relevant literature.
| S-EPMC2470923 | biostudies-literature
Project description:Renal sympathetic denervation, a potentially revolutionary interventional treatment for hypertension, faces an existential problem due to the inability to confirm successful ablation of the targeted renal sympathetic nerves. Based on the observation that renal sympathetic nerve activity exerts rhythmic, baroreflex-driven, and vasoconstrictive control of the renal vasculature, we developed a novel technique for identifying rhythmic sympathetic vascular control using a time-varying, 2-component Windkessel model of the renal circulation. This technology was tested in 2 different animal models of renal denervation; 10 rabbits underwent chronic, surgical renal denervation, and 9 pigs underwent acute, functional renal denervation via intrathecal administration of ropivacaine. Both methods of renal denervation reduced negative admittance gain, negative phase shift renal vascular control at known sympathetic vasomotor frequencies, consistent with a reduction in vasoconstrictive, baroreflex-driven renal sympathetic vasomotion. Classic measures like mean renal blood flow and mean renal vascular resistance were not significantly affected in either model of renal denervation. Renal sympathetic vasomotion monitoring could provide intraprocedural feedback for interventionists performing renal denervation and serve more broadly as a platform technology for the evaluation and treatment of diseases affecting the sympathetic nervous system.
| S-EPMC7673653 | biostudies-literature
Project description:Background and objectivesRenal infarction is an arterial vascular event that may cause irreversible damage to kidney tissues. This study describes the clinical characteristics of patients with renal infarction according to underlying mechanism of vascular injury.Design, setting, participants, & measurementsThis study retrospectively identified 94 patients with renal infarction diagnosed between 1989 and 2011 with the aim of highlighting potential correlations between demographic, clinical, and biologic characteristics and the etiology of renal infarction. Four groups were identified: renal infarction of cardiac origin (cardiac group, n=23), renal infarction associated with renal artery injury (renal injury group, n=29), renal infarction associated with hypercoagulability disorders (hypercoagulable group, n=15), and apparently idiopathic renal infarction (idiopathic group, n=27).ResultsClinical symptoms included abdominal and/or flank pain in 96.8% of cases; 46 patients had uncontrolled hypertension at diagnosis. Laboratory findings included increase of lactate dehydrogenase level (90.5%), increase in C-reactive protein level (77.6%), and renal impairment (40.4%). Compared with renal injury group patients, this study found that cardiac group patients were older (relative risk for 1 year increase=1.21, P=0.001) and displayed a lower diastolic BP (relative risk per 1 mmHg=0.94, P=0.05). Patients in the hypercoagulable group had a significantly lower diastolic BP (relative risk=0.86, P=0.005). Patients in the idiopathic group were older (relative risk=1.13, P=0.01) and less frequently men (relative risk=0.11, P=0.02). Seven patients required hemodialysis at the first evaluation, and zero patients died during the first 30 days.ConclusionsThis study suggests that the clinical and biologic characteristics of patients can provide valuable information about the causal mechanism involved in renal infarction occurrence.
| S-EPMC3586969 | biostudies-literature