ABSTRACT
<p><b>BACKGROUND</b>Renal sympathetic nerves are involved in the reflective activation of the sympathetic nervous system in circulatory control. Catheter-based renal denervation (RDN) ameliorated treatment-resistant hypertension safely, but 10%-20% of treated patients are nonresponders to radiofrequency denervation. The purpose of this study was to investigate the safety and efficiency of cryoablation for sympathetic denervation in a swine model and to explore a new way of RDN.</p><p><b>METHODS</b>Seven swines randomly assigned to two groups: Renal cryoablation (CR) group and control group. The control group underwent renal angiogram only. The CR group underwent renal angiogram plus bilateral renal cryoablation. Renal angiograms via femoral were performed before denervation, after denervation and prior to the sacrifice to access the diameter of renal arterial and the pressure of aorta abdominalis. Euthanasia of the swine was performed on 28-day to access norepinephrine (NE) changes of the renal cortex and the changes of renal nerves.</p><p><b>RESULTS</b>Cryoablation did not induce severe complications at any time point. There was no significant change in diameter of renal artery. CR reduced systolic blood pressure (BP) from 145.50 ± 9.95 mmHg at baseline to 119.00 ± 14.09 mmHg. There was a slight but insignificant decrease in diastolic BP. The main nerve changes at 28-day consisted of necrosis with perineurial fibrosis at the site of CR exposure in conjunction with the nerve vacuolation. Compared with the control group, renal tissue NE of CR group decreased by 89.85%.</p><p><b>CONCLUSIONS</b>Percutaneous catheter-based cryoablation of the renal artery is safe. CR could effectively reduce NE storing in the renal cortex, and the efficiency could be maintained 28-day at least.</p>
Subject(s)
Animals , Female , Male , Cryosurgery , Methods , Kidney , Swine , Sympathectomy , Methods , Treatment OutcomeABSTRACT
Objective To synthesize and analyze sodium 18F-fluoroacetate (FAC) and its precursor ethyl O-mesylglycolate (EOMG). Methods EOMG was synthesized using modified method. Its chemical purity was checked by HPLC and its structure was elucidated on the basis of spectral analyses. Final product of 18F-FAC was synthesized based on general nucleophilic reactions module Explora GN using EOMG as a precursor. Liquid chromatography Explora LC was applied to get rid of its chemical impurities.Then HPLC and radio-thin layer chromatography were used to assay its radiochemical purity, chemical purity and specific activity. Results EOMG was synthesized and identified. Its yield was 70% and its chemical purity was 97.0% (calculated by chromatographic peak area). The radiochemical purity of 18F-FAC was more than 98%, and its specific activity was 236. 5 MBq/μmol. Conclusion This synthetic method for 18F-FAC and its precursor can be defined as effective and highly quality-controlled.