The Optimization Effect Of Renal Denervation On Resistant Hypertension

Background:According to "The 2010 Chinese guidelines for the management of hypertension",patients with hypertension has exceeded tens of millions in China, accounting for about 1/5 of the total number of the patients with hypertension worldwide, and there is a trend of increasing year by year,So China is available definitely a big country with numerous hypertension patients. Although with many kinds of antihypertensive drugs available currently,the blood pressure of about 10-20% patients with hypertension still cannot reach to normal standards even if sufficient dose of many different kinds of antihypertensive drugs were given, Patients taking three different kinds of plenty of antihypertensive drugs(including a diuretic) but still with high blood pressure were academically defined as patients with refractory hypertension. Such patients are often associated with multiple cardiovascular risk factors. With long-term poor control of blood pressure, cardiovascular and renal complications come one after another, and the prognosis is poor. With no effective and feasible solutions, it is a very difficult problem in the field of cardiovascular clinical treatment. In addition, because hypertension is a source disease causing coronary heart disease, heart failure and arrhythmia, the goodcontrol of hypertension is expected to significantly improve the overall level of prevention and treatment of cardiovascular disease. The increased sympathetic activation is closely related with the occurrence of hypertension. According to the research in recent years: the excessive activation of renal sympathetic nerve plays an important role in the pathogenesis of hypertension.Objective:Excessive activation of rRenal sympathetic nerve activation is closely related to the pathogenesis of hypertension. In order to control hypertension effectively, this study aimed to investigate the the effect of optimization optimized renal sympathetic nerve catheter ablation to reduce the effect of renal sympathetic nerve to ablation refractory resistant hypertension.Methods:Rats were numbered according to the bodyweight and completely randomized grouped, by random numbers generated using statistical software.30 twelve weeks male spontaneously hypertensive rats(SHR) were randomly divided into SHR operation group 14d(n=10), SHR operation group 28d(n=10), SHR sham operation control group(n=10); 30 twelve weeks male Wistar-Kyoto rats(WKY) were randomly divided into WKY operation group14d(n=10), WKY operation group 28d(n=10), WKY sham operation control group(n=10); Of all the above groups, related indexes(blood pressure and heart rate, etc.) of sham operation groups before surgery, after surgery, 14 d and28d after operation are detected respectively. Blood pressure, heart rate andblood indexes of the operation groups were measured before operation, after operation and in reexamination. Catheter-based renal sympathetic denervation(RDN) via abdomen was applied to all operation groups. 4ablation, spiral distributed proximal to distal on each side of the renal artery,ablated for 30 s for each with 2W power. The SHR operation group of 14d(n=10) and WKY operation group of 14d(n=10) are put to death in 2 weeks after operation,SHR and WKY sham operation control group 、SHR and WKY operation group of 28 d are put on death in 4 weeks after operation.The following indicators were detected:1) Systolic blood pressure, diastolic blood pressure and heart rate of all rats under the quiet state were measured before and after operation;2), Rat plasma creatinine and urea were determination using enzymatic method(preoperation, postoperation and reexamination);3), 24 h urine protein was quantitatively determined with focal phenol red method, urine Na+, K+, CL- were detected using automatic biochemical analyzer(preoperation, postoperation and reexamination);4), The norepinephrine, epinephrine and dopamine content were detected using ELISA kits(preoperation and reexamination);5), Morphology changes of renal sympathetic nerve of SHR rats andWKY rats after Catheter-based renal sympathetic denervation were compared using renal artery paraffin sections HE staining.6), Renal sympathetic nerve positive area expression percentage of SHRrats and WKY rats after Catheter-based renal sympathetic denervation were compared using immunohistochemical staining of renal artery paraffin sections;7), Renal artery muscularis injury of SHR rats and WKY rats after Catheter-based renal sympathetic denervation was compared using Movat five color staining of renal artery paraffin sections;8), Kidney pathomorphological changes of SHR rats and WKY rats after Catheter-based renal sympathetic denervation were observed using HE staining;9),Myocardial fibrosis change of SHR rats and WKY rats after Catheter-based renal sympathetic denervation was observed using MASSON staining.Results:1, Compared to preoperation, blood pressure(systolic blood pressure and diastolic blood pressure) of SHR operation group and WKY operation group decreased significantly, but no obvious effect observed on the heart rate.2, Catheter-based renal sympathetic denervation had no significant effect on renal function in SHR and WKY rats.3, Catheter-based renal sympathetic denervation had no significant effect on the electrolyte and 24 h urine protein urine of SHR and WKY rats.4, At the time of reexamination, blood norepinephrine, epinephrine and dopamine of SHR operation group and WKY operation group weresignificantly lower than preoperation.5, Catheter-based renal sympathetic denervation had obvious damage on the renal sympathetic nerve morphology of SHR rats and WKY rats.6, Catheter-based renal sympathetic denervation could significantly reduce renal sympathetic neurotransmitter(Antibodies to tyrosine hydroxylas)positive expression area rate of SHR rats and WKY rats.7, Catheter-based renal sympathetic denervation had little injury on renal artery muscularis in SHR rats and WKY rats.8, Catheter-based renal sympathetic denervation had little effect on kidney glomerular morphology in SHR rats and WKY rats.9, Catheter-based renal sympathetic denervation could slightly relieve myocardial fibrosis of SHR rats, but had no significant effect on that of WKY rats.Conclusion:1, Using non continuous ablation with the power of 2W, radiofrequency catheter-based renal sympathetic denervation to decrease blood pressure via abdomen model was successfully constructed;2, Mechanism of radiofrequency catheter-based renal sympathetic denervation to reduce blood pressure via abdomen model is decreasing the blood pressure by reducing the sympathetic neurotransmitter release through the destruction of renal sympathetic nerve activity;3 Renal sympathetic nerve plays an important role in the pathogenesis ofhypertension.