Preliminary Study On The Effect Of Laparoscopic-assisted Renal Artery Epicardial Radiofrequency Ablation On Blood Pressure In Dogs Modeled For Hypertension

Background:Previous studies of renal artery sympathetic nerve ablation(Renal denervation)have shown controversial efficacy in lowering blood pressure.The purpose of this study was to provide evidence for the effectiveness of laparoscopic-assisted renal denervation(L-RDN)in the treatment of hypertension.Methods:Twenty beagle dogs underwent the carotid route to develop an animal model of neurogenic hypertension.The 20 beagles were then randomly assigned to the L-RDN group(n=12)and the sham-operated group(n=8).laparoscopic-assisted renal artery sympathetic nerve ablation was performed in the L-RDN group,while only laparoscopic placement was performed in the sham-operated group.Blood pressure changes were recorded at 2,4,6 and 8 weeks postoperatively.Changes in serum creatinine(sCr),blood urea nitrogen(BUN)and norepinephrine(NE)levels were analyzed.Histological changes in the renal arteries were observed.Results:Blood pressure and NE levels were significantly increased in experimental animals after hypertension induction(p<0.01).systolic and diastolic blood pressure in the L-RDN group decreased significantly at the 8th postoperative week compared with the preoperative period(p<0.0001,p<0.01).Invasive direct systolic(DSBP)and diastolic blood pressure(DDBP)in the L-RDN group decreased significantly compared with the preoperative period(p<0.0001,p<0.0001).In contrast,there was no significant decrease in blood pressure in the sham-operated group.In addition,the L-RDN group showed a significant decrease in NE levels compared with the sham-operated group(P<0.01),while neither sCr nor BUN changed significantly.Pathological examination showed no significant injury,tear or entrapment in the intima of the renal artery.Conclusions:Trans-laparoscopic-assisted radiofrequency ablation denervation of the renal artery epithelium can produce significant and long-lasting blood pressure reduction and lower blood norepinephrine levels in a canine model of neurogenic hypertension without affecting renal artery morphology and renal function,and has a good safety profile.