Long-term follow-up of renal arteries after radio-frequency catheter-based denervation using optical coherence tomography and angiography

Celiac ganglia neurolysis suppresses high blood pressure in rats

The efficacy of renal denervation in the treatment of resistant hypertension has been controversial, and new strategies for its therapy are urgently needed. We performed the celiac ganglia neurolysis (CGN) or sham surgery on both spontaneously hypertensive rat (SHR) and Dahl salt-sensitive rat models of hypertension. Following CGN surgery in both strains, systolic blood pressure, diastolic blood pressure and mean arterial pressure were all lower than the levels in the respective sham surgery rats, which were maintained until the end of the study, 18 weeks postoperatively in SHRs and 12 weeks postoperatively in Dahl rats. CGN therapy destroyed ganglion cell structure and significantly inhibited celiac ganglia nerve viability. Four and twelve weeks after CGN, the plasma renin, angiotensin II and aldosterone levels were markedly attenuated, and the nitric oxide content was significantly increased in the CGN group compared with the respective sham surgery rats. However, CGN did not result in statistical difference in malondialdehyde levels compared with sham surgery in both strains. The CGN has efficacy in reducing high blood pressure and may be an alternative for resistant hypertension. Minimally invasive endoscopic ultrasound-guided celiac ganglia neurolysis (EUS-CGN) and percutaneous CGN are safe and convenient treatment approaches. Moreover, for hypertensive patients who need surgery due to abdominal disease or pain relief from pancreatic cancer, intraoperative CGN or EUS-CGN will be a good choice for hypertension therapy. The graphical abstract of antihypertensive effect of CGN.

Kidney function and markers of renal damage after renal denervation. Does method of measurement matter? The Reshape CV-Risk Study

Data suggest that renal denervation (RDN) in treatment‐resistant hypertension (TRHT) is safe in terms of renal function. However, most studies report kidney function as creatinine‐based estimated glomerular filtration rate (eGFR), which may be biased by non‐renal factors. Damage markers other than albuminuria have never been evaluated after RDN. In this non‐randomized RDN trial, we studied changes in kidney function, assessed as measured GFR (mGFR) and various GFR estimates, six months and two years after RDN. We also examined changes in albuminuria and a biomarker of tubular dysfunction. Adult non‐diabetic patients with TRHT and eGFR ≥45 ml/min/1.73 m² were recruited from hypertension clinics. Before bilateral RDN, mGFR was measured by iohexol clearance. We estimated eGFR from serum creatinine and cystatin C (eGFR_crea, eGFR_cys, and eGFR_creacys), and albumin‐creatinine ratio (ACR) and N‐acetyl‐β‐D‐glucosaminidase (NAG)‐creatinine ratio (NAG‐CR) were measured in spot urines. All measurements were repeated after six and twenty‐four months.

Twenty patients, mean age 54 (±9) years and baseline mGFR 83 (±20) ml/min/1.73 m² underwent RDN. After six months, mGFR fell, eGFR_crea remained unchanged, whereas eGFR_cys and eGFR_creacys increased. At 2 years’ follow‐up, eGFR_creacys was significantly lower than at baseline. mGFR was 78 (±28) ml/min/1.73 m². Change in ambulatory systolic BP predicted change in eGFR_crea. Urinary NAG‐CR, but not ACR, increased during follow‐up.

Different GFR assessments gave diverging results after RDN. Therefore, care should be taken to method when evaluating kidney function after RDN. Increases in a tubular dysfunction biomarker suggest that kidney damage may occur. Long‐term renal follow‐up is needed after RDN.

Laparoscopic-based perivascular renal sympathetic nerve denervation: a feasibility study in a porcine model

Background

This study aims to evaluate the effects and safety of laparoscopic-based perivascular renal sympathetic nerve denervation (RDN) in a porcine model fed a high-fat diet.

Method

Thirty-six high-fat diet-fed Bama minipigs were randomly divided into an RDN group (n = 18), in which minipigs received laparoscopic-based perivascular RDN, and a sham group (n = 18). All pigs were fed the high-fat diet after the operation to establish a model of obesity-induced hypertension. Bama pigs in the RDN and sham groups were killed at 3 time points [2 days after RDN (n = 6), day 90 (n = 6) and day 180 (n = 6)].

Result

The systolic blood pressure (SBP) and noradrenaline (NE) concentration in the kidney tissue were significantly lower in the RDN group than in the sham group at 2 days (113.83 ± 3.26 mmHg vs 129.67 ± 3.32 mmHg, P = 0.011, and 112.02 ± 17.34 ng/g vs 268.48 ± 20.61 ng/g, P < 0.001, respectively), 90 days (116.83 ± 3.88 mmHg vs 145.00 ± 4.22 mmHg, P = 0.001, respectively) and 180 days (129.33 ± 2.87 mmHg vs 168.57 ± 2.86 mmHg, P < 0.001, and 152.15 ± 16.61 ng/g vs 318.97 ± 24.84 ng/g, P < 0.001, respectively) after the operation. The diastolic blood pressure (DBP) was significantly lower in the RDN group than in sham group at 90 and 180 days after the operation (72.17 ± 2.7 mmHg vs 81.50 ± 2.22 mmHg, P = 0.037, and 76.83 ± 2.75 mmHg vs 86.33 ± 2.22 mmHg P = 0.021, respectively). Based on the pathological evaluation, the renal sympathetic nerve fascicles were successfully disrupted by radiofrequency energy after laparoscopic-based perivascular RDN, but the intima was intact. Tyrosine hydroxylase (TH) expression was decreased, while the expression of the S100 protein was increased in treated renal arteries after RDN.

Conclusions

Laparoscopic-based perivascular RDN prevented the occurrence and development of hypertension, and thus it may be an efficient and safe method for controlling blood pressure in an experimental model.

Laparoscopic-based perivascular unilateral renal sympathetic nerve denervation for treating resistant hypertension: a case report

A 38-year-old man with a history of resistant hypertension for more than 10 years underwent laparoscopic-based perivascular unilateral renal sympathetic nerve denervation in 2012. After the operation, the patient’s blood pressure has been controllable while the antihypertensive drug intake has decreased over 6 years. Laparoscopic-based perivascular unilateral renal sympathetic nerve denervation may be a potentially feasible and effective option in treating patients with resistant hypertension.

The safety of renal denervation as assessed by optical coherence tomography: pre- and post-procedure comparison with multi-electrode ablation catheter in animal experiment

OBJECTIVE

To prove the effectiveness and safety of multi-electrode ablation catheter in renal denervation (RDN) by optical coherence tomography (OCT).

METHODS

Sixteen renal arteries were enrolled from 8 pigs. Angiography and OCT were performed to analyze the morphological changes before RDN and at 1-month follow-up. Blood pressure and creatinine were measured to prove the effectiveness and safety of the catheter.

RESULTS

One renal artery was excluded because of the small diameter. Fifteen renal arteries successfully underwent renal denervation and OCT. Mean blood pressure was significantly reduced at 1 month after RDN (122.40 ± 3.54 mmHg vs. 106.50 ± 2.06 mmHg, n = 8, P < .001). Creatinine follow-up after 1 month showed no significant change (45.37 ± 7.44 vs. 65.87 ± 49.20 μmol/L, n = 8, P = 0.275). The minimal lumen diameter showed that the renal artery immediately narrowed after the procedure (7.17 ± 0.60 mm vs. 5.93 ± 0.97 mm, n = 15, P < .001). Vasospasm, vascular wall edemas, and thrombus formations all showed significant changes after the procedure except renal artery dissection (0% vs. 21.4%, P = 0.067) under the OCT. Adverse event as renal artery occluded showed no significant difference (0% vs. 6.7%, P > .05). OCT results showed no significant difference in vasospasm, dissections, wall edemas, and thrombus formations (P > .05) at 1 month after the procedure.

CONCLUSION

This multi-electrode ablation catheter could cause minor injury to renal artery instantly after RDN, but it is found to be safe in the animal model at 1-month follow-up.