Microdissection of the Human Renal Nervous System: Implications for Performing Renal Denervation Procedures

Abstract

BACKGROUND. Despite the use of renal denervation (RDN) to treathypertension, the anatomy of therenal nervous system remainspoorly understood. We performed a detailed quantitative analysis ofthe human renal nervous system anatomy with the goal of optimizingRDN procedural safety and efficacy. METHODS. Sixty kidneys from 30 human cadavers were systematicallymicrodissected to quantify anatomic variations in renal nerve patterns RESULTS. Contrary to current clinical perception, not all renal innervationfollowed the main renal artery (MRA). A significant portion of the renalnerves (late arriving nerves [LANs]) frequently reached the kidney (73% ofthe right kidney [RK] and 53% of the left kidney [LK]) bypassing the MRA.The ratio of the MRA length/aortarenal hilar distance proved to be a usefulvariable to identify the presence/absence of these LANs (odds ratio: 0.001;95% confidence interval: 0.00002 to 0.0692; p¼0.001) with a cutoff of0.75 (sensitivity¼0.68, specificity¼0.83, and area under the receiver-operating characteristic curve at threshold¼0.76) (Figure). When present,polar arteries were also highly associated with the presence of LANs.Finally, the perivascular space around the proximal MRA was frequentlyoccupied by solar plexus ganglia (RK¼53%, LK¼83%) and/or by thelumbar sympathetic chain (RK¼63%, LK¼60%). Both carried innerva-tion to the kidneys but importantly also to other abdominal and pelvicorgans, which can be accidentally denervated if the proximal renal arteryis targeted for ablation. CONCLUSION. Our results may help guide future procedural treatment recommendations to increase the likelihood of safely reaching and destroying targeted nerves during RDN procedures.