Treatment of hypertension by renal vascular delivery of guanethidine

Abstract

Sympathetic nerves run through the adventitia surrounding renal arteries and are critical in the modulation of systemic hypertension. Hyperactivity of these nerves can cause renal hypertension, a disease prevalent in 30-40% of the adult population. Hypertension can be treated with neuromodulating agents (such as angiotensin converting enzyme inhibitors, angiotensin II inhibitors, or aldosterone receptor blockers), but requires adherence to strict regimens and often does not reach target blood pressure threshold to reduce risk of major cardiovascular events. A minimally invasive solution is presented here to reduce the activity of the sympathetic nerves surrounding the renal artery by locally delivering neurotoxic or sympathetic nerve-blocking agents into the adventitia. Extended elution of these agents may also be accomplished in order to tailor the therapy to the patient.

What is claimed is: 
     
         1 . A system for treating hypertension, said system comprising:
 a catheter adapted to be introduced into a patient's vasculature;   a needle adapted to be deployed from the catheter through a blood vessel wall into the adventitia surrounding the blood vessel; and   a source of guanethidine which can be delivered through the needle into the adventitia to lower the systemic blood pressure of the patient by a therapeutically beneficial amount.   
     
     
         2 . A system as in  claim 1 , wherein the needle is advanceable in a direction substantially normal to the blood vessel wall to a depth in the range from 200 μm to 6 mm. 
     
     
         3 . A system as in  claim 1 , wherein the source contains from 10 μg to 200 mg of guanethidine. 
     
     
         4 . A system as in  claim 1 , wherein the source contains from 50 μg to 100 mg. 
     
     
         5 . A system as in  claim 1 , wherein the source contains from 100 μg to 100 mg. 
     
     
         6 . A system as in  claim 1 , wherein the system is configured to deliver a dosage of the guanethidine, wherein the dosage is from 10 μg to 200 mg, from 50 μg to 100 mg, or from 100 μg to 100 mg, and wherein such dosage is effective to lower the systemic blood pressure of the patient by the therapeutically beneficial amount. 
     
     
         7 . A system as in  claim 6 , wherein the dosage is the amount in total that is delivered to the patient. 
     
     
         8 . A system as in  claim 1 , wherein the patient is human. 
     
     
         9 . A system as in  claim 1 , comprising a source of diagnostic agent. 
     
     
         10 . A system as in  claim 9 , wherein the diagnostic agent comprises a radio-opaque contrast medium. 
     
     
         11 . A system as in  claim 9 , wherein the diagnostic agent and the guanethidine are combined for concurrent delivery into the adventitia through the needle.